Signals API — MCP server

An MCP server that gives Claude / Cursor / any MCP client AI signals data: today's signals, what changed, and ranked AI models & repositories.

No API key needed for the free tier. Single file, Python standard library only — no pip install.

What it gives an agent

Every ranked row carries a citation string, so an agent can cite the number instead of inventing one. Entities whose number cannot be derived are published as unranked with the reason — we would rather return "not ranked" than a made-up value.

Related MCP server: hn-tech-signal-mcp

Install

1. Download mcp_server.py anywhere (e.g. ~/mcp/signals/mcp_server.py).

2. Add it to your MCP client config:

{
  "mcpServers": {
    "signals": {
      "command": "python3",
      "args": ["/absolute/path/to/mcp_server.py"]
    }
  }
}

Claude Desktop: ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows). Restart the client and the five tools appear.

Requires Python 3.9+. No dependencies, no key, no signup.

Try it without an MCP client

echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"daily_signals","arguments":{}}}' \
  | python3 mcp_server.py

Free tier vs the paid feed

This server reads the free endpoints, which cover one edition a day, 4 sources. If your agent needs more than that, there is a paid feed:

• 8 sources instead of 4 (adds arXiv, LMSYS Arena, hot-topic aggregation, hardware/chips)

• 4 updates a day instead of one daily edition (email / WebPush / API)

• full history and machine-readable archives, with a stable API key

• BASIC — CA$9.90/month — Core 4 sources, 18 boards × Top 3 per board, one morning push email (08:00 Beijing). Subscribe: https://data.jiangzhang.ca/signals4/buy?plan=basic

• PLUS — CA$29.90/month — All 8 sources, choose push method and times (4×/day), Top 3 per board, plus API access to today's signals and stats. Subscribe: https://data.jiangzhang.ca/signals4/buy?plan=plus

• BUSINESS — CA$129.90/month — PLUS, plus your own content and quantity per board (3–10), searchable history and full export. Subscribe: https://data.jiangzhang.ca/signals4/buy?plan=business

Attributed landing page (no plan chosen yet): → https://data.jiangzhang.ca/signals4/go?to=landing&src=mcp_github

Pay once instead of subscribing

There is also a one-time option (no subscription, no renewal): https://buy.stripe.com/00w28r4W08qq8CcecHgw008

The free endpoints stay free — this repo will not start requiring a key.

A trap worth knowing (we hit it ourselves)

The CDN in front of the API rejects the bare Python-urllib/… User-Agent and empty User-Agents with HTTP 403. requests, httpx, aiohttp, Go, node-fetch, axios, okhttp and curl are all fine — but if you write a plain-stdlib example and forget the header, you will see a 403 that looks like a broken API. This server always sends one. If you call the endpoints directly, set a User-Agent:

curl -H 'User-Agent: my-app/1.0' https://data.jiangzhang.ca/signals4/api/today.json

Data sources and license

Signals are collected from public APIs and public feeds (GitHub trending, Hugging Face, YouTube channels, arXiv, LMSYS Arena, silicon-valley news, hardware/chips). Each item links to its original source; we do not rewrite it. Derived rankings and momentum are recomputed from our own daily snapshots by an automated audit that also reconciles the site pages with the JSON endpoints.

Data: CC BY 4.0 — free to read, quote, cite and use commercially with attribution to Signals 4 (Signals API). Machine-readable mirror of the daily dataset: https://github.com/jiangzhangcc-glitch/ai-signals-daily

Provenance canary: signals4-canary-2f9d71c4a8 (kept for provenance if this data is mirrored).

Endpoints behind the tools

• https://data.jiangzhang.ca/signals4/api/today.json — today's 4 signals

• .../api/changes.json — deltas since the previous snapshot

• .../api/models.json · .../api/repos.json — ranked entities + citations

• .../api/archive.json — list of editions

• https://data.jiangzhang.ca/llms.txt — machine-readable site summary

Development

The server is a single file, stdio JSON-RPC, no framework. Read a request line, write a response line. initialize, tools/list, tools/call, ping are implemented; unknown methods return JSON-RPC -32601 rather than failing silently.

MIT licensed (the server code). The data keeps its own license above.