Files
Ben Taylor 9df63beeef fix(runtime): name useSingleEndpoint when a single-route envelope hits a multi-route runtime (#6579)
Closes
[OSS-882](https://linear.app/copilotkit/issue/OSS-882/add-to-existing-journeys-reach-for-the-v1-compat-copilotkit-wrapper).

## The failure

The v1-compatible `<CopilotKit>` provider pins `useSingleEndpoint` to
`true`
([`copilotkit.tsx:108`](https://github.com/CopilotKit/CopilotKit/blob/main/packages/react-core/src/components/copilot-provider/copilotkit.tsx#L108)),
so its startup handshake POSTs `{ method: "info" }` at the base path. A
multi-route runtime — the default — matches no route for that path and
answered a bare `{"error":"Not found"}`, indistinguishable from a wrong
`basePath` or an unmounted handler.

Two independent onboarding validation runs hit this on their first
browser attempt and each had to guess the cause. Both were
*add-to-existing-app* journeys; the greenfield one reached for
`CopilotKitProvider` and never saw it.

## What changed

**The runtime says what happened.** `detectSingleRouteEnvelope`
recognises a POST whose JSON body carries a `method` the single-route
endpoint accepts, and the multi-route handler uses it at the one point
routing gives up. The 404 now carries a `code` and a message naming the
prop, plus a `logger.warn` so it lands in the dev-server terminal too.
Deliberately conservative — wrong verb, non-JSON, unknown method, or a
JSON POST that isn't an envelope all stay ordinary 404s, unchanged in
status and shape.

**The client stops discarding it.** All four `/info` callers (two in
`agent-registry.ts`, two in `agent.ts`) threw away the response body and
reported only the status, so a server-side diagnosis reached nobody.
They now go through `runtimeInfoError`, which folds a string `message`
from the body into the thrown error. Any future server-side diagnosis
reaches the developer for free.

**Docs.** Five pages paired a v2 multi-route handler with `<CopilotKit>`
and never mentioned the prop. Rather than a warning under a snippet that
is still wrong to copy, the snippets themselves now pass
`useSingleEndpoint={false}`, with a short callout linking to the
provider/handler mapping.

Two pages were deliberately left alone: `backend/runtime-endpoints.mdx`
already documents the pairing in full, and `cookbook/arcade.mdx` uses
`mode: "single-route"` on purpose and already explains it.
`backend/copilot-runtime.mdx` keeps its snippet as-is — it pairs with
the v1 endpoint, where the default is correct — and gains the caveat
only on its "switch to v2 handlers" note.

Option 3 in the issue (reconsidering the compat default) is **not** in
this PR.

## Testing

### Both halves connect, end to end

Real `createCopilotRuntimeHandler` + real `CopilotKitCore` configured
the way the v1 wrapper configures it — no mocks on either side:

```
code   : runtime_info_fetch_failed
message: Runtime info request failed with status 404: Received a single-route
         request envelope ({ method: "..." }) but this runtime is mounted in
         multi-route mode, so the request matched no route. If the frontend uses
         <CopilotKit> from @copilotkit/react-core/v2, pass useSingleEndpoint={false}
         — that provider defaults it to true. Otherwise mount the runtime with
         mode: "single-route" to serve this envelope.

PASS — the diagnostic reached the client
```

The server-side `logger.warn` fired in the same run, carrying `{ url,
path, method: 'info' }`.

### Unit tests

`packages/runtime` — `single-route-envelope-diagnostic.test.ts` (2
positive, 5 control):

```
 ✓ src/v2/runtime/__tests__/single-route-envelope-diagnostic.test.ts (7 tests) 26ms
      Tests  7 passed (7)
```

`packages/core` — `runtime-info-error-detail.test.ts` (2 positive, 5
control):

```
 ✓ src/__tests__/runtime-info-error-detail.test.ts (7 tests) 267ms
      Tests  7 passed (7)
```

### Mutation checks

Every new test was verified to fail when its mechanism is broken, in
both directions.

