Composio Explained: Tool Integration for AI Agents
Composio is a tool integration platform for AI agents. An agent that needs to file a GitHub issue or post to Slack has to find the right API and get the user's permission first. Then it has to call the API correctly. Composio packages those steps into a session the agent drives at runtime, and its docs cite support for 1,000+ apps. By the end you will know how per-user sessions work and what they cost. You will also know what a session keeps between tasks.
What is Composio, in one sentence?
Composio is a platform that gives an AI agent runtime access to tools from 1,000+ apps through one session per user.
The unit you work with is the session. Composio's API reference notes that sessions were formerly called the tool router, which is why its endpoints still live under that path. You create one session per end user and hand its tools to your agent.
How does Composio differ from wiring up each app yourself?
| Composio session | Your own integrations or MCP servers | |
|---|---|---|
| Tools in the model's context | A small fixed set of meta tools. App schemas load only when needed | Every tool you register, up front |
| Finding the right tool | The agent searches the catalog by use case | You choose tools at build time |
| OAuth | Composio runs the OAuth flow and token refresh | You build and run each flow |
| Per-user isolation | Connections and calls scoped to a user ID | Your own design |
| Pricing | Per tool call (see below) | Your hosting and engineering time |
Composio-side facts come from its quickstart and how Composio works. The right column is our summary of what you take on without a platform.
How do Composio sessions and meta tools work?
A session gives the agent "a small fixed set" of meta tools. They find other tools and connect accounts, then run the calls. The docs name two: COMPOSIO_SEARCH_TOOLS finds tools by use case, and COMPOSIO_MANAGE_CONNECTIONS walks the user through connecting an account. The agent searches in one call and executes in the next without losing state.
A toolkit is a collection of related tools for one service, such as github. A tool is one action, named in a toolkit-action pattern such as GITHUB_CREATE_ISSUE. Every toolkit in the catalog is discoverable by default. When a matching skill exists, search results include its guidance too.
Standard sessions also include a sandbox called the workbench, where the agent can write Python and read files. It can also call tools in bulk from there.
The quickstart covers the OpenAI Agents SDK, the Claude Agent SDK and the Vercel AI SDK. LangChain and CrewAI are also supported. Any MCP client can use a session through its MCP URL and headers.
How does Composio handle authentication for each user?
You create a session with a user ID. Every connection in it is scoped to that ID, and so is every tool call. Auth is Composio-managed by default, and users approve a connection through a Connect Link. Composio handles the OAuth exchange and refreshes tokens.
Connected accounts outlive the session. Once a user connects a toolkit, future sessions reuse that account without asking again. The docs warn against using "default" as a user ID in production, and they mark the example user_123 as fit for local testing only.
What does Composio cost?
Per Composio's pricing page, accessed October 28, 2026:
| Plan | Price | Tool calls |
|---|---|---|
| Hobby | $0, no card required | 100,000 a month. Usage pauses at the cap |
| Pro | $29 a month, as usage credit | $0.0003 per tool call |
| Enterprise | Custom | Custom |
Hobby also includes 50,000 trigger events a month. On Pro, trigger events cost $0.003 each. A meta-tool call is a tool call too, so an agent that searches before it acts uses more than one call per action.
What does a Composio session remember?
The how Composio works page says a session scopes "logs, tool memory, MCP state, and workbench files" for a task. Sessions persist on the server with no time-based expiration. You store the session ID and reuse it across turns. Deleting a session makes it unusable at once.
A new session for the same user picks up that user's connected accounts. It does not inherit the old session's sandbox state. The docs do not say what "tool memory" contains, or whether anything learned in one session informs the next. Retention periods for workbench files and the sandbox are not published either. So Composio carries the user's identity and connected apps forward. What the agent learned about using those apps lives in your own system, if anywhere.
The bottom line
Use Composio when your agent needs many SaaS apps on behalf of many users and you do not want to run the OAuth flows yourself. Start on Hobby and reuse one session per user and task, then count the meta-tool calls in a real workflow before picking a plan. Keep what your agent learns about those apps somewhere you control.
How do you keep what an agent learns about its tools?
A Composio session forgets the hard-won details: which Slack channel the team actually uses or how a CRM stores deal stages. It also loses the sequence of calls that finally produced the right report. When a coding agent such as Claude Code uses Composio over MCP, those lessons end with the session. The next session searches and fumbles its way there again.
memU turns agent history into memory and reusable skills. A scheduled background task slices new session logs into jobs. The agent distills each job into readable Markdown, so a workflow that worked once becomes a skill it can follow next time. memU makes no LLM calls itself. It stores and retrieves what the agent prepared. A standing instruction in CLAUDE.md or AGENTS.md tells the agent to retrieve before it answers. All supported hosts, including Claude Code and Codex, share one backend.
The hosted version is free and syncs across devices. Get an API key from memu.so and send your agent one message:
Read https://memu.pro/SKILL.md, follow its instructions to install and configure memU, API Key is
YOUR_MEMU_API_KEY.
The self-hosted setup is in the memU GitHub repository.
FAQ
How many apps does Composio support?
Composio's docs cite support for 1,000+ apps. Every toolkit in the catalog is discoverable by an agent through a session by default.
Does Composio work with MCP?
Yes. Each session exposes an MCP URL and headers that any MCP-compatible client can use, including coding agents.
Is Composio free?
The Hobby plan is free with 100,000 tool calls a month, and usage pauses at that cap. Pro costs $29 a month in usage credit, then $0.0003 per tool call.
What is the Composio tool router?
Tool router is the former name of Composio sessions. A session gives an agent meta tools that find and run app tools for one user.
Do Composio sessions expire?
No. Sessions are long-lived records with no time-based expiration, though you can delete them. Workbench files and sandbox state are temporary, and their retention periods are not published.