hn-mcp-server

<div align="center">
  <h1>@cyanheads/hn-mcp-server</h1>
  <p><b>Browse Hacker News feeds, threads, and user profiles with full-text search via MCP. STDIO or Streamable HTTP.</b>
  <div>4 Tools</div>
  </p>
</div>

<div align="center">

[![Version](https://img.shields.io/badge/Version-0.5.10-blue.svg?style=flat-square)](./CHANGELOG.md) [![License](https://img.shields.io/badge/License-Apache%202.0-orange.svg?style=flat-square)](./LICENSE) [![Docker](https://img.shields.io/badge/Docker-ghcr.io-2496ED?style=flat-square&logo=docker&logoColor=white)](https://github.com/users/cyanheads/packages/container/package/hn-mcp-server) [![MCP SDK](https://img.shields.io/badge/MCP%20SDK-^1.29.0-green.svg?style=flat-square)](https://modelcontextprotocol.io/) [![npm](https://img.shields.io/npm/v/@cyanheads/hn-mcp-server?style=flat-square&logo=npm&logoColor=white)](https://www.npmjs.com/package/@cyanheads/hn-mcp-server) [![TypeScript](https://img.shields.io/badge/TypeScript-^5.9.3-3178C6.svg?style=flat-square)](https://www.typescriptlang.org/) [![Bun](https://img.shields.io/badge/Bun->=1.3.0-f9f1e1.svg?style=flat-square)](https://bun.sh/)

</div>

<div align="center">

[![Install in Claude Desktop](https://img.shields.io/badge/Install_in-Claude_Desktop-D97757?style=for-the-badge&logo=anthropic&logoColor=white)](https://github.com/cyanheads/hn-mcp-server/releases/latest/download/hn-mcp-server.mcpb) [![Install in Cursor](https://cursor.com/deeplink/mcp-install-dark.svg)](https://cursor.com/en/install-mcp?name=hn-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvaG4tbWNwLXNlcnZlciJdfQ==) [![Install in VS Code](https://img.shields.io/badge/VS_Code-Install_Server-0098FF?style=for-the-badge&logo=visualstudiocode&logoColor=white)](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22hn-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads/hn-mcp-server%22%5D%7D)

[![Framework](https://img.shields.io/badge/Built%20on-@cyanheads/mcp--ts--core-67E8F9?style=flat-square)](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)

</div>

<div align="center">

**Public Hosted Server:** [https://hn.caseyjhand.com/mcp](https://hn.caseyjhand.com/mcp)

</div>

---

## Tools

Four read-only tools for accessing Hacker News data:

| Tool Name | Description |
|:----------|:------------|
| `hn_get_stories` | Fetch stories from an HN feed (top, new, best, ask, show, jobs) with pagination. |
| `hn_get_thread` | Get an item and its comment tree as a threaded discussion with depth/count controls. |
| `hn_get_user` | Fetch a user profile with karma, about, and optionally their recent submissions. |
| `hn_search_content` | Search stories and comments via Algolia with type, author, date, and score filters. |

### `hn_get_stories`

Fetch stories from any HN feed with pagination support.

- Six feed types: `top`, `new`, `best`, `ask`, `show`, `jobs`
- Configurable count (1–100, default 30) and offset for pagination
- Returns enriched story objects with title, URL, score, author, comment count, and body text

---

### `hn_get_thread`

Retrieve an item and its full comment tree via ranked breadth-first traversal.

- Depth control (0–10, default 3) — depth 0 doubles as a single-item lookup
- Comment limit (1–200, default 50) caps total comments across all levels
- Breadth-first traversal preserves HN's ranking order
- Flat comment list with `depth`/`parentId` for tree reconstruction

---

### `hn_get_user`

Fetch a user profile with optional recent submission resolution.

- Profile includes karma, creation date, and about text (HTML stripped)
- Optionally resolves up to 50 most recent submissions into full items
- Submission resolution filters out dead/deleted items

---

### `hn_search_content`

Full-text search via the Algolia HN Search API.