Detector forced to `return null` — the two positives die, the four
controls hold:

```
   × names useSingleEndpoint when the envelope is an info call
   × diagnoses every method the single-route envelope accepts
   ✓ leaves an ordinary unmatched route as a plain 404
   ✓ leaves a JSON POST that is not an envelope as a plain 404
   ✓ leaves an unrecognized method name as a plain 404
   ✓ does not diagnose a non-JSON POST
```

Detector forced to `return "info"` — the controls die instead, proving
they are not vacuous:

```
   ✓ names useSingleEndpoint when the envelope is an info call
   ✓ diagnoses every method the single-route envelope accepts
   × leaves an ordinary unmatched route as a plain 404
   × leaves a JSON POST that is not an envelope as a plain 404
   × leaves an unrecognized method name as a plain 404
   × does not diagnose a non-JSON POST
```

`runtimeInfoError` with the detail dropped, then with the `typeof
message === "string"` guard removed — each kills a different pair:

```
mutation: detail dropped              → 2 failed | 5 passed
mutation: accept any message field    → 2 failed | 5 passed
restored                              → 7 passed
```

### Full suites, builds, docs

| Check | Result |
|---|---|
| `packages/core` full suite | `Test Files 60 passed (60)` / `Tests 662
passed (662)` |
| `packages/runtime` full suite | `Test Files 142 passed (142)` / `Tests
2067 passed (2067)` |
| `packages/core` `tsc --noEmit` | clean |
| `packages/runtime` `tsdown` | `416 files` — build complete |
| MDX compile, 5 edited pages | all `OK` |
| pre-commit `nx run-many -t test,publint,attw` | passed across affected
projects |
| CI on `f94d1ab0` | 72 pass, 3 skipping, 0 fail |

Both suites are fully green. An earlier revision of this description
reported 6
runtime failures as pre-existing on `main`; they were not. They were
artifacts
of a worktree whose `node_modules` had been assembled by hand, and a
proper
`pnpm install` cleared all of them along with the inspector-metadata
failures
from a stale `@copilotkit/shared` dist. `main` is clean.

🤖 Generated with [Claude Code](https://claude.com/claude-code)
2026-08-20 10:37:40 -05:00
..
…
…
2026-07-29 13:33:01 +00:00
…
…

Showcase Platform

Tagline: agent entry point for the showcase docs tree and from-scratch local setup. The fanout block below routes you to the right procedural doc.

Per-framework demos of CopilotKit (LangGraph, CrewAI, Mastra, Claude Agent SDK, etc.). Each package is a Next.js frontend + agent backend bundled in a Docker image. Railway deploys those images from main on push.

Agent Fanout — when X, see Y

When you need to... Read
Turn a red cell green (cell red→green SOP, bin/showcase test CLI) ./TESTING.md
Debug a failure mode locally (debugging loop, strategies, prod ops) ./DEBUGGING.md
Look up a framework / fixture / --isolate edge case ./GOTCHAS.md
Add a brand-new integration (per-package + external setup) ./INTEGRATION-CHECKLIST.md
Style a demo page (Tailwind v4, CopilotKit overrides, layout patterns) ./STYLING-GUIDE.md
Reason about which shell renders what / consolidate a new frontend ./FRONTEND-STRATEGY.md
Deploy / promote / pin / roll back a Railway service ./RAILWAY.md (fleet config) + ./bin/README.md (bin/railway CLI)
Understand aimock fixture semantics (fixtures + Railway reconstruction) ./aimock/README.md + ./aimock/RAILWAY.md
Operate showcase-harness (alerts, probes, hot reload, build/deploy) ./harness/README.md + ./harness/docs/rotation-drill.md
Track or check per-slug deviations from canonical ./integrations/<slug>/PARITY_NOTES.md

Anything below is from-scratch local setup — skip if your stack is already up.

Layout

showcase/
  bin/showcase                  # unified CLI — run showcase/bin/showcase <command> for help
  bin/railway                   # Ruby tool for Railway ops (snapshot/promote/pin) — see bin/README.md
  integrations/<slug>/          # one per framework (17 total) — Dockerfile, src/app/demos/*/, src/agents/ or equivalent
  shell/                        # hub: home page, /matrix, canonical /integrations/[slug]/[demo]/{preview,code}
  shell-dashboard/              # internal-only feature × integration grid (port 3002)
  harness/                      # showcase-harness service — see harness/README.md
  aimock/                       # aimock fixtures + Railway config — see aimock/README.md
  shared/
    feature-registry.json       # canonical features + categories (feeds the grid rows)
    constraints.yaml            # allowlist for which demos a package can expose
    local-ports.json            # deterministic host ports per package for local Docker runs
    python/ typescript/tools/   # shared agent utility code; CI stages these into each build context
  scripts/
    dev-local.sh                # low-level Docker Compose wrapper (prefer bin/showcase)
    cli/                        # command modules for bin/showcase
    generate-registry.ts        # builds shell/src/data/registry.json from all manifest.yaml
    bundle-demo-content.ts      # bundles per-demo source + README into shell/src/data/demo-content.json
  docker-compose.local.yml      # one service per package; ports from local-ports.json; env from .env
  .env.example                  # commit template — copy to .env and fill in

Generated data files

The shell apps consume JSON data files that are generated at build time by scripts in scripts/. These files are gitignored — every build path (Docker, CI, npm run build, npm run dev) regenerates them automatically.

