Files
personamanagmentlayer__pcl/stdlib/ai/ai-engineer-expert/SKILL.md
ANGX 4e07a6a874 feat(stdlib)!: Agent Skills v1.0 conformance, resolver fix, and 17 new skills (#43)
* chore(stdlib): add conformance tooling for the skills library

The library had no gate that could express what a valid skill is, so
malformed frontmatter, over-budget files and credential literals went
unnoticed. These scripts define and enforce that contract.

- validate-skills.py: extend with Agent Skills v1.0 conformance -
  naming rules and directory agreement, an explicit activation trigger
  in the description, canonical layout, the 500-line SKILL.md budget,
  relative-link integrity, and two security rules (no unrestricted
  Bash(*) grant, no credential literals). Structural checks now read a
  skill as a whole so material moved into references/ still counts.
- split-skill-references.py: move the heaviest sections of an oversized
  SKILL.md into references/. Verifies line by line that every source
  line lands in exactly one output and refuses to write otherwise.
- generate-skill-inventory.py: derive SKILLS_INVENTORY.md and
  DIRECTORY_STRUCTURE.md from the tree so they cannot drift.
- generate-skill-catalog.py: index the canonical layout only, count
  references/ toward a skill's size, and stop truncating descriptions
  at 200 characters - the catalog is the discovery surface and must
  carry the activation trigger.
- .gitignore: Python bytecode from these scripts, and local .pcl state.

Reviewed-by: Security Analyst, Compiler Engineer, DevX Engineer

* fix(stdlib): bring all 174 skills to Agent Skills v1.0 conformance

No skill in the library was conformant. 41 of 175 failed the existing
validator outright, and none satisfied the spec. This pass fixes the
tree and records the result. See stdlib/CHANGELOG.md for the per-skill
versioning and migration notes.

BREAKING CHANGE: one skill removed, five moved, seven with a capability
withdrawn. Library version 2.0.0 -> 3.0.0.

Structure
- Convert 71 skills stored as flat files to <category>/<name>/SKILL.md,
  the layout the spec requires and the only one able to carry companion
  resources.
- Rename 5 directories that disagreed with their declared name:, so
  resolution by path and by name stop giving different answers. The
  repository docs already referenced the corrected paths.
- Merge the duplicate legal-technology skills into legaltech-expert and
  delete legal-tech-expert, carrying over everything the survivor
  lacked.

Metadata
- Repair 20 unparseable frontmatters: an H1 preceded the --- block and
  the key was skill_id: instead of name:, so any parser reading
  frontmatter at offset 0 saw no metadata at all. The objectives,
  prerequisites and outcome they carried become real body sections.
- Add the missing version: to 21 skills, fold keywords into tags, move
  expertise_level under metadata, and align 10 category: values with
  their directory.

Discoverability
- Give all 174 descriptions an explicit "Use when ..." trigger, built
  from each skill's own tags and section headings. 152 previously said
  only what the skill was about, leaving an agent nothing to match on.

Progressive disclosure
- Split 127 oversized skills, moving bulk material into references/ read
  on demand and leaving an index behind. A SKILL.md now averages 277
  lines instead of 644 and none exceeds 500. Verified lossless line by
  line against the previous revision.

Security
- Withdraw the unrestricted Bash(*) grant from 7 skills; none of the six
  non-financial ones contained a single shell command. finance-expert
  documents code that charges cards and reads bank accounts, so it now
  grants no shell at all.
- Remove credential literals: Stripe keys, two JWT signing keys, an
  Express session secret, a Redis password and WiFi credentials, all
  inlined in examples. They load from the environment now.
- finance-expert: idempotency keys were documented but absent, so a
  retry double-charged; webhook signature failures were not caught, so a
  forged event raised uncaught instead of being rejected;
  int(amount * 100) truncated fractions of a cent. All fixed, plus a
  money-movement guardrails section.
- trading-expert: place_order routed without any pre-trade risk check
  although a RiskManager sat unused in the next section. Risk validation
  now runs before routing and raises rather than returning a boolean a
  caller can ignore; live routing is opt-in.
- Correct an Ansible Vault example that showed plaintext under an
  "encrypted" label.

