{
  "markdown": "# Reletter MCP Server\n\nGive AI agents and LLMs access to newsletter data from [Reletter](https://reletter.com). Search 7M+ email newsletters across **Substack**, **LinkedIn**, **Ghost**, **Beehiiv**, and **Kit**. Fetch metadata, contacts, issues, and chart rankings.\n\nThis is a remote Model Context Protocol (MCP) server that connects AI assistants like Claude, ChatGPT, and Cursor to the [Reletter API](https://reletter.com/developers).\n\n## Use cases\n\n- **Read and analyze newsletter issues** — pull the full body text of any indexed issue into your AI workflow\n- **Search and discover newsletters** — find newsletters by topic, platform, or audience size\n- **Find newsletters to pitch** — get your product, tool, or book featured. Filter by audience size, topic, or platform, then pull verified contact emails in one pass\n- **Build sponsorship, cross-promotion, and PR target lists** — pull verified contacts and export them to your CRM\n- **Monitor brand or keyword mentions** — track when your brand, competitors, or clients are mentioned across newsletters\n- **Track chart rankings** — daily Substack / LinkedIn / Kit / Reletter chart data\n\n## Tools\n\n- **search_publications** — Search for newsletters by topic, title, or author with filters\n- **search_issues** — Full-text search across newsletter issue bodies\n- **autocomplete** — Suggested keywords and matching newsletters for a partial query\n- **get_publication** — Full metadata for a newsletter (subscribers, engagement, social, rankings, SEO reach)\n- **list_issues** — Recent issues for a publication\n- **get_issue** — A single issue with body text\n- **contacts** — Email contacts, contact pages, social accounts for a newsletter\n- **chart_categories** — Available chart platforms and categories\n- **chart_rankings** — Latest chart rankings for a platform / category\n- **list_languages** — Reference list of languages\n- **api_quota** — Your API request quota and usage for the month\n\n## Setup\n\nYou need a Reletter API key. [Get one here](https://reletter.com/developers).\n\nFor autonomous agents that want to provision a key without a human in the loop, Reletter implements the [Machine Payments Protocol](https://mpp.dev). Hit `POST https://api.reletter.com/api/payments/buy/` to get a 402 challenge, pay with a Stripe Shared Payment Token or with USDC on Tempo, and the response carries an API key tied to a freshly-provisioned account. Current bundle tiers: `GET https://api.reletter.com/api/payments/bundles/`. See https://reletter.com/llms-full.txt for the full flow.\n\n### ChatGPT\n\n1. Go to **Settings** → **Apps** → **Advanced settings** and enable **Developer mode**\n2. Click **Create app**\n3. Enter Name: `Reletter`\n4. Enter MCP Server URL: `https://mcp.reletter.com`\n5. Click **Create** and enter your Reletter API key when prompted\n\n### Claude.ai\n\n1. Go to **Settings** → **Connectors**\n2. Click **Add custom connector** and enter name `Reletter` and MCP server URL `https://mcp.reletter.com`\n3. Click **Add** and enter your Reletter API key when prompted\n\n### Claude Desktop\n\nAdd to your config file and restart Claude Desktop:\n\n- macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`\n- Windows: `%APPDATA%\\Claude\\claude_desktop_config.json`\n\n```json\n{\n  \"mcpServers\": {\n    \"reletter\": {\n      \"url\": \"https://mcp.reletter.com\"\n    }\n  }\n}\n```\n\n### Claude Code\n\nAdd to your project's `.mcp.json`:\n\n```json\n{\n  \"mcpServers\": {\n    \"reletter\": {\n      \"type\": \"http\",\n      \"url\": \"https://mcp.reletter.com\"\n    }\n  }\n}\n```\n\n### Cursor\n\nGo to **Settings** → **MCP** → **Add new MCP server**. Set type to **URL** and enter `https://mcp.reletter.com`.\n\n---\n<details>\n<summary><h3>Development</h3></summary>\n\nIf you want to fork or customize this MCP server for your own needs, here is how you can run or deploy it.\n\n### Prerequisites\n\n- Node.js\n- A [Cloudflare account](https://dash.cloudflare.com) (for deployment)\n\n### Local dev\n\n```bash\nnpm install\nnpm start\n```\n\nThe server runs at `http://localhost:8789`. Test with the MCP Inspector:\n\n```bash\nnpx @modelcontextprotocol/inspector@latest\n```\n\n### Type-check\n\n```bash\nnpm run type-check\n```\n\n### Regenerate Cloudflare types\n\nAfter changing `wrangler.jsonc`:\n\n```bash\nnpm run cf-typegen\n```\n\n</details>\n",
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  "repo_slug": "getreletter/reletter-mcp",
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