Fix config argument, update deault config.

Add runtime proxy override, update readme

.gitignore

@@ -25,3 +25,6 @@ logs.txt
 .release
 core/test/
 .aider*
+.gocache/
+openserp
+.gomodcache/

Dockerfile

@@ -16,8 +16,13 @@ RUN go build -o /app/openserp .
 
 FROM zenika/alpine-chrome:with-chromedriver
 
+WORKDIR /usr/src/app
+
 COPY --from=builder /app/openserp /usr/local/bin/openserp
-ADD config.yaml /usr/src/app
+COPY config.yaml ./config.yaml
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
+  CMD wget --no-verbose --tries=1 --spider http://localhost:7000/health || exit 1
 
 ENTRYPOINT ["openserp"]
 

README.md

@@ -1,4 +1,4 @@
-# OpenSERP (Search Engine Results Page)
+# OpenSERP (Search Engine Results)
 
 ![OpenSERP](/logo.svg)
 
@@ -6,18 +6,18 @@
 [![Go Reference](https://pkg.go.dev/badge/github/karust/openserp?style=for-the-badge)](https://pkg.go.dev/github.com/karust/openserp)
 [![release](https://img.shields.io/github/release/karust/openserp)](https://github.com/karust/openserp/releases)
 
-<!--[![Docker Pulls](https://img.shields.io/docker/pulls/karust/openserp)](https://hub.docker.com/repository/docker/karust/openserp)-->
+<!-- [![Docker Pulls](https://img.shields.io/docker/pulls/karust/openserp)](https://hub.docker.com/repository/docker/karust/openserp) -->
 
-**OpenSERP** provides free API access to multiple search engines including **[Google, Yandex, Baidu, Bing, DuckDuckGo]**. Get comprehensive search results without expensive API subscriptions!
+**OpenSERP** provides free API and CLI access to multiple search engines including **Google, Yandex, Baidu, Bing, and DuckDuckGo**. Get comprehensive search results without expensive API subscriptions!
 
 ## Features
 
-- 🔍 **Multi-Engine Support**: Google, Yandex, Baidu, Bing, DuckDuckGo...
-- 🌐 **Megasearch**: Aggregate results from multiple engines simultaneously
-- 🖼 **Images**: Image search is also available!
-- 🎯 **Advanced Filtering**: Language, date range, file type, site-specific searches
-- 🌍 **Proxy Support**: HTTP/SOCKS5 proxy support
-- 🐳 **Docker Ready**: Easy deployment with Docker
+- 🔍 **Multi-engine** - search with dedicated endpoints for each engine
+- 🌐 **Megasearch** - cross-engine aggregation with deduplication
+- 🖼 **Images** - image search is also available
+- 🎯 **Advanced filters** - language, date range, file type, and site queries
+- 🌍 **Configurable** - proxy, cache, and resilient mode support
+- 🐳 **Docker-ready** - local and container deployment
 
 ## Quick Start⚡️
 
@@ -31,36 +31,36 @@ docker run -p 127.0.0.1:7000:7000 -it karust/openserp serve -a 0.0.0.0 -p 7000
 docker compose up --build
 ```
 
-### From Source
+### From source
 
 ```bash
-# Clone and build
 git clone https://github.com/karust/openserp.git
 cd openserp
 go build -o openserp .
-
-# Run the server
 ./openserp serve
 ```
 
-## 🌐 Megasearch & Megaimage - Search Everything at Once!
+## 🌐 Megasearch & Megaimage
 
-**Megasearch** aggregates results from multiple engines simultaneously with automatic deduplication. **Megaimage** does the same for image searches!
-
-### Megasearch (Web Results)
+Search all engines at once:
 
 ```bash
-# Search ALL engines at once
-curl "http://localhost:7000/mega/search?text=golang&limit=10"
-
-# Pick specific engines
-curl "http://localhost:7000/mega/search?text=golang&engines=duckduckgo,bing&limit=15"
-
-# Advanced filtering
-curl "http://localhost:7000/mega/search?text=Donald+Trump&engines=duckduckgo,bing&limit=20&date=20251005..20251005&lang=EN"
+curl "http://127.0.0.1:7000/mega/search?text=golang&limit=10"
 ```
 
-- API response example:
+Search only selected engines:
+
+```bash
+curl "http://127.0.0.1:7000/mega/search?text=golang&engines=duckduckgo,bing&limit=15"
+```
+
+Advanced filtering:
+
+```bash
+curl "http://127.0.0.1:7000/mega/search?text=Donald+Trump&engines=duckduckgo,bing&limit=20&date=20251005..20251005&lang=EN"
+```
+
+API response example:
 
 ```json
 [
@@ -68,48 +68,46 @@ curl "http://localhost:7000/mega/search?text=Donald+Trump&engines=duckduckgo,bin
     "rank": 1,
     "url": "https://en.wikipedia.org/wiki/Golden_Retriever",
     "title": "Golden Retriever - Wikipedia",
-    "description": "The Golden Retriever is a Scottish breed of retriever dog of medium size. It is characterised by a gentle and affectionate nature and a striking golden coat. It is a working dog, and registration is subject to successful completion of a working trial. [2] It is commonly kept as a companion dog and is among the most frequently registered breeds in several Western countries; some may compete in ...",
+    "description": "The Golden Retriever is a Scottish breed of retriever dog of medium size. It is characterised by a gentle and affectionate nature and a striking golden coat.",
     "ad": false,
     "engine": "duckduckgo"
   },
   {
     "rank": 2,
-    "url": "https://www.bing.com/ck/a?!&&p=6f15ac4589858d0a104cd6f55cc8e91e8d8d6da91f905b626921f67f2323a467JmltdHM9MTc1OTE5MDQwMA&ptn=3&ver=2&hsh=4&fclid=2357c2f4-6131-68de-359f-d48c607c691d&u=a1aHR0cHM6Ly93d3cuZ29sZGVucmV0cmlldmVyZm9ydW0uY29tL3RocmVhZHMvdW5kZXJzdGFuZGluZy13aHktZ29sZGVuLXJldHJpZXZlciVFMiU4MCU5OXMtbGlmZXNwYW4taGFsdmVkLWluLXRoZS1sYXN0LTM1LXllYXJzLjM1NzMyMi8&ntb=1",
-    "title": "Golden Retriever Dog Forums\nhttps://www.goldenretrieverforum.com › threads › understanding-why-g…",
-    "description": "Oct 20, 2024 · Back in the 1970s, Golden Retrievers routinely lived until 16 and 17 years old, they are now living until 9 or 10 years old. Golden Retrievers seem to be dying mostly of bone …",
+    "url": "https://www.bing.com/ck/a?!&&p=6f15ac4589858d0a104cd6f55cc8",
+    "title": "Golden Retriever Dog Forums",
+    "description": "Oct 20, 2024 · Back in the 1970s, Golden Retrievers routinely lived until 16 and 17 years old, they are now...",
     "ad": false,
     "engine": "bing"
   },
   {
     "rank": 3,
-    "url": "http://www.baidu.com/link?url=2544q3ugc68j0scVxdpWCSX-gl2AmuCy1l7uRR3loIfS1hmJWMiJKW4MDGWoZrLE7X-ybu1L7T8PspoL7iy_dK",
-    "title": "golden retrievers是什么意思_golden retrievers怎么读_解释_用法...",
-    "description": "\n\n2025年9月21日golden retrievers 读音:美英 golden retrievers基本解释 金毛猎犬 分词解释 golden金(黄)色的 retrievers寻猎物犬( retriever的名词复数 ) 词组短语 golden retrieversfor sale出售金毛寻回犬 golden retrieversnear me我附近的金毛寻回犬 golden retrieverspuppies金毛寻回犬幼犬...\ndanci.gei6.com/golden...retrievers...",
+    "url": "http://www.baidu.com/link?url==2544q3ugc68j0scVxdpWCSX-gl2AmuCy1l7uRR3loIfS1",
+    "title": "golden retrievers是什么意思",
+    "description": "2025年9月21日golden retrievers 读音:美英 golden retrievers基本解释 金毛猎犬 分词解释 golden金(黄)色的...",
     "ad": false,
     "engine": "baidu"
   }
 ]
 ```
 
-### Megaimage (Image Results)
+Image search:
 
 ```bash
-# Search images across ALL engines
-curl "http://localhost:7000/mega/image?text=golang logo&limit=20"
+curl "http://127.0.0.1:7000/mega/image?text=golang logo&limit=20"
 ```
 
-### Available Engines
+List available engines:
 
 ```bash
-# Check which engines are available
-curl "http://localhost:7000/mega/engines"
+curl "http://127.0.0.1:7000/mega/engines"
 ```
 
 **Available engines:** `google`, `yandex`, `baidu`, `bing`, `duckduckgo`
 
 ## 🔍 Individual Engine APIs
 
-### Search Parameters
+Common query parameters:
 
 | Parameter | Description          | Example                           |
 | --------- | -------------------- | --------------------------------- |
@@ -119,52 +117,63 @@ curl "http://localhost:7000/mega/engines"
 | `file`    | File extension       | `PDF`, `DOC`, `XLS`               |
 | `site`    | Site-specific search | `github.com`, `stackoverflow.com` |
 | `limit`   | Number of results    | `10`, `25`, `50`                  |
-| `answers` | Include Q&A results  | `true`, `false`                   |
 
-### Individual Engine Examples
+Engine-specific parameters:
+
+| Parameter | Supported engines                   | Notes                                                              |
+| --------- | ----------------------------------- | ------------------------------------------------------------------ |
+| `start`   | `google`, `bing`, `yandex`, `baidu` | Web search pagination offset.                                      |
+| `filter`  | `google`                            | Duplicate filter (`true` hides similar, `false` includes similar). |
+| `answers` | `google`                            | Include Google answer boxes in output with negative ranks.         |
+
+Examples:
 
 ```bash
-# DuckDuckGo search
-curl "http://localhost:7000/duck/search?text=golang&limit=7"
-
-# Google search
-curl "http://localhost:7000/google/search?text=golang&lang=EN&limit=10"
+curl "http://127.0.0.1:7000/duck/search?text=golang&limit=7"
+curl "http://127.0.0.1:7000/google/search?text=golang&lang=EN&limit=10"
+curl "http://127.0.0.1:7000/bing/search?text=golang&limit=10&start=20"
+curl "http://127.0.0.1:7000/yandex/search?text=golang&limit=10&start=10"
+curl "http://127.0.0.1:7000/bing/image?text=golang&limit=20"
 ```
 
-### Image Search
+## 🌍 Proxy Support
+
+OpenSERP supports HTTP and SOCKS5 proxies.
+
+Simple global proxy:
 
