Skip to main content
Composio TypeScript SDK supports multiple JavaScript runtimes with varying levels of compatibility.

​
Supported Platforms

​
Node.js ✅

Fully Supported - All features work out of the box. 
node >= 18.0.0

import { Composio } from '@composio/core';

const composio = new Composio({ apiKey: 'your-key' });
Features:
  • ✅ All API methods
  • ✅ File operations
  • ✅ Triggers (Pusher)
  • ✅ MCP servers
  • ✅ Tool Router
  • ✅ Custom tools

​
Bun ✅

Fully Supported - Optimized for Bun runtime. 
bun >= 1.0.0

import { Composio } from '@composio/core';

const composio = new Composio({ apiKey: 'your-key' });
Features:
  • ✅ All API methods
  • ✅ File operations (Bun.file)
  • ✅ Triggers
  • ✅ Faster performance than Node.js

​
Deno ⚠️

Partially Supported - Requires permissions. 
// Import from npm:
import { Composio } from 'npm:@composio/core';

const composio = new Composio({ apiKey: 'your-key' });
Required Permissions: 
deno run --allow-net --allow-read --allow-write --allow-env your-script.ts
Features:
  • ✅ All API methods
  • ⚠️ File operations (with —allow-read/—allow-write)
  • ✅ Triggers
  • ⚠️ May require additional permissions

​
Cloudflare Workers ⚠️

Partially Supported - No filesystem access. 
import { Composio } from '@composio/core';

export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext) {
    const composio = new Composio({ apiKey: env.COMPOSIO_API_KEY });
    
    const result = await composio.tools.execute('GITHUB_GET_REPOS', {
      userId: 'default',
      arguments: { owner: 'composio' }
    });
    
    // Important: Flush telemetry before worker terminates
    ctx.waitUntil(composio.flush());
    
    return new Response(JSON.stringify(result));
  }
};
Features:
  • ✅ Tool execution
  • ✅ Connected accounts
  • ✅ Auth configs
  • ❌ File operations (no fs)
  • ⚠️ Triggers (requires Durable Objects)
  • ⚠️ Must call flush() before termination
Limitations:
  • No filesystem access
  • No persistent storage
  • Must manually flush telemetry
  • Limited to 50ms CPU time

​
Browser ⚠️

Limited Support - Use for client-side auth flows only. 
import { Composio } from '@composio/core';

const composio = new Composio({ apiKey: 'your-public-key' });

// ⚠️ Don't expose your API key in browser!
// Use backend proxy for sensitive operations

const connectionRequest = await composio.connectedAccounts.link(
  'user_123',
  'auth_config_abc'
);

window.location.href = connectionRequest.redirectUrl;
Features:
  • ⚠️ Limited to public APIs
  • ✅ Connection flows
  • ❌ Tool execution (use backend)
  • ❌ File operations
  • ❌ Triggers
Security Warning:
Never expose your Composio API key in browser code. Use a backend proxy for sensitive operations.

​
Feature Compatibility Matrix

FeatureNode.jsBunDenoCloudflareBrowser
Tools API✅✅✅✅⚠️
Toolkits✅✅✅✅✅
Connected Accounts✅✅✅✅⚠️
Auth Configs✅✅✅✅⚠️
Triggers✅✅✅⚠️❌
File Operations✅✅⚠️❌❌
Custom Tools✅✅✅✅❌
MCP Servers✅✅⚠️❌❌
Tool Router✅✅✅⚠️❌

​
Platform-Specific Code

​
Cloudflare Workers

import { Composio } from '@composio/core';

export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext) {
    const composio = new Composio({
      apiKey: env.COMPOSIO_API_KEY,
      // Disable file operations
      autoUploadDownloadFiles: false
    });

    try {
      const tools = await composio.tools.get('default', {
        toolkits: ['github']
      });

      return new Response(JSON.stringify(tools));
    } finally {
      // Always flush telemetry
      ctx.waitUntil(composio.flush());
    }
  }
};

​
Deno

// deno.json
{
  "imports": {
    "@composio/core": "npm:@composio/core"
  },
  "tasks": {
    "dev": "deno run --allow-all main.ts"
  }
}

// main.ts
import { Composio } from '@composio/core';

const composio = new Composio({
  apiKey: Deno.env.get('COMPOSIO_API_KEY')!
});

const tools = await composio.tools.get('default', {
  toolkits: ['github']
});

console.log(tools);

​
Testing

Run platform-specific tests: 
# Node.js
pnpm test

# Node.js CJS/ESM compatibility
pnpm test:e2e:node

# Deno
pnpm test:e2e:deno

# Cloudflare Workers
pnpm test:e2e:cloudflare

​
Best Practices

  1. Platform Detection: Check runtime before using platform-specific features
  2. Graceful Degradation: Disable unsupported features
  3. Error Handling: Handle platform-specific errors
  4. Testing: Test on target platform
  5. Documentation: Document platform requirements

​
Troubleshooting

​
”fs module not found” in Cloudflare Workers

// Disable file operations
const composio = new Composio({
  apiKey: 'your-key',
  autoUploadDownloadFiles: false
});

​
”Telemetry not flushing” in Workers

// Always call flush()
ctx.waitUntil(composio.flush());

​
Permission errors in Deno

# Grant required permissions
deno run --allow-net --allow-env --allow-read --allow-write your-script.ts

​
Next Steps

Installation

Get started

Files API

File operations

Composio Class

Main SDK reference

Examples

View examples

Build docs developers (and LLMs) love

Get started for freeTalk to us