Closes#3217
When `getLanguageModel()` returns null and provider/model are undefined
(as with LangChainAdapter), the code constructed `"undefined/undefined"`
as a model string, causing a cryptic "Unknown provider" error.
Now checks each source of model info explicitly and throws a clear error
message directing users to provide an explicit agents config when using
adapters that don't expose model metadata.
Split from #3838.
Addresses PR feedback on #3814: replaces the "red-green tested locally"
rationale with actual unit coverage.
The inline `event.messageId || randomId()` fallback becomes an exported
`resolveMessageId` helper. The resolver now calls it; the helper is
covered by a small test suite asserting: provided ids pass through
verbatim; null / undefined / empty-string event ids fall back to the
"ck-<uuid>" shape; successive fallbacks produce distinct ids.
Covers the three branches added by the fix:
- getLanguageModel() returns a LanguageModel -> wired into BuiltInAgent
- provider + model strings present -> composed as "provider/model"
- neither present (e.g. LangChainAdapter) -> throws CopilotKitMisuseError
with adapter name in the message, instead of silently producing
"undefined/undefined" and failing downstream.
Also guards the partial-info case where only one of provider/model is set
to ensure the regression doesn't re-emerge via a half-populated adapter.
## Summary
Three connected features land together so the CopilotKit VS Code
extension becomes a coherent debugger/preview surface:
1. **Hook Explorer** — every V1 + V2 render hook can be discovered and
previewed live with auto-generated controls, an inline `▶️ Preview
Component` CodeLens, and a sidebar that lists every captured site.
2. **AG-UI Event Inspector** — live SSE debug stream of all AG-UI
events, filterable and color-coded, in a sidebar view + editor panel.
3. **A2UI Catalog sidebar → webview** — the last native TreeView gets
replaced with a Tailwind-styled webview that matches the other two, now
with a proper **Go to source** action on components and fixtures.
## Hook Explorer
### Discovery + preview
- oxc-based scanner walks the workspace and finds every call-site of any
hook in the registry (17 across V1 + V2, render + data).
- Preview panel bundles the user's source via Rolldown (IIFE format,
React externalized, CSS collected per `@copilotkit/a2ui-renderer`
pattern), executes it in the webview with a capture-only **stub** for
`@copilotkit/react-core` (+ `/v2`), and mounts the user's component just
long enough to record each hook's config.
- Auto-generated form on the left/top drives the `render` prop's
args/parameters/state/event live. V1 parameter arrays and V2 Zod /
Standard Schema all map through a unified `FormSchema` derived at
runtime from the captured config.
- `useCopilotAction`, `useCopilotAuthenticatedAction_c`,
`useCoAgentStateRender`, `useLangGraphInterrupt`, `useRenderTool`,
`useRenderToolCall`, `useDefaultRenderTool`, `useLazyToolRenderer`,
`useRenderCustomMessages`, `useRenderActivityMessage`,
`useHumanInTheLoop`, `useInterrupt`, `useFrontendTool`, `useComponent`,
`useDefaultTool` all previewable.
- Inline `▶️ Preview Component` CodeLens above every render-hook call
site, backed by the same `copilotkit.hooks.preview` command as the
sidebar.
- Imported render components work: rolldown walks transitive imports
from the hook's `render` prop through any number of sibling files.
- Cross-file hook switches are robust: controls are reset on load,
Harness only mounts once the real HostRoot is ready, a top-level error
boundary auto-recovers when you pick a different hook.
### Why the stub approach
Bundling the real `@copilotkit/react-core` through rolldown's IIFE
output hit a `__commonJSMin` TDZ chain (`require_clipboard`,
`require_graphql`, `require_context_helpers`, …) because the
chat/runtime-client/markdown graph has circular imports. Externalizing
react-core + routing to a Proxy-backed stub that captures hook configs
avoids the whole CJS wrapping problem, shrinks the preview bundle from
~24 MB to ~1.3 KB, and keeps the preview runtime path completely
runnable without a live CopilotKit backend. Tradeoff documented in
`copilotkit-stubs.ts`.
### Weather-themed fixtures
14+ fixtures under `packages/vscode-extension/test-workspace/hooks`,
each a distinct visual scenario (forecast card, severity-palette alerts
with imported CSS, forecast strip, live radar grid, conic-gradient
precipitation gauge, air-quality badge with imported render, pollen
report with a 2-hop import graph, HITL evacuation confirm,
sunrise/sunset gradient, etc.). Used both as regression fixtures and as
the demo surface for video.
### Styling
- Tailwind-via-CDN + VS Code CSS variables for theme-aware chrome.
- User-provided CSS imports collected by rolldown and injected as a
`<style>` tag per load.
- Controls + form fields converted to Tailwind; textarea matches input
styling.
- Framed "Rendered output" card so the render prop is visually
unmistakable.