 ```bash
-# Bing Images
-curl "http://localhost:7000/bing/image?text=golang&limit=20"
-
-# Baidu Images
-curl "http://localhost:7000/baidu/image?text=golang&limit=15"
-```
-
-## 🌐 Proxy Support
-
-OpenSERP supports HTTP and SOCKS5 proxies with authentication:
-
-```bash
-# SOCKS5 proxy
 ./openserp serve --proxy socks5://127.0.0.1:1080
-
-# HTTP proxy with authentication
 ./openserp search bing "query" --proxy http://user:pass@127.0.0.1:8080
 ```
 
+Advanced proxy configuration is available in [config.yaml](./config.yaml).
+You can enable tagged proxy pools and per-request override via `X-Use-Proxy: <tag>` or `X-Use-Proxy: direct`.
+
+## Health & Stats
+
+```bash
+curl -i "http://127.0.0.1:7000/health"
+curl "http://127.0.0.1:7000/stats"
+curl "http://127.0.0.1:7000/stats/cache"
+curl "http://127.0.0.1:7000/stats/proxy"
+curl "http://127.0.0.1:7000/stats/cb"
+```
+
+Useful response headers in server mode: `X-Cache`, `X-Fallback-Engine`,`X-Proxy-Mode`, `X-Proxy-Tag`, `X-Proxy-Used`
+
 ## License
 
-This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
+This project is licensed under the MIT License. See [LICENSE](LICENSE).
 
 ## 🤝 Contributing
 
-Contributions are welcome! Please feel free to submit a Pull Request.
+Contributions are welcome. Please feel free to submit a pull request.
 
 ## 👾 Issues & Support
 
-If you encounter any issues or have questions:
+If you encounter issues or have questions:
 
 - Open an issue on GitHub
-- Check existing issues for solutions
-- Review the documentation above
+- Check existing issues for similar reports
+- Review the documentation and example config

baidu/search.go

@@ -131,7 +131,7 @@ func (baid *Baidu) Search(query core.Query) ([]core.SearchResult, error) {
 		}
 		desc = strings.ReplaceAll(desc, title, "")
 
-		gR := core.SearchResult{Rank: i + 1, URL: linkText.String(), Title: title, Description: desc}
+		gR := core.SearchResult{Rank: query.Start + i + 1, URL: linkText.String(), Title: title, Description: desc}
 		searchResults = append(searchResults, gR)
 	}
 

baidu/search_raw.go

@@ -1,65 +1,20 @@
 package baidu
 
 import (
-	"context"
-	"crypto/tls"
 	"fmt"
-	"net"
 	"net/http"
-	"net/url"
 	"strings"
-	"time"
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/corpix/uarand"
 	"github.com/karust/openserp/core"
 	"github.com/sirupsen/logrus"
-
-	utls "github.com/refraction-networking/utls"
 )
 
 func baiduRequest(searchURL string, query core.Query) (*http.Response, error) {
-	// Create HTTP transport with proxy
-	transport := &http.Transport{}
-	if query.ProxyURL != "" {
-		proxyUrl, err := url.Parse(query.ProxyURL)
-		if err != nil {
-			return nil, err
-		}
-		transport.Proxy = http.ProxyURL(proxyUrl)
-	}
-
-	// Set insecure TLS
-	if query.Insecure {
-		transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-	}
-
-	transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-		dialer := &net.Dialer{}
-		rawConn, err := dialer.DialContext(ctx, network, addr)
-		if err != nil {
-			return nil, err
-		}
-
-		hostname := strings.Split(addr, ":")[0]
-		config := &utls.Config{
-			ServerName:         hostname,
-			InsecureSkipVerify: query.Insecure,
-		}
-
-		uconn := utls.UClient(rawConn, config, utls.HelloChrome_Auto)
-
-		if err := uconn.Handshake(); err != nil {
-			rawConn.Close()
-			return nil, err
-		}
-
-		return uconn, nil
-	}
-
-	baseClient := &http.Client{
-		Transport: transport,
-		Timeout:   time.Second * 10,
+	baseClient, err := core.NewRawHTTPClient(query)
+	if err != nil {
+		return nil, err
 	}
 
 	req, err := http.NewRequest("GET", searchURL, nil)
@@ -138,6 +93,11 @@ func Search(query core.Query) ([]core.SearchResult, error) {
 	if err != nil {
 		return nil, err
 	}
+	if query.Start > 0 {
+		for i := range results {
+			results[i].Rank = query.Start + i + 1
+		}
+	}
 	logrus.Debugf("Baidu Raw results : %v", results)
 
 	return core.DeduplicateResults(results), nil

baidu/url.go

@@ -66,6 +66,13 @@ func BuildURL(q core.Query) (string, error) {
 	if q.Limit != 0 {
 		params.Add("rn", strconv.Itoa(q.Limit))
 	}
+	if q.Start < 0 {
+		return "", errors.New("incorrect start provided")
+	}
+	if q.Start > 0 {
+		// Baidu uses "pn" as result offset for pagination.
+		params.Add("pn", strconv.Itoa(q.Start))
+	}
 
 	if len(params.Get("wd")) == 0 {
 		return "", errors.New("Empty query built")

bing/search.go

@@ -140,7 +140,7 @@ func (bing *Bing) Search(query core.Query) ([]core.SearchResult, error) {
 	}
 	bing.logger.Info("Found %d results (%d ads)", totalResults, len(adElements))
 
-	rank := 0
+	rank := query.Start
 	for _, result := range organicElements {
 		srchRes := core.SearchResult{}
 

bing/url.go

@@ -43,8 +43,15 @@ func BuildURL(q core.Query) (string, error) {
 		params.Add("setlang", strings.ToLower(q.LangCode))
 	}
 
-	// Set result offset (pagination) - Bing uses "first" parameter
-	if q.Limit > 0 {
+	// Set result offset (pagination) - Bing uses "first" parameter.
+	// When first is present, Bing may ignore custom count and return default page size.
+	if q.Start < 0 {
+		return "", errors.New("incorrect start provided")
+	}
+	if q.Start > 0 {
+		// Bing uses 1-based first-result index for pagination.
+		params.Add("first", strconv.Itoa(q.Start+1))
+	} else if q.Limit > 0 {
 		params.Add("count", strconv.Itoa(q.Limit))
 	}
 

cmd/proxy_policy.go

@@ -0,0 +1,30 @@
+package cmd
+
+import (
+	"strings"
+
+	"github.com/karust/openserp/core"
+)
+
+func buildEngineProxyPolicyMap() map[string]string {
+	return map[string]string{
+		"google":     config.GoogleConfig.Proxy,
+		"yandex":     config.YandexConfig.Proxy,
+		"baidu":      config.BaiduConfig.Proxy,
+		"bing":       config.BingConfig.Proxy,
+		"duckduckgo": config.DuckDuckGoConfig.Proxy,
+	}
+}
+
+func buildNormalizedProxyConfig(runtime string) (core.ProxyConfig, error) {
+	return core.NormalizeProxyConfig(core.ProxyConfig{
+		Runtime:        runtime,
+		Proxies:        config.Proxies,
+		EnginePolicies: buildEngineProxyPolicyMap(),
+	})
+}
+
+func resolveEngineProxyPolicy(proxyCfg core.ProxyConfig, engineName string) core.ProxyPolicy {
+	engineKey := strings.ToLower(strings.TrimSpace(engineName))
+	return core.ResolveEffectiveProxyPolicy(proxyCfg.Proxies.Global, proxyCfg.EnginePolicies[engineKey])
+}

cmd/root.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 
@@ -13,48 +14,104 @@ import (
 )
 
 const (
-	version               = "0.5.4"
+	version               = "0.6.0"
 	defaultConfigFilename = "config"
 	envPrefix             = "OPENSERP"
 )
 
 type Config struct {
-	App              AppConfig                `mapstructure:"app"`
-	Config2Capcha    Config2Captcha           `mapstructure:"2captcha"`
-	GoogleConfig     core.SearchEngineOptions `mapstructure:"google"`
-	YandexConfig     core.SearchEngineOptions `mapstructure:"yandex"`
-	BaiduConfig      core.SearchEngineOptions `mapstructure:"baidu"`
-	BingConfig       core.SearchEngineOptions `mapstructure:"bing"`
-	DuckDuckGoConfig core.SearchEngineOptions `mapstructure:"duckduckgo"`
+	Server           ServerConfig         `mapstructure:"server"`
+	App              AppConfig            `mapstructure:"app"`
+	Proxies          core.ProxiesConfig   `mapstructure:"proxies"`
+	Cache            CacheConfig          `mapstructure:"cache"`
+	Resilience       ResilienceConfig     `mapstructure:"resilience"`
+	CircuitBreaker   CircuitBreakerConfig `mapstructure:"circuit_breaker"`
+	CORS             CORSConfig           `mapstructure:"cors"`
+	Config2Capcha    Config2Captcha       `mapstructure:"2captcha"`
+	GoogleConfig     EngineConfig         `mapstructure:"google"`
+	YandexConfig     EngineConfig         `mapstructure:"yandex"`
+	BaiduConfig      EngineConfig         `mapstructure:"baidu"`
+	BingConfig       EngineConfig         `mapstructure:"bing"`
+	DuckDuckGoConfig EngineConfig         `mapstructure:"duckduckgo"`
 }
 
 type Config2Captcha struct {
 	ApiKey string `mapstructure:"apikey"`
 }
 
-type AppConfig struct {
+type ServerConfig struct {
 	Host          string `mapstructure:"host"`
 	Port          int    `mapstructure:"port"`
-	Timeout       int    `mapstructure:"timeout"`
 	ConfigPath    string `mapstructure:"config_path"`
-	IsBrowserHead bool   `mapstructure:"head"`
-	IsLeaveHead   bool   `mapstructure:"leave_head"`
-	IsLeakless    bool   `mapstructure:"leakless"`
 	IsDebug       bool   `mapstructure:"debug"`
 	IsVerbose     bool   `mapstructure:"verbose"`
 	IsRawRequests bool   `mapstructure:"raw_requests"`
-	ProxyURL      string `mapstructure:"proxy"`
 	Insecure      bool   `mapstructure:"insecure"`
+}
+
+type AppConfig struct {
+	Timeout       int    `mapstructure:"timeout"`
+	BrowserPath   string `mapstructure:"browser_path"`
+	IsBrowserHead bool   `mapstructure:"head"`
+	IsLeaveHead   bool   `mapstructure:"leave_head"`
+	IsLeakless    bool   `mapstructure:"leakless"`
 	IsStealth     bool   `mapstructure:"stealth"`
 }
 
+type EngineConfig struct {
+	core.SearchEngineOptions `mapstructure:",squash"`
+	Proxy                    string `mapstructure:"proxy"`
+}
+
+type CacheConfig struct {
+	TTLSeconds int `mapstructure:"ttl_seconds"`
+	MaxSize    int `mapstructure:"max_size"`
+}
+
+type ResilienceConfig struct {
+	MaxRetries            int  `mapstructure:"max_retries"`
+	AllowEndpointFallback bool `mapstructure:"allow_endpoint_fallback"`
+}
+
+type CircuitBreakerConfig struct {
+	Failures        int `mapstructure:"failures"`
+	RecoverySeconds int `mapstructure:"recovery_seconds"`
+	Successes       int `mapstructure:"successes"`
+}
+
+type CORSConfig struct {
+	Enabled      bool   `mapstructure:"enabled"`
+	AllowOrigins string `mapstructure:"allow_origins"`
+	AllowMethods string `mapstructure:"allow_methods"`
+	AllowHeaders string `mapstructure:"allow_headers"`
+	MaxAge       int    `mapstructure:"max_age"`
+}
+
 var config = Config{}
 
 var flagToConfigKey = map[string]string{
-	"config":       "app.config_path",
-	"leave":        "app.leave_head",
-	"raw":          "app.raw_requests",
-	"2captcha_key": "2captcha.apikey",
+	"host":                    "server.host",
+	"port":                    "server.port",
+	"timeout":                 "app.timeout",
+	"config":                  "server.config_path",
+	"browser-path":            "app.browser_path",
+	"verbose":                 "server.verbose",
+	"debug":                   "server.debug",
+	"head":                    "app.head",
+	"leakless":                "app.leakless",
+	"raw":                     "server.raw_requests",
+	"leave":                   "app.leave_head",
+	"2captcha_key":            "2captcha.apikey",
+	"proxy":                   "proxies.global",
+	"stealth":                 "app.stealth",
+	"insecure":                "server.insecure",
+	"cache_ttl":               "cache.ttl_seconds",
+	"cache_max_size":          "cache.max_size",
+	"max_retries":             "resilience.max_retries",
+	"allow_endpoint_fallback": "resilience.allow_endpoint_fallback",
+	"cb_failures":             "circuit_breaker.failures",
+	"cb_recovery":             "circuit_breaker.recovery_seconds",
+	"cb_successes":            "circuit_breaker.successes",
 }
 
 var RootCmd = &cobra.Command{
@@ -64,22 +121,15 @@ var RootCmd = &cobra.Command{
 	Version:      version,
 	SilenceUsage: true,
 	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
-		core.InitLogger(config.App.IsVerbose, config.App.IsDebug)
-
 		err := initializeConfig(cmd)
 		if err != nil {
 			return err
 		}
 
+		core.InitLogger(config.Server.IsVerbose, config.Server.IsDebug)
 		logrus.Debugf("Final config: %+v", config)
 		return nil
 	},
-
-	// Run: func(cmd *cobra.Command, args []string) {
-	// 	// Working with OutOrStdout/OutOrStderr allows us to unit test our command easier
-	// 	//out := cmd.OutOrStdout()
-	// 	logrus.Trace("Config:", config)
-	// },
 }
 
 // Bind each cobra flag to its associated viper configuration (config file and environment variable)
@@ -121,14 +171,27 @@ func parseFlagValue(flg *pflag.Flag) (interface{}, error) {
 // Initialize Viper
 func initializeConfig(cmd *cobra.Command) error {
 	v := viper.New()
+	setConfigDefaults(v)
 
-	// Base name of the config file, without the file extension
-	v.SetConfigName(defaultConfigFilename)
-	v.AddConfigPath(".")
+	explicitConfigPath := strings.TrimSpace(cmd.Flag("config").Value.String())
+	if explicitConfigPath == "" {
+		explicitConfigPath = strings.TrimSpace(os.Getenv(envPrefix + "_SERVER_CONFIG_PATH"))
+	}
+
+	if explicitConfigPath != "" {
+		v.SetConfigFile(explicitConfigPath)
+	} else {
+		// Base name of the config file, without the file extension
+		v.SetConfigName(defaultConfigFilename)
+		v.AddConfigPath(".")
+	}
 
 	// 1. Config file (lowest priority). Return an error if we cannot parse the config file.
 	err := v.ReadInConfig()
 	if err != nil {
+		if explicitConfigPath != "" {
+			return fmt.Errorf("cannot read config %q: %w", explicitConfigPath, err)
+		}
 		err = fmt.Errorf("cannot read config: %v", err)
 		logrus.Warn(err)
 	}
@@ -145,32 +208,143 @@ func initializeConfig(cmd *cobra.Command) error {
 	// 3. Command flags (highest priority). Bind the current command's flags to viper
 	bindFlags(cmd, v)
 
+	if err := validateRemovedConfigPaths(v); err != nil {
+		return err
+	}
+
 	// Dump Viper values to config struct
+	if err := validateEngineProxyTags(v); err != nil {
+		return err
+	}
+
 	err = v.Unmarshal(&config)
 	if err != nil {
 		return fmt.Errorf("cannot unmarshall config: %v", err)
 	}
 
-	if config.App.IsDebug {
+	config.Proxies, err = core.NormalizeProxiesConfig(config.Proxies)
+	if err != nil {
+		return fmt.Errorf("invalid proxies config: %w", err)
+	}
+
+	if config.Server.IsDebug {
 		logrus.Debug("Viper config:")
 		v.Debug()
 	}
 	return nil
 }
 
+func validateEngineProxyTags(v *viper.Viper) error {
+	for _, engineName := range []string{"google", "yandex", "baidu", "bing", "duckduckgo"} {
+		key := engineName + ".proxy"
+		if !v.IsSet(key) {
+			continue
+		}
+
+		raw := v.Get(key)
+		tag, ok := raw.(string)
+		if !ok {
+			return fmt.Errorf("invalid %s.proxy config: proxy must be a string tag", engineName)
+		}
+
+		if _, err := core.NormalizeProxyTag(tag); err != nil {
+			return fmt.Errorf("invalid %s.proxy config: %w", engineName, err)
+		}
+	}
+
+	return nil
+}
+
+func validateRemovedConfigPaths(v *viper.Viper) error {
+	legacyKeys := map[string]string{
+		"app.proxy":                    "use proxies.global or proxies.entries with per-engine proxy tags instead",
+		"proxy_pool":                   "use proxies.entries and proxies.health.failure_threshold instead",
+		"proxy_pool.urls":              "use proxies.entries instead",
+		"proxy_pool.failure_threshold": "use proxies.health.failure_threshold instead",
+		"app.host":                     "move to server.host",
+		"app.port":                     "move to server.port",
+		"app.debug":                    "move to server.debug",
+		"app.verbose":                  "move to server.verbose",
+		"app.raw_requests":             "move to server.raw_requests",
+		"app.insecure":                 "move to server.insecure",
+		"proxies.defaults":             "use proxies.global or per-engine proxy tags instead",
+		"proxies.defaults.mode":        "use proxies.global or per-engine proxy tags instead",
+		"proxies.defaults.tag":         "use per-engine proxy tags on each engine instead",
+		"google.proxy.mode":            "use google.proxy: <tag> or omit it for direct mode",
+		"google.proxy.tag":             "use google.proxy: <tag>",
+		"yandex.proxy.mode":            "use yandex.proxy: <tag> or omit it for direct mode",
+		"yandex.proxy.tag":             "use yandex.proxy: <tag>",
+		"baidu.proxy.mode":             "use baidu.proxy: <tag> or omit it for direct mode",
+		"baidu.proxy.tag":              "use baidu.proxy: <tag>",
+		"bing.proxy.mode":              "use bing.proxy: <tag> or omit it for direct mode",
+		"bing.proxy.tag":               "use bing.proxy: <tag>",
+		"duckduckgo.proxy.mode":        "use duckduckgo.proxy: <tag> or omit it for direct mode",
+		"duckduckgo.proxy.tag":         "use duckduckgo.proxy: <tag>",
+	}
+
+	for key, hint := range legacyKeys {
+		if v.IsSet(key) {
+			return fmt.Errorf("config key %q is removed in proxy v2: %s", key, hint)
+		}
+	}
+	return nil
+}
+
+func setConfigDefaults(v *viper.Viper) {
+	v.SetDefault("server.host", "127.0.0.1")
+	v.SetDefault("server.port", 7070)
+	v.SetDefault("server.debug", false)
+	v.SetDefault("server.verbose", false)
+	v.SetDefault("server.raw_requests", false)
+	v.SetDefault("server.insecure", false)
+
+	v.SetDefault("app.timeout", 30)
+	v.SetDefault("app.browser_path", "")
+	v.SetDefault("app.head", false)
+	v.SetDefault("app.leave_head", false)
+	v.SetDefault("app.leakless", false)
+	v.SetDefault("app.stealth", false)
+
+	v.SetDefault("proxies.entries", []interface{}{})
+	v.SetDefault("proxies.global", "")
+	v.SetDefault("proxies.health.failure_threshold", core.DefaultProxyFailureThreshold)
+
+	v.SetDefault("cache.ttl_seconds", 300)
+	v.SetDefault("cache.max_size", 1000)
+	// Keep stage2 defaults stable even when config file is absent.
+	v.SetDefault("resilience.max_retries", 3)
+	v.SetDefault("resilience.allow_endpoint_fallback", false)
+	v.SetDefault("circuit_breaker.failures", 5)
+	v.SetDefault("circuit_breaker.recovery_seconds", 60)
+	v.SetDefault("circuit_breaker.successes", 2)
+	v.SetDefault("cors.enabled", true)
+	v.SetDefault("cors.allow_origins", "*")
+	v.SetDefault("cors.allow_methods", "GET, POST, OPTIONS")
+	v.SetDefault("cors.allow_headers", "Origin, Content-Type, Accept, Authorization, X-Use-Proxy")
+	v.SetDefault("cors.max_age", 86400)
+}
+
 func init() {
-	RootCmd.PersistentFlags().IntVarP(&config.App.Port, "port", "p", 7070, "Port number to run server")
-	RootCmd.PersistentFlags().StringVarP(&config.App.Host, "host", "a", "127.0.0.1", "Host address to run server")
+	RootCmd.PersistentFlags().IntVarP(&config.Server.Port, "port", "p", 7070, "Port number to run server")
+	RootCmd.PersistentFlags().StringVarP(&config.Server.Host, "host", "a", "127.0.0.1", "Host address to run server")
 	RootCmd.PersistentFlags().IntVarP(&config.App.Timeout, "timeout", "t", 30, "Timeout to fail request")
-	RootCmd.PersistentFlags().StringVarP(&config.App.ConfigPath, "config", "c", "", "Configuration file path")
-	RootCmd.PersistentFlags().BoolVarP(&config.App.IsVerbose, "verbose", "v", false, "Use verbose output")
-	RootCmd.PersistentFlags().BoolVarP(&config.App.IsDebug, "debug", "d", false, "Use debug output. Disable headless browser")
+	RootCmd.PersistentFlags().StringVarP(&config.Server.ConfigPath, "config", "c", "", "Configuration file path")
+	RootCmd.PersistentFlags().StringVarP(&config.App.BrowserPath, "browser-path", "", "", "Custom browser binary path (Chrome/Chromium/Edge/Brave..)")
+	RootCmd.PersistentFlags().BoolVarP(&config.Server.IsVerbose, "verbose", "v", false, "Use verbose output")
+	RootCmd.PersistentFlags().BoolVarP(&config.Server.IsDebug, "debug", "d", false, "Use debug output. Disable headless browser")
 	RootCmd.PersistentFlags().BoolVarP(&config.App.IsBrowserHead, "head", "", false, "Enable browser UI")
 	RootCmd.PersistentFlags().BoolVarP(&config.App.IsLeakless, "leakless", "l", false, "Use leakless mode to insure browser instances are closed after search")
-	RootCmd.PersistentFlags().BoolVarP(&config.App.IsRawRequests, "raw", "r", false, "Disable browser usage, use HTTP requests")
+	RootCmd.PersistentFlags().BoolVarP(&config.Server.IsRawRequests, "raw", "r", false, "Disable browser usage, use HTTP requests")
 	RootCmd.PersistentFlags().BoolVarP(&config.App.IsLeaveHead, "leave", "", false, "Leave browser and tabs opened after search is made")
 	RootCmd.PersistentFlags().StringVarP(&config.Config2Capcha.ApiKey, "2captcha_key", "", "", "2 captcha api key")
-	RootCmd.PersistentFlags().StringVarP(&config.App.ProxyURL, "proxy", "x", "", "HTTP or Socks5 proxy URL (e.g. http://user:pass@127.0.0.1:8080)")
+	RootCmd.PersistentFlags().StringVarP(&config.Proxies.Global, "proxy", "x", "", "Force a single proxy for all engines (same as proxies.global)")
 	RootCmd.PersistentFlags().BoolVarP(&config.App.IsStealth, "stealth", "s", false, "Use stealth browser plugin")
-	RootCmd.PersistentFlags().BoolVarP(&config.App.Insecure, "insecure", "k", false, "Allow insecure TLS connections")
+	RootCmd.PersistentFlags().BoolVarP(&config.Server.Insecure, "insecure", "k", false, "Allow insecure TLS connections")
+	RootCmd.PersistentFlags().IntVar(&config.Cache.TTLSeconds, "cache_ttl", 300, "Cache TTL in seconds (0 to disable)")
+	RootCmd.PersistentFlags().IntVar(&config.Cache.MaxSize, "cache_max_size", 1000, "Maximum number of cached responses")
+	RootCmd.PersistentFlags().IntVar(&config.Resilience.MaxRetries, "max_retries", 3, "Max retry attempts per search engine (0 to disable)")
+	RootCmd.PersistentFlags().BoolVar(&config.Resilience.AllowEndpointFallback, "allow_endpoint_fallback", false, "Allow dedicated endpoints to fallback to other engines")
+	RootCmd.PersistentFlags().IntVar(&config.CircuitBreaker.Failures, "cb_failures", 5, "Consecutive failures before circuit breaker opens")
+	RootCmd.PersistentFlags().IntVar(&config.CircuitBreaker.RecoverySeconds, "cb_recovery", 60, "Seconds before retrying an engine with open circuit")
+	RootCmd.PersistentFlags().IntVar(&config.CircuitBreaker.Successes, "cb_successes", 2, "Consecutive successful half-open checks needed to close circuit")
 }

cmd/search.go

@@ -25,24 +25,46 @@ var searchCMD = &cobra.Command{
 }
 
 func search(cmd *cobra.Command, args []string) {
-	var err error
-	engineType := args[0]
+	engineType := normalizeEngineArg(args[0])
 	query := core.Query{
 		Text:     args[1],
 		Limit:    10,
-		ProxyURL: config.App.ProxyURL,
-		Insecure: config.App.Insecure,
+		Filter:   true,
+		Insecure: config.Server.Insecure,
+	}
+
+	proxyRuntime := core.ProxyRuntimeBrowser
+	if config.Server.IsRawRequests {
+		proxyRuntime = core.ProxyRuntimeRaw
+	}
+
+	proxyCfg, err := buildNormalizedProxyConfig(proxyRuntime)
+	if err != nil {
+		logrus.Errorf("Error validating proxy config: %v", err)
+		return
+	}
+
+	policy := resolveEngineProxyPolicy(proxyCfg, engineType)
+
+	selectedProxy, err := selectCLIProxy(proxyCfg, policy)
+	if err != nil {
+		logrus.Errorf("Error selecting proxy for %s: %v", engineType, err)
+		return
+	}
+
+	if config.Server.IsRawRequests {
+		query.ProxyURL = selectedProxy
 	}
 
 	logrus.Infof("Starting SERP search request using %s engine for query: %s", engineType, query.Text)
 
 	var results []core.SearchResult
-	if config.App.IsRawRequests {
+	if config.Server.IsRawRequests {
 		logrus.Infof("Using raw requests mode for %s search", engineType)
 		results, err = searchRaw(engineType, query)
 	} else {
 		logrus.Infof("Using browser mode for %s search", engineType)
-		results, err = searchBrowser(engineType, query)
+		results, err = searchBrowser(engineType, query, selectedProxy)
 	}
 
 	if err != nil {
