> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.merge.dev/merge-agent-handler/build/authentication/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.merge.dev/_mcp/server.

# Authentication

> Build once. Connect to every API, tool, and LLM. Ship products and agents to production without owning the integration stack.

## Docs

- [Link](https://docs.merge.dev/merge-agent-handler/build/authentication/link.md): How to integrate Agent Handler's Link component: when it runs, how to embed it, callback handling, error states.
- [Magic Link](https://docs.merge.dev/merge-agent-handler/build/authentication/magic-link.md): How Magic Link works in Agent Handler: when to use it instead of embedded Link, callback URLs, and authorization code exchange for server-to-server flows.
- [Link customization](https://docs.merge.dev/merge-agent-handler/build/authentication/link-customization.md): How to upload a logo, enable co-branding, and customize the Link flow's appearance.