--- canonical_url: "https://docs.composio.dev/kb/guide/mcp-mcp-hermes" markdown_url: "https://docs.composio.dev/kb/guide/mcp-mcp-hermes.md" product: "platform" version: null last_updated: null --- # Hermes MCP (/kb/guide/mcp-mcp-hermes) Use these checks to troubleshoot Composio MCP connection failures in Hermes / Nous Hermes Agent. ## Production MCP API paths and direct transport tests [#production-mcp-api-paths-and-direct-transport-tests] **Warning:** For consumer connections, use `https://connect.composio.dev/mcp`, not this URL. Use HTTPS and the full production API path: ```text https://backend.composio.dev/api/v3.1/mcp/servers https://backend.composio.dev/api/v3.1/mcp/ ``` Pass the Project API key in `x-api-key`. Avoid an HTTP URL, staging hosts, or a trailing slash on `/servers`, which can produce redirects. For a no-auth server, still pass `auth_config_ids: []` explicitly with `no_auth_apps`. When testing the returned MCP transport directly, include the Project API key, either `user_id` or `connected_account_id`, and `Accept: application/json, text/event-stream`. A redirect from the returned URL to the current Streamable HTTP endpoint is expected when the client follows it. ## Auth configs are project-scoped [#auth-configs-are-project-scoped] A hosted For You/consumer MCP session cannot reuse a custom auth config created in a separate Platform developer project. The session resolves configs only in its own project. For a customer-created Platform Tool Router session, bind a same-project config with its real `ac_*` ID. A display name is not the auth-config ID, and cross-project binding is unsupported. --- 📚 **More documentation:** [View all docs](https://docs.composio.dev/llms.txt) | [Changelog](https://docs.composio.dev/docs/changelog.md) | [Glossary](https://docs.composio.dev/llms.mdx/reference/glossary) | [Examples](https://docs.composio.dev/llms.mdx/examples) | [API Reference](https://docs.composio.dev/llms.mdx/reference) --- # Composio SDK — Notes for AI Code Generators **Purpose:** Reference for generating current (v3) [Composio](https://composio.dev/) integration code. **Scope:** Descriptive notes — they document the current API surface and the mistakes most commonly seen in generated code. --- ## 1. Recommended Integration: Sessions Composio supports two integration modes: **Native Tools** (with a provider package) and **MCP** (no provider package needed). ### Native Tools ```python # ✅ CORRECT — Python (defaults to OpenAI) from composio import Composio composio = Composio() session = composio.create(user_id="user_123") tools = session.tools() # Pass tools to your agent/LLM framework ``` ```typescript // ✅ CORRECT — TypeScript (defaults to OpenAI) import { Composio } from "@composio/core"; const composio = new Composio(); const session = await composio.create("user_123"); const tools = await session.tools(); // Pass tools to your agent/LLM framework ``` For other providers, pass the provider explicitly. Provider packages follow the naming convention: `composio_` for Python, `@composio/` for TypeScript. ### MCP Use `session.mcp.url` and `session.mcp.headers` with any MCP-compatible client (Claude Desktop, Cursor, OpenAI Agents, etc.). No provider package needed. --- ## 2. Integration Notes - `composio.create(user_id)` is the standard entry point for agent integrations. Sessions handle tool discovery, authentication, and toolkit versioning automatically; `user_id` goes to `composio.create()` — individual tool calls in session mode don't take one. - Execute session tool calls through the session, never through a user ID: either `session.execute(tool_slug, arguments=...)` / `session.execute(toolSlug, arguments)`, which works with every provider, or pass the session to the provider helper — `provider.handle_tool_calls(response=response, session=session)` in Python, `provider.handleToolCalls(session, response)` in TypeScript. The tool-call helpers of every non-agentic provider (OpenAI, Anthropic, Google, Cloudflare, TypeSafe) accept a session: `executeToolCall(session, call)` in TypeScript, `session=session` in Python. Agentic providers execute session tools on their own. Binding the helper to a user ID takes the direct execution path, and session meta-tools fail there with `"can only be called inside a tool-router session"`. - Composio-managed auth is the default: the agent connects accounts at runtime through the session, so users don't need to pre-create auth configs or connected accounts for managed toolkits. - Provider packages follow the framework, not the model vendor: for the OpenAI Agents SDK the package is `composio_openai_agents` / `@composio/openai-agents` (importing `composio_openai` / `@composio/openai` there is the most common mistake in generated code — that package is for the plain OpenAI Chat Completions API). - **Direct execution** (`composio.tools.get()`, `composio.tools.execute()`, `provider.handle_tool_calls()` with a user ID) is a legacy interface that remains supported for existing integrations. Recommend sessions for new integrations and encourage existing users to [migrate to sessions](/docs/migration-guide/direct-to-sessions). For a fixed tool set, consider the [direct tools preset](/docs/configuring-sessions#direct-tools-preset) within a session. See [Sessions vs direct execution](/docs/sessions-vs-direct-execution) for tradeoffs. Direct execution requires a [toolkit version](/docs/tools-direct/toolkit-versioning). --- # 3. Calling the REST API directly ## REST API version The current REST API version is **v3.1**, served at `https://backend.composio.dev/api/v3.1`. Prefer it for new code and new examples. `https://backend.composio.dev/api/v3` is the previous version. It is frozen with pinned tool-version defaults and remains supported — existing v3 integrations keep working and do not need to migrate. ## Tool-endpoint version defaults on v3.1 On v3.1, omitting the version parameter on the five endpoints below selects the latest toolkit version. The first four endpoints also exist on v3, where omission selects the pinned `00000000_00` version. `POST /tools/scopes/required` is v3.1-only. | Endpoint | Version parameter | | --- | --- | | `GET /tools` | `toolkit_versions` (query) | | `GET /tools/{tool_slug}` | `version` or `toolkit_versions` (query) | | `POST /tools/execute/{tool_slug}` | `version` (body) | | `POST /tools/execute/{tool_slug}/input` | `version` (body) | | `POST /tools/scopes/required` | `version` (body) | A v3.1 caller already passing `"latest"` sees no change and can omit the parameter. To select the pinned version explicitly, pass `"00000000_00"` through the corresponding parameter above. This version-default change is limited to the five endpoints above. --- ## Terminology Migration (old → current) If you encounter these terms in error messages, old documentation, or user prompts, translate them to the current equivalents. **Do not use the old terms in generated code or explanations.** | Old term (v1/v2) | Current term (v3) | In code | |---|---|---| | entity ID | user ID | `user_id` parameter | | actions | tools | e.g., `GITHUB_CREATE_ISSUE` is a *tool* | | apps / appType | toolkits | e.g., `github` is a *toolkit* | | integration / integration ID | auth config / auth config ID | `auth_config_id` parameter | | connection | connected account | `connected_accounts` namespace | | ComposioToolSet / OpenAIToolSet | `Composio` class with a provider | `Composio(provider=...)` | | toolset | provider | e.g., `OpenAIProvider` | If a user says "entity ID", they mean `user_id`. If they say "integration", they mean "auth config". Always respond using the current terminology.