@@ -60,42 +82,51 @@ func search(cmd *cobra.Command, args []string) {
 
 	fmt.Println(string(b))
 }
-func searchBrowser(engineType string, query core.Query) ([]core.SearchResult, error) {
+
+func searchBrowser(engineType string, query core.Query, browserProxyURL string) ([]core.SearchResult, error) {
 	var engine core.SearchEngine
+	if core.IsAuthenticatedSocksProxyURL(browserProxyURL) {
+		return nil, fmt.Errorf(
+			"%w: browser runtime does not support authenticated SOCKS proxy %s",
+			core.ErrProxyUnavailable,
+			core.MaskProxyURL(browserProxyURL),
+		)
+	}
 
 	opts := core.BrowserOpts{
-		IsHeadless:          !config.App.IsBrowserHead, // Disable headless if browser head mode is set
+		IsHeadless:          !config.App.IsBrowserHead,
 		IsLeakless:          config.App.IsLeakless,
 		Timeout:             time.Second * time.Duration(config.App.Timeout),
 		LeavePageOpen:       config.App.IsLeaveHead,
 		CaptchaSolverApiKey: config.Config2Capcha.ApiKey,
-		ProxyURL:            config.App.ProxyURL,
-		Insecure:            config.App.Insecure,
+		BrowserPath:         config.App.BrowserPath,
+		ProxyURL:            browserProxyURL,
+		Insecure:            config.Server.Insecure,
 		UseStealth:          config.App.IsStealth,
 	}
 
-	if config.App.IsDebug {
+	if config.Server.IsDebug {
 		opts.IsHeadless = false
 	}
 
 	browser, err := core.NewBrowser(opts)
 	if err != nil {
-		logrus.Error(err)
+		return nil, err
 	}
 
 	switch strings.ToLower(engineType) {
 	case "yandex":
-		engine = yandex.New(*browser, config.YandexConfig)
+		engine = yandex.New(*browser, config.YandexConfig.SearchEngineOptions)
 	case "google":
-		engine = google.New(*browser, config.GoogleConfig)
+		engine = google.New(*browser, config.GoogleConfig.SearchEngineOptions)
 	case "baidu":
-		engine = baidu.New(*browser, config.BaiduConfig)
+		engine = baidu.New(*browser, config.BaiduConfig.SearchEngineOptions)
 	case "bing":
-		engine = bing.New(*browser, config.BingConfig)
-	case "duck":
-		engine = duckduckgo.New(*browser, config.DuckDuckGoConfig)
+		engine = bing.New(*browser, config.BingConfig.SearchEngineOptions)
+	case "duckduckgo":
+		engine = duckduckgo.New(*browser, config.DuckDuckGoConfig.SearchEngineOptions)
 	default:
-		logrus.Infof("No `%s` search engine found", engineType)
+		return nil, fmt.Errorf("no %q search engine found", engineType)
 	}
 
 	return engine.Search(query)
@@ -114,13 +145,42 @@ func searchRaw(engineType string, query core.Query) ([]core.SearchResult, error)
 	case "bing":
 		logrus.Warn("Bing does not support raw HTTP requests mode. Please use browser mode instead.")
 		return nil, fmt.Errorf("bing does not support raw requests mode")
-	case "duck":
+	case "duckduckgo":
 		logrus.Warn("DuckDuckGo does not support raw HTTP requests mode. Please use browser mode instead.")
 		return nil, fmt.Errorf("duckduckgo does not support raw requests mode")
 	default:
-		logrus.Infof("No `%s` search engine found", engineType)
+		return nil, fmt.Errorf("no %q search engine found", engineType)
+	}
+}
+
+func selectCLIProxy(proxyCfg core.ProxyConfig, policy core.ProxyPolicy) (string, error) {
+	if policy.Mode == core.ProxyModeOff {
+		return "", nil
+	}
+
+	if global := strings.TrimSpace(proxyCfg.Proxies.Global); global != "" {
+		return global, nil
+	}
+
+	if proxyCfg.Registry == nil {
+		return "", fmt.Errorf("%w: no proxy registry configured", core.ErrProxyUnavailable)
+	}
+
+	selected := proxyCfg.Registry.NextByTag(policy.Tag)
+	if selected == "" {
+		return "", fmt.Errorf("%w: no healthy proxy available for tag %q", core.ErrProxyUnavailable, policy.Tag)
+	}
+
+	return selected, nil
+}
+
+func normalizeEngineArg(raw string) string {
+	switch strings.ToLower(strings.TrimSpace(raw)) {
+	case "duck":
+		return "duckduckgo"
+	default:
+		return strings.ToLower(strings.TrimSpace(raw))
 	}
-	return nil, nil
 }
 
 func init() {

cmd/serve.go

@@ -2,6 +2,8 @@ package cmd
 
 import (
 	"fmt"
+	"strings"
+	"sync"
 	"time"
 
 	"github.com/karust/openserp/baidu"
@@ -21,9 +23,7 @@ type rawEngine struct {
 }
 
 func (r *rawEngine) Search(q core.Query) ([]core.SearchResult, error) {
-	// Inject proxy settings from config
-	q.ProxyURL = config.App.ProxyURL
-	q.Insecure = config.App.Insecure
+	q.Insecure = config.Server.Insecure
 
 	switch r.name {
 	case "google":
@@ -63,52 +63,309 @@ var serveCMD = &cobra.Command{
 }
 
 func serve(cmd *cobra.Command, args []string) {
-	if config.App.IsRawRequests {
+	corsCfg := core.DefaultCORSConfig()
+	corsCfg.AllowOrigins = config.CORS.AllowOrigins
+	corsCfg.AllowMethods = config.CORS.AllowMethods
+	corsCfg.AllowHeaders = config.CORS.AllowHeaders
+	corsCfg.MaxAge = config.CORS.MaxAge
+
+	proxyRuntime := core.ProxyRuntimeBrowser
+	if config.Server.IsRawRequests {
+		proxyRuntime = core.ProxyRuntimeRaw
+	}
+
+	proxyCfg, err := buildNormalizedProxyConfig(proxyRuntime)
+	if err != nil {
+		logrus.Errorf("invalid proxy configuration: %v", err)
+		return
+	}
+
+	if config.Server.IsRawRequests {
 		logrus.Warn("Browserless results are very inconsistent or may not even work!")
-		serv := core.NewServer(config.App.Host, config.App.Port,
+		serverOpts := buildServerOptions(corsCfg, proxyCfg)
+		serv := core.NewServerWithOptions(config.Server.Host, config.Server.Port, serverOpts,
 			&rawEngine{name: "google"},
 			&rawEngine{name: "yandex"},
 			&rawEngine{name: "baidu"},
 		)
-		serv.Listen()
+		if err := serv.Listen(); err != nil {
+			logrus.Error(err)
+		}
 		return
 	}
 
-	opts := core.BrowserOpts{
-		IsHeadless:          !config.App.IsBrowserHead, // Disable headless if browser head mode is set
+	baseOpts := core.BrowserOpts{
+		IsHeadless:          !config.App.IsBrowserHead,
 		IsLeakless:          config.App.IsLeakless,
 		Timeout:             time.Second * time.Duration(config.App.Timeout),
 		LeavePageOpen:       config.App.IsLeaveHead,
 		CaptchaSolverApiKey: config.Config2Capcha.ApiKey,
-		ProxyURL:            config.App.ProxyURL,
-		Insecure:            config.App.Insecure,
+		BrowserPath:         config.App.BrowserPath,
+		Insecure:            config.Server.Insecure,
 		UseStealth:          config.App.IsStealth,
 	}
-
-	if config.App.IsDebug {
-		opts.IsHeadless = false
+	if config.Server.IsDebug {
+		baseOpts.IsHeadless = false
 	}
 
-	browser, err := core.NewBrowser(opts)
+	engines, err := buildBrowserEngines(baseOpts, proxyCfg)
 	if err != nil {
 		logrus.Error(err)
 		return
 	}
 
-	yand := yandex.New(*browser, config.YandexConfig)
-	gogl := google.New(*browser, config.GoogleConfig)
-	baidu := baidu.New(*browser, config.BaiduConfig)
-	bing := bing.New(*browser, config.BingConfig)
-	ddg := duckduckgo.New(*browser, config.DuckDuckGoConfig)
-
-	serv := core.NewServer(config.App.Host, config.App.Port, gogl, yand, baidu, bing, ddg)
-
-	err = serv.Listen()
-	if err != nil {
+	serverOpts := buildServerOptions(corsCfg, proxyCfg)
+	serv := core.NewServerWithOptions(config.Server.Host, config.Server.Port, serverOpts, engines...)
+	if err := serv.Listen(); err != nil {
 		logrus.Error(err)
 	}
 }
 
+func buildServerOptions(corsCfg core.CORSConfig, proxyCfg core.ProxyConfig) core.ServerOptions {
+	return core.ServerOptions{
+		CacheTTL:              time.Duration(config.Cache.TTLSeconds) * time.Second,
+		CacheMaxSize:          config.Cache.MaxSize,
+		EnableCORS:            config.CORS.Enabled,
+		CORS:                  corsCfg,
+		AllowEndpointFallback: config.Resilience.AllowEndpointFallback,
+		Resilience: core.ResilientConfig{
+			Retry: core.RetryConfig{
+				MaxRetries:     config.Resilience.MaxRetries,
+				InitialBackoff: 1 * time.Second,
+				MaxBackoff:     30 * time.Second,
+				BackoffFactor:  2.0,
+			},
+			CircuitBreaker: core.CircuitBreakerConfig{
+				FailureThreshold: config.CircuitBreaker.Failures,
+				RecoveryTimeout:  time.Duration(config.CircuitBreaker.RecoverySeconds) * time.Second,
+				SuccessThreshold: config.CircuitBreaker.Successes,
+			},
+			Proxy: proxyCfg,
+		},
+	}
+}
+
+type browserPool struct {
+	mu      sync.Mutex
+	base    core.BrowserOpts
+	browser map[string]*core.Browser
+}
+
+func newBrowserPool(base core.BrowserOpts) *browserPool {
+	return &browserPool{
+		base:    base,
+		browser: map[string]*core.Browser{},
+	}
+}
+
+func (p *browserPool) get(proxyURL string) (*core.Browser, error) {
+	key := strings.TrimSpace(proxyURL)
+	if key == "" {
+		key = "direct"
+	}
+
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if b, ok := p.browser[key]; ok {
+		return b, nil
+	}
+
+	opts := p.base
+	opts.ProxyURL = proxyURL
+	b, err := core.NewBrowser(opts)
+	if err != nil {
+		return nil, err
+	}
+
+	// Reuse one launched browser per unique effective proxy so startup stays lazy
+	// and engines with identical proxy policy don't spawn duplicate browser processes.
+	p.browser[key] = b
+	return b, nil
+}
+
+type pooledBrowserEngine struct {
+	name    string
+	limiter *rate.Limiter
+	opts    core.SearchEngineOptions
+	factory func(core.Browser, core.SearchEngineOptions) core.SearchEngine
+	pool    *browserPool
+
+	mu      sync.Mutex
+	engines map[string]core.SearchEngine
+}
+
+func (e *pooledBrowserEngine) Search(q core.Query) ([]core.SearchResult, error) {
+	engine, err := e.getOrCreate(q.ProxyURL)
+	if err != nil {
+		return nil, err
+	}
+	return engine.Search(q)
+}
+
+func (e *pooledBrowserEngine) SearchImage(q core.Query) ([]core.SearchResult, error) {
+	engine, err := e.getOrCreate(q.ProxyURL)
+	if err != nil {
+		return nil, err
+	}
+	return engine.SearchImage(q)
+}
+
+func (e *pooledBrowserEngine) IsInitialized() bool {
+	return true
+}
+
+func (e *pooledBrowserEngine) Name() string {
+	return e.name
+}
+
+func (e *pooledBrowserEngine) GetRateLimiter() *rate.Limiter {
+	return e.limiter
+}
+
+func (e *pooledBrowserEngine) getOrCreate(proxyURL string) (core.SearchEngine, error) {
+	key := strings.TrimSpace(proxyURL)
+	if key == "" {
+		key = "direct"
+	}
+
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if engine, ok := e.engines[key]; ok {
+		return engine, nil
+	}
+
+	browser, err := e.pool.get(proxyURL)
+	if err != nil {
+		return nil, err
+	}
+
+	engine := e.factory(*browser, e.opts)
+	e.engines[key] = engine
+	return engine, nil
+}
+
+type browserEngineSpec struct {
+	name    string
+	opts    core.SearchEngineOptions
+	factory func(core.Browser, core.SearchEngineOptions) core.SearchEngine
+}
+
+func browserEngineSpecs() []browserEngineSpec {
+	return []browserEngineSpec{
+		{
+			name: "google",
+			opts: config.GoogleConfig.SearchEngineOptions,
+			factory: func(browser core.Browser, opts core.SearchEngineOptions) core.SearchEngine {
+				return google.New(browser, opts)
+			},
+		},
+		{
+			name: "yandex",
+			opts: config.YandexConfig.SearchEngineOptions,
+			factory: func(browser core.Browser, opts core.SearchEngineOptions) core.SearchEngine {
+				return yandex.New(browser, opts)
+			},
+		},
+		{
+			name: "baidu",
+			opts: config.BaiduConfig.SearchEngineOptions,
+			factory: func(browser core.Browser, opts core.SearchEngineOptions) core.SearchEngine {
+				return baidu.New(browser, opts)
+			},
+		},
+		{
+			name: "bing",
+			opts: config.BingConfig.SearchEngineOptions,
+			factory: func(browser core.Browser, opts core.SearchEngineOptions) core.SearchEngine {
+				return bing.New(browser, opts)
+			},
+		},
+		{
+			name: "duckduckgo",
+			opts: config.DuckDuckGoConfig.SearchEngineOptions,
+			factory: func(browser core.Browser, opts core.SearchEngineOptions) core.SearchEngine {
+				return duckduckgo.New(browser, opts)
+			},
+		},
+	}
+}
+
+func buildBrowserEngines(baseOpts core.BrowserOpts, proxyCfg core.ProxyConfig) ([]core.SearchEngine, error) {
+	pool := newBrowserPool(baseOpts)
+	specs := browserEngineSpecs()
+
+	engines := make([]core.SearchEngine, 0, len(specs))
+	for _, spec := range specs {
+		policy := resolveEngineProxyPolicy(proxyCfg, spec.name)
+		if err := validateBrowserProxyPolicy(proxyCfg, policy); err != nil {
+			return nil, fmt.Errorf("browser proxy validation failed for engine %s: %w", spec.name, err)
+		}
+
+		opts := spec.opts
+		opts.Init()
+		engines = append(engines, &pooledBrowserEngine{
+			name:    spec.name,
+			limiter: rate.NewLimiter(rate.Every(opts.GetRatelimit()), opts.RateBurst),
+			opts:    opts,
+			factory: spec.factory,
+			pool:    pool,
+			engines: map[string]core.SearchEngine{},
+		})
+	}
+
+	return engines, nil
+}
+
+func validateBrowserProxyPolicy(proxyCfg core.ProxyConfig, policy core.ProxyPolicy) error {
+	if policy.Mode != core.ProxyModeTagPool {
+		return nil
+	}
+
+	proxyURL := strings.TrimSpace(proxyCfg.Proxies.Global)
+	if proxyURL != "" {
+		return validateBrowserProxyURL(proxyURL)
+	}
+
+	for _, entry := range proxyCfg.Proxies.Entries {
+		if !entryHasTag(entry, policy.Tag) {
+			continue
+		}
+		if err := validateBrowserProxyURL(entry.URL); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func validateBrowserProxyURL(proxyURL string) error {
+	// Browser startup must stop immediately on authenticated SOCKS because Chrome
+	// cannot use that proxy shape reliably and retrying a different proxy hides the misconfiguration.
+	if core.IsAuthenticatedSocksProxyURL(proxyURL) {
+		return fmt.Errorf(
+			"%w: browser runtime does not support authenticated SOCKS proxy %s",
+			core.ErrProxyUnavailable,
+			core.MaskProxyURL(proxyURL),
+		)
+	}
+	return nil
+}
+
+func entryHasTag(entry core.ProxyEntryConfig, tag string) bool {
+	tag = strings.TrimSpace(strings.ToLower(tag))
+	if tag == "" {
+		return false
+	}
+	for _, entryTag := range entry.Tags {
+		if strings.TrimSpace(strings.ToLower(entryTag)) == tag {
+			return true
+		}
+	}
+	return false
+}
+
 func init() {
 	RootCmd.AddCommand(serveCMD)
 }

cmd/serve_test.go

@@ -0,0 +1,105 @@
+package cmd
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/karust/openserp/core"
+)
+
+func TestValidateBrowserProxyPolicyRejectsAuthenticatedSocks(t *testing.T) {
+	tests := []struct {
+		name     string
+		proxyCfg core.ProxyConfig
+		policy   core.ProxyPolicy
+	}{
+		{
+			name: "global authenticated socks",
+			proxyCfg: core.ProxyConfig{
+				Proxies: core.ProxiesConfig{
+					Global: "socks5h://user:pass@127.0.0.1:1080",
+				},
+			},
+			policy: core.ProxyPolicy{Mode: core.ProxyModeTagPool},
+		},
+		{
+			name: "tag pool authenticated socks",
+			proxyCfg: core.ProxyConfig{
+				Proxies: core.ProxiesConfig{
+					Entries: []core.ProxyEntryConfig{
+						{URL: "socks5://user:pass@127.0.0.1:1080", Tags: []string{"us"}},
+					},
+				},
+			},
+			policy: core.ProxyPolicy{Mode: core.ProxyModeTagPool, Tag: "us"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateBrowserProxyPolicy(tt.proxyCfg, tt.policy)
+			if err == nil {
+				t.Fatal("expected browser proxy validation to fail")
+			}
+			if !strings.Contains(err.Error(), "authenticated SOCKS proxy") {
+				t.Fatalf("expected explicit authenticated SOCKS error, got %v", err)
+			}
+		})
+	}
+}
+
+func TestValidateBrowserProxyPolicyAllowsHTTPAuthAndPlainSocks(t *testing.T) {
+	tests := []struct {
+		name     string
+		proxyCfg core.ProxyConfig
+		policy   core.ProxyPolicy
+	}{
+		{
+			name: "global http auth",
+			proxyCfg: core.ProxyConfig{
+				Proxies: core.ProxiesConfig{
+					Global: "http://user:pass@127.0.0.1:8080",
+				},
+			},
+			policy: core.ProxyPolicy{Mode: core.ProxyModeTagPool},
+		},
+		{
+			name: "tag pool plain socks",
+			proxyCfg: core.ProxyConfig{
+				Proxies: core.ProxiesConfig{
+					Entries: []core.ProxyEntryConfig{
+						{URL: "socks5://127.0.0.1:1080", Tags: []string{"eu"}},
+					},
+				},
+			},
+			policy: core.ProxyPolicy{Mode: core.ProxyModeTagPool, Tag: "eu"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := validateBrowserProxyPolicy(tt.proxyCfg, tt.policy); err != nil {
+				t.Fatalf("expected browser proxy validation to succeed, got %v", err)
+			}
+		})
+	}
+}
+
+func TestValidateBrowserProxyPolicyRejectsTaggedAuthenticatedSocksInPool(t *testing.T) {
+	proxyCfg := core.ProxyConfig{
+		Proxies: core.ProxiesConfig{
+			Entries: []core.ProxyEntryConfig{
+				{URL: "http://127.0.0.1:8080", Tags: []string{"default"}},
+				{URL: "socks5://user:pass@127.0.0.1:1080", Tags: []string{"default"}},
+			},
+		},
+	}
+
+	err := validateBrowserProxyPolicy(proxyCfg, core.ProxyPolicy{Mode: core.ProxyModeTagPool, Tag: "default"})
+	if err == nil {
+		t.Fatal("expected browser proxy validation to fail for tag pool")
+	}
+	if !strings.Contains(err.Error(), "authenticated SOCKS proxy") {
+		t.Fatalf("expected explicit authenticated SOCKS error, got %v", err)
+	}
+}

config.yaml

@@ -1,22 +1,60 @@
-app:
-  host: 0.0.0.0
-  port: 7000
-  debug: false
-  verbose: true
-  timeout: 15
-  head: false
-  leakless: false
-  leave_head: false
-  stealth: false
-  insecure: true
+server:
+  host: 0.0.0.0 # API host to bind
+  port: 7000 # API port to bind
+  debug: false # Enable debug logs and force browser UI mode
+  verbose: true # Enable info-level request logs
+  raw_requests: false # true = raw HTTP mode, false = browser mode
+  insecure: true # Allow insecure TLS connections
 
-2captcha:
-  apikey: "123123123123123"
+app:
+  timeout: 15 # Browser/search timeout in seconds
+  browser_path: "" # Custom browser binary path (chrome/chromium/edge..)
+  head: false # Show browser UI (headful mode)
+  leakless: false # Force browser process cleanup after request
+  leave_head: false # Keep tabs open after request for debugging
+  stealth: false # Enable stealth browser plugin
+
+proxies:
+  # Force a single proxy for all engines.
+  # Same behavior as passing --proxy on the CLI.
+  #global: http://127.0.0.1:8080
+
+  # Advanced mode: define tagged proxy pools and opt engines in with `proxy: <tag>`.
+  #entries:
+  #  - url: http://127.0.0.1:8080
+  #    tags: [default, us]
+  #  - url: socks5h://127.0.0.1:1080
+  #    tags: [eu]
+  health:
+    failure_threshold: 3 # Disable proxy after this many consecutive failures
+
+cache:
+  ttl_seconds: 60 # Dedicated endpoint cache TTL in seconds (0 disables cache)
+  max_size: 1000 # Maximum cached dedicated responses before oldest-entry eviction
+
+resilience:
+  max_retries: 2 # Retry attempts per engine request (0 disables retries)
+  allow_endpoint_fallback: false # Keep dedicated endpoints engine-pure by default
+
+# circuit_breaker:
+#   failures: 5 # Consecutive failures required to open circuit
+#   recovery_seconds: 60 # Wait time before moving open circuit to half-open
+#   successes: 2 # Consecutive half-open successes required to close circuit
+
+cors:
+  enabled: true
+  allow_origins: "*"
+  allow_methods: "GET, POST, OPTIONS"
+  allow_headers: "Origin, Content-Type, Accept, Authorization, X-Use-Proxy"
+  max_age: 86400
+
+# 2captcha:
+#   apikey: "123123123123123"
 
 google:
-  rate_requests: 4 # Number of requests per Minute
-  rate_burst: 2 # Number of non-ratelimited requests per Minute
-  captcha: true
+  rate_requests: 4 # Allowed average requests per minute
+  rate_burst: 2 # Burst requests before limiter applies
+  captcha: true # Enable captcha solver path
 
 yandex:
   rate_requests: 4
@@ -25,10 +63,12 @@ yandex:
 baidu:
   rate_requests: 4
   rate_burst: 2
+  # No proxy tag means direct traffic
 
 bing:
   rate_requests: 4
   rate_burst: 2
+  # No proxy tag means direct traffic
 
 duckduckgo:
   rate_requests: 4

core/browser.go

@@ -1,8 +1,11 @@
 package core
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"net/url"
+	"os"
 	"strings"
 	"time"
 
@@ -23,6 +26,7 @@ type BrowserOpts struct {
 	LeavePageOpen       bool          // Leave pages and browser open
 	WaitLoadTime        time.Duration // Time to wait till page loads
 	CaptchaSolverApiKey string        // 2Captcha api key
+	BrowserPath         string        // Explicit browser executable path
 	ProxyURL            string        // Proxy URL
 	Insecure            bool          // Allow insecure TLS connections
 	UseStealth          bool          // Use go-rod stealth plugin
@@ -51,35 +55,45 @@ func NewBrowser(opts BrowserOpts) (*Browser, error) {
 	opts.Check()
 	logrus.Debugf("Browser options: %+v", opts)
 
-	path, has := launcher.LookPath()
-	logrus.Debug("Browser found: ", has)
+	path, err := resolveBrowserBinaryPath(opts.BrowserPath, launcher.LookPath)
+	if err != nil {
+		return nil, err
+	}
 
 	// Create launcher
-	l := launcher.New().Bin(path).Leakless(opts.IsLeakless).Headless(opts.IsHeadless).Set("disable-blink-features", "AutomationControlled").
+	l := launcher.New().Leakless(opts.IsLeakless).Headless(opts.IsHeadless).Set("disable-blink-features", "AutomationControlled").
 		Delete("enable-automation")
+	if path != "" {
+		logrus.Debugf("Using browser binary: %s", path)
+		l = l.Bin(path)
+	}
 
 	// Configure proxy if specified
 	if opts.ProxyURL != "" {
+		normalizedProxyURL, err := NormalizeProxyURL(opts.ProxyURL)
+		if err != nil {
+			return nil, fmt.Errorf("invalid proxy URL: %v", err)
+		}
+		opts.ProxyURL = normalizedProxyURL
+
 		proxyUrl, err := url.Parse(opts.ProxyURL)
 		if err != nil {
 			return nil, fmt.Errorf("invalid proxy URL: %v", err)
 		}
 
-		// Make sure the proxy URL includes the scheme when passed to launcher
-		// This ensures proper handling of SOCKS5 proxies
-		proxyStr := proxyUrl.String()
-		logrus.Debugf("Setting up proxy: %s", proxyStr)
+		// Chrome's proxy-server flag must not contain credentials.
+		// Auth (if needed) is handled separately via DevTools auth callbacks.
+		proxyStr := proxyURLForBrowserLaunch(proxyUrl)
+		logrus.Debugf("Setting up proxy: %s", MaskProxyURL(proxyStr))
 		l = l.Proxy(proxyStr)
 
 		// Check if proxy has auth credentials
 		if proxyUrl.User != nil {
 			username := proxyUrl.User.Username()
-			logrus.Debugf("Using proxy authentication: %s:****", username)
-			// We'll handle auth in the Navigate method
+			logrus.Debugf("Proxy credentials configured for %s proxy: %s:****", proxyUrl.Scheme, username)
 		}
 	}
 
-	var err error
 	b := Browser{BrowserOpts: opts}
 	b.browserAddr, err = l.Launch()
 
@@ -91,6 +105,52 @@ func NewBrowser(opts BrowserOpts) (*Browser, error) {
 	return &b, err
 }
 
+func proxyURLForBrowserLaunch(u *url.URL) string {
+	if u == nil {
+		return ""
+	}
+	clone := *u
+	// Chrome expects socks5 scheme in --proxy-server; socks5h is not accepted.
+	if clone.Scheme == "socks5h" {
+		clone.Scheme = "socks5"
+	}
+	clone.User = nil
+	clone.Path = ""
+	clone.RawPath = ""
+	clone.RawQuery = ""
+	clone.Fragment = ""
+	return clone.String()
+}
+
+func validateBrowserBinaryPath(path string) error {
+	info, err := os.Stat(path)
+	if err != nil {
+		return err
+	}
+	if info.IsDir() {
+		return fmt.Errorf("path points to a directory")
+	}
+	return nil
+}
+
+// resolveBrowserBinaryPath prefers an explicit browser path. If no explicit path is provided,
+// it falls back to launcher autodiscovery and lets Rod handle auto-download when no binary is found.
+func resolveBrowserBinaryPath(browserPath string, lookPath func() (string, bool)) (string, error) {
+	if browserPath != "" {