File Generator Shell apps What it does
registry.json generate-registry.ts shell, shell-docs, shell-dojo, shell-dashboard Integration manifest — scans integrations/*/manifest.yaml, builds the full catalog with metadata, feature flags, categories
demo-content.json bundle-demo-content.ts shell, shell-docs, shell-dojo Bundled source code from every demo directory — powers the Code tab, Snippet components, dojo cell viewer
constraints.json generate-registry.ts shell Filter facets for the integration explorer (categories, frameworks, features)
search-index.json generate-search-index.ts shell, shell-docs Cmd-K search entries — scans MDX docs, AG-UI content, and registry data
starter-content.json bundle-starter-content.ts shell Starter template source bundles for the "Get Started" code viewer
docs-status.json probe-docs.ts shell-dashboard Per-feature docs reachability — HTTP HEAD on og_docs_url, file-exists check on shell-docs MDX

Each generator writes to the src/data/ directory of every shell app that consumes it. Shell apps are independent — no shell cross-imports another shell's data directory.

Prerequisites

  • macOS or Linux
  • Homebrew
  • Docker engine. Any of: Docker Desktop, Colima (recommended, no GUI / no sign-in), or OrbStack.
  • Node 22+ and npm (for shell / shell-dashboard dev servers — they're not in the compose)

Colima install (one time)

brew install colima docker docker-buildx docker-compose

# Tell the docker CLI where its plugins live
mkdir -p ~/.docker
cat > ~/.docker/config.json <<'JSON'
{
  "cliPluginsExtraDirs": ["/opt/homebrew/lib/docker/cli-plugins"]
}
JSON

# Start the engine (adjust resources to taste; needed for building 17 images)
colima start --cpu 4 --memory 8 --disk 60

# Verify
docker compose version

Colima auto-starts with brew services start colima if you want it on login.

API keys

One .env file feeds every container. Not committed.

cp showcase/.env.example showcase/.env
# Edit showcase/.env and fill in:
#   OPENAI_API_KEY=<required>
#   ANTHROPIC_API_KEY=<optional; needed for Claude Agent SDK demos and a few others>
#   LANGSMITH_API_KEY=<optional; enables LangSmith tracing for LangGraph demos>

Only OPENAI_API_KEY is strictly required. Missing optional keys fail gracefully (per-package).

bin/showcase CLI — quick reference

For the full invocation table (control-plane vs --direct, per-demo scoping matrix) and the cell red→green SOP, see ./TESTING.md. For debugging workflows (aimock rebuild cycles, fixture validation, probe testing, diagnostics), see ./DEBUGGING.md.

# from any directory — paths resolved relative to the script itself

./showcase/bin/showcase up langgraph-python                 # start infra + one integration
./showcase/bin/showcase test langgraph-python --d5 --isolate # run D5 probes (canonical)
./showcase/bin/showcase down                                 # tear down
Command Description
test <slug> Run probes against a running service (see TESTING.md for full flag table)
up [slugs...] Start infra (aimock, pocketbase, dashboard) + named packages. No args = infra only
down [slugs...] Stop services. No args = stop everything
build [slugs...] Build Docker images
rebuild <slug> Rebuild a slug (handles symlink deref that raw docker build cannot)
recreate <slug> Force-recreate a service (picks up new image)
restart <slug> Restart container (picks up src/ edits — see Iterating on a demo below)
ps Show running services
ports Print slug to host port mapping
logs <slug> Follow container logs (supports --grep, --since, -n, --no-follow)
doctor Check local environment and stack health

Container exposes port 10000 internally → host port in shared/local-ports.json. The image and entrypoint are the same ones Railway runs.

Hooking local containers into the shell

The shell app's /preview route iframes integration.backend_url (Railway) by default. Set SHOWCASE_LOCAL=1 when running shell to swap in the localhost ports from local-ports.json instead — per-slug, falling back to Railway for anything you don't have running.

cd showcase/shell
npm install                     # once
SHOWCASE_LOCAL=1 npm run dev    # /preview iframes http://localhost:<port>/demos/...

In production the env var is unset → Railway URLs, unchanged.

shell-dashboard — feature × integration matrix

Internal overview of which packages support which features, linking to the canonical /preview and /code routes on shell. Lives at http://localhost:3002 and reads the same registry.json shell does.

cd showcase/shell-dashboard
npm install
npm run dev

Column ordering lives in shell-dashboard/src/lib/sort-order.ts — internal to this app, not part of the public registry.

