Mastra × Composio
Runnable references for using Composio tools with Mastra
agents. Every example uses the unauthenticated HACKERNEWS toolkit, so no
connected account is required — set two keys and run.
These examples double as tests: they are typechecked and linted on every PR, and executed nightly against the staging backend.
Setup
pnpm install
cp .env.example .env # then fill in COMPOSIO_API_KEY and OPENAI_API_KEY
COMPOSIO_API_KEY— Composio dashboardOPENAI_API_KEY— the examples default to OpenAI (gpt-5-mini)
Examples
| File | What it shows | Run |
|---|---|---|
src/index.ts |
Direct tools: fetch one Composio tool as a Mastra tool | bun ts/examples/mastra/src/index.ts |
src/tool-router.ts |
Tool Router (v1-canonical): composio.sessions.create(...) → session.tools() |
bun ts/examples/mastra/src/tool-router.ts |
src/cloudflare.ts |
The same Tool Router agent path on the Cloudflare Workers runtime | bun run cf:dev (then GET localhost:8787/) |
From this folder you can also use pnpm start (index), pnpm tool-router, and
pnpm cf:dev.
Using Anthropic instead of OpenAI
The model setup lives in src/hackernews-agent/direct.ts and
src/hackernews-agent/tool-router.ts. Replace the OpenAI provider in the agent
you want to run and add ANTHROPIC_API_KEY to its environment type:
import { createAnthropic } from '@ai-sdk/anthropic';
// ...
const anthropic = createAnthropic({
apiKey: requireKey(env, 'ANTHROPIC_API_KEY'),
});
model: anthropic('claude-haiku-4-5'),
Add @ai-sdk/anthropic to the dependencies and configure the Anthropic key in
the Node environment or Worker bindings, depending on the runtime.
Runtime notes
- Node/Bun:
src/index.tsandsrc/tool-router.tsread keys fromprocess.envviadotenv. - Cloudflare Workers:
src/cloudflare.tsreads keys from the Workerenvbinding (noprocess.env). Provide both keys withwrangler secret put COMPOSIO_API_KEYandwrangler secret put OPENAI_API_KEY. CI validates the Worker build withwrangler deploy --dry-run.