+		if err := validateBrowserBinaryPath(browserPath); err != nil {
+			return "", fmt.Errorf("invalid browser_path %q: %w", browserPath, err)
+		}
+		return browserPath, nil
+	}
+
+	path, has := lookPath()
+	if has {
+		return path, nil
+	}
+
+	return "", nil
+}
+
 // Check whether browser instance is already created
 func (b *Browser) IsInitialized() bool {
 	if b.browserAddr != "" {
@@ -104,9 +164,14 @@ func (b *Browser) IsInitialized() bool {
 func (b *Browser) Navigate(URL string) (*rod.Page, error) {
 	logrus.Debug("Navigate to: ", URL)
 
-	b.browser = rod.New().ControlURL(b.browserAddr)
-	b.browser.MustConnect()
-	b.browser.SetCookies(nil)
+	browser := rod.New().ControlURL(b.browserAddr).Timeout(b.Timeout)
+	if err := browser.Connect(); err != nil {
+		return nil, fmt.Errorf("browser connect failed: %w", err)
+	}
+	b.browser = browser
+	if err := b.browser.SetCookies(nil); err != nil {
+		return nil, fmt.Errorf("browser cookie reset failed: %w", err)
+	}
 
 	// Handle proxy authentication before any navigations
 	if b.ProxyURL != "" {
@@ -114,39 +179,66 @@ func (b *Browser) Navigate(URL string) (*rod.Page, error) {
 
 		// Always ignore certificate errors when using proxies
 		// This fixes the ERR_CERT_AUTHORITY_INVALID error for SOCKS5 proxies
-		b.browser.MustIgnoreCertErrors(true)
+		if err := b.browser.IgnoreCertErrors(true); err != nil {
+			return nil, fmt.Errorf("configure proxy cert handling failed: %w", err)
+		}
 
-		if proxyUrl.User != nil {
+		if proxyUrl.User != nil && (proxyUrl.Scheme == "http" || proxyUrl.Scheme == "https") {
 			username := proxyUrl.User.Username()
 			password, _ := proxyUrl.User.Password()
 			// Launch auth handler before any navigation occurs
-			go b.browser.MustHandleAuth(username, password)()
+			go func() {
+				if err := b.browser.HandleAuth(username, password)(); err != nil {
+					logrus.Debugf("Proxy auth handler stopped: %v", err)
+				}
+			}()
+		} else if proxyUrl.User != nil && (proxyUrl.Scheme == "socks5" || proxyUrl.Scheme == "socks5h") {
+			// This callback handles HTTP proxy auth challenges; it doesn't authenticate SOCKS proxies.
+			logrus.Debug("SOCKS proxy credentials are not handled by browser auth callback")
 		}
 	} else if b.Insecure {
 		// Still respect the insecure flag if no proxy is used
-		b.browser.MustIgnoreCertErrors(true)
+		if err := b.browser.IgnoreCertErrors(true); err != nil {
+			return nil, fmt.Errorf("configure insecure mode failed: %w", err)
+		}
 	}
 
-	ua := strings.ReplaceAll(b.browser.MustVersion().UserAgent, "HeadlessChrome/", "Chrome/")
+	version, err := b.browser.Version()
+	if err != nil {
+		return nil, fmt.Errorf("read browser version failed: %w", err)
+	}
+	ua := strings.ReplaceAll(version.UserAgent, "HeadlessChrome/", "Chrome/")
 
 	var page *rod.Page
 
 	if b.UseStealth {
-		page = stealth.MustPage(b.browser)
-		page.MustEmulate(devices.Device{
+		page, err = stealth.Page(b.browser)
+		if err != nil {
+			return nil, fmt.Errorf("create stealth page failed: %w", err)
+		}
+		err = page.Emulate(devices.Device{
 			AcceptLanguage: b.LanguageCode,
 			UserAgent:      ua,
 		})
+		if err != nil {
+			return nil, fmt.Errorf("emulate stealth page failed: %w", err)
+		}
 
 	} else {
-		page = b.browser.MustPage("about:blank")
+		page, err = b.browser.Page(proto.TargetCreateTarget{URL: "about:blank"})
+		if err != nil {
+			return nil, fmt.Errorf("create page failed: %w", err)
+		}
 
-		page.MustEmulate(devices.Device{
+		err = page.Emulate(devices.Device{
 			AcceptLanguage: b.LanguageCode,
 			UserAgent:      ua,
 		})
+		if err != nil {
+			return nil, fmt.Errorf("emulate page failed: %w", err)
+		}
 
-		proto.EmulationSetDeviceMetricsOverride{
+		err = proto.EmulationSetDeviceMetricsOverride{
 			Width:             1920,
 			Height:            1080,
 			DeviceScaleFactor: 1,
@@ -154,25 +246,37 @@ func (b *Browser) Navigate(URL string) (*rod.Page, error) {
 			ScreenWidth:       &[]int{1920}[0],
 			ScreenHeight:      &[]int{1080}[0],
 		}.Call(page)
+		if err != nil {
+			return nil, fmt.Errorf("set device metrics failed: %w", err)
+		}
 	}
 	//EnableCustomStealth(page)
 
-	err := page.Navigate(URL)
+	timedPage := page.Timeout(b.Timeout)
+
+	err = timedPage.Navigate(URL)
 	if err != nil {
 		return nil, err
 	}
 
 	// Avoid panics from MustWaitLoad when the target navigates/closes mid-wait
-	if werr := page.WaitLoad(); werr != nil {
-		logrus.Debugf("WaitLoad returned early: %v", werr)
+	if werr := timedPage.WaitLoad(); werr != nil {
+		if errors.Is(werr, context.DeadlineExceeded) {
+			// Some engines keep loading background resources while the DOM is already usable.
+			// Treat load timeout as non-fatal and let engine-specific selector timeouts decide.
+			logrus.Debugf("WaitLoad timed out after %s; continuing with partial page state", b.Timeout)
+		} else {
+			logrus.Debugf("WaitLoad returned early: %v", werr)
+		}
 	}
-	wait := page.MustWaitRequestIdle()
+
 	// may cause bugs with google
 	if b.WaitRequests {
+		wait := timedPage.WaitRequestIdle(300*time.Millisecond, nil, nil, nil)
 		wait()
 	}
 
-	time.Sleep(2 * time.Second)
+	time.Sleep(b.WaitLoadTime)
 	return page, nil
 }
 

core/cache.go

@@ -0,0 +1,140 @@
+package core
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"sync"
+	"time"
+)
+
+type CacheEntry struct {
+	Data      []byte
+	CreatedAt time.Time
+	ExpiresAt time.Time
+}
+
+// ResponseCache is a bounded in-memory TTL cache for dedicated endpoint responses.
+type ResponseCache struct {
+	mu        sync.Mutex
+	entries   map[string]CacheEntry
+	ttl       time.Duration
+	maxSize   int
+	hits      int
+	misses    int
+	bypasses  int
+	evictions int
+}
+
+func NewResponseCache(ttl time.Duration, maxSize int) *ResponseCache {
+	return &ResponseCache{
+		entries: make(map[string]CacheEntry),
+		ttl:     ttl,
+		maxSize: maxSize,
+	}
+}
+
+func BuildCacheKey(engine string, action string, q Query) string {
+	raw := fmt.Sprintf(
+		"%s|%s|%s|%s|%s|%s|%s|%d|%d|%t|%t|%s",
+		engine,
+		action,
+		q.Text,
+		q.LangCode,
+		q.DateInterval,
+		q.Filetype,
+		q.Site,
+		q.Limit,
+		q.Start,
+		q.Filter,
+		q.Answers,
+		q.ProxyOverride,
+	)
+	hash := sha256.Sum256([]byte(raw))
+	return hex.EncodeToString(hash[:])
+}
+
+func (c *ResponseCache) Get(key string) ([]byte, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.pruneExpiredLocked(time.Now())
+
+	entry, ok := c.entries[key]
+	if !ok {
+		c.misses++
+		return nil, false
+	}
+
+	c.hits++
+	return entry.Data, true
+}
+
+func (c *ResponseCache) Set(key string, data []byte) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	now := time.Now()
+	c.pruneExpiredLocked(now)
+
+	if _, exists := c.entries[key]; !exists && len(c.entries) >= c.maxSize {
+		c.evictOldestLocked()
+	}
+
+	c.entries[key] = CacheEntry{
+		Data:      data,
+		CreatedAt: now,
+		ExpiresAt: now.Add(c.ttl),
+	}
+}
+
+func (c *ResponseCache) RecordBypass() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.bypasses++
+}
+
+func (c *ResponseCache) Stats() map[string]interface{} {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.pruneExpiredLocked(time.Now())
+
+	return map[string]interface{}{
+		"status":      true,
+		"entries":     len(c.entries),
+		"hits":        c.hits,
+		"misses":      c.misses,
+		"bypasses":    c.bypasses,
+		"evictions":   c.evictions,
+		"ttl_seconds": int(c.ttl / time.Second),
+		"max_size":    c.maxSize,
+	}
+}
+
+func (c *ResponseCache) pruneExpiredLocked(now time.Time) {
+	for key, entry := range c.entries {
+		if !now.Before(entry.ExpiresAt) {
+			delete(c.entries, key)
+		}
+	}
+}
+
+func (c *ResponseCache) evictOldestLocked() {
+	var (
+		oldestKey     string
+		oldestCreated time.Time
+	)
+
+	for key, entry := range c.entries {
+		if oldestKey == "" || entry.CreatedAt.Before(oldestCreated) {
+			oldestKey = key
+			oldestCreated = entry.CreatedAt
+		}
+	}
+
+	if oldestKey != "" {
+		delete(c.entries, oldestKey)
+		c.evictions++
+	}
+}

core/cache_test.go

@@ -0,0 +1,155 @@
+package core
+
+import (
+	"testing"
+	"time"
+)
+
+func TestResponseCacheSetAndGet(t *testing.T) {
+	cache := NewResponseCache(5*time.Second, 10)
+	key := BuildCacheKey("google", "search", Query{Text: "golang", Limit: 10})
+
+	if _, ok := cache.Get(key); ok {
+		t.Fatal("expected initial cache miss")
+	}
+
+	data := []byte(`[{"rank":1}]`)
+	cache.Set(key, data)
+
+	got, ok := cache.Get(key)
+	if !ok {
+		t.Fatal("expected cache hit")
+	}
+	if string(got) != string(data) {
+		t.Fatalf("unexpected cached value: got %s want %s", got, data)
+	}
+}
+
+func TestResponseCacheExpiration(t *testing.T) {
+	cache := NewResponseCache(40*time.Millisecond, 10)
+	key := BuildCacheKey("google", "search", Query{Text: "expire"})
+	cache.Set(key, []byte(`[]`))
+
+	if _, ok := cache.Get(key); !ok {
+		t.Fatal("expected cache hit before expiration")
+	}
+
+	time.Sleep(60 * time.Millisecond)
+
+	if _, ok := cache.Get(key); ok {
+		t.Fatal("expected cache miss after expiration")
+	}
+}
+
+func TestResponseCacheEvictsOldestEntry(t *testing.T) {
+	cache := NewResponseCache(time.Minute, 2)
+
+	firstKey := BuildCacheKey("google", "search", Query{Text: "first"})
+	secondKey := BuildCacheKey("google", "search", Query{Text: "second"})
+	thirdKey := BuildCacheKey("google", "search", Query{Text: "third"})
+
+	cache.Set(firstKey, []byte(`["first"]`))
+	time.Sleep(10 * time.Millisecond)
+	cache.Set(secondKey, []byte(`["second"]`))
+	time.Sleep(10 * time.Millisecond)
+	cache.Set(thirdKey, []byte(`["third"]`))
+
+	if _, ok := cache.Get(firstKey); ok {
+		t.Fatal("expected oldest entry to be evicted")
+	}
+	if _, ok := cache.Get(secondKey); !ok {
+		t.Fatal("expected newer entry to remain cached")
+	}
+	if _, ok := cache.Get(thirdKey); !ok {
+		t.Fatal("expected newest entry to remain cached")
+	}
+}
+
+func TestResponseCacheStats(t *testing.T) {
+	cache := NewResponseCache(time.Minute, 2)
+	key := BuildCacheKey("google", "search", Query{Text: "stats"})
+
+	if _, ok := cache.Get(key); ok {
+		t.Fatal("expected miss for empty cache")
+	}
+
+	cache.Set(key, []byte(`[]`))
+	if _, ok := cache.Get(key); !ok {
+		t.Fatal("expected cache hit")
+	}
+	cache.RecordBypass()
+
+	stats := cache.Stats()
+	if got := stats["status"]; got != true {
+		t.Fatalf("expected enabled status, got %v", got)
+	}
+	if got := stats["entries"].(int); got != 1 {
+		t.Fatalf("expected 1 entry, got %d", got)
+	}
+	if got := stats["hits"].(int); got != 1 {
+		t.Fatalf("expected 1 hit, got %d", got)
+	}
+	if got := stats["misses"].(int); got != 1 {
+		t.Fatalf("expected 1 miss, got %d", got)
+	}
+	if got := stats["bypasses"].(int); got != 1 {
+		t.Fatalf("expected 1 bypass, got %d", got)
+	}
+}
+
+func TestBuildCacheKeyChangesWithPaginationAndFlags(t *testing.T) {
+	base := Query{
+		Text:     "golang",
+		LangCode: "EN",
+		Limit:    10,
+		Start:    0,
+		Filter:   true,
+		Answers:  false,
+	}
+
+	baseKey := BuildCacheKey("google", "search", base)
+
+	if same := BuildCacheKey("google", "search", base); same != baseKey {
+		t.Fatal("expected deterministic key for same query")
+	}
+	if changed := BuildCacheKey("google", "search", Query{
+		Text:     "golang",
+		LangCode: "EN",
+		Limit:    20,
+		Start:    0,
+		Filter:   true,
+		Answers:  false,
+	}); changed == baseKey {
+		t.Fatal("expected limit to affect cache key")
+	}
+	if changed := BuildCacheKey("google", "search", Query{
+		Text:     "golang",
+		LangCode: "EN",
+		Limit:    10,
+		Start:    10,
+		Filter:   true,
+		Answers:  false,
+	}); changed == baseKey {
+		t.Fatal("expected start to affect cache key")
+	}
+	if changed := BuildCacheKey("google", "search", Query{
+		Text:     "golang",
+		LangCode: "EN",
+		Limit:    10,
+		Start:    0,
+		Filter:   false,
+		Answers:  false,
+	}); changed == baseKey {
+		t.Fatal("expected filter to affect cache key")
+	}
+	if changed := BuildCacheKey("google", "search", Query{
+		Text:     "golang",
+		LangCode: "EN",
+		Limit:    10,
+		Start:    0,
+		Filter:   true,
+		Answers:  true,
+	}); changed == baseKey {
+		t.Fatal("expected answers to affect cache key")
+	}
+}

core/circuit_breaker.go

@@ -0,0 +1,210 @@
+package core
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+type CircuitState int
+
+const (
+	CircuitClosed CircuitState = iota
+	CircuitOpen
+	CircuitHalfOpen
+)
+
+func (s CircuitState) String() string {
+	switch s {
+	case CircuitClosed:
+		return "closed"
+	case CircuitOpen:
+		return "open"
+	case CircuitHalfOpen:
+		return "half-open"
+	default:
+		return "unknown"
+	}
+}
+
+type CircuitBreakerConfig struct {
+	FailureThreshold int
+	RecoveryTimeout  time.Duration
+	SuccessThreshold int
+}
+
+func DefaultCircuitBreakerConfig() CircuitBreakerConfig {
+	return CircuitBreakerConfig{
+		FailureThreshold: 5,
+		RecoveryTimeout:  60 * time.Second,
+		SuccessThreshold: 2,
+	}
+}
+
+// CircuitBreaker tracks failure state for one engine.
+type CircuitBreaker struct {
+	mu              sync.RWMutex
+	name            string
+	state           CircuitState
+	config          CircuitBreakerConfig
+	failureCount    int
+	successCount    int
+	lastFailureTime time.Time
+	lastStateChange time.Time
+}
+
+func NewCircuitBreaker(name string, cfg CircuitBreakerConfig) *CircuitBreaker {
+	return &CircuitBreaker{
+		name:            name,
+		state:           CircuitClosed,
+		config:          cfg,
+		lastStateChange: time.Now(),
+	}
+}
+
+func (cb *CircuitBreaker) AllowRequest() bool {
+	cb.mu.Lock()
+	defer cb.mu.Unlock()
+
+	switch cb.state {
+	case CircuitClosed:
+		return true
+	case CircuitOpen:
+		if time.Since(cb.lastFailureTime) >= cb.config.RecoveryTimeout {
+			cb.setState(CircuitHalfOpen)
+			logrus.Infof("[CircuitBreaker][%s] Recovery timeout elapsed, moving to half-open", cb.name)
+			return true
+		}
+		return false
+	case CircuitHalfOpen:
+		return true
+	default:
+		return true
+	}
+}
+
+func (cb *CircuitBreaker) RecordSuccess() {
+	cb.mu.Lock()
+	defer cb.mu.Unlock()
+
+	switch cb.state {
+	case CircuitHalfOpen:
+		cb.successCount++
+		if cb.successCount >= cb.config.SuccessThreshold {
+			cb.setState(CircuitClosed)
+			cb.failureCount = 0
+			cb.successCount = 0
+			logrus.Infof("[CircuitBreaker][%s] Recovered, circuit closed", cb.name)
+		}
+	case CircuitClosed:
+		cb.failureCount = 0
+	}
+}
+
+func (cb *CircuitBreaker) RecordFailure() {
+	cb.mu.Lock()
+	defer cb.mu.Unlock()
+
+	cb.lastFailureTime = time.Now()
+
+	switch cb.state {
+	case CircuitClosed:
+		cb.failureCount++
+		if cb.failureCount >= cb.config.FailureThreshold {
+			cb.setState(CircuitOpen)
+			logrus.Warnf("[CircuitBreaker][%s] Circuit OPENED after %d consecutive failures (will retry in %s)",
+				cb.name, cb.failureCount, cb.config.RecoveryTimeout)
+		}
+	case CircuitHalfOpen:
+		cb.setState(CircuitOpen)
+		cb.successCount = 0
+		logrus.Warnf("[CircuitBreaker][%s] Failed during half-open, circuit re-opened", cb.name)
+	}
+}
+
+func (cb *CircuitBreaker) State() CircuitState {
+	cb.mu.RLock()
+	defer cb.mu.RUnlock()
+	return cb.state
+}
+
+func (cb *CircuitBreaker) Stats() map[string]interface{} {
+	cb.mu.RLock()
+	defer cb.mu.RUnlock()
+
+	stats := map[string]interface{}{
+		"engine":        cb.name,
+		"state":         cb.state.String(),
+		"failure_count": cb.failureCount,
+		"last_changed":  cb.lastStateChange.Format(time.RFC3339),
+	}
+
+	if cb.state == CircuitOpen {
+		remaining := cb.config.RecoveryTimeout - time.Since(cb.lastFailureTime)
+		if remaining < 0 {
+			remaining = 0
+		}
+
+		// Expose retry_in as integer seconds for easier client-side processing.
+		retryInSeconds := int64(0)
+		if remaining > 0 {
+			retryInSeconds = int64((remaining + time.Second - time.Nanosecond) / time.Second)
+		}
+		stats["retry_in"] = retryInSeconds
+	}
+
+	return stats
+}
+
+func (cb *CircuitBreaker) setState(state CircuitState) {
+	cb.state = state
+	cb.lastStateChange = time.Now()
+}
+
+type CircuitBreakerManager struct {
+	mu       sync.RWMutex
+	breakers map[string]*CircuitBreaker
+	config   CircuitBreakerConfig
+}
+
+func NewCircuitBreakerManager(cfg CircuitBreakerConfig) *CircuitBreakerManager {
+	return &CircuitBreakerManager{
+		breakers: make(map[string]*CircuitBreaker),
+		config:   cfg,
+	}
+}
+
+func (m *CircuitBreakerManager) Get(engineName string) *CircuitBreaker {
+	m.mu.RLock()
+	if cb, ok := m.breakers[engineName]; ok {
+		m.mu.RUnlock()
+		return cb
+	}
+	m.mu.RUnlock()
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if cb, ok := m.breakers[engineName]; ok {
+		return cb
+	}
+
+	cb := NewCircuitBreaker(engineName, m.config)
+	m.breakers[engineName] = cb
+	return cb
+}
+
+func (m *CircuitBreakerManager) AllStats() []map[string]interface{} {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	stats := make([]map[string]interface{}, 0, len(m.breakers))
+	for _, cb := range m.breakers {
+		stats = append(stats, cb.Stats())
+	}
+	return stats
+}
+
+var ErrCircuitOpen = fmt.Errorf("circuit breaker is open - engine temporarily disabled")

core/circuit_breaker_test.go

@@ -0,0 +1,165 @@
+package core
+
+import (
+	"testing"
+	"time"
+)
+
+func newTestCircuitBreaker(t *testing.T, cfg CircuitBreakerConfig) *CircuitBreaker {
+	t.Helper()
+	return NewCircuitBreaker("test-engine", cfg)
+}
+
+// TestCircuitBreaker_OpensAfterThreshold verifies that consecutive failures in closed state
+// move the breaker to open exactly on configured threshold and block new requests.
+func TestCircuitBreaker_OpensAfterThreshold(t *testing.T) {
+	cfg := CircuitBreakerConfig{
+		FailureThreshold: 3,
+		RecoveryTimeout:  time.Second,
+		SuccessThreshold: 1,
+	}
+	cb := newTestCircuitBreaker(t, cfg)
+
+	cb.RecordFailure()
+	cb.RecordFailure()
+	if cb.State() != CircuitClosed {
+		t.Fatalf("expected closed after 2 failures, got: %s", cb.State())
+	}
+
+	cb.RecordFailure()
+	if cb.State() != CircuitOpen {
+		t.Fatalf("expected open after %d failures, got: %s", cfg.FailureThreshold, cb.State())
+	}
+	if cb.AllowRequest() {
+		t.Error("expected request blocked in open state")
+	}
+}
+
+// TestCircuitBreaker_RecoveryToHalfOpen verifies timed recovery from open to half-open
+// when recovery timeout elapses and a new request is attempted.
+func TestCircuitBreaker_RecoveryToHalfOpen(t *testing.T) {
+	cfg := CircuitBreakerConfig{
+		FailureThreshold: 2,
+		RecoveryTimeout:  50 * time.Millisecond,
+		SuccessThreshold: 1,
+	}
+	cb := newTestCircuitBreaker(t, cfg)
+
+	cb.RecordFailure()
+	cb.RecordFailure()
+	if cb.State() != CircuitOpen {
+		t.Fatal("expected open")
+	}
+
+	time.Sleep(60 * time.Millisecond)
+	if !cb.AllowRequest() {
+		t.Error("should allow request after recovery timeout")
+	}
+	if cb.State() != CircuitHalfOpen {
+		t.Errorf("expected half-open, got: %s", cb.State())
+	}
+}
+
+// TestCircuitBreaker_HalfOpenSuccessClosesCircuit verifies that half-open state closes
+// only after configured number of successful probes.
+func TestCircuitBreaker_HalfOpenSuccessClosesCircuit(t *testing.T) {
+	cfg := CircuitBreakerConfig{
+		FailureThreshold: 1,
+		RecoveryTimeout:  20 * time.Millisecond,
+		SuccessThreshold: 2,
+	}
+	cb := newTestCircuitBreaker(t, cfg)
+
+	cb.RecordFailure()
+	if cb.State() != CircuitOpen {
+		t.Fatalf("expected open, got: %s", cb.State())
+	}
+
+	time.Sleep(30 * time.Millisecond)
+	if !cb.AllowRequest() {
+		t.Fatal("expected request to pass in recovery window")
+	}
+	if cb.State() != CircuitHalfOpen {
+		t.Fatalf("expected half-open after recovery timeout, got: %s", cb.State())
+	}
+
+	cb.RecordSuccess()
+	if cb.State() != CircuitHalfOpen {
+		t.Fatalf("expected to stay half-open until success threshold reached, got: %s", cb.State())
+	}
+
+	cb.RecordSuccess()
+	if cb.State() != CircuitClosed {
+		t.Fatalf("expected closed after success threshold reached, got: %s", cb.State())
+	}
+}
+
+// TestCircuitBreaker_HalfOpenFailureReopens verifies that a failed probe in half-open
+// immediately re-opens the circuit.
+func TestCircuitBreaker_HalfOpenFailureReopens(t *testing.T) {
+	cfg := CircuitBreakerConfig{
+		FailureThreshold: 1,
+		RecoveryTimeout:  20 * time.Millisecond,
+		SuccessThreshold: 1,
+	}
+	cb := newTestCircuitBreaker(t, cfg)
+
+	cb.RecordFailure()
+	time.Sleep(30 * time.Millisecond)
+	if !cb.AllowRequest() {
+		t.Fatal("expected probe request in half-open")
+	}
+	if cb.State() != CircuitHalfOpen {
+		t.Fatalf("expected half-open, got: %s", cb.State())
+	}
+
+	cb.RecordFailure()
+	if cb.State() != CircuitOpen {
+		t.Fatalf("expected open after failed half-open probe, got: %s", cb.State())
+	}
+}
+
+// TestCircuitBreaker_Stats verifies stats payload fields and that retry_in is exposed
+// only when breaker is open.
+func TestCircuitBreaker_Stats(t *testing.T) {
+	cb := NewCircuitBreaker("test-engine", DefaultCircuitBreakerConfig())
+	cb.RecordFailure()
+
+	stats := cb.Stats()
+	if stats["engine"] != "test-engine" {
+		t.Fatalf("expected engine=test-engine, got: %v", stats["engine"])
+	}
+	if stats["state"] != "closed" {
+		t.Fatalf("expected state=closed, got: %v", stats["state"])
+	}
+	if stats["failure_count"].(int) != 1 {
+		t.Fatalf("expected failure_count=1, got: %v", stats["failure_count"])
+	}
+	if _, ok := stats["retry_in"]; ok {
+		t.Fatalf("did not expect retry_in in closed state, got: %v", stats["retry_in"])
+	}
+
+	openCfg := CircuitBreakerConfig{FailureThreshold: 1, RecoveryTimeout: time.Second, SuccessThreshold: 1}
+	openCB := NewCircuitBreaker("open-engine", openCfg)
+	openCB.RecordFailure()
+	openStats := openCB.Stats()
+	retryIn, ok := openStats["retry_in"].(int64)
+	if !ok {
+		t.Fatalf("expected retry_in int64 in open state, got: %T", openStats["retry_in"])
+	}
+	if retryIn <= 0 {
+		t.Fatalf("expected retry_in > 0 in open state, got: %d", retryIn)
+	}
+}
+
+// TestCircuitBreakerManager_AllStats verifies manager creates and reports per-engine breakers.
+func TestCircuitBreakerManager_AllStats(t *testing.T) {
+	mgr := NewCircuitBreakerManager(DefaultCircuitBreakerConfig())
+	mgr.Get("google")
+	mgr.Get("yandex")
+
+	stats := mgr.AllStats()
+	if len(stats) != 2 {
+		t.Errorf("expected 2 entries, got: %d", len(stats))
+	}
+}

core/common.go

@@ -54,15 +54,28 @@ func ConvertSearchResultsMap(searchResultsMap map[string]SearchResult) *[]Search
 }
 
 type Query struct {
-	Text         string
-	LangCode     string // eg. EN, ES, RU...
-	DateInterval string // format: YYYYMMDD..YYYMMDD - 20181010..20231010
-	Filetype     string // File extension to search.
-	Site         string // Search site
-	Limit        int    // Limit the number of results
-	Answers      bool   // Include question and answers from SERP page to results with negative indexes
-	ProxyURL     string // Proxy URL for raw requests
-	Insecure     bool   // Allow insecure TLS connections
+	Text          string
+	LangCode      string // eg. EN, ES, RU...
+	DateInterval  string // format: YYYYMMDD..YYYMMDD - 20181010..20231010
+	Filetype      string // File extension to search.
+	Site          string // Search site
+	Limit         int    // Limit the number of results
