> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://mailchimp.com/developer/marketing/api-concepts/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://mailchimp.com/developer/_mcp/server.

# API core concepts

> Find all the Mailchimp API documentation and tools developers need to send marketing and transactional emails.

## Docs

- [API structure](https://mailchimp.com/developer/marketing/api-concepts/api-structure.md): How the Marketing API is organized—REST conventions and the root URL.
- [Authentication](https://mailchimp.com/developer/marketing/api-concepts/authentication.md): Choose between an API key and an OAuth 2 access token, then attach it to a request.
- [API keys](https://mailchimp.com/developer/marketing/api-concepts/authentication/api-keys.md): How Mailchimp API keys behave, and where they can and cannot be used.
- [OAuth 2](https://mailchimp.com/developer/marketing/api-concepts/authentication/oauth-2.md): How Mailchimp's OAuth 2 flow works, and what your application gets from it.
- [Methods and parameters](https://mailchimp.com/developer/marketing/api-concepts/methods-and-parameters.md): Get to know some of the conventions of the Marketing API.
- [Rate limits and timeouts](https://mailchimp.com/developer/marketing/api-concepts/rate-limits-and-timeouts.md): Connection limits, throttling, and the 120-second timeout on Marketing API calls.
- [Errors](https://mailchimp.com/developer/marketing/api-concepts/errors.md): A glossary of Marketing API errors and how to troubleshoot them.
- [Webhooks](https://mailchimp.com/developer/marketing/api-concepts/webhooks.md): Keep your data store in sync with your Mailchimp audience via webhooks.
- [Batch operations](https://mailchimp.com/developer/marketing/api-concepts/batch-operations.md): Scale large or long-running calls to the Marketing API with batch requests.
- [Alternative schemas](https://mailchimp.com/developer/marketing/api-concepts/alternative-schemas.md): Details about Marketing API endpoints that accept or return multiple types of data.
- [Audiences endpoints (beta)](https://mailchimp.com/developer/marketing/api-concepts/audiences-endpoints-beta.md): Learn about the new audiences endpoints and the concepts they're introducing.