CopilotKit
github.com/copilotkit/copilotkit- Category
- AI Agents
- Rank
- No. 13Tools index
- Type
- APP
- Builder
- copilotkit
- GitHub
- 37.4k stars
- Latest release
- v1.71.2
- Date
About
A frontend stack for building in-app AI copilots and generative UI across React, Angular, mobile, and Slack.
What it does
CopilotKit is a collection of npm packages that connect an agent running on a server to whatever surface a user is on: a web app, a mobile app, or a chat workspace. The agent talks to the frontend over an event-based streaming protocol called AG-UI, which the same team publishes as a separate project, so the agent is something the runtime speaks to over the wire rather than a library you import. React hooks share app state with the agent, render tool calls as live components, and pause for human approval, while a framework-neutral core carries the same machinery to other frameworks and chat platforms.
Why it's ranked here
Breadth backed by visible upkeep is the argument. It is MIT licensed, tests and lint run across every package in the monorepo, and the dependency configuration raises security floors on 74 transitive dependencies and patches one outright, the shape of a project tracking advisories rather than one that pinned once and moved on. The protocol underneath it is published as a separate project that the README says Google, LangChain, AWS and Microsoft have adopted, and a Python SDK means a backend team is not forced into TypeScript to use it.
What's good
The chat-platform abstraction is real, not aspirational. The boundary a Slack or Teams integration must satisfy is declared as explicit exported types, and the core ships fake adapter and fake agent test doubles so a new platform package can be tested against the contract before it ever touches a real workspace. One test helper is deliberately kept out of the main entry point, with the reasoning written down in the code, so a testing library never leaks into consumers' runtime dependencies. Publish correctness is enforced by automated checks on every package rather than left to good intentions.
Tradeoffs
The surface area is the cost. One backend has to satisfy frontend packages for React, Angular, Vue, React Native and web components, plus Slack, Teams, Discord, Telegram and WhatsApp channels, and the project's own support table marks the chat platforms Beta behind an early-access request form. Two headline features, Self-Learning and the Intelligence Platform, are gated the same way, and a license verifier is pinned in the tree, so some of what the marketing sells is not what the MIT-licensed code hands you. The two contributor guides contradict each other on package layout, so the documentation site is not optional.
How to use it well
Start from the official create command and decide early whether you want the packaged chat interface or the headless path: the headless hooks give you the agent connection with no interface attached, while the packaged one brings its own stylesheet. Share app state with the agent through the dedicated readable-state hook rather than stuffing it into prompts. For a Slack or Teams deployment, write against the platform adapter contract and test with the shipped fake adapter before touching a real workspace. Pin your versions, because several exported hooks and types carry a suffix that nothing in the codebase explains.
Technical notes+
The repo-root AGENTS.md states a three-layer architecture: frontend, an Express or Hono runtime, and the agent (LangGraph, CrewAI, built-in, or custom), connected over AG-UI, an event-based SSE protocol published as a separate upstream project. packages/react-core/src/hooks/index.ts exports eighteen hooks mapping to the README feature list: useCopilotReadable for shared state, useFrontendTool and useRenderToolCall for tool calls that resolve to rendered components, useHumanInTheLoop for the pause-and-ask flow, useLangGraphInterrupt for LangGraph. packages/core/src/core/index.ts re-exports framework-neutral machinery: core, agent-registry, context-store, suggestion-engine, run-handler, state-manager. packages/channels-core/src/index.ts declares PlatformAdapter, RunRenderer, IngressSink, ConversationStore and SurfaceCapabilities, ships FakeAdapter and FakeAgent as test utilities, and withholds runStateStoreConformance to a channels/testing subpath so vitest stays out of consumer module graphs. packages/channels-slack/src/index.ts fills the seam with a Block Kit renderer, a markdown-to-mrkdwn converter and three streaming message classes. packages/react-ui/src/index.tsx imports its stylesheet at the entry point; useCopilotChatHeadless_c and useAgent are the headless path, and several exports carry an undefined _c suffix. sdk-python/copilotkit/__init__.py exports CopilotKitRemoteEndpoint, LangGraphAGUIAgent and CopilotKitMiddleware. Build spine: Nx, pnpm, tsdown, vitest via nx run-many, oxlint and oxfmt; publint and @arethetypeswrong/cli run as nx targets; pnpm.overrides covers 74 dependencies and patches eventsource.
Observed
- License
- MIT
- Frontend interfaces
- npm packages for React, Angular, Vue, React Native, web components and voice, plus a Python SDK for backends
- Chat platform support
- Slack, Teams, Discord, Telegram and WhatsApp channel packages built on a shared adapter core; the support table marks chat platforms Beta behind an early-access form
- Commercial gating
- Self-Learning and the Intelligence Platform require early access; a license-verifier package is pinned in the dependency overrides
- Publish checks
- Automated publish-correctness and type-resolution checks wired as build targets across every package
Read from README.md, package.json, LICENSE, AGENTS.md, CLAUDE.md, packages/core/src/index.ts, packages/core/src/core/index.ts, packages/runtime/src/index.ts, packages/react-core/src/index.tsx, packages/react-core/src/hooks/index.ts, packages/react-ui/src/index.tsx, packages/channels-core/src/index.ts, packages/channels-slack/src/index.ts, packages/angular/src/index.ts, sdk-python/copilotkit/__init__.py.
Tech Stack
Comments (0)
No comments yet
Editorially curated, with community endorsements as a secondary signal. Corrections welcome.