+	Start         int    // Search offset for pagination (Google uses 0, 10, 20...)
+	Filter        bool   // Filter duplicates (google) (false: include similar, true: hide similar)
+	Answers       bool   // Include question and answers from SERP page to results with negative indexes
+	ProxyURL      string // Proxy URL for raw requests
+	ProxyOverride string // Request-scoped proxy override: tag or direct
+	Insecure      bool   // Allow insecure TLS connections
+}
+
+func ComputePagination(start int, pageSize int) (int, int, error) {
+	if pageSize <= 0 {
+		return 0, 0, errors.New("pageSize must be > 0")
+	}
+	if start < 0 {
+		return 0, 0, errors.New("start must be >= 0")
+	}
+	return start / pageSize, start % pageSize, nil
 }
 
 func (q Query) IsEmpty() bool {
@@ -85,11 +98,30 @@ func (searchQuery *Query) InitFromContext(reqCtx *fiber.Ctx) error {
 	}
 	searchQuery.Limit = limit
 
+	start, err := strconv.Atoi(reqCtx.Query("start", "0"))
+	if err != nil {
+		return err
+	}
+	if start < 0 {
+		return errors.New("start must be >= 0")
+	}
+	searchQuery.Start = start
+
+	searchQuery.Filter, err = strconv.ParseBool(reqCtx.Query("filter", "1"))
+	if err != nil {
+		return err
+	}
+
 	searchQuery.Answers, err = strconv.ParseBool(reqCtx.Query("answers", "0"))
 	if err != nil {
 		return err
 	}
 
+	searchQuery.ProxyOverride, err = NormalizeProxyRequestOverride(reqCtx.Get("X-Use-Proxy"))
+	if err != nil {
+		return err
+	}
+
 	if searchQuery.IsEmpty() {
 		return errors.New("Query cannot be empty")
 	}

core/http_client.go

@@ -0,0 +1,74 @@
+package core
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	utls "github.com/refraction-networking/utls"
+)
+
+const rawHTTPTimeout = 10 * time.Second
+
+func NewRawHTTPClient(query Query) (*http.Client, error) {
+	transport, err := newRawTransport(query)
+	if err != nil {
+		return nil, err
+	}
+
+	return &http.Client{
+		Transport: transport,
+		Timeout:   rawHTTPTimeout,
+	}, nil
+}
+
+func newRawTransport(query Query) (*http.Transport, error) {
+	transport := &http.Transport{}
+	if query.Insecure {
+		transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+	}
+
+	proxyURL, err := NormalizeProxyURL(query.ProxyURL)
+	if err != nil {
+		return nil, err
+	}
+	if proxyURL != "" {
+		parsed, err := url.Parse(proxyURL)
+		if err != nil {
+			return nil, err
+		}
+
+		// Keep proxied requests on the standard transport path so SOCKS5/SOCKS5H
+		// resolution and routing are handled by the configured proxy correctly.
+		transport.Proxy = http.ProxyURL(parsed)
+		return transport, nil
+	}
+
+	transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+		dialer := &net.Dialer{}
+		rawConn, err := dialer.DialContext(ctx, network, addr)
+		if err != nil {
+			return nil, err
+		}
+
+		hostname := strings.Split(addr, ":")[0]
+		config := &utls.Config{
+			ServerName:         hostname,
+			InsecureSkipVerify: query.Insecure,
+		}
+
+		uconn := utls.UClient(rawConn, config, utls.HelloChrome_Auto)
+		if err := uconn.Handshake(); err != nil {
+			rawConn.Close()
+			return nil, err
+		}
+
+		return uconn, nil
+	}
+
+	return transport, nil
+}

core/middleware.go

@@ -0,0 +1,144 @@
+package core
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/sirupsen/logrus"
+)
+
+type JSONErrorResponse struct {
+	Error   string `json:"error"`
+	Code    int    `json:"code"`
+	Message string `json:"message,omitempty"`
+}
+
+type CORSConfig struct {
+	AllowOrigins string
+	AllowMethods string
+	AllowHeaders string
+	MaxAge       int
+}
+
+func DefaultCORSConfig() CORSConfig {
+	return CORSConfig{
+		AllowOrigins: "*",
+		AllowMethods: "GET, POST, OPTIONS",
+		AllowHeaders: "Origin, Content-Type, Accept, Authorization, X-Use-Proxy",
+		MaxAge:       86400,
+	}
+}
+
+func CORSMiddleware(cfg CORSConfig) fiber.Handler {
+	cfg = normalizeCORSConfig(cfg)
+
+	return func(c *fiber.Ctx) error {
+		c.Set("Access-Control-Allow-Origin", cfg.AllowOrigins)
+		c.Set("Access-Control-Allow-Methods", cfg.AllowMethods)
+		c.Set("Access-Control-Allow-Headers", cfg.AllowHeaders)
+		c.Set("Access-Control-Max-Age", fmt.Sprintf("%d", cfg.MaxAge))
+
+		if c.Method() == "OPTIONS" {
+			return c.SendStatus(fiber.StatusNoContent)
+		}
+		return c.Next()
+	}
+}
+
+// normalizeCORSConfig keeps CORS behavior predictable when config provides partial values.
+func normalizeCORSConfig(cfg CORSConfig) CORSConfig {
+	defaults := DefaultCORSConfig()
+
+	if strings.TrimSpace(cfg.AllowOrigins) == "" {
+		cfg.AllowOrigins = defaults.AllowOrigins
+	}
+	if strings.TrimSpace(cfg.AllowMethods) == "" {
+		cfg.AllowMethods = defaults.AllowMethods
+	}
+	if strings.TrimSpace(cfg.AllowHeaders) == "" {
+		cfg.AllowHeaders = defaults.AllowHeaders
+	}
+	if cfg.MaxAge <= 0 {
+		cfg.MaxAge = defaults.MaxAge
+	}
+
+	return cfg
+}
+
+func RequestLoggerMiddleware() fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		start := time.Now()
+		err := c.Next()
+
+		latency := time.Since(start)
+		status := c.Response().StatusCode()
+		if err != nil {
+			if e, ok := err.(*fiber.Error); ok {
+				status = e.Code
+			} else {
+				status = fiber.StatusInternalServerError
+			}
+		}
+
+		logFields := logrus.Fields{
+			"method":  c.Method(),
+			"path":    c.Path(),
+			"status":  status,
+			"latency": latency.String(),
+			"ip":      c.IP(),
+		}
+		if query := c.Query("text"); query != "" {
+			logFields["query"] = query
+		}
+
+		entry := logrus.WithFields(logFields)
+		if status >= 500 {
+			entry.Errorf("%s - request failed", c.Path())
+		} else if status >= 400 {
+			entry.Warnf("%s - request error", c.Path())
+		} else {
+			entry.Infof("%s - request completed", c.Path())
+		}
+
+		return err
+	}
+}
+
+func JSONErrorMiddleware() fiber.ErrorHandler {
+	return func(c *fiber.Ctx, err error) error {
+		code := fiber.StatusInternalServerError
+		if e, ok := err.(*fiber.Error); ok {
+			code = e.Code
+		}
+
+		resp := JSONErrorResponse{
+			Error:   statusText(code),
+			Code:    code,
+			Message: err.Error(),
+		}
+
+		c.Set("Content-Type", "application/json")
+		return c.Status(code).JSON(resp)
+	}
+}
+
+func statusText(code int) string {
+	switch {
+	case code == 400:
+		return "bad_request"
+	case code == 404:
+		return "not_found"
+	case code == 429:
+		return "rate_limited"
+	case code == 503:
+		return "service_unavailable"
+	case code >= 400 && code < 500:
+		return "client_error"
+	case code >= 500:
+		return "server_error"
+	default:
+		return "error"
+	}
+}

core/middleware_test.go

@@ -0,0 +1,109 @@
+package core
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gofiber/fiber/v2"
+)
+
+func TestStatusText(t *testing.T) {
+	tests := []struct {
+		code     int
+		expected string
+	}{
+		{400, "bad_request"},
+		{404, "not_found"},
+		{429, "rate_limited"},
+		{503, "service_unavailable"},
+		{401, "client_error"},
+		{500, "server_error"},
+		{200, "error"},
+	}
+
+	for _, tt := range tests {
+		result := statusText(tt.code)
+		if result != tt.expected {
+			t.Errorf("statusText(%d) = %s, want %s", tt.code, result, tt.expected)
+		}
+	}
+}
+
+// Middleware unit tests validate CORS behavior itself (header composition and preflight semantics).
+func TestCORSMiddleware_UsesConfiguredHeaders(t *testing.T) {
+	app := fiber.New()
+	app.Use(CORSMiddleware(CORSConfig{
+		AllowOrigins: "https://example.com",
+		AllowMethods: "GET,OPTIONS",
+		AllowHeaders: "Authorization,Content-Type",
+		MaxAge:       1200,
+	}))
+	app.Get("/ping", func(c *fiber.Ctx) error {
+		return c.SendStatus(fiber.StatusOK)
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/ping", nil)
+	resp, err := app.Test(req, -1)
+	if err != nil {
+		t.Fatalf("request failed: %v", err)
+	}
+
+	if got := resp.Header.Get("Access-Control-Allow-Origin"); got != "https://example.com" {
+		t.Fatalf("unexpected allow-origin: %q", got)
+	}
+	if got := resp.Header.Get("Access-Control-Allow-Methods"); got != "GET,OPTIONS" {
+		t.Fatalf("unexpected allow-methods: %q", got)
+	}
+	if got := resp.Header.Get("Access-Control-Allow-Headers"); got != "Authorization,Content-Type" {
+		t.Fatalf("unexpected allow-headers: %q", got)
+	}
+	if got := resp.Header.Get("Access-Control-Max-Age"); got != "1200" {
+		t.Fatalf("unexpected max-age: %q", got)
+	}
+}
+
+func TestCORSMiddleware_OPTIONSReturnsNoContent(t *testing.T) {
+	app := fiber.New()
+	app.Use(CORSMiddleware(DefaultCORSConfig()))
+	app.Get("/ping", func(c *fiber.Ctx) error {
+		return c.SendStatus(fiber.StatusOK)
+	})
+
+	req := httptest.NewRequest(http.MethodOptions, "/ping", nil)
+	resp, err := app.Test(req, -1)
+	if err != nil {
+		t.Fatalf("request failed: %v", err)
+	}
+	if resp.StatusCode != fiber.StatusNoContent {
+		t.Fatalf("expected 204 for OPTIONS, got %d", resp.StatusCode)
+	}
+}
+
+func TestNormalizeCORSConfig_FillsMissingValues(t *testing.T) {
+	cfg := normalizeCORSConfig(CORSConfig{
+		AllowOrigins: "https://example.com",
+	})
+	def := DefaultCORSConfig()
+
+	if cfg.AllowOrigins != "https://example.com" {
+		t.Fatalf("expected custom allow_origins preserved, got %q", cfg.AllowOrigins)
+	}
+	if cfg.AllowMethods != def.AllowMethods {
+		t.Fatalf("expected default allow_methods, got %q", cfg.AllowMethods)
+	}
+	if cfg.AllowHeaders != def.AllowHeaders {
+		t.Fatalf("expected default allow_headers, got %q", cfg.AllowHeaders)
+	}
+	if cfg.MaxAge != def.MaxAge {
+		t.Fatalf("expected default max_age, got %d", cfg.MaxAge)
+	}
+}
+
+func TestDefaultCORSConfig_IncludesProxyOverrideHeader(t *testing.T) {
+	cfg := DefaultCORSConfig()
+	if got := cfg.AllowHeaders; !strings.Contains(got, "X-Use-Proxy") {
+		t.Fatalf("expected allow_headers to include X-Use-Proxy, got %q", got)
+	}
+}

core/proxy.go

@@ -0,0 +1,561 @@
+package core
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	ProxyRuntimeBrowser          = "browser"
+	ProxyRuntimeRaw              = "raw"
+	ProxyModeOff                 = "off"
+	ProxyModeTagPool             = "tag_pool"
+	DefaultProxyFailureThreshold = 3
+	ProxyOverrideDirect          = "direct"
+)
+
+var supportedProxySchemes = map[string]struct{}{
+	"http":    {},
+	"https":   {},
+	"socks5":  {},
+	"socks5h": {},
+}
+
+var ErrProxyUnavailable = errors.New("proxy unavailable")
+
+type ProxyPolicy struct {
+	Mode string `json:"mode" mapstructure:"mode"`
+	Tag  string `json:"tag,omitempty" mapstructure:"tag"`
+}
+
+type ProxyEntryConfig struct {
+	URL  string   `json:"url" mapstructure:"url"`
+	Tags []string `json:"tags" mapstructure:"tags"`
+}
+
+type ProxiesHealthConfig struct {
+	FailureThreshold int `json:"failure_threshold" mapstructure:"failure_threshold"`
+}
+
+type ProxiesConfig struct {
+	Global  string              `json:"global,omitempty" mapstructure:"global"`
+	Entries []ProxyEntryConfig  `json:"entries" mapstructure:"entries"`
+	Health  ProxiesHealthConfig `json:"health" mapstructure:"health"`
+}
+
+type ProxyConfig struct {
+	Runtime        string            // raw or browser runtime behavior
+	Proxies        ProxiesConfig     // canonical proxy inventory
+	EnginePolicies map[string]string // engine-specific proxy tags
+	Registry       *ProxyRegistry    // optional shared registry from caller
+}
+
+type ProxyTagSummary struct {
+	Configured int `json:"configured"`
+	Healthy    int `json:"healthy"`
+}
+
+type ProxyStatsEntry struct {
+	Proxy    string   `json:"proxy"`
+	Tags     []string `json:"tags"`
+	Healthy  bool     `json:"healthy"`
+	Failures int      `json:"failures"`
+	Disabled bool     `json:"disabled"`
+}
+
+type ProxyEngineStats struct {
+	Tag           string `json:"tag,omitempty"`
+	SelectedProxy string `json:"selected_proxy"`
+}
+
+type ProxyStats struct {
+	ConfiguredCount int                         `json:"configured_count"`
+	HealthyCount    int                         `json:"healthy_count"`
+	UnhealthyCount  int                         `json:"unhealthy_count"`
+	Tags            map[string]ProxyTagSummary  `json:"tags"`
+	Entries         []ProxyStatsEntry           `json:"entries"`
+	Engines         map[string]ProxyEngineStats `json:"engines,omitempty"`
+}
+
+type proxyState struct {
+	url      string
+	tags     []string
+	failures int
+	disabled bool
+}
+
+type ProxyRegistry struct {
+	mu               sync.Mutex
+	states           map[string]*proxyState
+	order            []string
+	tagIndex         map[string][]string
+	nextByTag        map[string]int
+	failureThreshold int
+}
+
+func DefaultProxiesConfig() ProxiesConfig {
+	return ProxiesConfig{
+		Global:  "",
+		Entries: []ProxyEntryConfig{},
+		Health:  ProxiesHealthConfig{FailureThreshold: DefaultProxyFailureThreshold},
+	}
+}
+
+func DefaultProxyConfig() ProxyConfig {
+	return ProxyConfig{
+		Runtime:        ProxyRuntimeBrowser,
+		Proxies:        DefaultProxiesConfig(),
+		EnginePolicies: map[string]string{},
+	}
+}
+
+func NormalizeProxyConfig(cfg ProxyConfig) (ProxyConfig, error) {
+	cfg.Runtime = normalizeProxyRuntime(cfg.Runtime)
+
+	var err error
+	cfg.Proxies, err = NormalizeProxiesConfig(cfg.Proxies)
+	if err != nil {
+		return cfg, err
+	}
+
+	if cfg.EnginePolicies == nil {
+		cfg.EnginePolicies = map[string]string{}
+	}
+	normalizedEnginePolicies := make(map[string]string, len(cfg.EnginePolicies))
+	for rawEngine, rawTag := range cfg.EnginePolicies {
+		engine := normalizeEngineName(rawEngine)
+		if engine == "" {
+			continue
+		}
+		tag := normalizeTag(rawTag)
+		if tag == "" {
+			continue
+		}
+		normalizedEnginePolicies[engine] = tag
+	}
+	cfg.EnginePolicies = normalizedEnginePolicies
+
+	if cfg.Registry == nil {
+		if len(cfg.Proxies.Entries) > 0 {
+			registry, err := NewProxyRegistry(cfg.Proxies.Entries, cfg.Proxies.Health.FailureThreshold)
+			if err != nil {
+				return cfg, err
+			}
+			cfg.Registry = registry
+		}
+	}
+
+	return cfg, nil
+}
+
+func NormalizeProxiesConfig(cfg ProxiesConfig) (ProxiesConfig, error) {
+	global, err := NormalizeProxyURL(cfg.Global)
+	if err != nil {
+		return cfg, fmt.Errorf("invalid proxies.global: %w", err)
+	}
+	cfg.Global = global
+
+	failureThreshold := cfg.Health.FailureThreshold
+	if failureThreshold <= 0 {
+		failureThreshold = DefaultProxyFailureThreshold
+	}
+
+	normalizedEntries := make([]ProxyEntryConfig, 0, len(cfg.Entries))
+	entryByURL := make(map[string]int, len(cfg.Entries))
+
+	for i, rawEntry := range cfg.Entries {
+		proxyURL, err := NormalizeProxyURL(rawEntry.URL)
+		if err != nil {
+			return cfg, fmt.Errorf("invalid proxies.entries[%d].url: %w", i, err)
+		}
+		if proxyURL == "" {
+			return cfg, fmt.Errorf("invalid proxies.entries[%d].url: value is required", i)
+		}
+
+		tags, err := normalizeProxyTags(rawEntry.Tags)
+		if err != nil {
+			return cfg, fmt.Errorf("invalid proxies.entries[%d].tags: %w", i, err)
+		}
+
+		if idx, ok := entryByURL[proxyURL]; ok {
+			normalizedEntries[idx].Tags = mergeTags(normalizedEntries[idx].Tags, tags)
+			continue
+		}
+
+		normalizedEntries = append(normalizedEntries, ProxyEntryConfig{
+			URL:  proxyURL,
+			Tags: tags,
+		})
+		entryByURL[proxyURL] = len(normalizedEntries) - 1
+	}
+
+	cfg.Entries = normalizedEntries
+	cfg.Health = ProxiesHealthConfig{FailureThreshold: failureThreshold}
+	return cfg, nil
+}
+
+func NormalizeProxyURL(raw string) (string, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return "", nil
+	}
+
+	parsed, err := url.Parse(raw)
+	if err != nil {
+		return "", err
+	}
+	if parsed.Scheme == "" {
+		return "", fmt.Errorf("proxy URL must include a scheme")
+	}
+	if parsed.Host == "" {
+		return "", fmt.Errorf("proxy URL must include a host")
+	}
+
+	parsed.Scheme = strings.ToLower(parsed.Scheme)
+	if _, ok := supportedProxySchemes[parsed.Scheme]; !ok {
+		return "", fmt.Errorf("unsupported proxy scheme %q", parsed.Scheme)
+	}
+
+	return parsed.String(), nil
+}
+
+func NormalizeProxyURLs(rawURLs []string) ([]string, error) {
+	normalized := make([]string, 0, len(rawURLs))
+	seen := make(map[string]struct{}, len(rawURLs))
+
+	for _, raw := range rawURLs {
+		proxyURL, err := NormalizeProxyURL(raw)
+		if err != nil {
+			return nil, err
+		}
+		if proxyURL == "" {
+			continue
+		}
+		if _, ok := seen[proxyURL]; ok {
+			continue
+		}
+		seen[proxyURL] = struct{}{}
+		normalized = append(normalized, proxyURL)
+	}
+
+	return normalized, nil
+}
+
+func MaskProxyURL(raw string) string {
+	proxyURL, err := NormalizeProxyURL(raw)
+	if err != nil || proxyURL == "" {
+		return "invalid-proxy"
+	}
+
+	parsed, err := url.Parse(proxyURL)
+	if err != nil {
+		return "invalid-proxy"
+	}
+
+	return fmt.Sprintf("%s://%s", parsed.Scheme, parsed.Host)
+}
+
+func ResolveEffectiveProxyPolicy(globalProxyURL string, engineTag string) ProxyPolicy {
+	if strings.TrimSpace(globalProxyURL) != "" {
+		return ProxyPolicy{Mode: ProxyModeTagPool}
+	}
+
+	tag := normalizeTag(engineTag)
+	if tag == "" {
+		return ProxyPolicy{Mode: ProxyModeOff}
+	}
+
+	return ProxyPolicy{Mode: ProxyModeTagPool, Tag: tag}
+}
+
+func NormalizeProxyTag(raw string) (string, error) {
+	tag := normalizeTag(raw)
+	if tag == "" {
+		return "", fmt.Errorf("value is required")
+	}
+	return tag, nil
+}
+
+func NormalizeProxyRequestOverride(raw string) (string, error) {
+	override := normalizeTag(raw)
+	if override == "" {
+		return "", nil
+	}
+	if override == ProxyOverrideDirect {
+		return ProxyOverrideDirect, nil
+	}
+	return NormalizeProxyTag(override)
+}
+
+func IsAuthenticatedSocksProxyURL(raw string) bool {
+	normalized, err := NormalizeProxyURL(raw)
+	if err != nil || normalized == "" {
+		return false
+	}
+
+	parsed, err := url.Parse(normalized)
+	if err != nil {
+		return false
+	}
+
+	if (parsed.Scheme == "socks5" || parsed.Scheme == "socks5h") && parsed.User != nil {
+		return true
+	}
+
+	return false
+}
+
+func NewProxyRegistry(entries []ProxyEntryConfig, failureThreshold int) (*ProxyRegistry, error) {
+	if failureThreshold <= 0 {
+		failureThreshold = DefaultProxyFailureThreshold
+	}
+
+	states := make(map[string]*proxyState, len(entries))
+	order := make([]string, 0, len(entries))
+	tagIndex := make(map[string][]string)
+
+	for idx, entry := range entries {
+		proxyURL, err := NormalizeProxyURL(entry.URL)
+		if err != nil {
+			return nil, fmt.Errorf("invalid proxy registry entry[%d] url: %w", idx, err)
+		}
+		if proxyURL == "" {
+			return nil, fmt.Errorf("invalid proxy registry entry[%d] url: value is required", idx)
+		}
+
+		tags, err := normalizeProxyTags(entry.Tags)
+		if err != nil {
+			return nil, fmt.Errorf("invalid proxy registry entry[%d] tags: %w", idx, err)
+		}
+
+		states[proxyURL] = &proxyState{url: proxyURL, tags: tags}
+		order = append(order, proxyURL)
+		for _, tag := range tags {
+			tagIndex[tag] = append(tagIndex[tag], proxyURL)
+		}
+	}
+
+	return &ProxyRegistry{
+		states:           states,
+		order:            order,
+		tagIndex:         tagIndex,
+		nextByTag:        make(map[string]int, len(tagIndex)),
+		failureThreshold: failureThreshold,
+	}, nil
+}
+
+func (r *ProxyRegistry) NextByTag(tag string) string {
+	tag = normalizeTag(tag)
+	if tag == "" {
+		return ""
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	urls := r.tagIndex[tag]
+	if len(urls) == 0 {
+		return ""
+	}
+
+	if r.allDisabledLocked(urls) {
+		logrus.Warnf("Proxy tag pool exhausted for %q, re-enabling tagged proxies", tag)
+		for _, proxyURL := range urls {
+			state := r.states[proxyURL]
+			state.disabled = false
+			state.failures = 0
+		}
+	}
+
+	start := r.nextByTag[tag]
+	for i := 0; i < len(urls); i++ {
+		idx := (start + i) % len(urls)
+		proxyURL := urls[idx]
+		state := r.states[proxyURL]
+		if state.disabled {
+			continue
+		}
+
+		r.nextByTag[tag] = (idx + 1) % len(urls)
+		logrus.Debugf("Selected proxy for tag=%s: %s", tag, MaskProxyURL(proxyURL))
+		return proxyURL
+	}
+
+	return ""
+}
+
+func (r *ProxyRegistry) ReportFailure(proxyURL string) {
+	proxyURL, err := NormalizeProxyURL(proxyURL)
+	if err != nil || proxyURL == "" {
+		return
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	state, ok := r.states[proxyURL]
+	if !ok {
+		return
+	}
+
+	state.failures++
+	if state.failures >= r.failureThreshold {
+		state.disabled = true
+		logrus.Warnf("Disabled proxy after %d failures: %s", state.failures, MaskProxyURL(proxyURL))
+	}
+}
+
+func (r *ProxyRegistry) ReportSuccess(proxyURL string) {
+	proxyURL, err := NormalizeProxyURL(proxyURL)
+	if err != nil || proxyURL == "" {
+		return
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	state, ok := r.states[proxyURL]
+	if !ok {
+		return
+	}
+
+	state.failures = 0
+	state.disabled = false
+}
+
+func (r *ProxyRegistry) HasHealthyProxyForTag(tag string) bool {
+	tag = normalizeTag(tag)
+	if tag == "" {
+		return false
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	for _, proxyURL := range r.tagIndex[tag] {
+		if state, ok := r.states[proxyURL]; ok && !state.disabled {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (r *ProxyRegistry) BuildStats() ProxyStats {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	stats := ProxyStats{
+		Tags:    map[string]ProxyTagSummary{},
+		Entries: make([]ProxyStatsEntry, 0, len(r.order)),
+	}
+
+	for _, proxyURL := range r.order {
+		state := r.states[proxyURL]
+		healthy := !state.disabled
+		if healthy {
+			stats.HealthyCount++
+		} else {
+			stats.UnhealthyCount++
+		}
+		stats.ConfiguredCount++
+
+		stats.Entries = append(stats.Entries, ProxyStatsEntry{
+			Proxy:    MaskProxyURL(state.url),
+			Tags:     append([]string(nil), state.tags...),
+			Healthy:  healthy,
+			Failures: state.failures,
+			Disabled: state.disabled,
+		})
+
+		for _, tag := range state.tags {
+			summary := stats.Tags[tag]
+			summary.Configured++
+			if healthy {
+				summary.Healthy++
+			}
+			stats.Tags[tag] = summary
+		}
+	}
+
+	return stats
+}
+
+func (r *ProxyRegistry) allDisabledLocked(urls []string) bool {
+	if len(urls) == 0 {
+		return false
+	}
+	for _, proxyURL := range urls {
+		if state, ok := r.states[proxyURL]; ok && !state.disabled {
+			return false
+		}
+	}
+	return true
+}
+
+func normalizeProxyRuntime(runtime string) string {
+	switch strings.ToLower(strings.TrimSpace(runtime)) {
+	case ProxyRuntimeRaw:
+		return ProxyRuntimeRaw
+	default:
+		return ProxyRuntimeBrowser
+	}
+}
+
+func normalizeProxyTags(tags []string) ([]string, error) {
+	if len(tags) == 0 {
+		return nil, fmt.Errorf("at least one tag is required")
+	}
+
+	seen := make(map[string]struct{}, len(tags))
+	normalized := make([]string, 0, len(tags))
+	for _, rawTag := range tags {
+		tag := normalizeTag(rawTag)
+		if tag == "" {
+			continue
+		}
+		if _, ok := seen[tag]; ok {
+			continue
+		}
+		seen[tag] = struct{}{}
+		normalized = append(normalized, tag)
+	}
+
+	if len(normalized) == 0 {
+		return nil, fmt.Errorf("at least one non-empty tag is required")
+	}
+
+	sort.Strings(normalized)
+	return normalized, nil
+}
+
+func normalizeTag(raw string) string {
+	return strings.ToLower(strings.TrimSpace(raw))
+}
+
+func mergeTags(base []string, additional []string) []string {
+	combined := make(map[string]struct{}, len(base)+len(additional))
