jasonkneen CopilotKit
CopilotKit's APIs move. Anything written down in a skill file is a copy that starts drifting the day it is written, so this skill carries almost no API detail on purpose. It tells you where the current answer lives and how to get it.
Look it up before you write code. Not because the docs are more convenient, but because they are regenerated from the source and a recollection is not.
The search tools
An MCP server, copilotkit-docs, is bundled with this plugin. It exposes four search tools
and two exploration tools over four separate corpora. Picking the wrong one is the most
common way to come up empty:
| Tool | Corpus | Use it for |
|---|---|---|
search-docs |
docs.copilotkit.ai | Usage, configuration, guides, quickstarts, the generated API reference |
search-code |
CopilotKit library source | How something is implemented, and exact signatures. Library packages only — not examples or showcases |
search-ag-ui-docs |
AG-UI protocol docs | The protocol itself: event types, transports, the SDKs |
search-ag-ui-code |
AG-UI protocol SDK source | Protocol implementation detail |
explore-docs / explore-code |
either tree | Browsing structure when you do not yet know what to search for |
CopilotKit questions go to the first two. AG-UI protocol questions go to the second two —
they are a different repository, and search-docs will not find them.
These are semantic searches. Several short, differently-phrased queries beat one long one. If a query returns something off-target, rephrase rather than widen — and if you get a plausible-looking page that does not actually contain the term you need, say so instead of reasoning from the title.
Setup
The server is registered once per tool, and installing the skills does not register it. Check first — if the search tools above are already available, skip this.
Claude Code — the CopilotKit plugin declares the server in its .mcp.json, so a
plugin install needs nothing. A skills-only install (npx skills add) does not carry
that file, so register it:
claude mcp add --transport sse copilotkit-mcp https://mcp.copilotkit.ai/sse
Codex:
codex mcp add copilotkit --url https://mcp.copilotkit.ai/mcp
Anything else — https://mcp.copilotkit.ai/mcp for streamable HTTP,
https://mcp.copilotkit.ai/sse for SSE. Keep the path: the bare host returns 404.
Per-tool instructions cover Cursor, Windsurf, Cline, GitHub
Copilot and VS Code.
Without the server, the documentation works as a plain
site, and appending .md to any docs URL returns that page as Markdown.
Where the answers are
Worth knowing so a search has somewhere to land:
- Getting started — quickstart, and the CLI for the CLI-driven path
- Frontend — frontend tools, human-in-the-loop, prebuilt components, styling, attachments, voice
- Runtime — the runtime, HTTP endpoints, runners, factory mode, server adapters, auth
- Agent frameworks — one quickstart per framework under
/integrations/ - Intelligence — overview and the pages under it
- Not working — common issues,
error reference, and the generated
CopilotKitCoreErrorCodefor a code the app actually reported - Protocol — AG-UI, and the AG-UI docs for the protocol itself
Before you debug anything
Run the CLI's wiring check first — npx copilotkit@latest verify --json. It settles up to
eleven things in one command and is almost always faster than reading the project. See the
copilotkit-cli skill.
Two versions exist
v2 is current. Import from the /v2 subpath — @copilotkit/react-core/v2,
@copilotkit/runtime/v2. The package root is the deprecated v1 surface and still resolves,
so mixing the two raises nothing at import time and surfaces later as a runtime mismatch.
Check which subpath a project imports before trusting anything else about it. v1 is
deprecated but supported; the migration guide covers moving off it.