leo-tavily-mcp

Tavily web search as a Leo provider package, over MCP.

Leo's web_search tool doesn't search anything itself — it resolves a WebSearchProvider and asks that. This server is one, reachable as a package the hub installs at runtime rather than one it has to be rebuilt for.

What it answers

The web_search role in leo_mcp::providers:

search({ query, max_results }) -> { results: [{ title, url, snippet, score? }] }

Results come back as JSON in a text content block, which is the convention the hub's bridge reads.

Related MCP server: Tavily MCP Server

Configuration

One setting, declared by the package descriptor and handed to this process by Leo as an environment variable under its settings key, verbatim:

Leo only hands over keys the package declared in entitlements.settings_read and the owner consented to — never the whole settings table. The name is lower-case because it is the settings key; renaming it on either side means the credential silently never arrives.

With no key configured the tool returns isError with a message naming the setting. That is deliberate: an empty result set would reach Leo as "the web has nothing on that".

Running it

npm install
node index.js          # speaks MCP over stdio
npm test               # checks the response mapping, no network needed

Why plain JavaScript

This ships as a git tarball pinned to a commit SHA rather than an npm package, and npm does not reliably run build steps for a tarball URL. A TypeScript source tree would install and then fail to start on somebody else's machine, at the far end, where it is hardest to diagnose.

Registry entry

{
  "name": "tavily",
  "label": "Web Search",
  "mcp": {
    "transport": "stdio",
    "command": "npx",
    "args": ["-y", "https://github.com/TheBananaStand/leo-tavily-mcp/archive/<40-char-sha>.tar.gz"]
  },
  "descriptor": {
    "provides": ["web_search"],
    "fields": [
      { "key": "tavily_api_key", "label": "API Key", "field_type": "password", "required": true }
    ],
    "entitlements": {
      "settings_read": ["tavily_api_key"],
      "network": ["api.tavily.com"],
      "sends": [
        { "to": "api.tavily.com", "classes": ["search_queries"],
          "because": "The search text and nothing else." }
      ]
    }
  }
}

The URL must name a full 40-character commit SHA. A tag looks equally specific and is not — refs/tags/v1.0.0 is a pointer its owner can move after the entry has been reviewed, so the hub rejects it as unpinned.

License

MIT