Getting started
Authentication is the most common stumbling block. Before you build, read the authentication reference—Claude’s auth support differs from the generic MCP spec in a few important ways.
Key resources
- SDK Examples: TypeScript and Python SDKs contain server implementation examples
- Protocol Specification: modelcontextprotocol.io
- Hosting Solutions: Platforms like Cloudflare offer remote MCP server hosting with autoscaling and OAuth management
- Auth Specifications: Review the authorization spec with emphasis on third-party service flows
Transport & authentication
Supported transports
Claude supports both Streamable HTTP and the legacy HTTP+SSE transport. The legacy HTTP+SSE transport is being deprecated in favor of Streamable HTTP.Authentication features
- Supports the 2025-03-26, 2025-06-18, and 2025-11-25 auth specifications
- Dynamic Client Registration (DCR) enabled
- OAuth callback:
https://claude.ai/api/mcp/auth_callback(hosted surfaces); loopback redirect for Claude Code — see callback URLs - Token refresh and expiry support
- Custom credentials for non-DCR servers
Protocol features
Supported
Not yet supported
- Resource subscriptions
- Sampling
- Advanced/draft capabilities
Technical specifications
| Constraint | Limit |
|---|---|
| Claude.ai/Desktop max tool result size | ~150,000 characters |
| Claude Code max tool result size | 25,000 tokens (configurable via MAX_MCP_OUTPUT_TOKENS) |
| Claude Code timeout | Configurable via MCP_TOOL_TIMEOUT |
| Claude.ai/Desktop timeout | 300 seconds (5 minutes) |
| Transport protocol | Streamable HTTP (legacy HTTP+SSE being deprecated) |
Testing your server
- Add directly to Claude via Settings > Connectors
- Use the MCP inspector tool to validate auth flows
Related topics
MCP Overview
Understanding the Model Context Protocol.
Submit to Directory
Review requirements and submit your connector.