composio

Composio maintains a centralized tool registry of 1000+ pre-built toolkits with OpenAPI-based schemas, enabling agents to dynamically discover and register tools from external services without manual integration. The registry is versioned and accessible via both SDK and MCP protocol, with automatic schema validation and tool metadata caching. Tools are organized hierarchically by service (Slack, GitHub, Salesforce, etc.) with standardized parameter and return type definitions.

Composio provides a centralized authentication system that handles OAuth 2.0 flows, API key storage, and custom auth protocols across all integrated services. Credentials are stored securely in the backend and automatically injected into tool invocations via session-based routing, eliminating the need for agents to manage authentication state. The system supports credential scoping per user, per session, and per tool, with automatic token refresh and expiration handling.

Composio provides a command-line interface (@composio/cli) for local development workflows, including toolkit inspection, custom tool registration, authentication testing, and binary distribution. The CLI supports commands for listing tools, viewing schemas, testing tool execution, and managing local MCP server instances. The CLI is distributed as a Node.js binary and supports both interactive and scripted usage.

Composio enables agents to maintain execution context across multiple tool invocations, including conversation history, execution state, and user context. The context management system automatically tracks tool call sequences, results, and errors, allowing agents to learn from previous executions and make informed decisions. Context is scoped per session and can be persisted to external storage for multi-turn conversations. The system supports context summarization to manage token usage in long conversations.

Composio implements automatic error handling and retry logic for tool execution failures, including exponential backoff, jitter, and configurable retry policies. The system distinguishes between retryable errors (rate limits, transient failures) and non-retryable errors (authentication failures, invalid parameters), applying appropriate handling for each. Retry behavior is configurable per tool or globally, with detailed error reporting including failure reasons and retry attempts.

Composio provides rate limiting and quota management at multiple levels: per-tool rate limits (enforced by external services), per-user quotas (enforced by Composio), and per-session execution limits. The system tracks usage across all tool invocations and enforces limits transparently, returning quota exceeded errors when limits are reached. Rate limit information is available in tool metadata, allowing agents to make informed decisions about tool selection.

Composio uses session objects to encapsulate tool execution context, including authenticated credentials, user identity, and execution environment. Sessions route tool calls to the appropriate provider implementation and automatically inject authentication, file handling, and execution metadata. The routing layer supports both local execution (via SDK) and remote execution (via MCP protocol), with transparent fallback and load balancing across multiple endpoints.

Composio provides a Model Context Protocol (MCP) server implementation that exposes all 1000+ tools as MCP resources, enabling integration with any MCP-compatible client (Claude, LLMs, custom agents). The platform offers both hosted MCP endpoints (mcp.composio.dev) for zero-setup integration and local MCP server binaries for self-hosted deployments. The MCP layer handles schema translation, credential injection, and execution routing transparently.

Composio provides a trigger engine that enables agents to subscribe to real-time events from external services via webhooks and WebSocket connections (Pusher-based). Triggers are defined declaratively per toolkit and automatically handle event ingestion, filtering, and delivery to agent handlers. The system supports both push (webhook) and pull (polling) modes, with automatic retry logic and event deduplication.

Composio abstracts file operations (upload, download, storage) behind a transparent file service that uses S3-based backend storage with presigned URLs. Agents can pass file paths or file objects to tools, and Composio automatically handles upload to S3, generates presigned URLs for tool access, and manages cleanup. The system supports streaming for large files and automatic MIME type detection.

Composio allows developers to define custom tools by providing OpenAPI schemas or Python/TypeScript function signatures, which are automatically converted to tool schemas and integrated into the tool registry. Custom tools support modifiers (decorators) for adding authentication, rate limiting, logging, and error handling without modifying core tool logic. Custom tools can be versioned and shared across agent deployments.

Composio provides provider packages for major LLM frameworks (OpenAI, Anthropic, LangChain, CrewAI, Gemini, Google) that translate between framework-specific function calling formats and Composio's unified tool schema. The provider layer handles framework-specific details (tool definition format, response parsing, error handling) transparently, allowing agents to use Composio tools regardless of underlying LLM provider. Providers are versioned independently and support both synchronous and asynchronous execution.

Composio maintains versioned toolkit definitions, allowing agents to pin specific versions of tool schemas and implementations. Version management is handled transparently — agents can request a specific toolkit version, and Composio routes tool calls to the appropriate implementation. The system supports semantic versioning and provides migration guides for breaking changes. Deprecated toolkit versions are maintained for backward compatibility.

Composio provides a tool search API that enables agents and developers to discover tools by name, category, capability, or natural language description. The search layer supports semantic filtering (e.g., 'tools that send messages') and returns ranked results with relevance scores. Search results include tool metadata (authentication requirements, parameters, rate limits) to help agents select appropriate tools. The search index is updated in real-time as new tools are added to the registry.