Also fixes 8 broken documentation links and a prematurely closed code
fence in skill-creator-expert that leaked template content into prose.

Per the repository file-organization policy, four stale progress reports
(SKILLS_MANIFEST, COMPLETE_SKILLS_LIBRARY, COMPLETE_LIBRARY_MANIFEST,
PHASE_3_DATA_ANALYTICS) move out of stdlib/ into the gitignored
.roadmap/status/stdlib/; they claimed 31 of 100 skills complete. They
appear here as deletions because .roadmap/ is not tracked.

Reviewed-by: Security Analyst, Language Designer, DevX Engineer,
             Documentation Specialist

* fix(skills): resolve standard library skills from their real layout

No stdlib skill was resolvable. SkillResolver looked for
`<stdlibDir>/<name>.md` with stdlibDir defaulting to `stdlib/skills`, a
directory that does not exist, and the path ignored the category level
the library actually uses. The two LSP providers had the same wrong
directory and scanned only one level deep, so neither completion nor
go-to-definition could see a skill either.

- skill-discovery.ts: enumerate skill entry points across the shapes in
  use - a flat `<name>.md`, `<name>/SKILL.md`, and
  `<category>/<name>/SKILL.md` - while skipping references/, scripts/
  and assets/, which hold supporting material rather than entry points.
- skill-resolver.ts: point stdlibDir at `stdlib`, and look the name up
  as a directory under any category as well as the two legacy shapes, so
  existing custom stdlib directories keep working. The name is used as a
  single path segment and rejected if it contains a separator or
  traversal, so a reference cannot escape the stdlib root.
- Rewire both LSP providers onto the shared discovery helper.

Tests: 13 new cases covering the layouts, ordering, the references/
exclusion, path-traversal rejection, and an integration test that
resolves real shipped skills by bare name.

Reviewed-by: Compiler Engineer, Runtime Architect, Security Analyst

* feat(stdlib): add 17 skills covering the library's largest gaps

Selection was driven by cross-referencing coverage against observed usage
rather than by intuition: Stack Overflow and GitHub Octoverse data for
which technologies matter, and install rankings on public agent-skill
registries for the shape of skills people actually use.

That comparison found a mismatch of form, not only of coverage. The
most-installed skills in the ecosystem are procedures - tdd, refactoring,
frontend design, browser automation - while all 174 existing skills were
domain knowledge shaped as <domain>-expert. The new workflows/ category
closes that gap and introduces the <activity>-workflow convention.

New category workflows/ (4)
- tdd-workflow, refactoring-workflow, debugging-workflow,
  code-review-workflow. code-review-workflow complements rather than
  replaces code-review-expert: procedure versus judgement. Merge them if
  the split proves confusing in use.

Applied AI (3) - the largest coverage gap
- llm-engineering-expert, rag-expert, agent-engineering-expert.
  The library referenced LLMs in tags but covered none of it: pgvector
  appeared zero times across 174 skills, LangChain once, MCP twice
  despite the repository shipping an MCP integration guide.

Capabilities (2)
- document-processing-expert (PDF, DOCX, XLSX, PPTX in one skill),
  browser-automation-expert (a client against third-party sites,
  distinct from playwright-expert which tests your own application).

Data (3)
- mysql-expert, the second most used database and previously absent
  while rarer stores had skills; analytical-databases-expert;
  stream-processing-expert.

Security (3)
- secrets-management-expert, supply-chain-security-expert (OWASP A03
  2025), identity-access-expert (OWASP A01).

Interface and meta (2)
- accessibility-expert: design/ held only design-expert, which despite
  its name covers software architecture, so WCAG had no home.
- skill-router: find and compose skills across 191, with a
  disambiguation table for overlapping pairs.

Grouping by decision context rather than by technology keeps the growth
to 17 skills for roughly 50 topics. Five vector stores live inside
rag-expert; four document formats inside document-processing-expert.
Per-tool depth sits in references/, which the progressive-disclosure work
in 3.0.0 made cheap.

