--- canonical_url: "https://docs.composio.dev/kb/guide/toolkits-mailchimp" markdown_url: "https://docs.composio.dev/kb/guide/toolkits-mailchimp.md" product: "platform" version: null last_updated: null --- # Mailchimp (/kb/guide/toolkits-mailchimp) ## Mailchimp server prefix is the URL prefix before .admin.mailchimp.com [#mailchimp-server-prefix-is-the-url-prefix-before-adminmailchimpcom] When connecting Mailchimp, pass the correct server prefix. It is the part of the Mailchimp URL before `.admin.mailchimp.com`. For example, if the Mailchimp URL is `https://us19.admin.mailchimp.com/`, the server prefix is `us19`. A wrong prefix can cause Mailchimp API calls to fail even if the API key/token itself looks correct. ## Use subdomain or dc, not server\_prefix, for Mailchimp connectionConfig [#use-subdomain-or-dc-not-server_prefix-for-mailchimp-connectionconfig] For Mailchimp API connection configuration, send `connectionConfig.subdomain` with the server prefix value, or use the legacy alias `dc`. Do not send `server_prefix`; that key is ignored by the validator and may fall back to a default such as `us21`. The UI label may say Server Prefix, but the API field name is `subdomain`. ## Some Mailchimp tools require at least the Mailchimp Essentials plan [#some-mailchimp-tools-require-at-least-the-mailchimp-essentials-plan] If Mailchimp tools fail despite the connection looking correct, check the customer's Mailchimp plan. Some Mailchimp API/tool capabilities require at least the Mailchimp Essentials plan. A free Mailchimp account may not be enough for the requested tool flow. ## Mailchimp Proxy Execute with raw access token also needs subdomain [#mailchimp-proxy-execute-with-raw-access-token-also-needs-subdomain] When using Proxy Execute with Mailchimp custom connection data, include both the OAuth access token and Mailchimp `subdomain`/server prefix. The endpoint can then be called through `/api/v3/tools/execute/proxy` with `toolkitSlug: "mailchimp"`, `authScheme: "OAUTH2"`, and `val` containing `access_token` plus `subdomain` such as `us20`. ## Mailchimp has trigger support in the supported-trigger toolkit list [#mailchimp-has-trigger-support-in-the-supported-trigger-toolkit-list] Mailchimp appears in the supported-trigger toolkit list. Before using a specific Mailchimp trigger, verify that the exact trigger or event exists in the current toolkit. If it does not, submit the use case through the Composio request portal. --- 📚 **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.