+	for _, tag := range base {
+		combined[tag] = struct{}{}
+	}
+	for _, tag := range additional {
+		combined[tag] = struct{}{}
+	}
+
+	merged := make([]string, 0, len(combined))
+	for tag := range combined {
+		merged = append(merged, tag)
+	}
+	sort.Strings(merged)
+	return merged
+}
+
+func normalizeEngineName(raw string) string {
+	return strings.ToLower(strings.TrimSpace(raw))
+}

core/proxy_integration_test.go

@@ -0,0 +1,234 @@
+//go:build integration
+// +build integration
+
+package core
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/karust/openserp/testutil"
+	"golang.org/x/time/rate"
+)
+
+const proxyIntegrationEnabledEnv = "OPENSERP_PROXY_TESTS"
+
+type proxyIntegrationURLs struct {
+	targetURL       string
+	socks5hAuthURL  string
+	socks5hPlainURL string
+	httpAuthURL     string
+	httpPlainURL    string
+	badSocks5URL    string
+	badHTTPURL      string
+}
+
+func TestIntegrationSocks5hAuthProxyDNS(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyFetchesTarget(t, cfg.targetURL, cfg.socks5hAuthURL)
+}
+
+func TestIntegrationSocks5hPlainProxyDNS(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyFetchesTarget(t, cfg.targetURL, cfg.socks5hPlainURL)
+}
+
+func TestIntegrationHTTPAuthProxy(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyFetchesTarget(t, cfg.targetURL, cfg.httpAuthURL)
+}
+
+func TestIntegrationHTTPPlainProxy(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyFetchesTarget(t, cfg.targetURL, cfg.httpPlainURL)
+}
+
+func TestIntegrationRawSOCKSProxyPoolRotation(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyPoolRotation(t, cfg.targetURL, []string{cfg.badSocks5URL, cfg.socks5hAuthURL})
+}
+
+func TestIntegrationRawHTTPProxyPoolRotation(t *testing.T) {
+	cfg := proxyIntegrationConfig(t)
+	assertProxyPoolRotation(t, cfg.targetURL, []string{cfg.badHTTPURL, cfg.httpAuthURL})
+}
+
+type proxyIntegrationEngine struct {
+	targetURL string
+	limiter   *rate.Limiter
+	proxies   []string
+}
+
+func (e *proxyIntegrationEngine) Name() string {
+	return "google"
+}
+
+func (e *proxyIntegrationEngine) IsInitialized() bool {
+	return true
+}
+
+func (e *proxyIntegrationEngine) GetRateLimiter() *rate.Limiter {
+	return e.limiter
+}
+
+func (e *proxyIntegrationEngine) Search(q Query) ([]SearchResult, error) {
+	e.proxies = append(e.proxies, q.ProxyURL)
+
+	body, err := fetchViaRawProxy(q.ProxyURL, q.Insecure, e.targetURL)
+	if err != nil {
+		return nil, err
+	}
+
+	return []SearchResult{{
+		Rank:        1,
+		URL:         e.targetURL,
+		Title:       "proxy-ok",
+		Description: body,
+	}}, nil
+}
+
+func (e *proxyIntegrationEngine) SearchImage(q Query) ([]SearchResult, error) {
+	return nil, ErrSearchTimeout
+}
+
+func proxyIntegrationConfig(t *testing.T) proxyIntegrationURLs {
+	t.Helper()
+	testutil.RequireIntegration(t)
+
+	if os.Getenv(proxyIntegrationEnabledEnv) != "1" {
+		t.Skipf("set %s=1 to run proxy integration tests", proxyIntegrationEnabledEnv)
+	}
+
+	return proxyIntegrationURLs{
+		targetURL:       envOrDefault("OPENSERP_PROXY_TEST_TARGET_URL", "http://proxy-target:8080/"),
+		socks5hAuthURL:  envOrDefault("OPENSERP_PROXY_TEST_SOCKS5H_AUTH_URL", "socks5h://test:test@127.0.0.1:19080"),
+		socks5hPlainURL: envOrDefault("OPENSERP_PROXY_TEST_SOCKS5H_PLAIN_URL", "socks5h://127.0.0.1:19082"),
+		httpAuthURL:     envOrDefault("OPENSERP_PROXY_TEST_HTTP_AUTH_URL", "http://test:test@127.0.0.1:18888"),
+		httpPlainURL:    envOrDefault("OPENSERP_PROXY_TEST_HTTP_PLAIN_URL", "http://127.0.0.1:18889"),
+		badSocks5URL:    envOrDefault("OPENSERP_PROXY_TEST_BAD_SOCKS5_URL", "socks5://127.0.0.1:19081"),
+		badHTTPURL:      envOrDefault("OPENSERP_PROXY_TEST_BAD_HTTP_URL", "http://127.0.0.1:18890"),
+	}
+}
+
+func assertProxyFetchesTarget(t *testing.T, targetURL, proxyURL string) {
+	t.Helper()
+
+	target := mustParseURL(t, targetURL)
+	assertHostCannotResolveTarget(t, target.Hostname())
+
+	body, err := fetchViaRawProxy(proxyURL, false, targetURL)
+	if err != nil {
+		t.Fatalf("expected proxied request via %s to succeed, got %v", proxyURL, err)
+	}
+	if !strings.Contains(body, "proxy-ok") {
+		t.Fatalf("expected proxy target response, got %q", body)
+	}
+}
+
+func assertProxyPoolRotation(t *testing.T, targetURL string, pool []string) {
+	t.Helper()
+
+	engine := &proxyIntegrationEngine{
+		targetURL: targetURL,
+		limiter:   rate.NewLimiter(rate.Inf, 1),
+	}
+
+	opts := DefaultServerOptions()
+	opts.Resilience.Retry.MaxRetries = 1
+	opts.Resilience.Retry.InitialBackoff = 0
+	opts.Resilience.Retry.MaxBackoff = 0
+	opts.Resilience.Retry.BackoffFactor = 1
+	opts.Resilience.Proxy = ProxyConfig{
+		Runtime: ProxyRuntimeRaw,
+		Proxies: ProxiesConfig{
+			Health: ProxiesHealthConfig{FailureThreshold: 1},
+		},
+		EnginePolicies: map[string]string{"google": "default"},
+	}
+	for _, proxyURL := range pool {
+		opts.Resilience.Proxy.Proxies.Entries = append(opts.Resilience.Proxy.Proxies.Entries, ProxyEntryConfig{
+			URL:  proxyURL,
+			Tags: []string{"default"},
+		})
+	}
+
+	srv := NewServerWithOptions("127.0.0.1", 7190, opts, engine)
+	resp := request(t, srv, "/google/search?text=proxy")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("expected rotated proxy request to succeed, got %d", resp.StatusCode)
+	}
+
+	if len(engine.proxies) != 2 {
+		t.Fatalf("expected 2 proxy attempts, got %d", len(engine.proxies))
+	}
+	if engine.proxies[0] != pool[0] || engine.proxies[1] != pool[1] {
+		t.Fatalf("unexpected proxy rotation order: %#v", engine.proxies)
+	}
+
+	statsResp := request(t, srv, "/stats/proxy")
+	var stats map[string]interface{}
+	if err := json.NewDecoder(statsResp.Body).Decode(&stats); err != nil {
+		t.Fatalf("decode stats: %v", err)
+	}
+
+	if got := stats["healthy_count"].(float64); got != 1 {
+		t.Fatalf("expected healthy_count=1, got %v", got)
+	}
+	if got := stats["unhealthy_count"].(float64); got != 1 {
+		t.Fatalf("expected unhealthy_count=1, got %v", got)
+	}
+}
+
+func fetchViaRawProxy(proxyURL string, insecure bool, targetURL string) (string, error) {
+	client, err := NewRawHTTPClient(Query{
+		ProxyURL: proxyURL,
+		Insecure: insecure,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := client.Get(targetURL)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	return string(bodyBytes), nil
+}
+
+func assertHostCannotResolveTarget(t *testing.T, hostname string) {
+	t.Helper()
+
+	if _, err := net.DefaultResolver.LookupHost(context.Background(), hostname); err == nil {
+		t.Fatalf("expected direct host-side DNS lookup for %q to fail", hostname)
+	}
+}
+
+func mustParseURL(t *testing.T, raw string) *url.URL {
+	t.Helper()
+
+	parsed, err := url.Parse(raw)
+	if err != nil {
+		t.Fatalf("parse target URL %q: %v", raw, err)
+	}
+	return parsed
+}
+
+func envOrDefault(key, fallback string) string {
+	if value := strings.TrimSpace(os.Getenv(key)); value != "" {
+		return value
+	}
+	return fallback
+}

core/proxy_test.go

@@ -0,0 +1,345 @@
+package core
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+	"time"
+
+	socks5 "github.com/armon/go-socks5"
+	xcontext "golang.org/x/net/context"
+)
+
+func TestNormalizeProxyURL(t *testing.T) {
+	tests := []struct {
+		name    string
+		raw     string
+		want    string
+		wantErr bool
+	}{
+		{name: "empty", raw: "", want: ""},
+		{name: "http", raw: "http://127.0.0.1:8080", want: "http://127.0.0.1:8080"},
+		{name: "https", raw: "https://127.0.0.1:8443", want: "https://127.0.0.1:8443"},
+		{name: "socks5", raw: "socks5://127.0.0.1:1080", want: "socks5://127.0.0.1:1080"},
+		{name: "socks5h upper", raw: "SOCKS5H://127.0.0.1:1080", want: "socks5h://127.0.0.1:1080"},
+		{name: "missing scheme", raw: "127.0.0.1:8080", wantErr: true},
+		{name: "missing host", raw: "http://", wantErr: true},
+		{name: "unsupported scheme", raw: "ftp://127.0.0.1:21", wantErr: true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := NormalizeProxyURL(tt.raw)
+			if tt.wantErr {
+				if err == nil {
+					t.Fatalf("expected error for %q", tt.raw)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if got != tt.want {
+				t.Fatalf("expected %q, got %q", tt.want, got)
+			}
+		})
+	}
+}
+
+func TestNormalizeProxiesConfigDefaultsAndDeduplicates(t *testing.T) {
+	cfg, err := NormalizeProxiesConfig(ProxiesConfig{
+		Global: " HTTP://proxy-global:8080 ",
+		Entries: []ProxyEntryConfig{
+			{URL: " http://proxy-one:8080 ", Tags: []string{"default", "us"}},
+			{URL: "http://proxy-one:8080", Tags: []string{"de", "us"}},
+			{URL: "socks5://proxy-two:1080", Tags: []string{"default"}},
+		},
+	})
+	if err != nil {
+		t.Fatalf("normalize proxies config: %v", err)
+	}
+
+	if cfg.Global != "http://proxy-global:8080" {
+		t.Fatalf("expected normalized global proxy, got %q", cfg.Global)
+	}
+	if cfg.Health.FailureThreshold != DefaultProxyFailureThreshold {
+		t.Fatalf("expected default failure threshold %d, got %d", DefaultProxyFailureThreshold, cfg.Health.FailureThreshold)
+	}
+	if len(cfg.Entries) != 2 {
+		t.Fatalf("expected 2 deduplicated entries, got %d", len(cfg.Entries))
+	}
+	if cfg.Entries[0].URL != "http://proxy-one:8080" {
+		t.Fatalf("unexpected normalized URL for first entry: %s", cfg.Entries[0].URL)
+	}
+	if len(cfg.Entries[0].Tags) != 3 {
+		t.Fatalf("expected merged tags in first entry, got %#v", cfg.Entries[0].Tags)
+	}
+}
+
+func TestNormalizeProxiesConfigRejectsInvalidEntries(t *testing.T) {
+	_, err := NormalizeProxiesConfig(ProxiesConfig{
+		Entries: []ProxyEntryConfig{{URL: "ftp://proxy:21", Tags: []string{"default"}}},
+	})
+	if err == nil {
+		t.Fatal("expected invalid scheme error")
+	}
+
+	_, err = NormalizeProxiesConfig(ProxiesConfig{
+		Entries: []ProxyEntryConfig{{URL: "http://proxy:8080", Tags: []string{" "}}},
+	})
+	if err == nil {
+		t.Fatal("expected empty tags error")
+	}
+
+	_, err = NormalizeProxiesConfig(ProxiesConfig{
+		Global:  "ftp://proxy:21",
+		Entries: []ProxyEntryConfig{{URL: "http://proxy:8080", Tags: []string{"default"}}},
+	})
+	if err == nil {
+		t.Fatal("expected invalid global proxy scheme error")
+	}
+}
+
+func TestResolveEffectiveProxyPolicy(t *testing.T) {
+	offPolicy := ResolveEffectiveProxyPolicy("", "")
+	if offPolicy.Mode != ProxyModeOff {
+		t.Fatalf("expected mode off, got %s", offPolicy.Mode)
+	}
+	if offPolicy.Tag != "" {
+		t.Fatalf("expected empty tag for off mode, got %q", offPolicy.Tag)
+	}
+
+	tagOnlyPolicy := ResolveEffectiveProxyPolicy("", "US")
+	if tagOnlyPolicy.Mode != ProxyModeTagPool || tagOnlyPolicy.Tag != "us" {
+		t.Fatalf("unexpected effective policy with tag override: %#v", tagOnlyPolicy)
+	}
+
+	globalPolicy := ResolveEffectiveProxyPolicy("http://proxy-global:8080", "eu")
+	if globalPolicy.Mode != ProxyModeTagPool || globalPolicy.Tag != "" {
+		t.Fatalf("expected global proxy to ignore engine tags, got %#v", globalPolicy)
+	}
+}
+
+func TestProxyRegistryRoundRobinAndFailureRecovery(t *testing.T) {
+	registry, err := NewProxyRegistry([]ProxyEntryConfig{
+		{URL: "http://proxy1:8080", Tags: []string{"default"}},
+		{URL: "http://proxy2:8080", Tags: []string{"default"}},
+	}, 2)
+	if err != nil {
+		t.Fatalf("new proxy registry: %v", err)
+	}
+
+	if got := registry.NextByTag("default"); got != "http://proxy1:8080" {
+		t.Fatalf("expected first proxy1, got %s", got)
+	}
+	if got := registry.NextByTag("default"); got != "http://proxy2:8080" {
+		t.Fatalf("expected second proxy2, got %s", got)
+	}
+
+	registry.ReportFailure("http://proxy1:8080")
+	registry.ReportFailure("http://proxy1:8080")
+	if got := registry.NextByTag("default"); got != "http://proxy2:8080" {
+		t.Fatalf("expected proxy2 while proxy1 disabled, got %s", got)
+	}
+
+	registry.ReportFailure("http://proxy2:8080")
+	registry.ReportFailure("http://proxy2:8080")
+	if got := registry.NextByTag("default"); got != "http://proxy1:8080" {
+		t.Fatalf("expected tag pool reset to proxy1 after exhaustion, got %s", got)
+	}
+
+	registry.ReportFailure("http://proxy1:8080")
+	registry.ReportSuccess("http://proxy1:8080")
+	stats := registry.BuildStats()
+	if stats.UnhealthyCount != 0 {
+		t.Fatalf("expected no unhealthy proxies after success recovery, got %d", stats.UnhealthyCount)
+	}
+	if stats.HealthyCount != 2 {
+		t.Fatalf("expected two healthy proxies, got %d", stats.HealthyCount)
+	}
+}
+
+func TestMaskProxyURLRedactsCredentials(t *testing.T) {
+	if got := MaskProxyURL("http://user:pass@127.0.0.1:8080"); got != "http://127.0.0.1:8080" {
+		t.Fatalf("unexpected masked proxy value: %s", got)
+	}
+}
+
+func TestProxyURLForBrowserLaunchStripsCredentials(t *testing.T) {
+	u, err := url.Parse("http://user:pass@127.0.0.1:18888")
+	if err != nil {
+		t.Fatalf("parse proxy URL: %v", err)
+	}
+
+	got := proxyURLForBrowserLaunch(u)
+	want := "http://127.0.0.1:18888"
+	if got != want {
+		t.Fatalf("expected %q, got %q", want, got)
+	}
+}
+
+func TestProxyURLForBrowserLaunchNormalizesSocks5h(t *testing.T) {
+	u, err := url.Parse("socks5h://test:test@127.0.0.1:19080")
+	if err != nil {
+		t.Fatalf("parse proxy URL: %v", err)
+	}
+
+	got := proxyURLForBrowserLaunch(u)
+	want := "socks5://127.0.0.1:19080"
+	if got != want {
+		t.Fatalf("expected %q, got %q", want, got)
+	}
+}
+
+func TestProxyStatsMaskCredentials(t *testing.T) {
+	registry, err := NewProxyRegistry([]ProxyEntryConfig{
+		{URL: "http://user:pass@proxy.example:8080", Tags: []string{"default"}},
+	}, 1)
+	if err != nil {
+		t.Fatalf("new proxy registry: %v", err)
+	}
+
+	stats := registry.BuildStats()
+	if len(stats.Entries) != 1 {
+		t.Fatalf("expected one proxy stats entry, got %d", len(stats.Entries))
+	}
+	if got := stats.Entries[0].Proxy; got != "http://proxy.example:8080" {
+		t.Fatalf("expected masked proxy in stats, got %q", got)
+	}
+}
+
+func TestNormalizeProxyTag(t *testing.T) {
+	tag, err := NormalizeProxyTag(" US ")
+	if err != nil {
+		t.Fatalf("normalize proxy tag: %v", err)
+	}
+	if tag != "us" {
+		t.Fatalf("expected normalized tag us, got %q", tag)
+	}
+
+	if _, err := NormalizeProxyTag("   "); err == nil {
+		t.Fatal("expected empty proxy tag validation error")
+	}
+}
+
+func TestNormalizeProxyRequestOverride(t *testing.T) {
+	override, err := NormalizeProxyRequestOverride(" direct ")
+	if err != nil {
+		t.Fatalf("normalize direct proxy override: %v", err)
+	}
+	if override != ProxyOverrideDirect {
+		t.Fatalf("expected direct override, got %q", override)
+	}
+
+	override, err = NormalizeProxyRequestOverride(" US ")
+	if err != nil {
+		t.Fatalf("normalize tagged proxy override: %v", err)
+	}
+	if override != "us" {
+		t.Fatalf("expected normalized tag override us, got %q", override)
+	}
+
+	override, err = NormalizeProxyRequestOverride("")
+	if err != nil {
+		t.Fatalf("normalize empty override: %v", err)
+	}
+	if override != "" {
+		t.Fatalf("expected empty override, got %q", override)
+	}
+}
+
+func TestIsAuthenticatedSocksProxyURL(t *testing.T) {
+	if !IsAuthenticatedSocksProxyURL("socks5h://user:pass@127.0.0.1:1080") {
+		t.Fatal("expected authenticated socks proxy to be detected")
+	}
+	if IsAuthenticatedSocksProxyURL("socks5://127.0.0.1:1080") {
+		t.Fatal("expected plain socks proxy to remain browser-compatible")
+	}
+	if IsAuthenticatedSocksProxyURL("http://user:pass@127.0.0.1:8080") {
+		t.Fatal("expected HTTP auth proxy to remain browser-compatible")
+	}
+}
+
+func TestNewRawHTTPClientSocks5hUsesProxyDNS(t *testing.T) {
+	target := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("proxied"))
+	}))
+	defer target.Close()
+
+	targetAddr, err := net.ResolveTCPAddr("tcp", target.Listener.Addr().String())
+	if err != nil {
+		t.Fatalf("resolve target listener: %v", err)
+	}
+
+	const proxyOnlyHost = "proxy-target.invalid"
+	proxyAddr := startSOCKS5TestServer(t, proxyOnlyHost, targetAddr.IP)
+
+	directClient := &http.Client{Timeout: 500 * time.Millisecond}
+	targetURL := fmt.Sprintf("http://%s:%d/", proxyOnlyHost, targetAddr.Port)
+	if _, err := directClient.Get(targetURL); err == nil {
+		t.Fatal("expected direct request to fail without proxy DNS")
+	}
+
+	client, err := NewRawHTTPClient(Query{ProxyURL: "socks5h://" + proxyAddr})
+	if err != nil {
+		t.Fatalf("new raw http client: %v", err)
+	}
+
+	resp, err := client.Get(targetURL)
+	if err != nil {
+		t.Fatalf("expected proxied request to succeed, got %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatalf("read proxied body: %v", err)
+	}
+	if string(body) != "proxied" {
+		t.Fatalf("unexpected proxied body: %q", string(body))
+	}
+}
+
+type staticResolver struct {
+	host string
+	ip   net.IP
+}
+
+func (r staticResolver) Resolve(ctx xcontext.Context, name string) (xcontext.Context, net.IP, error) {
+	if name == r.host {
+		return ctx, r.ip, nil
+	}
+	return ctx, nil, net.UnknownNetworkError(name)
+}
+
+func startSOCKS5TestServer(t *testing.T, host string, ip net.IP) string {
+	t.Helper()
+
+	server, err := socks5.New(&socks5.Config{
+		Resolver: staticResolver{host: host, ip: ip},
+		Logger:   log.New(io.Discard, "", 0),
+	})
+	if err != nil {
+		t.Fatalf("create socks5 server: %v", err)
+	}
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen socks5: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = listener.Close()
+	})
+
+	go func() {
+		_ = server.Serve(listener)
+	}()
+
+	return listener.Addr().String()
+}

core/resilient.go

@@ -0,0 +1,436 @@
+package core
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+)
+
+// ResilientSearcher wraps engines with retry and circuit breaker protection.
+type ResilientSearcher struct {
+	engines   []SearchEngine
+	cbManager *CircuitBreakerManager
+	retryCfg  RetryConfig
+
+	proxyRuntime  string
+	proxyCfg      ProxyConfig
+	proxyRegistry *ProxyRegistry
+	proxyDefaults ProxyPolicy
+
+	effectivePolicies map[string]ProxyPolicy
+}
+
+type ProxyExecutionMeta struct {
+	Mode string `json:"mode"`
+	Tag  string `json:"tag,omitempty"`
+	Used string `json:"used"`
+}
+
+type ResilientConfig struct {
+	Retry          RetryConfig
+	CircuitBreaker CircuitBreakerConfig
+	Proxy          ProxyConfig
+}
+
+func DefaultResilientConfig() ResilientConfig {
+	return ResilientConfig{
+		Retry:          DefaultRetryConfig(),
+		CircuitBreaker: DefaultCircuitBreakerConfig(),
+		Proxy:          DefaultProxyConfig(),
+	}
+}
+
+func NewResilientSearcher(engines []SearchEngine, cfg ResilientConfig) *ResilientSearcher {
+	proxyCfg, err := NormalizeProxyConfig(cfg.Proxy)
+	if err != nil {
+		logrus.Errorf("Invalid proxy config, using defaults: %v", err)
+		proxyCfg = DefaultProxyConfig()
+		proxyCfg, _ = NormalizeProxyConfig(proxyCfg)
+	}
+
+	rs := &ResilientSearcher{
+		engines:           engines,
+		cbManager:         NewCircuitBreakerManager(cfg.CircuitBreaker),
+		retryCfg:          cfg.Retry,
+		proxyRuntime:      proxyCfg.Runtime,
+		proxyCfg:          proxyCfg,
+		proxyRegistry:     proxyCfg.Registry,
+		proxyDefaults:     ResolveEffectiveProxyPolicy(proxyCfg.Proxies.Global, ""),
+		effectivePolicies: make(map[string]ProxyPolicy, len(engines)),
+	}
+
+	for _, engine := range engines {
+		engineName := normalizeEngineName(engine.Name())
+		override := proxyCfg.EnginePolicies[engineName]
+		effective := ResolveEffectiveProxyPolicy(proxyCfg.Proxies.Global, override)
+		rs.effectivePolicies[engineName] = effective
+	}
+
+	return rs
+}
+
+// SearchPrimary keeps dedicated endpoints engine-pure (no fallback).
+func (rs *ResilientSearcher) SearchPrimary(primaryEngine SearchEngine, q Query) ([]SearchResult, string, ProxyExecutionMeta, error) {
+	results, proxyMeta, err := rs.searchWithProtection(primaryEngine, q, false)
+	if err != nil {
+		return nil, primaryEngine.Name(), proxyMeta, err
+	}
+	return results, primaryEngine.Name(), proxyMeta, nil
+}
+
+// SearchWithFallback retries primary and then tries other initialized engines.
+func (rs *ResilientSearcher) SearchWithFallback(primaryEngine SearchEngine, q Query) ([]SearchResult, string, ProxyExecutionMeta, error) {
+	return rs.searchWithFallback(primaryEngine, q, false)
+}
+
+func (rs *ResilientSearcher) SearchImagePrimary(primaryEngine SearchEngine, q Query) ([]SearchResult, string, ProxyExecutionMeta, error) {
+	results, proxyMeta, err := rs.searchWithProtection(primaryEngine, q, true)
+	if err != nil {
+		return nil, primaryEngine.Name(), proxyMeta, err
+	}
+	return results, primaryEngine.Name(), proxyMeta, nil
+}
+
+func (rs *ResilientSearcher) SearchImageWithFallback(primaryEngine SearchEngine, q Query) ([]SearchResult, string, ProxyExecutionMeta, error) {
+	return rs.searchWithFallback(primaryEngine, q, true)
+}
+
+func (rs *ResilientSearcher) searchWithFallback(primaryEngine SearchEngine, q Query, isImage bool) ([]SearchResult, string, ProxyExecutionMeta, error) {
+	results, proxyMeta, err := rs.searchWithProtection(primaryEngine, q, isImage)
+	if err == nil {
+		return results, primaryEngine.Name(), proxyMeta, nil
+	}
+	if errors.Is(err, ErrProxyUnavailable) {
+		logrus.Warnf("[Resilient] Primary engine %s proxy policy failed closed: %s", primaryEngine.Name(), err)
+		return nil, primaryEngine.Name(), proxyMeta, err
+	}
+
+	action := "failed"
+	successMessage := "Fallback to %s succeeded with %d results"
+	if isImage {
+		action = "image search failed"
+		successMessage = "Image fallback to %s succeeded with %d results"
+	}
+
+	logrus.Warnf("[Resilient] Primary engine %s %s: %s. Trying fallback engines...", primaryEngine.Name(), action, err)
+	for _, fallbackEngine := range rs.engines {
+		if fallbackEngine.Name() == primaryEngine.Name() || !fallbackEngine.IsInitialized() {
+			continue
+		}
+
+		results, fallbackMeta, fallbackErr := rs.searchWithProtection(fallbackEngine, q, isImage)
+		if fallbackErr == nil {
+			logrus.Infof("[Resilient] "+successMessage, fallbackEngine.Name(), len(results))
+			return results, fallbackEngine.Name(), fallbackMeta, nil
+		}
+		logrus.Warnf("[Resilient] Fallback engine %s also failed: %s", fallbackEngine.Name(), fallbackErr)
+	}
+
+	return nil, primaryEngine.Name(), proxyMeta, ErrAllEnginesFailed
+}
+
+func (rs *ResilientSearcher) searchWithProtection(engine SearchEngine, q Query, isImage bool) ([]SearchResult, ProxyExecutionMeta, error) {
+	cb := rs.cbManager.Get(engine.Name())
+	if !cb.AllowRequest() {
+		return nil, ProxyExecutionMeta{}, ErrCircuitOpen
+	}
+
+	policy := rs.effectivePolicyForQuery(engine.Name(), q)
+	attemptMeta := rs.baseProxyMeta(policy)
+
+	result := RetryableSearch(rs.retryCfg, engine.Name(), func() ([]SearchResult, error) {
+		limiter := engine.GetRateLimiter()
+		if limiter != nil {
+			if err := limiter.Wait(context.Background()); err != nil {
+				return nil, err
+			}
+		}
+
+		attemptQuery := q
+		proxyURL := ""
+		reportToRegistry := false
+		attemptMeta = rs.baseProxyMeta(policy)
+
+		switch policy.Mode {
+		case ProxyModeOff:
+			attemptQuery.ProxyURL = ""
+			attemptMeta.Used = "direct"
+		case ProxyModeTagPool:
+			proxyURL = rs.selectProxyForQuery(policy, q)
+			if proxyURL == "" {
+				return nil, fmt.Errorf("%w: no healthy proxy available for tag %q", ErrProxyUnavailable, policy.Tag)
+			}