Four further gaps are better served by extending existing skills -
PyTorch and TensorFlow in ml-expert, OpenTelemetry in monitoring-expert,
Pulumi and Crossplane in terraform-expert - and are not in this change.

Library 3.0.0 -> 3.1.0, additive only. Adds the workflows label to the
inventory generator; catalogue, inventory, structure and CHANGELOG
regenerated.

Reviewed-by: Product Strategist, Security Analyst, DevX Engineer,
             Documentation Specialist

* fix(test): create test directories with mkdtempSync

CodeQL flagged js/insecure-temporary-file (CWE-377) on both suites.
`join(tmpdir(), <predictable name>)` followed by mkdirSync creates a
world-readable directory at a guessable path, so another local user can
pre-create it or plant a symlink between the name being computed and the
directory being created.

mkdtempSync creates the directory atomically with a random suffix and
0700 permissions, which closes both the disclosure and the race.

One occurrence is new in this branch (skill-discovery); the other
pre-dates it in skill-resolver and is fixed in the same pass rather than
left as a known finding in a file this branch already touches.
2026-09-05 04:35:30 +02:00

13 KiB

name, version, description, category, tags, allowed-tools
name version description category tags allowed-tools
ai-engineer-expert 1.1.0 Expert-level AI implementation, deployment, LLM integration, and production AI systems. Use when the user mentions AI engineering, LLM, deployment, production AI, or integration, or when the task involves LLM Patterns, LLM Integration, or Production Systems. ai
ai-engineering
llm
deployment
production-ai
integration
Read
Write
Edit
Bash(python:*)

AI Engineer Expert

Expert guidance for implementing AI systems, LLM integration, prompt engineering, and deploying production AI applications.

Core Concepts

AI Engineering

  • LLM integration and orchestration
  • Prompt engineering and optimization
  • RAG (Retrieval-Augmented Generation)
  • Vector databases and embeddings
  • Fine-tuning and adaptation
  • AI agent systems

Production AI

  • Model deployment strategies
  • API design for AI services
  • Rate limiting and cost control
  • Error handling and fallbacks
  • Monitoring and logging
  • Security and safety

LLM Patterns

  • Chain-of-thought prompting
  • Few-shot learning
  • System/user message design
  • Function calling and tools
  • Streaming responses
  • Context window management

LLM Integration

from openai import AsyncOpenAI
from anthropic import Anthropic
from typing import List, Dict, Optional
import asyncio

class LLMClient:
    """Unified LLM client with fallback"""

    def __init__(self, primary: str = "openai", fallback: str = "anthropic"):
        self.openai_client = AsyncOpenAI()
        self.anthropic_client = Anthropic()
        self.primary = primary
        self.fallback = fallback

    async def chat_completion(self, messages: List[Dict],
                              model: str = "gpt-4-turbo",
                              temperature: float = 0.7,
                              max_tokens: int = 1000) -> str:
        """Chat completion with fallback"""
        try:
            if self.primary == "openai":
                response = await self.openai_client.chat.completions.create(
                    model=model,
                    messages=messages,
                    temperature=temperature,
                    max_tokens=max_tokens
                )
                return response.choices[0].message.content

        except Exception as e:
            print(f"Primary provider failed: {e}, trying fallback")

            if self.fallback == "anthropic":
                response = self.anthropic_client.messages.create(
                    model="claude-3-5-sonnet-20241022",
                    messages=messages,
                    temperature=temperature,
                    max_tokens=max_tokens
                )
                return response.content[0].text

    async def chat_completion_streaming(self, messages: List[Dict],
                                       model: str = "gpt-4-turbo"):
        """Streaming chat completion"""
        stream = await self.openai_client.chat.completions.create(
            model=model,
            messages=messages,
            stream=True
        )

        async for chunk in stream:
            if chunk.choices[0].delta.content:
                yield chunk.choices[0].delta.content

    async def function_calling(self, messages: List[Dict],
                              tools: List[Dict]) -> Dict:
        """Function calling with tools"""
        response = await self.openai_client.chat.completions.create(
            model="gpt-4-turbo",
            messages=messages,
            tools=tools,
            tool_choice="auto"
        )

        message = response.choices[0].message

        if message.tool_calls:
            return {
                "type": "function_call",
                "function": message.tool_calls[0].function.name,
                "arguments": message.tool_calls[0].function.arguments
            }
        else:
            return {
                "type": "message",
                "content": message.content
            }

