search-mcp

An MCP server with one tool: broad web search for current, time-sensitive information. It returns short snippets (title, url, snippet), not full pages. It is backed by the keyless multi-engine ddgs library, which fans out across several web search engines with fallback (its encyclopedia engines, Wikipedia and Grokipedia, are left out: encyclopedic hits are the wrong answer for current events).

It is deliberately small. It is meant to sit next to other, non-overlapping tools (an offline encyclopedia, a curated news feed, structured local data), so a small local model can pick the right tool from the docstrings alone. Design rationale: CLAUDE.md.

Tool

web_search(query, max_results=10, region=None)

Every result is one JSON text block with a status field. Callers branch on it, never on prose:

{"status":"ok","query":"...","backend":"auto-web","region":"wt-wt","safesearch":"moderate","max_results":10,
 "attempts":1,"count":2,"results":[{"title":"...","url":"https://...","snippet":"..."}]}

• ok: the search ran and returned results. (results:[] is reserved for a backend that can prove a search was empty; ddgs can't, see below.)

• refused: input the caller can fix (blank query, max_results out of range, malformed region), with reason and advice. It is returned as a normal result, never raised.

• error: the search backend failed (blocked, rate-limited, timed out, network down), with kind and detail. A backend outage is always reported as an error, never as an empty result. A failed search is retried server-side first (SEARCH_ATTEMPTS, default 2), because a second try with a different engine order often succeeds. Every result echoes attempts, so an error has already been retried. kind:"empty_or_blocked" means no engine returned anything: ddgs counts an engine that blocks or rate-limits it as "no results", so it can't tell an obscure query from a blocked server. One reworded retry is reasonable; otherwise treat search as unavailable.

All resolved parameters are echoed back, so a result is reproducible. The tool declares a title and all four MCP hints: read-only, non-destructive, idempotent, open-world.

Related MCP server: DuckDuckGo MCP Server

Run

uv sync
uv run search-mcp serve                     # stdio, for a local MCP client
SEARCH_MCP_TOKEN=secret uv run search-mcp serve --transport http --host 0.0.0.0 --port 8000   # streamable-http at /mcp
uv run pytest                               # no network: the backend is faked

TLS note: behind a TLS-inspecting proxy, uv may report UnknownIssuer. Pass --system-certs (or set UV_NATIVE_TLS=1) so it trusts the OS certificate store.

Claude Desktop / Claude Code (stdio)

{
  "mcpServers": {
    "search": { "command": "uv", "args": ["--directory", "/path/to/search-mcp", "run", "search-mcp", "serve"] }
  }
}

Docker

docker build -t search-mcp .
docker run --rm -p 8000:8000 -e SEARCH_MCP_TOKEN=... search-mcp

The server is stateless: no database, no volume. It needs outbound HTTPS to the public search engines.

Auth and exposure

Auth is deliberately simple: stdio, or streamable-HTTP with a single bearer token (SEARCH_MCP_TOKEN) on a private network, for example behind mcpo. There is no OAuth, no users and no audit log, by design. To publish it more widely, put a management layer in front of it: an MCP gateway or auth proxy that handles OAuth, users and audit for all your servers at once.

A note on the backend

ddgs gets its results by scraping search-engine result pages. It needs no API key, but it is not a sanctioned API, and engines may rate-limit or block it. That shows up here as status:"error". The backend sits behind a single function (src/search_mcp/backend.py), so a sanctioned API (Brave, Mojeek) or a self-hosted SearXNG can replace it by editing that one file.

AI assistance

search-mcp is developed openly with the help of Claude (Anthropic). Commits Claude helped write carry a Co-Authored-By: Claude trailer. The code and design are open source so the work can be inspected, reused, and given back.

License

MPL-2.0 © Daniel Núñez.