+			attemptQuery.ProxyURL = proxyURL
+			reportToRegistry = policy.Tag != ""
+			attemptMeta.Used = MaskProxyURL(proxyURL)
+		}
+
+		var (
+			results []SearchResult
+			err     error
+		)
+		if isImage {
+			results, err = engine.SearchImage(attemptQuery)
+		} else {
+			results, err = engine.Search(attemptQuery)
+		}
+
+		if reportToRegistry {
+			rs.reportProxyAttempt(proxyURL, err)
+		}
+
+		return results, err
+	})
+
+	if result.Err != nil {
+		if !errors.Is(result.Err, ErrProxyUnavailable) {
+			cb.RecordFailure()
+		}
+		return nil, attemptMeta, result.Err
+	}
+
+	cb.RecordSuccess()
+	return result.Results, attemptMeta, nil
+}
+
+// SearchAllParallel applies retry/circuit protections per engine for mega search.
+func (rs *ResilientSearcher) SearchAllParallel(q Query, engines []SearchEngine) []MegaSearchResult {
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+	var allResults []MegaSearchResult
+
+	for _, engine := range engines {
+		if !engine.IsInitialized() {
+			continue
+		}
+		if !rs.cbManager.Get(engine.Name()).AllowRequest() {
+			logrus.Infof("[Resilient] Skipping %s in megasearch (circuit open)", engine.Name())
+			continue
+		}
+
+		wg.Add(1)
+		go func(eng SearchEngine) {
+			defer wg.Done()
+
+			results, _, err := rs.searchWithProtection(eng, q, false)
+			if err != nil {
+				return
+			}
+
+			mu.Lock()
+			for _, r := range results {
+				allResults = append(allResults, MegaSearchResult{
+					SearchResult: r,
+					Engine:       eng.Name(),
+				})
+			}
+			mu.Unlock()
+		}(engine)
+	}
+
+	wg.Wait()
+	return allResults
+}
+
+func (rs *ResilientSearcher) SearchAllImageParallel(q Query, engines []SearchEngine) []MegaSearchResult {
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+	var allResults []MegaSearchResult
+
+	for _, engine := range engines {
+		if !engine.IsInitialized() {
+			continue
+		}
+		if !rs.cbManager.Get(engine.Name()).AllowRequest() {
+			logrus.Infof("[Resilient] Skipping %s in megaimage (circuit open)", engine.Name())
+			continue
+		}
+
+		wg.Add(1)
+		go func(eng SearchEngine) {
+			defer wg.Done()
+
+			results, _, err := rs.searchWithProtection(eng, q, true)
+			if err != nil {
+				return
+			}
+
+			mu.Lock()
+			for _, r := range results {
+				allResults = append(allResults, MegaSearchResult{
+					SearchResult: r,
+					Engine:       eng.Name(),
+				})
+			}
+			mu.Unlock()
+		}(engine)
+	}
+
+	wg.Wait()
+	return allResults
+}
+
+func (rs *ResilientSearcher) GetCircuitBreakerStats() []map[string]interface{} {
+	return rs.cbManager.AllStats()
+}
+
+func (rs *ResilientSearcher) GetProxyStats() ProxyStats {
+	stats := ProxyStats{
+		ConfiguredCount: 0,
+		HealthyCount:    0,
+		UnhealthyCount:  0,
+		Tags:            map[string]ProxyTagSummary{},
+		Entries:         []ProxyStatsEntry{},
+	}
+
+	if rs.proxyRegistry != nil {
+		stats = rs.proxyRegistry.BuildStats()
+	}
+
+	engines := map[string]ProxyEngineStats{}
+	for _, engine := range rs.engines {
+		engineName := normalizeEngineName(engine.Name())
+		policy := rs.effectivePolicyForEngine(engineName)
+		engineStats := ProxyEngineStats{}
+
+		switch policy.Mode {
+		case ProxyModeOff:
+			engineStats.SelectedProxy = "direct"
+		case ProxyModeTagPool:
+			engineStats.Tag = policy.Tag
+			if global := strings.TrimSpace(rs.proxyCfg.Proxies.Global); global != "" {
+				engineStats.SelectedProxy = MaskProxyURL(global)
+			} else {
+				engineStats.SelectedProxy = "pooled"
+			}
+		}
+
+		engines[engineName] = engineStats
+	}
+	if len(engines) > 0 {
+		stats.Engines = engines
+	}
+
+	return stats
+}
+
+func (rs *ResilientSearcher) ResolveMegaProxyMeta(q Query, engines []SearchEngine) ProxyExecutionMeta {
+	if len(engines) == 0 {
+		return ProxyExecutionMeta{Mode: ProxyModeOff, Used: "direct"}
+	}
+
+	allOff := true
+	proxiedTags := map[string]struct{}{}
+	hasOff := false
+
+	for _, engine := range engines {
+		policy := rs.effectivePolicyForQuery(engine.Name(), q)
+		if policy.Mode == ProxyModeOff {
+			hasOff = true
+			continue
+		}
+
+		allOff = false
+		if policy.Tag != "" {
+			proxiedTags[policy.Tag] = struct{}{}
+		}
+	}
+
+	if allOff {
+		return ProxyExecutionMeta{Mode: ProxyModeOff, Used: "direct"}
+	}
+
+	meta := ProxyExecutionMeta{Mode: ProxyModeTagPool}
+	if len(proxiedTags) == 1 {
+		for tag := range proxiedTags {
+			meta.Tag = tag
+		}
+	}
+
+	if q.ProxyOverride == "" {
+		if global := strings.TrimSpace(rs.proxyCfg.Proxies.Global); global != "" && !hasOff {
+			meta.Used = MaskProxyURL(global)
+			return meta
+		}
+	}
+
+	if rs.proxyRuntime == ProxyRuntimeRaw {
+		meta.Used = "multiple"
+		if hasOff {
+			meta.Used = "mixed"
+		}
+		return meta
+	}
+	meta.Used = "multiple"
+	if hasOff {
+		meta.Used = "mixed"
+	}
+	return meta
+}
+
+func (rs *ResilientSearcher) baseProxyMeta(policy ProxyPolicy) ProxyExecutionMeta {
+	meta := ProxyExecutionMeta{Mode: policy.Mode}
+	if policy.Mode == ProxyModeTagPool {
+		meta.Tag = policy.Tag
+		return meta
+	}
+	meta.Used = "direct"
+	return meta
+}
+
+func (rs *ResilientSearcher) effectivePolicyForEngine(engineName string) ProxyPolicy {
+	engineName = normalizeEngineName(engineName)
+	if policy, ok := rs.effectivePolicies[engineName]; ok {
+		return policy
+	}
+	return rs.proxyDefaults
+}
+
+func (rs *ResilientSearcher) effectivePolicyForQuery(engineName string, q Query) ProxyPolicy {
+	switch q.ProxyOverride {
+	case "":
+		return rs.effectivePolicyForEngine(engineName)
+	case ProxyOverrideDirect:
+		return ProxyPolicy{Mode: ProxyModeOff}
+	default:
+		return ProxyPolicy{Mode: ProxyModeTagPool, Tag: q.ProxyOverride}
+	}
+}
+
+func (rs *ResilientSearcher) selectProxyForTag(tag string) string {
+	if rs.proxyRegistry == nil {
+		return ""
+	}
+	return rs.proxyRegistry.NextByTag(tag)
+}
+
+func (rs *ResilientSearcher) reportProxyAttempt(proxyURL string, err error) {
+	if rs.proxyRegistry == nil || proxyURL == "" {
+		return
+	}
+
+	if err != nil {
+		rs.proxyRegistry.ReportFailure(proxyURL)
+		return
+	}
+
+	rs.proxyRegistry.ReportSuccess(proxyURL)
+}
+
+func (rs *ResilientSearcher) selectProxyForQuery(policy ProxyPolicy, q Query) string {
+	if policy.Mode != ProxyModeTagPool {
+		return ""
+	}
+	if q.ProxyOverride == "" {
+		if global := strings.TrimSpace(rs.proxyCfg.Proxies.Global); global != "" {
+			return global
+		}
+	}
+	return rs.selectProxyForTag(policy.Tag)
+}
+
+var ErrAllEnginesFailed = fmt.Errorf("all search engines failed")

core/retry.go

@@ -0,0 +1,100 @@
+package core
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+// RetryConfig controls retry behavior.
+type RetryConfig struct {
+	MaxRetries     int
+	InitialBackoff time.Duration
+	MaxBackoff     time.Duration
+	BackoffFactor  float64
+}
+
+func DefaultRetryConfig() RetryConfig {
+	return RetryConfig{
+		MaxRetries:     3,
+		InitialBackoff: time.Second,
+		MaxBackoff:     30 * time.Second,
+		BackoffFactor:  2.0,
+	}
+}
+
+type RetryResult struct {
+	Results  []SearchResult
+	Err      error
+	Attempts int
+	Engine   string
+}
+
+// RetryableSearch executes searchFn with exponential backoff retries.
+// CAPTCHA and proxy-unavailable errors are not retried.
+func RetryableSearch(cfg RetryConfig, engineName string, searchFn func() ([]SearchResult, error)) RetryResult {
+	if cfg.BackoffFactor <= 0 {
+		cfg.BackoffFactor = 2.0
+	}
+
+	var lastErr error
+	for attempt := 0; attempt <= cfg.MaxRetries; attempt++ {
+		if attempt > 0 {
+			backoff := calculateBackoff(cfg, attempt)
+			logrus.Warnf("[%s] Retry attempt %d/%d after %s", engineName, attempt, cfg.MaxRetries, backoff)
+			time.Sleep(backoff)
+		}
+
+		results, err := searchFn()
+		if err == nil {
+			if attempt > 0 {
+				logrus.Infof("[%s] Succeeded on retry attempt %d", engineName, attempt)
+			}
+			return RetryResult{
+				Results:  results,
+				Attempts: attempt + 1,
+				Engine:   engineName,
+			}
+		}
+
+		lastErr = err
+		if errors.Is(err, ErrCaptcha) {
+			logrus.Warnf("[%s] CAPTCHA detected, skipping retries", engineName)
+			return RetryResult{
+				Err:      err,
+				Attempts: attempt + 1,
+				Engine:   engineName,
+			}
+		}
+		if errors.Is(err, ErrProxyUnavailable) {
+			logrus.Warnf("[%s] Proxy unavailable, skipping retries", engineName)
+			return RetryResult{
+				Err:      err,
+				Attempts: attempt + 1,
+				Engine:   engineName,
+			}
+		}
+
+		logrus.Warnf("[%s] Attempt %d failed: %s", engineName, attempt+1, err)
+	}
+
+	return RetryResult{
+		Err:      fmt.Errorf("all %d attempts failed for %s: %w", cfg.MaxRetries+1, engineName, lastErr),
+		Attempts: cfg.MaxRetries + 1,
+		Engine:   engineName,
+	}
+}
+
+func calculateBackoff(cfg RetryConfig, attempt int) time.Duration {
+	backoff := float64(cfg.InitialBackoff) * math.Pow(cfg.BackoffFactor, float64(attempt-1))
+	if backoff > float64(cfg.MaxBackoff) {
+		backoff = float64(cfg.MaxBackoff)
+	}
+	if backoff < 0 {
+		backoff = 0
+	}
+	return time.Duration(backoff)
+}

core/retry_test.go

@@ -0,0 +1,86 @@
+package core
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestRetryableSearch_SuccessOnFirstAttempt(t *testing.T) {
+	cfg := RetryConfig{MaxRetries: 3, InitialBackoff: 10 * time.Millisecond, MaxBackoff: 100 * time.Millisecond, BackoffFactor: 2.0}
+	calls := 0
+
+	result := RetryableSearch(cfg, "test", func() ([]SearchResult, error) {
+		calls++
+		return []SearchResult{{Title: "result1"}}, nil
+	})
+
+	if result.Err != nil {
+		t.Fatalf("expected no error, got: %v", result.Err)
+	}
+	if result.Attempts != 1 {
+		t.Errorf("expected 1 attempt, got: %d", result.Attempts)
+	}
+	if calls != 1 {
+		t.Errorf("expected 1 call, got: %d", calls)
+	}
+}
+
+func TestRetryableSearch_AllAttemptsFail(t *testing.T) {
+	cfg := RetryConfig{MaxRetries: 2, InitialBackoff: 10 * time.Millisecond, MaxBackoff: 50 * time.Millisecond, BackoffFactor: 2.0}
+	calls := 0
+
+	result := RetryableSearch(cfg, "test", func() ([]SearchResult, error) {
+		calls++
+		return nil, errors.New("persistent failure")
+	})
+
+	if result.Err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if calls != 3 {
+		t.Errorf("expected 3 calls (1 + 2 retries), got: %d", calls)
+	}
+	if result.Attempts != 3 {
+		t.Errorf("expected 3 attempts, got: %d", result.Attempts)
+	}
+}
+
+func TestRetryableSearch_CaptchaNotRetried(t *testing.T) {
+	cfg := RetryConfig{MaxRetries: 3, InitialBackoff: 10 * time.Millisecond, MaxBackoff: 100 * time.Millisecond, BackoffFactor: 2.0}
+	calls := 0
+
+	result := RetryableSearch(cfg, "test", func() ([]SearchResult, error) {
+		calls++
+		return nil, ErrCaptcha
+	})
+
+	if !errors.Is(result.Err, ErrCaptcha) {
+		t.Fatalf("expected ErrCaptcha, got: %v", result.Err)
+	}
+	if calls != 1 {
+		t.Errorf("expected 1 call, got: %d", calls)
+	}
+}
+
+func TestCalculateBackoff(t *testing.T) {
+	cfg := RetryConfig{InitialBackoff: 1 * time.Second, MaxBackoff: 10 * time.Second, BackoffFactor: 2.0}
+
+	tests := []struct {
+		attempt  int
+		expected time.Duration
+	}{
+		{1, 1 * time.Second},
+		{2, 2 * time.Second},
+		{3, 4 * time.Second},
+		{4, 8 * time.Second},
+		{5, 10 * time.Second},
+	}
+
+	for _, tt := range tests {
+		got := calculateBackoff(cfg, tt.attempt)
+		if got != tt.expected {
+			t.Errorf("attempt %d: expected %s, got %s", tt.attempt, tt.expected, got)
+		}
+	}
+}

core/server.go

@@ -1,11 +1,13 @@
 package core
 
 import (
-	"context"
+	"encoding/json"
+	"errors"
 	"fmt"
+	"runtime"
 	"sort"
 	"strings"
-	"sync"
+	"time"
 
 	"github.com/gofiber/fiber/v2"
 	"github.com/sirupsen/logrus"
@@ -24,227 +26,363 @@ type Server struct {
 	app           *fiber.App
 	addr          string
 	searchEngines []SearchEngine
+	cache         *ResponseCache
+	resilient     *ResilientSearcher
+	startTime     time.Time
+	opts          ServerOptions
+}
+
+type ServerOptions struct {
+	CacheTTL              time.Duration
+	CacheMaxSize          int
+	EnableCORS            bool
+	CORS                  CORSConfig
+	AllowEndpointFallback bool
+	Resilience            ResilientConfig
+}
+
+func DefaultServerOptions() ServerOptions {
+	return ServerOptions{
+		CacheTTL:              5 * time.Minute,
+		CacheMaxSize:          1000,
+		EnableCORS:            true,
+		CORS:                  DefaultCORSConfig(),
+		AllowEndpointFallback: false,
+		Resilience:            DefaultResilientConfig(),
+	}
 }
 
 func NewServer(host string, port int, searchEngines ...SearchEngine) *Server {
+	return NewServerWithOptions(host, port, DefaultServerOptions(), searchEngines...)
+}
+
+func NewServerWithOptions(host string, port int, opts ServerOptions, searchEngines ...SearchEngine) *Server {
 	addr := fmt.Sprintf("%s:%d", host, port)
+	app := fiber.New(fiber.Config{
+		ErrorHandler: JSONErrorMiddleware(),
+	})
+
 	serv := Server{
-		app:           fiber.New(),
+		app:           app,
 		addr:          addr,
 		searchEngines: searchEngines,
+		resilient:     NewResilientSearcher(searchEngines, opts.Resilience),
+		startTime:     time.Now(),
+		opts:          opts,
 	}
+	logrus.Info("Resilient search enabled: retry + circuit breaker")
+	if opts.AllowEndpointFallback {
+		logrus.Warn("Dedicated endpoint fallback is enabled")
+	}
+	if opts.CacheTTL > 0 && opts.CacheMaxSize > 0 {
+		serv.cache = NewResponseCache(opts.CacheTTL, opts.CacheMaxSize)
+		logrus.Infof("Response cache enabled: TTL=%s, MaxSize=%d", opts.CacheTTL, opts.CacheMaxSize)
+	}
+
+	if opts.EnableCORS {
+		app.Use(CORSMiddleware(opts.CORS))
+	}
+	app.Use(RequestLoggerMiddleware())
+
+	app.Get("/health", serv.handleHealthCheck)
+	app.Get("/stats", serv.handleStats)
+	app.Get("/stats/cache", serv.handleCacheStats)
+	app.Get("/stats/proxy", serv.handleProxyStats)
+	app.Get("/stats/cb", serv.handleCircuitBreakerStats)
 
 	for _, engine := range searchEngines {
 		locEngine := engine
-		limiter := engine.GetRateLimiter()
 
-		// Custom endpoint mapping for DuckDuckGo
 		endpointName := strings.ToLower(locEngine.Name())
 		if endpointName == "duckduckgo" {
 			endpointName = "duck"
 		}
 
 		serv.app.Get(fmt.Sprintf("/%s/search", endpointName), func(c *fiber.Ctx) error {
-			q := Query{}
-			err := q.InitFromContext(c)
-			if err != nil {
-				logrus.Errorf("Error while setting %s query: %s", locEngine.Name(), err)
-				return err
-			}
-
-			logrus.Infof("Starting SERP search request using %s engine for query: %s", locEngine.Name(), q.Text)
-
-			err = limiter.Wait(context.Background())
-			if err != nil {
-				logrus.Errorf("Ratelimiter error during %s query: %s", locEngine.Name(), err)
-			}
-
-			res, err := locEngine.Search(q)
-			if err != nil {
-				switch err {
-				case ErrCaptcha:
-					err = fmt.Errorf("captcha found, please stop sending requests for a while\n%s", err)
-				case ErrSearchTimeout:
-					err = fmt.Errorf("%s", err)
-				}
-
-				logrus.Errorf("Error during %s search: %s", locEngine.Name(), err)
-				return fiber.NewError(fiber.StatusServiceUnavailable, err.Error())
-			}
-
-			logrus.Infof("Successfully completed SERP search using %s engine, returned %d results", locEngine.Name(), len(res))
-			return c.JSON(res)
+			return serv.handleDedicatedEndpoint(c, locEngine, false)
 		})
 
 		serv.app.Get(fmt.Sprintf("/%s/image", endpointName), func(c *fiber.Ctx) error {
-			q := Query{}
-			err := q.InitFromContext(c)
-			if err != nil {
-				logrus.Errorf("Error while setting %s query: %s", locEngine.Name(), err)
-				return err
-			}
-
-			logrus.Infof("Starting SERP image search request using %s engine for query: %s", locEngine.Name(), q.Text)
-
-			err = limiter.Wait(context.Background())
-			if err != nil {
-				logrus.Errorf("Ratelimiter error during %s query: %s", locEngine.Name(), err)
-			}
-
-			res, err := locEngine.SearchImage(q)
-
-			if err != nil && len(res) > 0 {
-				logrus.Warnf("Partial results returned from %s image search despite error: %s", locEngine.Name(), err)
-				c.Status(503)
-				return c.JSON(res)
-			}
-
-			if err != nil {
-				switch err {
-				case ErrCaptcha:
-					err = fmt.Errorf("captcha found, please stop sending requests for a while: %s", err)
-				case ErrSearchTimeout:
-					err = fmt.Errorf("%s", err)
-				}
-
-				logrus.Errorf("Error during %s image search: %s", locEngine.Name(), err)
-				return fiber.NewError(fiber.StatusServiceUnavailable, err.Error())
-			}
-
-			logrus.Infof("Successfully completed SERP image search using [%s], returned %d results", locEngine.Name(), len(res))
-			return c.JSON(res)
+			return serv.handleDedicatedEndpoint(c, locEngine, true)
 		})
 	}
 
-	// Add megasearch endpoint
 	serv.app.Get("/mega/search", serv.handleMegaSearch)
-
-	// Add megasearch image endpoint
 	serv.app.Get("/mega/image", serv.handleMegaImage)
-
-	// Add endpoint to list available engines
 	serv.app.Get("/mega/engines", serv.handleListEngines)
 
 	return &serv
 }
 
-// MegaSearchResult represents a search result with engine information
+func (s *Server) handleDedicatedEndpoint(c *fiber.Ctx, engine SearchEngine, isImage bool) error {
+	q := Query{}
+	if err := q.InitFromContext(c); err != nil {
+		logrus.Errorf("Error while setting %s query: %s", engine.Name(), err)
+		return err
+	}
+
+	action := "search"
+	if isImage {
+		action = "image"
+	}
+	logrus.Infof("Starting SERP %s request using %s engine for query: %s", action, engine.Name(), q.Text)
+
+	if hit, err := s.tryServeCacheHit(
+		c,
+		cacheHitCandidate{
+			key:        BuildCacheKey(engine.Name(), action, q),
+			logMessage: fmt.Sprintf("Cache hit for %s %s: %s", engine.Name(), action, q.Text),
+		},
+	); hit || err != nil {
+		return err
+	}
+
+	var (
+		res        []SearchResult
+		usedEngine string
+		proxyMeta  ProxyExecutionMeta
+		searchErr  error
+	)
+
+	if isImage {
+		if s.opts.AllowEndpointFallback {
+			res, usedEngine, proxyMeta, searchErr = s.resilient.SearchImageWithFallback(engine, q)
+		} else {
+			res, usedEngine, proxyMeta, searchErr = s.resilient.SearchImagePrimary(engine, q)
+		}
+	} else {
+		if s.opts.AllowEndpointFallback {
+			res, usedEngine, proxyMeta, searchErr = s.resilient.SearchWithFallback(engine, q)
+		} else {
+			res, usedEngine, proxyMeta, searchErr = s.resilient.SearchPrimary(engine, q)
+		}
+	}
+	s.applyProxyHeaders(c, proxyMeta)
+
+	if searchErr != nil {
+		errToReturn := searchErr
+		switch searchErr {
+		case ErrCaptcha:
+			errToReturn = fmt.Errorf("captcha found, please stop sending requests for a while: %w", searchErr)
+		case ErrSearchTimeout:
+			errToReturn = fmt.Errorf("%s", searchErr)
+		default:
+			if errors.Is(searchErr, ErrProxyUnavailable) {
+				errToReturn = fmt.Errorf("%s", searchErr)
+			}
+		}
+		logrus.Errorf("Error during resilient %s %s: %s", engine.Name(), action, searchErr)
+		return fiber.NewError(fiber.StatusServiceUnavailable, errToReturn.Error())
+	}
+
+	cacheStatus := ""
+	// Avoid caching fallback-served responses so the requested engine can recover
+	// without the endpoint continuing to serve another engine until TTL expiry.
+	if s.cache != nil {
+		cacheStatus = "BYPASS"
+		switch {
+		case usedEngine != engine.Name():
+			s.cache.RecordBypass()
+		case len(res) == 0:
+			s.cache.RecordBypass()
+		default:
+			cacheKey := BuildCacheKey(engine.Name(), action, q)
+			if s.cacheJSON(cacheKey, res) {
+				cacheStatus = "MISS"
+			}
+		}
+		c.Set("X-Cache", cacheStatus)
+	}
+
+	if usedEngine != "" && usedEngine != engine.Name() {
+		c.Set("X-Fallback-Engine", usedEngine)
+	}
+
+	logrus.Infof("Successfully completed SERP %s using %s, returned %d results", action, usedEngine, len(res))
+	return c.JSON(res)
+}
+
+type HealthStatus struct {
+	Status  string                 `json:"status"`
+	Uptime  string                 `json:"uptime"`
+	Engines []EngineHealth         `json:"engines"`
+	System  map[string]interface{} `json:"system"`
+}
+
+type EngineHealth struct {
+	Name        string `json:"name"`
+	Initialized bool   `json:"initialized"`
+	Status      string `json:"status"`
+}
+
+// handleHealthCheck returns current service and engine status.
+// Degraded state stays HTTP 200 to avoid unnecessary restarts in orchestrators.
+func (s *Server) handleHealthCheck(c *fiber.Ctx) error {
+	engines := make([]EngineHealth, 0, len(s.searchEngines))
+	availableEngines := 0
+
+	for _, engine := range s.searchEngines {
+		status := "ready"
+		isAvailable := true
+		if !engine.IsInitialized() {
+			status = "not_initialized"
+			isAvailable = false
+		}
+
+		for _, cbStat := range s.resilient.GetCircuitBreakerStats() {
+			engineName, _ := cbStat["engine"].(string)
+			if engineName != engine.Name() {
+				continue
+			}
+			circuitState, _ := cbStat["state"].(string)
+			if circuitState == "open" {
+				status = "circuit_open"
+				isAvailable = false
+			}
+			break
+		}
+
+		if isAvailable {
+			availableEngines++
+		}
+
+		engines = append(engines, EngineHealth{
+			Name:        engine.Name(),
+			Initialized: engine.IsInitialized(),
+			Status:      status,
+		})
+	}
+
+	overallStatus := "healthy"
+	totalEngines := len(s.searchEngines)
+	switch {
+	case totalEngines == 0 || availableEngines == 0:
+		overallStatus = "unhealthy"
+	case availableEngines < totalEngines:
+		overallStatus = "degraded"
+	}
+
+	var memStats runtime.MemStats
+	runtime.ReadMemStats(&memStats)
+
+	health := HealthStatus{
+		Status:  overallStatus,
+		Uptime:  time.Since(s.startTime).Round(time.Second).String(),
+		Engines: engines,
+		System: map[string]interface{}{
+			"goroutines": runtime.NumGoroutine(),
+			"memory_mb":  memStats.Alloc / 1024 / 1024,
+			"go_version": runtime.Version(),
+		},
+	}
+
+	if overallStatus == "unhealthy" {
+		c.Status(fiber.StatusServiceUnavailable)
+	}
+	return c.JSON(health)
+}
+
+func (s *Server) handleStats(c *fiber.Ctx) error {
+	return c.JSON(map[string]interface{}{
+		"cache":            s.cacheStatsPayload(),
+		"proxy":            s.resilient.GetProxyStats(),
+		"circuit_breakers": s.resilient.GetCircuitBreakerStats(),
+	})
+}
+
+func (s *Server) handleCacheStats(c *fiber.Ctx) error {
+	return c.JSON(s.cacheStatsPayload())
+}
+
+func (s *Server) handleProxyStats(c *fiber.Ctx) error {
+	return c.JSON(s.resilient.GetProxyStats())
+}
+
+func (s *Server) handleCircuitBreakerStats(c *fiber.Ctx) error {
+	return c.JSON(map[string]interface{}{
+		"circuit_breakers": s.resilient.GetCircuitBreakerStats(),
+	})
+}
+
 type MegaSearchResult struct {
 	SearchResult
 	Engine string `json:"engine"`
 }
 
-// handleMegaSearch handles the /megasearch endpoint
 func (s *Server) handleMegaSearch(c *fiber.Ctx) error {
-	q := Query{}
-	err := q.InitFromContext(c)
-	if err != nil {
-		logrus.Errorf("Error while setting megasearch query: %s", err)
-		return err
-	}
-
-	// Get engines parameter to filter which engines to use
-	enginesParam := c.Query("engines", "")
-	var enginesToUse []SearchEngine
-
-	if enginesParam != "" {
-		// Parse comma-separated list of engines
-		engineNames := strings.Split(enginesParam, ",")
-		for _, engineName := range engineNames {
-			engineName = strings.TrimSpace(strings.ToLower(engineName))
-			for _, engine := range s.searchEngines {