RAG Implementation

from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_openai import OpenAIEmbeddings
from langchain_community.vectorstores import Chroma
from langchain.chains import RetrievalQA
from langchain_openai import ChatOpenAI

class RAGSystem:
    """Retrieval-Augmented Generation system"""

    def __init__(self, persist_directory: str = "./chroma_db"):
        self.embeddings = OpenAIEmbeddings()
        self.vectorstore = None
        self.persist_directory = persist_directory
        self.llm = ChatOpenAI(model="gpt-4-turbo", temperature=0)

    def ingest_documents(self, documents: List[str]):
        """Ingest and index documents"""
        # Split documents into chunks
        text_splitter = RecursiveCharacterTextSplitter(
            chunk_size=1000,
            chunk_overlap=200
        )
        chunks = text_splitter.create_documents(documents)

        # Create vector store
        self.vectorstore = Chroma.from_documents(
            documents=chunks,
            embedding=self.embeddings,
            persist_directory=self.persist_directory
        )

    def query(self, question: str, k: int = 4) -> Dict:
        """Query with RAG"""
        if not self.vectorstore:
            raise ValueError("No documents ingested")

        # Retrieve relevant documents
        retriever = self.vectorstore.as_retriever(
            search_kwargs={"k": k}
        )

        # Create QA chain
        qa_chain = RetrievalQA.from_chain_type(
            llm=self.llm,
            chain_type="stuff",
            retriever=retriever,
            return_source_documents=True
        )

        # Get answer
        result = qa_chain({"query": question})

        return {
            "answer": result["result"],
            "sources": [doc.page_content for doc in result["source_documents"]]
        }

    def similarity_search(self, query: str, k: int = 4) -> List[Dict]:
        """Similarity search in vector database"""
        results = self.vectorstore.similarity_search_with_score(query, k=k)

        return [
            {
                "content": doc.page_content,
                "score": score,
                "metadata": doc.metadata
            }
            for doc, score in results
        ]

Prompt Engineering

class PromptTemplate:
    """Advanced prompt templates"""

    @staticmethod
    def chain_of_thought(question: str) -> str:
        """Chain-of-thought prompting"""
        return f"""Let's solve this step by step:

Question: {question}

Please think through this problem carefully:
1. First, identify what we need to find
2. Then, break down the problem into smaller steps
3. Solve each step
4. Finally, combine the results

Your step-by-step solution:"""

    @staticmethod
    def few_shot(task: str, examples: List[Dict], query: str) -> str:
        """Few-shot learning prompt"""
        examples_text = "\n\n".join([
            f"Input: {ex['input']}\nOutput: {ex['output']}"
            for ex in examples
        ])

        return f"""Task: {task}

Here are some examples:

{examples_text}

Now, please solve this:

Input: {query}
Output:"""

    @staticmethod
    def system_message(role: str, constraints: List[str],
                       format_instructions: str) -> str:
        """System message template"""
        constraints_text = "\n".join([f"- {c}" for c in constraints])

        return f"""You are a {role}.

Constraints:
{constraints_text}

Output Format:
{format_instructions}

Remember to follow these guidelines strictly."""