## AG-UI Event Inspector
### Runtime (`@copilotkit/runtime` + `@copilotkit/shared`)
- `DebugEventBus` — in-memory pub/sub on `BaseCopilotRuntime`, only
instantiated when `NODE_ENV != production`.
- Event tap in `createSseEventResponse` broadcasts every AG-UI event
with metadata (agentId, threadId, runId, timestamp).
- `GET /debug-events` SSE endpoint — returns 404 in production, streams
`DebugEventEnvelope` JSON to connected clients, initial `: connected`
comment flushes headers immediately.
### VSCode Extension
- `DebugStream` — Node SSE client with auto-reconnect, exponential
backoff, URL validation, error surfacing.
- `InspectorPanel` (editor panel, command `CopilotKit: Open AG-UI
Inspector`) and `InspectorViewProvider` (sidebar view) both use a shared
`DebugStream` instance — events persist when switching tabs.
- Inspector React app: `ConnectionBar`, `FilterBar`, `EventList`,
`EventDetail`.
- Color scheme: purple (lifecycle), red (errors), blue (text), orange
(tools), green (reasoning), teal (state), yellow (activity), gray
(unknown).
## A2UI Catalog → webview
- Replaces `ComponentPreviewProvider` (native TreeDataProvider) with
`CatalogListViewProvider` (WebviewViewProvider), matching the Hooks and
Inspector sidebars.
- New React webview with refresh header, component rows (name + relative
path + `auto` badge when no fixture), expandable fixtures list.
- Click a component row → preview (or toggle if it has fixtures); click
a fixture row → preview that fixture.
- Hover action buttons: `▷` preview + `</>` go-to-source on every row.
- "Go to source" opens the component file for component rows; for
fixture rows it opens the fixture file and jumps the cursor to the named
fixture key.
## Test coverage
- Runtime: DebugEventBus unit tests (8), handleDebugEvents endpoint (5),
fetch-router routes (4), integration across Express/Hono/Node/Fetch (9).
- Hooks: scanner + 16 fixture bundle-smoke test, regression guard
against `node_<builtin>` self-references, CSS collector test, stub-based
capture E2E, cross-kind controls remount, FormRenderer defensive
rendering.
- Inspector + webview: DebugStream reconnect (10), inspector components
(17), colors (9).
- Total: **178 tests** passing for the vscode-extension package; runtime
suite unchanged.
## Test plan
- [ ] `pnpm nx run copilotkit-vscode-extension:build` and `pnpm nx run
copilotkit-vscode-extension:test` both green
- [ ] F5 launches the Extension Dev Host with `test-workspace` open
- [ ] Hooks sidebar lists every fixture hook; click a row → preview
opens; `</>` button opens the source
- [ ] `▶️ Preview Component` CodeLens shows above every render hook in a
`.tsx` file; clicking it opens the preview
- [ ] Form controls drive the render live; cross-kind hook switches
(action ↔ custom-message) don't crash; a forced render-prop throw
recovers when a different hook is picked
- [ ] Imported-render fixtures (`ImportedAirQuality`,
`ImportedPollenReport`) bundle and preview correctly
- [ ] A2UI Catalog sidebar is the new webview, refresh works, `</>` on a
fixture opens the fixture file and reveals the named key
- [ ] AG-UI Inspector connects to `GET /debug-events`, filters + detail
work, events survive sidebar/panel switch, invalid URL shows red error
- ThreadStoreRegistry.register() now fires onThreadStoreUnregistered
before overwriting an existing store so subscribers (web inspector)
don't stay subscribed to stale stores on replacement; test extended
to verify both events fire in order
- Wire handleClearThreads to POST /threads/clear route; add RouteInfo
variant, router pattern, and fetch-handler case so the inspector can
actually call it
- Add handleGetThreadMessages tool-call mapping test using properly
typed Message objects (role as const, type as const) — exercises the
real mapping code path without mocking getThreadMessages
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Excludes showcase/shell-docs and showcase/shell-dojo demo-content.json from
the size check in lefthook.yml — these data files were added by main but
weren't in the exemption list, causing the pre-commit hook to reject them.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- middleware SKILL: beforeRequestMiddleware runs AFTER hooks.onRequest (not before); cite fetch-handler.ts:136-147 for exact order
- agent-runners/in-memory ref: delete globalThis[Symbol] leaves module-captured reference intact; use in-place Map.clear() on data.stores + data.historicRunsBackup; flag missing official reset helper as follow-up
- intelligence-mode SKILL: identifyUser does NOT forward thrown Response (resolveIntelligenceUser converts to generic 500); gate auth rejection in hooks.onRequest which does forward Responses
- built-in-agent/factory-modes ref: custom factory example now checks abortSignal.aborted at entry and between yields; note that agent.abortRun() only flips the flag — generator must consult it
- setup-endpoint Express delegate: stream SSE via Readable.fromWeb().pipe(res) instead of buffering via arrayBuffer(); applies to both the recommended pattern and the CRITICAL "Correct" example. Add Node 18.17+ note.