Iterating on a demo

  1. Edit the demo in integrations/<slug>/src/app/demos/<demo-id>/page.tsx (and the backend under src/agents/ if applicable).
  2. Rebundle so /code in shell reflects the edit: cd showcase && npx tsx scripts/bundle-demo-content.ts.
  3. If you changed manifest.yaml or added a feature to shared/feature-registry.json: npx tsx scripts/generate-registry.ts.
  4. Rebuild + restart the container: showcase/bin/showcase up <slug> (or restart <slug> for pure src/ edits — see DEBUGGING.md "Dev Iteration Speed").
  5. The grid in shell-dashboard and /preview in shell now show the new state.

Relationship to Railway

  • Dockerfile, entrypoint.sh, and build context (shared_python/, shared_typescript/) are shared between local and Railway.
  • .github/workflows/showcase_deploy.yml builds each image on push to main and pushes it to Railway. Per-PR deploys are opt-in via gh workflow run showcase_deploy.yml -r <branch> -f service=<slug>.
  • The only real differences at runtime are env var values and the URL. If something works locally in Docker, it works on Railway (and vice versa).

Dashboard SOPs (catalog.json + PocketBase)

The dashboard at showcase.copilotkit.ai reads two data sources:

  1. Static catalog.json — generated at build time by pnpm generate-registry. Contains the full 38-feature × 17-integration cell matrix with status (wired / stub / unshipped), parity tiers, and feature categories. Changes require a generator run + commit.
  2. Live PocketBase probe results — streamed via SSE. Probes discover demo routes automatically and update the dashboard in real time. No manual intervention needed for probe data.

Known limitation — PocketBase fetch cap: useLiveStatus.ts fetches status records with a hard INITIAL_CAP (currently 2000). PocketBase returns records in rowid (creation) order. If the total record count exceeds the cap, later-created dimensions (e.g. e2e:<slug>/<featureId> per-cell records from the 6-hourly e2e-demos probe) get silently truncated, causing the dashboard to show D2 instead of D4 across the board. If new probe types are added and the dashboard regresses to D2, raise INITIAL_CAP in shell-dashboard/src/hooks/useLiveStatus.ts. The correct long-term fix is dimension-scoped fetching or sort=-updated so the cap never silently drops functional records.

Key invariants:

  • Parity tiers are never manually set. They are computed by comparing each integration's wired feature set against the reference integration's.
  • The reference integration is auto-detected as the integration with the most wired features (ties broken alphabetically). No reference: true flag exists.
  • catalog.json is gitignored — the generator emits it into the shell apps' src/data/ directories, which are already in .gitignore.
  • The stub status means: feature declared in manifest, demo entry exists, but no route field. Today only langgraph-python/cli-start qualifies.

SOP 1: Wire a new demo on an existing integration

  1. Edit showcase/integrations/<slug>/manifest.yaml — add the feature to features[] and a corresponding demos[] entry with a route.
  2. Run pnpm generate-registry — updates registry.json AND catalog.json. The cell flips from unshipped to wired. Parity tiers auto-recompute.
  3. Commit the manifest + both generated files. PR, merge.
  4. CI rebuilds the package image + dashboard image. Railway auto-deploys both.
  5. Ops probes discover the new demo route and begin probing. Dashboard updates live via PocketBase SSE — no further action needed.

SOP 2: Code fix on an existing demo (no manifest change)

  1. Edit code under showcase/integrations/<slug>/src/....
  2. PR, merge. No generator run needed (manifest unchanged).
  3. CI rebuilds the package image. Railway auto-deploys.
  4. Probes re-probe on the next tick. If the fix turns a red cell green, the dashboard updates live. Zero manual steps beyond the normal PR workflow.

SOP 3: Add a brand-new integration

  1. Create showcase/integrations/<new-slug>/manifest.yaml with features[] + demos[].
  2. Add {"slug": "<new-slug>", "name": "<Display Name>"} to showcase/shared/packages.json.
  3. Provision a Railway service (manual: railway service create or Dashboard UI).
  4. Run pnpm generate-registry — catalog gains 38 new cells (mostly unshipped, some wired). Parity tier computed automatically.
  5. Commit, PR, merge. CI + Railway deploy. Probes discover the new service automatically via the Railway discovery filter.

For the full per-package + external-setup checklist see ./INTEGRATION-CHECKLIST.md.

SOP 4: Reference migration (move the reference integration)

  1. No manual flag needed — the generator auto-detects the reference as the integration with the most wired features (ties broken alphabetically).
  2. If you want a different integration to be reference, wire more features on it until it leads the count.
  3. Run pnpm generate-registry — all parity tiers recompute automatically.
  4. Commit, PR, merge.