Reletter
Search and analyze 7M+ newsletters, issues, contacts, and chart rankings from Reletter.
Open source Repository Open in the app JSON README (API)
About
Search and analyze 7M+ newsletters, issues, contacts, and chart rankings from Reletter.
Details
- Kind
- MCP servers
- Topic
- Marketing & analytics
- Publisher
- com.reletter
- Origin
- official
- Category
- ferramentas
- Transport
- http
- Version
- 0.1.0
- Last push
- 2026-08-07T15:43:17Z
- Repository state
- ativo
- Language
- TypeScript
- License
- MIT
- Added
- 2026-08-29 03:01:20
- Updated
- 2026-08-29 03:01:20
- Origin id
com.reletter/reletter
README
# Reletter MCP Server
Give 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.
This 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).
## Use cases
- **Read and analyze newsletter issues** — pull the full body text of any indexed issue into your AI workflow
- **Search and discover newsletters** — find newsletters by topic, platform, or audience size
- **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
- **Build sponsorship, cross-promotion, and PR target lists** — pull verified contacts and export them to your CRM
- **Monitor brand or keyword mentions** — track when your brand, competitors, or clients are mentioned across newsletters
- **Track chart rankings** — daily Substack / LinkedIn / Kit / Reletter chart data
## Tools
- **search_publications** — Search for newsletters by topic, title, or author with filters
- **search_issues** — Full-text search across newsletter issue bodies
- **autocomplete** — Suggested keywords and matching newsletters for a partial query
- **get_publication** — Full metadata for a newsletter (subscribers, engagement, social, rankings, SEO reach)
- **list_issues** — Recent issues for a publication
- **get_issue** — A single issue with body text
- **contacts** — Email contacts, contact pages, social accounts for a newsletter
- **chart_categories** — Available chart platforms and categories
- **chart_rankings** — Latest chart rankings for a platform / category
- **list_languages** — Reference list of languages
- **api_quota** — Your API request quota and usage for the month
## Setup
You need a Reletter API key. [Get one here](https://reletter.com/developers).
For 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.
### ChatGPT
1. Go to **Settings** → **Apps** → **Advanced settings** and enable **Developer mode**
2. Click **Create app**
3. Enter Name: `Reletter`
4. Enter MCP Server URL: `https://mcp.reletter.com`
5. Click **Create** and enter your Reletter API key when prompted
### Claude.ai
1. Go to **Settings** → **Connectors**
2. Click **Add custom connector** and enter name `Reletter` and MCP server URL `https://mcp.reletter.com`
3. Click **Add** and enter your Reletter API key when prompted
### Claude Desktop
Add to your config file and restart Claude Desktop:
- macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`
- Windows: `%APPDATA%\Claude\claude_desktop_config.json`
```json
{
"mcpServers": {
"reletter": {
"url": "https://mcp.reletter.com"
}
}
}
```
### Claude Code
Add to your project's `.mcp.json`:
```json
{
"mcpServers": {
"reletter": {
"type": "http",
"url": "https://mcp.reletter.com"
}
}
}
```
### Cursor
Go to **Settings** → **MCP** → **Add new MCP server**. Set type to **URL** and enter `https://mcp.reletter.com`.
---
<details>
<summary><h3>Development</h3></summary>
If you want to fork or customize this MCP server for your own needs, here is how you can run or deploy it.
### Prerequisites
- Node.js
- A [Cloudflare account](https://dash.cloudflare.com) (for deployment)
### Local dev
```bash
npm install
npm start
```
The server runs at `http://localhost:8789`. Test with the MCP Inspector:
```bash
npx @modelcontextprotocol/inspector@latest
```
### Type-check
```bash
npm run type-check
```
### Regenerate Cloudflare types
After changing `wrangler.jsonc`:
```bash
npm run cf-typegen
```
</details>