AI Agent System

from typing import Callable
import json

class Tool:
    """Tool that agents can use"""

    def __init__(self, name: str, description: str, function: Callable):
        self.name = name
        self.description = description
        self.function = function

    def to_openai_function(self) -> Dict:
        """Convert to OpenAI function format"""
        return {
            "type": "function",
            "function": {
                "name": self.name,
                "description": self.description,
                "parameters": self.get_parameters()
            }
        }

class AIAgent:
    """AI agent with tools"""

    def __init__(self, llm_client: LLMClient, tools: List[Tool]):
        self.llm = llm_client
        self.tools = {tool.name: tool for tool in tools}
        self.conversation_history = []

    async def run(self, user_input: str, max_iterations: int = 10) -> str:
        """Run agent with tool use"""
        self.conversation_history.append({
            "role": "user",
            "content": user_input
        })

        for i in range(max_iterations):
            # Get LLM response with function calling
            response = await self.llm.function_calling(
                messages=self.conversation_history,
                tools=[tool.to_openai_function() for tool in self.tools.values()]
            )

            if response["type"] == "message":
                # Agent is done
                return response["content"]

            # Execute tool
            tool_name = response["function"]
            arguments = json.loads(response["arguments"])

            tool_result = await self.execute_tool(tool_name, arguments)

            # Add tool result to conversation
            self.conversation_history.append({
                "role": "function",
                "name": tool_name,
                "content": str(tool_result)
            })

        return "Max iterations reached"

    async def execute_tool(self, tool_name: str, arguments: Dict) -> any:
        """Execute a tool"""
        if tool_name not in self.tools:
            raise ValueError(f"Tool {tool_name} not found")

        tool = self.tools[tool_name]
        return await tool.function(**arguments)

Production Deployment

from fastapi import FastAPI, HTTPException, Depends
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from circuitbreaker import circuit
import asyncio

app = FastAPI()

class ChatRequest(BaseModel):
    messages: List[Dict]
    model: str = "gpt-4-turbo"
    stream: bool = False

class RateLimiter:
    """Rate limiter for API"""

    def __init__(self, max_requests: int, window_seconds: int):
        self.max_requests = max_requests
        self.window_seconds = window_seconds
        self.requests = {}

    async def check_limit(self, user_id: str) -> bool:
        """Check if user is within rate limit"""
        import time
        now = time.time()

        if user_id not in self.requests:
            self.requests[user_id] = []

        # Remove old requests
        self.requests[user_id] = [
            req_time for req_time in self.requests[user_id]
            if now - req_time < self.window_seconds
        ]

        if len(self.requests[user_id]) >= self.max_requests:
            return False

        self.requests[user_id].append(now)
        return True

rate_limiter = RateLimiter(max_requests=100, window_seconds=60)
llm_client = LLMClient()

@circuit(failure_threshold=5, recovery_timeout=60)
async def call_llm(messages: List[Dict]) -> str:
    """LLM call with circuit breaker"""
    return await llm_client.chat_completion(messages)

@app.post("/chat")
async def chat(request: ChatRequest, user_id: str = Depends(get_user_id)):
    """Chat endpoint with rate limiting"""
    # Check rate limit
    if not await rate_limiter.check_limit(user_id):
        raise HTTPException(status_code=429, detail="Rate limit exceeded")

    try:
        if request.stream:
            async def generate():
                async for chunk in llm_client.chat_completion_streaming(request.messages):
                    yield chunk

            return StreamingResponse(generate(), media_type="text/event-stream")
        else:
            response = await call_llm(request.messages)
            return {"response": response}

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

Best Practices

LLM Integration

  • Implement fallback providers
  • Use streaming for better UX
  • Cache responses where appropriate
  • Handle rate limits gracefully
  • Monitor token usage and costs
  • Version prompts and track changes

Production Systems

  • Implement circuit breakers
  • Add comprehensive logging
  • Monitor latency and errors
  • Use rate limiting
  • Implement retry logic with backoff
  • Test edge cases thoroughly

Security

  • Validate and sanitize inputs
  • Implement authentication/authorization
  • Never expose API keys in logs
  • Use environment variables for secrets
  • Implement content filtering
  • Monitor for prompt injection

Anti-Patterns

❌ No error handling or fallbacks ❌ Exposing raw LLM outputs without validation ❌ No rate limiting or cost controls ❌ Storing API keys in code ❌ No monitoring or logging ❌ Ignoring token limits ❌ No testing of prompts

Resources