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MCP

The MCP server is mounted at /mcp and served over streamable HTTP.

Public OSS Tools

These tools are available in OSS without gateway auth:

  • get_note
  • get_post
  • get_post_comments
  • get_profile
  • get_profile_posts
  • get_profile_notes

These tools read public Substack content only.

Authenticated Tools

The codebase also defines authenticated MCP operations for:

  • create_note
  • delete_note
  • get_me
  • get_my_notes
  • get_my_posts
  • get_my_following

Those tools require an explicit token argument carrying the base64-encoded Substack credential JSON.

Whether authenticated tools are exposed depends on the active runtime and extension setup.

Transport Notes

  • Path: /mcp
  • Transport: streamable HTTP
  • Root MCP app path: /
  • HTTP mode: stateless

Extension Hooks

Extensions can register more MCP tools through the GatewayExtension interface. This is how custom deployments can add additional capabilities or custom auth handling on top of OSS.