runtime

name	runtime
description	@copilotkit/runtime — mount a fetch-native CopilotRuntime on any JS server, wire middleware, pick an AgentRunner, instantiate BuiltInAgent (Factory Mode with TanStack AI is the preferred default) or plug in any of 12 external agent frameworks (Mastra, LangGraph, CrewAI Crews/Flows, PydanticAI, ADK, LlamaIndex, Agno, AWS Strands, MS Agent Framework, AG2, A2A), enable Intelligence mode for durable threads + websocket, register server-side tools via defineTool, and wire voice transcription. Uses the fetch-based createCopilotRuntimeHandler primitive — the Express/Hono adapters are discouraged. Load the reference under references/ that matches your task.
type	core
library	copilotkit
library_version	1.69.0
requires	[]
sources	["CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/core/fetch-handler.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/core/runtime.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/core/hooks.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/core/middleware.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/runner/agent-runner.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/runner/in-memory.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/runner/intelligence.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/intelligence-platform/client.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/transcription-service/transcription-service.ts","CopilotKit/CopilotKit:packages/runtime/src/v2/runtime/handlers/handle-transcribe.ts","CopilotKit/CopilotKit:packages/runtime/src/agent/index.ts","CopilotKit/CopilotKit:packages/runtime/src/agent/converters/tanstack.ts","CopilotKit/CopilotKit:packages/sqlite-runner/src/sqlite-runner.ts","CopilotKit/CopilotKit:packages/shared/src/transcription-errors.ts"]

CopilotKit Runtime

@copilotkit/runtime is the server half of CopilotKit: it accepts AG-UI protocol requests, dispatches them to an AbstractAgent (built-in or external), runs the stream through an AgentRunner, and responds as Server-Sent Events.

This SKILL.md is the index. Read the reference under references/ that matches your task — do not try to absorb the whole package from this file.

Mental Model — the three dictionaries you hand to CopilotRuntime

new CopilotRuntime({
  agents, // Record<string, AbstractAgent>     — see wiring-external-agents or built-in-agent
  runner, // AgentRunner (optional)            — see agent-runners
  intelligence, // CopilotKitIntelligence (optional) — see intelligence-mode (auto-wires runner)
  mcpApps, // McpAppsConfig (optional)          — see wiring-mcp-apps-middleware
  a2ui, // A2UIConfig (optional)             — see packages/a2ui-renderer skill
  hooks, // { onRequest, onBeforeHandler }    — see middleware
  beforeRequestMiddleware,
  afterRequestMiddleware, // legacy — see middleware
  transcription, // TranscriptionService (optional)  — see transcription
});

You then mount it:

import { createCopilotRuntimeHandler } from "@copilotkit/runtime/v2";
const handler = createCopilotRuntimeHandler({
  runtime,
  basePath: "/api/copilotkit",
});
export default { fetch: handler };

When to load which reference

Task	Reference
Mounting on any fetch-native server (Cloudflare Workers, Bun, Deno, Vercel Edge, Next.js App Router, React Router v7, TanStack Start) or delegating from Express/Node	references/setup-endpoint.md