Reletter is the newsletter data platform that tracks and indexes 6m+ email newsletters across Substack, LinkedIn and Ghost. We provide subscriber numbers, chart rankings, contact details, full issue text and lots more.
This org hosts our open-source SDKs and tools.
- reletter-mcp: MCP server connecting Claude, ChatGPT, and Cursor to Reletter
- reletter-python: official Python client (
pip install reletter) - API docs: REST reference
- llms-full.txt: full API reference in a single markdown file, for LLMs