- Filter by content type: `story`, `comment`, `ask_hn`, `show_hn`, `front_page`
- Filter by author, date range (ISO 8601), and minimum points
- Sort by relevance or date
- Pagination with page/count controls

## Features

Built on [`@cyanheads/mcp-ts-core`](https://github.com/cyanheads/mcp-ts-core):

- Declarative tool definitions — single file per tool, framework handles registration and validation
- Unified error handling across all tools
- Structured logging with request correlation
- Runs locally (stdio/HTTP) from the same codebase

HN-specific:

- Server-level `instructions` orientation forwarded to LLM clients on `initialize` — item types, ID reuse across tools, case-sensitive usernames, and field sparsity expectations
- Concurrent batch fetching with configurable parallelism for item resolution
- HTML entity decoding and tag stripping with code block and link preservation
- No API keys required — HN APIs are public

## Getting Started

### Public Hosted Instance

A public instance is available at `https://hn.caseyjhand.com/mcp` — no installation required. Point any MCP client at it via Streamable HTTP:

```json
{
  "mcpServers": {
    "hn-mcp-server": {
      "type": "streamable-http",
      "url": "https://hn.caseyjhand.com/mcp"
    }
  }
}
```

### Self-Hosted / Local

Add to your MCP client configuration file:

```json
{
  "mcpServers": {
    "hn-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/hn-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}
```

Or with npx (no Bun required):

```json
{
  "mcpServers": {
    "hn-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/hn-mcp-server"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}
```

Or with Docker:

```json
{
  "mcpServers": {
    "hn-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "ghcr.io/cyanheads/hn-mcp-server:latest"
      ]
    }
  }
}
```

### Prerequisites

- [Bun v1.3.0](https://bun.sh/) or higher (or Node.js >= 24)

### Installation

```sh
git clone https://github.com/cyanheads/hn-mcp-server.git
cd hn-mcp-server
bun install
```

## Configuration

All configuration is via environment variables. No API keys required — HN APIs are public.

| Variable | Description | Default |
|:---------|:------------|:--------|
| `HN_CONCURRENCY_LIMIT` | Max concurrent HTTP requests for batch item fetches (1–50). | `10` |
| `MCP_TRANSPORT_TYPE` | Transport: `stdio` or `http`. | `stdio` |
| `MCP_HTTP_PORT` | HTTP server port. | `3010` |
| `MCP_HTTP_HOST` | HTTP server host. | `localhost` |
| `MCP_LOG_LEVEL` | Log level: `debug`, `info`, `notice`, `warning`, `error`. | `info` |
| `LOGS_DIR` | Directory for log files (Node.js only). | `<project-root>/logs` |

## Running the Server

### Local Development

```sh
MCP_TRANSPORT_TYPE=stdio bun --watch src/index.ts   # Dev mode (stdio, auto-reload)
MCP_TRANSPORT_TYPE=http bun --watch src/index.ts    # Dev mode (HTTP, auto-reload)
bun run test                                         # Run test suite
bun run devcheck                                     # Lint + format + typecheck + audit
```

### Production

```sh
bun run build
bun run start:stdio     # or start:http
```

### Docker

```sh
docker build -t hn-mcp-server .
docker run -p 3010:3010 hn-mcp-server
```

## Project Structure

| Directory | Purpose |
|:----------|:--------|
| `src/index.ts` | `createApp()` entry point. |
| `src/config/` | Server-specific env var parsing with Zod. |
| `src/services/hn/` | HN Firebase + Algolia API client and domain types. |
| `src/mcp-server/tools/definitions/` | Tool definitions (`*.tool.ts`). |

## Development Guide

See [`CLAUDE.md`](./CLAUDE.md) for development guidelines and architectural rules. The short version:

- Handlers throw, framework catches — no `try/catch` in tool logic
- Use `ctx.log` for request-scoped logging
- All tools are read-only — no auth scopes required

## Contributing

Issues and pull requests are welcome. Run checks before submitting:

```sh
bun run devcheck
bun run test
```

## License

Apache-2.0 — see [LICENSE](LICENSE) for details.