Benjamin Taylor
e1f88ebc12
Addresses review feedback that channel-host.mts is doing too much.
Two changes, both scoped to the starters:
1. Channel construction moves to a new `channels.mts` beside `agent.ts` —
name resolution, `createChannel`, and the `onMessage` handler. That is
also the file to edit to customise a Channel (commands, reactions,
onMention), which previously meant editing the host.
The per-framework agent import moves with it, so `channel-host.mts` is now
byte-identical in all 15 starters rather than 13 + 2.
2. The host no longer stands up an HTTP server. Its comment claimed the
server was what "keeps the lifecycle-owning process alive"; that is false.
An open undici WebSocket holds the event loop on its own — verified with a
standalone repro where a process with no HTTP server and no timers of its
own stayed up indefinitely on a single WebSocket connection. The server was
therefore serving a second, uncalled copy of the runtime API on port 8300
for no reason.
With the server gone, `createCopilotNodeListener` was the wrong factory —
it builds a request listener purely for its activation side effect. The
host now uses `createCopilotRuntimeHandler` + `ready()`, which is the
documented long-running-host pattern (see fetch-handler.ts). This also
drops `node:http`, `basePath`, and the CHANNEL_PORT env var.
Behaviour is unchanged: same Channel, same agent, same status reporting, and
the same non-zero exit on activation failure.
Verified: 14/14 starters with a `typecheck:channel` script pass; mastra has no
such script by design (166dc94691) and its pre-existing Mastra `Memory` type
error is byte-identical before and after. `npm run channel` exercised on both
failure paths — missing channels.json, and missing INTELLIGENCE_API_KEY with a
name supplied — confirming the new `./channels.mjs` specifier resolves under
tsx as well as tsc. `parity:check` output identical to the pre-change baseline.
Refs #6315
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
4.4 KiB
CopilotKit <> MCP Apps Starter
This is a starter template for integrating MCP Apps with CopilotKit. It uses the Three.js example from the official Model Context Protocol organization on GitHub.
https://github.com/user-attachments/assets/8908af31-2b64-4426-9c83-c51ab86256de
Project Structure
.
├── app/ # Next.js App Router pages and API routes
│ ├── page.tsx # Main page
│ └── api/copilotkit/ # CopilotKit API route
├── threejs-server/ # MCP App Server (Three.js)
│ ├── server.ts # Server entry point
│ ├── src/ # Three.js app source
│ └── package.json
├── scripts/ # MCP server run scripts
├── next.config.ts
├── tsconfig.json
└── package.json
Prerequisites
Getting Started
- Install dependencies using your preferred package manager:
# Using npm (default)
npm install
# Using pnpm
pnpm install
# Using yarn
yarn install
# Using bun
bun install
The
postinstallscript automatically installs the MCP server dependencies inthreejs-server/.
- Set up your environment variables:
echo 'OPENAI_API_KEY=your-openai-api-key-here' > .env
- Start the development servers:
# Using npm (default)
npm run dev
# Using pnpm
pnpm dev
# Using yarn
yarn dev
# Using bun
bun run dev
This starts both the Next.js app and the MCP server concurrently.
Running a Channel
channel-host.mts mounts the same agent as an Intelligence Channel
(Slack, Teams). It requires INTELLIGENCE_API_KEY and a declared Channel in
.copilotkit/channels.json — set both up with copilotkit init or
copilotkit channels add, which write that file and the credentials your
.env needs, then:
npm run channel
The host reads which Channel to hold from .copilotkit/channels.json. If a
project declares more than one, set INTELLIGENCE_CHANNEL_NAME to pick one.
The host holds no provider credentials and exposes no provider endpoint — Intelligence owns the provider edge — so the same file works for every provider.
The Channel itself is declared in channels.mts — that is where to add commands,
reactions, or an onMention handler. channel-host.mts only owns the process
lifetime, and is byte-identical in every starter.
Once startup finishes, the log reports the truth per Channel:
Channel "<name>" is online.— the session is up and can send.Channel "<name>" is declared but no provider is attached yet.— a normal waiting state, not a failure. Runcopilotkit channels statusto see what setup remains.
Neither message proves the provider app is installed, reachable, or that anyone can message it — verify that separately (invite the bot, then message it) before treating the Channel as working.
Available Scripts
The following scripts can also be run using your preferred package manager:
dev- Starts both the UI and MCP server in development modedev:ui- Starts only the Next.js UI serverdev:mcp- Starts only the MCP App Serverbuild- Builds the Next.js application for productionstart- Starts the production serverchannel- Holds an Intelligence Channel open (see "Running a Channel" above)typecheck:channel- Type-checks the channel host on its owntsconfig.channel.json
Customization
The main UI component is in app/page.tsx. You can:
- Modify the theme colors and styling
- Add new frontend actions
- Customize the CopilotKit sidebar appearance
The MCP App Server code is in threejs-server/.
Documentation
- CopilotKit Documentation - Explore CopilotKit's capabilities
- Next.js Documentation - Learn about Next.js features and API
- MCP Apps Documentation - Learn more about MCP Apps and how to use it
Contributing
Feel free to submit issues and enhancement requests! This starter is designed to be easily extensible.
License
This project is licensed under the MIT License - see the LICENSE file for details.