- built-in-agent frontmatter: maxSteps defaults to undefined (AI SDK stops after one generation), not 1.
- built-in-agent examples: replace bare anthropic("claude-sonnet-4") / anthropicText("claude-sonnet-4") with the dated id "claude-sonnet-4-5-20250929" (AnthropicMessagesModelId in @ai-sdk/anthropic@3.0.49 does not accept the bare form).
- 0-to-working-chat Next.js: align catch-all with migration-playbook — use [[...slug]] so the bare /api/copilotkit basePath also routes.
- migration-playbook v1->v2 parameters: v1 entries default to required: true; only map to .optional() when required: false was explicit. Prevents silently flipping the contract.
- switching-agents Recipe 2 (Tabs): hold activeAgent in a ref so the onAgentsChanged subscribe effect only re-binds on copilotkit change, not on every tab click.
- a2ui-rendering custom-catalog example: use the real createCatalog(definitions, renderers) signature with Zod schemas; remove the bogus extractSchema<T>() generic (types erase at runtime).
- spa-without-runtime clipboard handler: correct the comment — returning a structured error does NOT trigger onError with tool_handler_failed; only thrown handlers do.
- agent-runners: agent_thread_locked fires only on Intelligence 409, not SSE;
SSE surfaces "Thread already running" as a plain 500 body
- agent-runners: SqliteAgentRunner install-hint is unreachable — the import of
@copilotkit/sqlite-runner fails at module load if better-sqlite3 is missing
- agent-runners: soften "CopilotIntelligenceRuntimeOptions explicitly excludes
runner" — the field is simply not declared; excess-property checks flag it
- agent-runners/sqlite: mirror real schema (CREATE INDEX IF NOT EXISTS)
- middleware: consistent afterRequestMiddleware signature across Wrong/Correct
examples; document the full { runtime, response, path, messages?, threadId?,
runId? } shape
- server-side-tools: Factory Mode example now uses AI SDK + the real converter
(convertToolDefinitionsToVercelAITools); TanStack caveat called out since
defineTool output is not a TanStack tool and there is no built-in converter
- setup-endpoint: Cloudflare Workers example hoists runtime/handler to module
scope behind a lazy getter; openaiText signature corrected to createOpenaiChat
when passing an explicit API key (openaiText config omits apiKey)
- transcription: JSON payload mode works in both multi-route and single-endpoint
— dispatch is by Content-Type, not endpoint mode
- wiring-external-agents/mastra: getLocalAgents requires resourceId; remote
Mastra section now points at HttpAgent instead of misshaping getRemoteAgents
- package.json: add per-condition types to every exports entry so bundler and
moduleResolution: "bundler"/"node16" both pick up the matching .d.mts/.d.cts
intent edit-package-json replaced "files": ["skills"] instead of appending, excluding dist/ from runtime and react-core published packages. publint caught it (pkg.exports.[].import/require -> file not published). Restoring dist + skills.
a2ui-renderer was unaffected (had existing "files": ["dist"] which got appended correctly).
- Keep deletion of sdk-python/copilotkit/langgraph_agent.py (deprecated LangGraphAgent
removed in this PR; main's unrelated bug fixes are superseded by our removal)
- Resolve poetry.lock conflict by taking main's ag_ui_langgraph 0.0.33
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Review-loop fixes on the runtime surface:
- sse-response.ts: wrap DebugEventBus.broadcast in try/catch inside the
observer's next — a buggy subscriber used to propagate an exception
that RxJS routed to `error`, killing the SSE stream for an unrelated
reason. Logged via the existing logError helper instead.
- sse-response.ts: non-abort write failures no longer fall through
silently. Previously streamClosed stayed false and the next event
re-attempted a broken writer. Now logs + sets streamClosed.
- sse-connect-agent-id.test.ts: new unit test that feeds a synthetic
observable into handleSseConnect and asserts the emitted envelope
carries the route-resolved agentId ('weather-agent') rather than
the literal 'connect'. Regression guard for the fix in 7f3a8c27c
that the /run-based integration tests didn't cover.
- debug-events.suite.ts: replaced a version of this assertion that
couldn't reliably drive /connect in the integration runtime with a
pointer to the unit test above.
- fetch-router.ts: clarify the cpk-debug-events comment — the prefix
is what guards against agent-name collision, not the ordering of
router branches.
- debug-stream.ts (extension client): include the underlying JSON parse
error message in the emitted error so a truncated SSE frame can be
distinguished from a runtime/protocol version mismatch.