-				if strings.ToLower(engine.Name()) == engineName {
-					enginesToUse = append(enginesToUse, engine)
-					break
-				}
-			}
-		}
-	} else {
-		// Use all engines if no specific engines specified
-		enginesToUse = s.searchEngines
-	}
-
-	if len(enginesToUse) == 0 {
-		return fiber.NewError(fiber.StatusBadRequest, "No valid search engines specified")
-	}
-
-	// Log which engines will be used
-	engineNames := make([]string, len(enginesToUse))
-	for i, engine := range enginesToUse {
-		engineNames[i] = engine.Name()
-	}
-	logrus.Infof("Starting SERP megasearch request using engines: %s for query: %s", strings.Join(engineNames, ", "), q.Text)
-
-	// Execute searches in parallel across selected engines
-	results := s.searchSelectedEngines(q, enginesToUse)
-
-	// Deduplicate results while preserving engine information
-	dedupedResults := s.deduplicateMegaResults(results)
-
-	logrus.Infof("Successfully completed SERP megasearch using %d engines, returned %d deduplicated results", len(enginesToUse), len(dedupedResults))
-	return c.JSON(dedupedResults)
+	return s.handleMegaEndpoint(c, "search", s.resilient.SearchAllParallel)
 }
 
-// handleMegaImage handles the /mega/image endpoint
 func (s *Server) handleMegaImage(c *fiber.Ctx) error {
+	return s.handleMegaEndpoint(c, "image", s.resilient.SearchAllImageParallel)
+}
+
+func (s *Server) handleMegaEndpoint(c *fiber.Ctx, action string, run func(Query, []SearchEngine) []MegaSearchResult) error {
 	q := Query{}
-	err := q.InitFromContext(c)
-	if err != nil {
-		logrus.Errorf("Error while setting megasearch image query: %s", err)
+	if err := q.InitFromContext(c); err != nil {
+		logrus.Errorf("Error while setting mega %s query: %s", action, err)
 		return err
 	}
 
-	// Get engines parameter to filter which engines to use
-	enginesParam := c.Query("engines", "")
-	var enginesToUse []SearchEngine
-
-	if enginesParam != "" {
-		// Parse comma-separated list of engines
-		engineNames := strings.Split(enginesParam, ",")
-		for _, engineName := range engineNames {
-			engineName = strings.TrimSpace(strings.ToLower(engineName))
-			for _, engine := range s.searchEngines {
-				if strings.ToLower(engine.Name()) == engineName {
-					enginesToUse = append(enginesToUse, engine)
-					break
-				}
-			}
-		}
-	} else {
-		// Use all engines if no specific engines specified
-		enginesToUse = s.searchEngines
-	}
-
+	enginesToUse := s.resolveEngines(c.Query("engines", ""))
 	if len(enginesToUse) == 0 {
 		return fiber.NewError(fiber.StatusBadRequest, "No valid search engines specified")
 	}
 
-	// Log which engines will be used
 	engineNames := make([]string, len(enginesToUse))
 	for i, engine := range enginesToUse {
 		engineNames[i] = engine.Name()
 	}
-	logrus.Infof("Starting SERP megasearch image request using engines: %s for query: %s", strings.Join(engineNames, ", "), q.Text)
+	engineNamesJoined := strings.Join(engineNames, ",")
+	s.applyProxyHeaders(c, s.resilient.ResolveMegaProxyMeta(q, enginesToUse))
+	logrus.Infof("Starting SERP mega %s request using engines: %s for query: %s", action, engineNamesJoined, q.Text)
 
-	// Execute image searches in parallel across selected engines
-	results := s.searchSelectedEnginesImage(q, enginesToUse)
+	cacheHitCandidates := []cacheHitCandidate{
+		{
+			key:        s.buildMegaCacheKey(action, enginesToUse, q),
+			logMessage: fmt.Sprintf("Cache hit for mega %s: engines=%s query=%s", action, engineNamesJoined, q.Text),
+		},
+	}
+	cacheableEngines := s.megaCacheableEngines(enginesToUse)
+	if len(cacheableEngines) > 0 && len(cacheableEngines) < len(enginesToUse) {
+		cacheHitCandidates = append(cacheHitCandidates, cacheHitCandidate{
+			key:        s.buildMegaCacheKey(action, cacheableEngines, q),
+			logMessage: fmt.Sprintf("Cache hit for mega %s partial set: engines=%s query=%s", action, engineNamesJoined, q.Text),
+		})
+	}
+	if hit, err := s.tryServeCacheHit(c, cacheHitCandidates...); hit || err != nil {
+		return err
+	}
 
-	// Deduplicate results while preserving engine information
+	results := run(q, enginesToUse)
 	dedupedResults := s.deduplicateMegaResults(results)
 
-	logrus.Infof("Successfully completed SERP megasearch image using %d engines, returned %d deduplicated results", len(enginesToUse), len(dedupedResults))
+	if s.cache != nil {
+		c.Set("X-Cache", s.cacheMegaResults(action, enginesToUse, q, dedupedResults))
+	}
+
+	logrus.Infof("Successfully completed SERP mega %s using %d engines, returned %d deduplicated results", action, len(enginesToUse), len(dedupedResults))
 	return c.JSON(dedupedResults)
 }
 
-// handleListEngines lists all available search engines
 func (s *Server) handleListEngines(c *fiber.Ctx) error {
 	var engines []map[string]interface{}
 
 	for _, engine := range s.searchEngines {
-		engines = append(engines, map[string]interface{}{
+		engineInfo := map[string]interface{}{
 			"name":        engine.Name(),
 			"initialized": engine.IsInitialized(),
-		})
+		}
+
+		for _, cbStat := range s.resilient.GetCircuitBreakerStats() {
+			engineName, _ := cbStat["engine"].(string)
+			if engineName == engine.Name() {
+				engineInfo["circuit_state"] = cbStat["state"]
+				break
+			}
+		}
+
+		engines = append(engines, engineInfo)
 	}
 
 	return c.JSON(map[string]interface{}{
@@ -253,123 +391,178 @@ func (s *Server) handleListEngines(c *fiber.Ctx) error {
 	})
 }
 
-// searchSelectedEngines performs parallel searches across selected engines
-func (s *Server) searchSelectedEngines(q Query, engines []SearchEngine) []MegaSearchResult {
-	var wg sync.WaitGroup
-	var mu sync.Mutex
-	var allResults []MegaSearchResult
-
-	for _, engine := range engines {
-		wg.Add(1)
-		go func(eng SearchEngine) {
-			defer wg.Done()
-
-			// Apply rate limiting
-			limiter := eng.GetRateLimiter()
-			if limiter != nil {
-				err := limiter.Wait(context.Background())
-				if err != nil {
-					logrus.Errorf("Ratelimiter error during %s megasearch: %s", eng.Name(), err)
-				}
-			}
-
-			// Perform search
-			results, err := eng.Search(q)
-			if err != nil {
-				logrus.Errorf("Error during %s megasearch: %s", eng.Name(), err)
-				return
-			}
-
-			// Convert to MegaSearchResult with engine info
-			mu.Lock()
-			for _, result := range results {
-				megaResult := MegaSearchResult{
-					SearchResult: result,
-					Engine:       eng.Name(),
-				}
-				allResults = append(allResults, megaResult)
-			}
-			mu.Unlock()
-		}(engine)
+func (s *Server) resolveEngines(enginesParam string) []SearchEngine {
+	if enginesParam == "" {
+		return s.searchEngines
 	}
 
-	wg.Wait()
-	return allResults
-}
-
-// searchSelectedEnginesImage performs parallel image searches across selected engines
-func (s *Server) searchSelectedEnginesImage(q Query, engines []SearchEngine) []MegaSearchResult {
-	var wg sync.WaitGroup
-	var mu sync.Mutex
-	var allResults []MegaSearchResult
-
-	for _, engine := range engines {
-		wg.Add(1)
-		go func(eng SearchEngine) {
-			defer wg.Done()
-
-			// Apply rate limiting
-			limiter := eng.GetRateLimiter()
-			if limiter != nil {
-				err := limiter.Wait(context.Background())
-				if err != nil {
-					logrus.Errorf("Ratelimiter error during %s megasearch image: %s", eng.Name(), err)
-				}
+	var enginesToUse []SearchEngine
+	seen := make(map[string]bool)
+	engineNames := strings.Split(enginesParam, ",")
+	for _, engineName := range engineNames {
+		engineName = strings.TrimSpace(strings.ToLower(engineName))
+		if engineName == "" || seen[engineName] {
+			continue
+		}
+		for _, engine := range s.searchEngines {
+			if strings.ToLower(engine.Name()) == engineName {
+				enginesToUse = append(enginesToUse, engine)
+				seen[engineName] = true
+				break
 			}
-
-			// Perform image search
-			results, err := eng.SearchImage(q)
-			if err != nil {
-				logrus.Errorf("Error during %s megasearch image: %s", eng.Name(), err)
-				return
-			}
-
-			// Convert to MegaSearchResult with engine info
-			mu.Lock()
-			for _, result := range results {
-				megaResult := MegaSearchResult{
-					SearchResult: result,
-					Engine:       eng.Name(),
-				}
-				allResults = append(allResults, megaResult)
-			}
-			mu.Unlock()
-		}(engine)
+		}
 	}
-
-	wg.Wait()
-	return allResults
+	return enginesToUse
 }
 
-// deduplicateMegaResults deduplicates results while preserving engine information
 func (s *Server) deduplicateMegaResults(results []MegaSearchResult) []MegaSearchResult {
 	urlMap := make(map[string]MegaSearchResult)
 
-	// Process results and keep the first occurrence of each URL
 	for _, result := range results {
 		if result.URL == "" {
 			continue
 		}
-
 		if _, exists := urlMap[result.URL]; !exists {
 			urlMap[result.URL] = result
 		}
 	}
 
-	// Convert map back to slice and sort by rank
 	var deduped []MegaSearchResult
 	for _, result := range urlMap {
 		deduped = append(deduped, result)
 	}
 
-	// Sort by rank
 	sort.Slice(deduped, func(i, j int) bool {
 		return deduped[i].Rank < deduped[j].Rank
 	})
-
 	return deduped
 }
 
+type cacheHitCandidate struct {
+	key        string
+	logMessage string
+}
+
+func (s *Server) tryServeCacheHit(c *fiber.Ctx, candidates ...cacheHitCandidate) (bool, error) {
+	if s.cache == nil {
+		return false, nil
+	}
+	for _, candidate := range candidates {
+		cached, ok := s.cache.Get(candidate.key)
+		if !ok {
+			continue
+		}
+		c.Set("Content-Type", "application/json")
+		c.Set("X-Cache", "HIT")
+		logrus.Info(candidate.logMessage)
+		return true, c.Send(cached)
+	}
+	return false, nil
+}
+
+func (s *Server) cacheJSON(cacheKey string, payload interface{}) bool {
+	if s.cache == nil {
+		return false
+	}
+	data, err := json.Marshal(payload)
+	if err != nil {
+		s.cache.RecordBypass()
+		return false
+	}
+	s.cache.Set(cacheKey, data)
+	return true
+}
+
+func (s *Server) cacheMegaResults(action string, enginesToUse []SearchEngine, q Query, dedupedResults []MegaSearchResult) string {
+	cacheStatus := "BYPASS"
+	if s.cache == nil {
+		return cacheStatus
+	}
+	if len(dedupedResults) == 0 {
+		s.cache.RecordBypass()
+		return cacheStatus
+	}
+
+	cacheEngines := s.megaCacheableEngines(enginesToUse)
+	if len(cacheEngines) == 0 {
+		s.cache.RecordBypass()
+		return cacheStatus
+	}
+
+	if s.cacheJSON(s.buildMegaCacheKey(action, cacheEngines, q), dedupedResults) {
+		return "MISS"
+	}
+	return cacheStatus
+}
+
+func (s *Server) buildMegaCacheKey(action string, engines []SearchEngine, q Query) string {
+	names := make([]string, 0, len(engines))
+	for _, eng := range engines {
+		names = append(names, strings.ToLower(strings.TrimSpace(eng.Name())))
+	}
+	sort.Strings(names)
+
+	// Deduplicate engine names in key to keep cache stable when order differs
+	// or repeated names are passed in the engines query parameter.
+	uniq := names[:0]
+	last := ""
+	for _, name := range names {
+		if name == last {
+			continue
+		}
+		uniq = append(uniq, name)
+		last = name
+	}
+
+	return BuildCacheKey("mega:"+strings.Join(uniq, ","), action, q)
+}
+
+func (s *Server) megaCacheableEngines(engines []SearchEngine) []SearchEngine {
+	open := make(map[string]bool)
+	for _, stat := range s.resilient.GetCircuitBreakerStats() {
+		name, _ := stat["engine"].(string)
+		state, _ := stat["state"].(string)
+		if strings.EqualFold(state, "open") {
+			open[strings.ToLower(strings.TrimSpace(name))] = true
+		}
+	}
+
+	cacheable := make([]SearchEngine, 0, len(engines))
+	for _, eng := range engines {
+		if open[strings.ToLower(strings.TrimSpace(eng.Name()))] {
+			continue
+		}
+		cacheable = append(cacheable, eng)
+	}
+	return cacheable
+}
+
+func (s *Server) cacheStatsPayload() interface{} {
+	if s.cache == nil {
+		return map[string]interface{}{"status": false}
+	}
+	return s.cache.Stats()
+}
+
+func (s *Server) applyProxyHeaders(c *fiber.Ctx, meta ProxyExecutionMeta) {
+	mode := meta.Mode
+	if mode == "" {
+		mode = ProxyModeOff
+	}
+
+	tag := meta.Tag
+	used := meta.Used
+
+	if mode == ProxyModeOff {
+		tag = ""
+		used = "direct"
+	}
+
+	c.Set("X-Proxy-Mode", mode)
+	c.Set("X-Proxy-Tag", tag)
+	c.Set("X-Proxy-Used", used)
+}
+
 func (s *Server) Listen() error {
 	return s.app.Listen(s.addr)
 }

docker-compose.yaml

@@ -9,10 +9,10 @@ services:
       - 7000:7000
     command: serve -l
     #volumes:
-    #  - ./config.yaml:/usr/src/app/config.yaml
+    #  - ./config.yaml:/usr/src/app/config.yaml:ro
     environment:
-      OPENSERP_APP_HOST: "0.0.0.0"
-      OPENSERP_APP_PORT: 7000
+      OPENSERP_SERVER_HOST: "0.0.0.0"
+      OPENSERP_SERVER_PORT: 7000
       OPENSERP_BAIDU_RATE_REQUESTS: 6   # Number of requests per Minute
       OPENSERP_BAIDU_RATE_BURST: 2      # Number of non-ratelimited requests per Minute
-    
+    

go.mod

@@ -22,6 +22,7 @@ require (
 require (
 	github.com/andybalholm/brotli v1.2.0 // indirect
 	github.com/andybalholm/cascadia v1.3.3 // indirect
+	github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 // indirect
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect

go.sum

@@ -6,6 +6,8 @@ github.com/andybalholm/brotli v1.2.0 h1:ukwgCxwYrmACq68yiUqwIWnGY0cTPox/M94sVwTo
 github.com/andybalholm/brotli v1.2.0/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
 github.com/andybalholm/cascadia v1.3.3 h1:AG2YHrzJIm4BZ19iwJ/DAua6Btl3IwJX+VI4kktS1LM=
 github.com/andybalholm/cascadia v1.3.3/go.mod h1:xNd9bqTn98Ln4DwST8/nG+H0yuB8Hmgu1YHNnWw0GeA=
+github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
+github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
 github.com/corpix/uarand v0.2.0 h1:U98xXwud/AVuCpkpgfPF7J5TQgr7R5tqT8VZP5KWbzE=
 github.com/corpix/uarand v0.2.0/go.mod h1:/3Z1QIqWkDIhf6XWn/08/uMHoQ8JUoTIKc2iPchBOmM=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=

google/search.go

@@ -113,9 +113,11 @@ func (gogl *Google) checkCaptcha(page *rod.Page) bool {
 
 func (gogl *Google) preparePage(page *rod.Page) {
 	// Remove "similar queries" lists
-	_, err := page.Eval(";(() => { document.querySelectorAll(`div[data-initq]`).forEach( el => el.remove());  })();")
+	_, err := page.Eval(`() => {
+		document.querySelectorAll("div[data-initq]").forEach((el) => el.remove())
+	}`)
 	if err != nil {
-		gogl.logger.Error("Page preparation failed: %s", err)
+		gogl.logger.Debug("Page preparation skipped: %s", err)
 	}
 }
 
@@ -185,7 +187,7 @@ func (gogl *Google) Search(query core.Query) ([]core.SearchResult, error) {
 		return nil, err
 	}
 
-	rank := 0
+	rank := query.Start
 	for _, resEl := range searchResultElems {
 		srchRes := core.SearchResult{}
 

google/search_raw.go

@@ -1,64 +1,19 @@
 package google
 
 import (
-	"context"
-	"crypto/tls"
-	"net"
 	"net/http"
-	"net/url"
 	"strings"
-	"time"
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/corpix/uarand"
 	"github.com/karust/openserp/core"
 	"github.com/sirupsen/logrus"
-
-	utls "github.com/refraction-networking/utls"
 )
 
 func googleRequest(searchURL string, query core.Query) (*http.Response, error) {
-	// Create HTTP transport with proxy
-	transport := &http.Transport{}
-	if query.ProxyURL != "" {
-		proxyUrl, err := url.Parse(query.ProxyURL)
-		if err != nil {
-			return nil, err
-		}
-		transport.Proxy = http.ProxyURL(proxyUrl)
-	}
-
-	// Set insecure TLS
-	if query.Insecure {
-		transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-	}
-
-	transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-		dialer := &net.Dialer{}
-		rawConn, err := dialer.DialContext(ctx, network, addr)
-		if err != nil {
-			return nil, err
-		}
-
-		hostname := strings.Split(addr, ":")[0]
-		config := &utls.Config{
-			ServerName:         hostname,
-			InsecureSkipVerify: query.Insecure,
-		}
-
-		uconn := utls.UClient(rawConn, config, utls.HelloChrome_Auto)
-
-		if err := uconn.Handshake(); err != nil {
-			rawConn.Close()
-			return nil, err
-		}
-
-		return uconn, nil
-	}
-
-	baseClient := &http.Client{
-		Transport: transport,
-		Timeout:   time.Second * 10,
+	baseClient, err := core.NewRawHTTPClient(query)
+	if err != nil {
+		return nil, err
 	}
 
 	req, err := http.NewRequest("GET", searchURL, nil)
@@ -162,6 +117,12 @@ func Search(query core.Query) ([]core.SearchResult, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	if query.Start > 0 {
+		for i := range results {
+			results[i].Rank = query.Start + i + 1
+		}
+	}
 	logrus.Debugf("Google Raw results : %v", results)
 
 	return results, nil

google/search_test.go

@@ -2,32 +2,8 @@ package google
 
 import (
 	"testing"
-	"time"
-
-	"github.com/karust/openserp/core"
 )
 
-var browser *core.Browser
-
-func init() {
-	opts := core.BrowserOpts{IsHeadless: true, IsLeakless: false, Timeout: time.Second * 5, LeavePageOpen: false}
-	browser, _ = core.NewBrowser(opts)
-}
-
-func TestSearchGoogle(t *testing.T) {
-	gogl := New(*browser, core.SearchEngineOptions{})
-
-	query := core.Query{Text: "HEY", Limit: 10}
-	results, err := gogl.Search(query)
-	if err != nil {
-		t.Fatalf("Cannot [SearchGoogle]: %s", err)
-	}
-
-	if len(results) == 0 {
-		t.Fatalf("[SearchGoogle] returned empty result")
-	}
-}
-
 func TestParseSourceImageURL(t *testing.T) {
 	//href1 := `/imgres?imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F26%2FMarmota_marmota_Alpes2.jpg&tbnid=Be_RycOe8xzlpM&vet=12ahUKEwjkh6WzwIeAAxWV_yoKHRzHC9wQMygAegUIARD0AQ..i&imgrefurl=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FAlpine_marmot&docid=7miWbc2QiSw9uM&w=801&h=599&q=alpine%20marmot&ved=2ahUKEwjkh6WzwIeAAxWV_yoKHRzHC9wQMygAegUIARD0AQ`
 	href2 := `/imgres?imgurl=https%3A%2F%2Fstatic.wikia.nocookie.net%2Fnaturerules1%2Fimages%2Ff%2Ff2%2F13d79d934ccf6f7919777fcb6dbb6e6c.jpg%2Frevision%2Flatest%3Fcb%3D20210218225522&tbnid=JxC8NUyBjdNbdM&vet=12ahUKEwiHrJnN1YeAAxXvEBAIHfRADAAQMygCegUIARD4AQ..i&imgrefurl=https%3A%2F%2Fnaturerules1.fandom.com%2Fwiki%2FAlpine_Marmot&docid=XXYeDjL67badNM&w=1600&h=1200&q=alpine%20marmot&ved=2ahUKEwiHrJnN1YeAAxXvEBAIHfRADAAQMygCegUIARD4AQ`
@@ -47,21 +23,3 @@ func TestParseSourceImageURL(t *testing.T) {
 		t.Fatalf("Want: %v, Got: %v", want, got)
 	}
 }
-
-func TestImageSearch(t *testing.T) {
-	gogl := New(*browser, core.SearchEngineOptions{})
-	query := core.Query{Text: "Ferrari Testarossa", Limit: 77}
-	results, err := gogl.SearchImage(query)
-
-	if err != nil {
-		t.Fatalf("Cannot search images: %s", err)
-	}
-
-	if len(results) < 77 {
-		t.Fatalf("Returned not full result")
-	}
-
-	if results[0].URL == "" {
-		t.Fatalf("First result doesn't contain URL, %v+", results[0])
-	}
-}

google/url.go

@@ -259,6 +259,19 @@ func BuildURL(q core.Query) (string, error) {
 		params.Add("num", strconv.Itoa(q.Limit))
 	}
 
+	// Set result offset for pagination
+	if q.Start < 0 {
+		return "", errors.New("incorrect start param provided")
+	}
+	if q.Start > 0 {
+		params.Add("start", strconv.Itoa(q.Start))
+	}
+
+	// Google default is filter=1; send only when user asks to include similar results.
+	if !q.Filter {
+		params.Add("filter", "0")
+	}
+
 	if q.LangCode != "" {
 		params.Add("hl", q.LangCode)
 		params.Add("lr", "lang_"+strings.ToLower(q.LangCode))

testutil/integration.go

@@ -0,0 +1,25 @@
+package testutil
+
+import (
+	"os"
+	"strings"
+	"testing"
+)
+
+const IntegrationEnv = "OPENSERP_INTEGRATION_TESTS"
+
+func RequireIntegration(t *testing.T) {
+	t.Helper()
+	if strings.TrimSpace(os.Getenv(IntegrationEnv)) != "1" {
+		t.Skipf("set %s=1 to run integration tests", IntegrationEnv)
+	}
+}
+
+func RequireEnv(t *testing.T, key string) string {
+	t.Helper()
+	value := strings.TrimSpace(os.Getenv(key))
+	if value == "" {
+		t.Skipf("set %s to run this integration test", key)
+	}
+	return value
+}

yandex/search.go

@@ -115,9 +115,17 @@ func (yand *Yandex) parseResults(results rod.Elements, pageNum int) []core.Searc
 
 func (yand *Yandex) Search(query core.Query) ([]core.SearchResult, error) {
 	yand.logger.Debug("Starting search, query: %+v", query)
+	if query.Start < 0 {
+		return nil, fmt.Errorf("incorrect start provided")
+	}
 
 	allResults := []core.SearchResult{}
-	searchPage := 0
+	const pageSize = 10
+	searchPage, skipOnFirstPage, err := core.ComputePagination(query.Start, pageSize)
+	if err != nil {
+		return nil, err
+	}
+	startPage := searchPage
 
 	for len(allResults) < query.Limit {
 		url, err := BuildURL(query, searchPage)
@@ -158,6 +166,13 @@ func (yand *Yandex) Search(query core.Query) ([]core.SearchResult, error) {
 		}
 
 		r := yand.parseResults(elements, searchPage)
+		if searchPage == startPage && skipOnFirstPage > 0 {
+			if skipOnFirstPage >= len(r) {
+				r = []core.SearchResult{}
+			} else {
+				r = r[skipOnFirstPage:]
+			}
+		}
 		allResults = append(allResults, r...)
 
 		searchPage++

yandex/search_raw.go

@@ -1,64 +1,19 @@
 package yandex
 
 import (
-	"context"
-	"crypto/tls"
-	"net"
 	"net/http"
-	"net/url"
 	"strings"
-	"time"
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/corpix/uarand"
 	"github.com/karust/openserp/core"
 	"github.com/sirupsen/logrus"
-
-	utls "github.com/refraction-networking/utls"
 )
 
 func yandexRequest(searchURL string, query core.Query) (*http.Response, error) {
-	// Create HTTP transport with proxy
-	transport := &http.Transport{}
-	if query.ProxyURL != "" {
-		proxyUrl, err := url.Parse(query.ProxyURL)
-		if err != nil {
-			return nil, err
-		}
-		transport.Proxy = http.ProxyURL(proxyUrl)
-	}
-
-	// Set insecure TLS
-	if query.Insecure {
-		transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-	}
-
-	transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-		dialer := &net.Dialer{}
-		rawConn, err := dialer.DialContext(ctx, network, addr)
-		if err != nil {
-			return nil, err
-		}
-
-		hostname := strings.Split(addr, ":")[0]
-		config := &utls.Config{
-			ServerName:         hostname,
-			InsecureSkipVerify: query.Insecure,
-		}
-
-		uconn := utls.UClient(rawConn, config, utls.HelloChrome_Auto)
-
-		if err := uconn.Handshake(); err != nil {
-			rawConn.Close()
-			return nil, err
-		}
-
-		return uconn, nil
-	}
-
-	baseClient := &http.Client{
-		Transport: transport,
-		Timeout:   time.Second * 10,
+	baseClient, err := core.NewRawHTTPClient(query)
+	if err != nil {
+		return nil, err
 	}
 
 	req, err := http.NewRequest("GET", searchURL, nil)
@@ -120,7 +75,12 @@ func yandexResultParser(response *http.Response) ([]core.SearchResult, error) {
 }
 
 func Search(query core.Query) ([]core.SearchResult, error) {
-	googleURL, err := BuildURL(query, 1)
+	startPage, skipOnFirstPage, err := core.ComputePagination(query.Start, 10)
+	if err != nil {
+		return nil, err
+	}
+
+	googleURL, err := BuildURL(query, startPage)
 	if err != nil {
 		return nil, err
 	}
@@ -136,6 +96,19 @@ func Search(query core.Query) ([]core.SearchResult, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	if skipOnFirstPage > 0 {
+		if skipOnFirstPage >= len(results) {
+			results = []core.SearchResult{}
+		} else {
+			results = results[skipOnFirstPage:]
+		}
+	}
+	if query.Start > 0 {
+		for i := range results {
+			results[i].Rank = query.Start + i + 1
+		}
+	}
 	logrus.Debugf("Yandex Raw results : %v", results)
 
 	return results, nil