Per PR review suggestion (14) — a cpk- prefix makes collision with a
user-named agent essentially impossible. The earlier change only
documented the route as reserved; renaming it removes the hazard.
Rename scope:
- URL path segment (/debug-events → /cpk-debug-events) in the router,
handler switch arms, method-not-allowed check, and integration suite.
- RouteInfo union discriminator ('debug-events' → 'cpk-debug-events')
in hooks.ts and its two consumers in fetch-handler.ts.
- VS Code DebugStream client URL.
- Docs page (event-inspector.mdx) — both the Callout and the Steps copy.
Left unchanged (internal names that describe the feature but aren't the
public route):
- packages/runtime/src/v2/runtime/handlers/handle-debug-events.ts
- packages/runtime/src/v2/runtime/core/debug-event-bus.ts
- packages/shared/src/debug-event-envelope.ts (and the DebugEventEnvelope
type)
- 'debug-event' (singular) message type in the VS Code webview bridge —
that's the extension host ↔ webview protocol, not the HTTP route.
Critical
- scripts/hooks/check-binaries.sh: restore showcase data-file exclusions
(demo-content / search-index / starter-content >1 MB) that the inline
refactor dropped; add 'set -eu' so silent shell failures don't hide
policy violations.
- packages/vscode-extension/src/extension/preview-panel.ts: drop 'blob:'
from CSP script-src — it lets arbitrary-string JS execute via Blob URL
and defeats most of CSP's XSS protection.
- packages/vscode-extension/package.json: set private: true. The extension
ships as a .vsix via vsce, not npm, and workspace:* devDependencies
would break an accidental 'npm publish'.
Important
- runtime: forward the real agentId from handleConnectAgent into
handleSseConnect / createSseEventResponse so DebugEventBus envelopes
on /connect carry the actual agent name instead of the literal
'connect'. Updates handle-connect.ts, sse/connect.ts.
- hooks/panel.ts CSP: narrow connect-src from 'https:' to just the
Tailwind CDN. The preview path never drives a real CopilotKit runtime
— all hook calls route through the stub — so there's no legitimate
https: fetch to allow from inside bundled user code.
- extension/utils.ts getNonce(): switch to crypto.randomBytes. Math.random()
is not acceptable for a value that gates inline-script execution.
- .github/workflows/vscode-extension.yml:
* Build step uses 'nx run copilotkit-vscode-extension:build' instead
of 'pnpm run build' (targeted build with Nx caching, not full
monorepo rebuild).
* Added explicit 'Type check' step (tsc --noEmit).
* Added Lint step gated with continue-on-error until the Nx target
exists, so a missing target doesn't break the pipeline.
* Publish job now queries the Marketplace for the current published
version and skips 'vsce publish' when the local package.json
version matches — stops every docs/CI-only push to main from
failing on duplicate-version errors.
- hooks/hook-scanner.ts: bound the synchronous walk at 20 000 files so a
pathologically large workspace can't freeze the extension host; flag
kept in module-level constant with a rationale comment.
- sse-response.ts: document that debugEventBus.broadcast intentionally
runs before the stream-closed gate so debug subscribers see trailing
events even after the SSE client disconnects.
- inspector-panel.ts: subscribe to DebugStream lazily on show() rather
than in the constructor; unsubscribe on panel dispose. Avoids firing
the event callback on every envelope when no panel is open.
Suggestions
- fetch-router.ts: document 'debug-events' as a reserved route so it
can't be shadowed by an agent literally named 'debug-events'.
- activate.ts findValuePosition: add optional startOffset parameter,
document the first-occurrence limitation + the follow-up path for
per-fixture precision.
- activate-hook-explorer.ts isInsideWorkspace: fix JSDoc to reflect the
code (root itself is excluded).
Tests the /debug-events SSE endpoint across Express, Hono, Node, and
Fetch Direct adapters. Verifies SSE response format, event flow through
the DebugEventBus, envelope structure (timestamp, agentId, threadId,
runId, event), full event sequence, HTTP method validation (405 for
POST), and NODE_ENV=production guard (404).
Key implementation detail: reader.cancel() must NOT be awaited on
tee'd ReadableStreams (created by response.clone() in the fetch
handler) because Node.js blocks until the other tee branch is also
consumed/cancelled.
## Summary
- Fixes#2986
- `reqOrRequest instanceof Request` fails when `@hono/node-server`
polyfills the Request class with a different prototype
- Replaced with a duck-type check (`isRequestLike`) that verifies `url`,
`method`, and `headers` properties exist
- The `!res` guard ensures IncomingMessage objects (which always come
with a ServerResponse) are still routed correctly
## Test plan
- [x] Added `request-duck-type.test.ts` covering native Request,
polyfilled Request, null/undefined, and missing properties
- [x] All 1225 existing runtime tests pass
- [x] Build passes
Mike Ryan