opencode-metasearch2

OpenCode plugin that adds a web_search tool powered by metasearch2 -- a fast meta-search engine that aggregates results from Google, Bing, Brave, and others. No API keys required.

Credits

Built on metasearch2 by mat-1 -- an awesome open-source meta-search engine written in Rust. All the heavy lifting (search aggregation, ranking, deduplication) happens there.

Quick start

npm install opencode-metasearch2

Add to your opencode.json:

{
  "plugins": {
    "metasearch": "opencode-metasearch2"
  }
}

That's it. The plugin ships with pre-built binaries for macOS, Linux, and Windows -- no Rust toolchain needed. On first run it spawns metasearch2 locally and exposes a web_search tool to your agent.

Tool

web_search

Search the web using a local metasearch engine that aggregates results from Google, Bing, Brave, and others. Returns raw JSON with search results, featured snippets, direct answers, and infoboxes.

| Argument | Type | Default | Description | |---|---|---|---| | query | string | (required) | The search query | | type | "all" \| "images" | "all" | "all" for web results, "images" for image search |

Web search response

[{
  "search_results": [
    {
      "result": { "url": "https://...", "title": "...", "description": "..." },
      "engines": ["google", "bing", "brave"],
      "score": 1.55
    }
  ],
  "featured_snippet": {
    "url": "https://...", "title": "...", "description": "...", "engine": "google"
  },
  "answer": { "html": "42", "engine": "numbat" },
  "infobox": { "html": "<h2>...</h2>", "engine": "wikipedia" }
}]

All fields except search_results are optional -- they appear when metasearch2 finds a direct answer, featured snippet, or infobox (Wikipedia, GitHub, StackOverflow, MDN, docs.rs).

Image search response

[{
  "image_results": [
    {
      "result": {
        "image_url": "https://...",
        "page_url": "https://...",
        "title": "...",
        "width": 1200,
        "height": 800
      },
      "engines": ["google", "bing"],
      "score": 1.5
    }
  ]
}]

How it works

1. Locates or installs the metasearch binary
2. Writes a config to ~/.config/metasearch/config.toml enabling the JSON API and image search
3. Spawns the binary as a child process
4. Polls until the HTTP API is healthy (up to 10s)
5. Exposes a web_search tool to your agent

The metasearch2 process is killed automatically when the session ends.

Configuration

| Variable | Default | Description | |---|---|---| | METASEARCH_BIN | (auto-resolved) | Path to the metasearch2 binary | | METASEARCH_PORT | 28019 | Port for the local HTTP API | | METASEARCH_AUTO_INSTALL | true | Set to false to skip auto cargo install | | XDG_CONFIG_HOME | ~/.config | Base directory for the config file |

Advanced: engine configuration

The plugin generates a default ~/.config/metasearch/config.toml on first run. You can edit it to enable/disable engines, adjust ranking weights, or block domains:

api = true
bind = "0.0.0.0:28019"

[image_search]
enabled = true

[engines]
google_scholar = true       # enable (off by default)
marginalia = false          # disable

[engines.brave]
weight = 2.0               # boost Brave results

[urls.weight]
".quora.com" = 0            # hide Quora results
".pinterest.com" = 0        # hide Pinterest results

Available engines: google (default), bing (default), brave (default), marginalia (default), google_scholar, rightdao, stract, yep. See the metasearch2 docs for all options.

Binary resolution

The plugin checks for the binary in order:

1. METASEARCH_BIN environment variable
2. Bundled platform package (@galelmalah/metasearch2-*) -- installed automatically as an optionalDependency
3. $CARGO_HOME/bin/metasearch (default: ~/.cargo/bin/metasearch)
4. /tmp/metasearch2-build/bin/metasearch
5. Auto-install: runs cargo install metasearch if none of the above exist

Benchmark

npx tsx benchmark.ts       # 5 queries
npx tsx benchmark.ts 20    # 20 queries

Reports startup timing (binary resolution, config, spawn, health check) and per-query search latencies with min/max/avg/p50/p95.

Development

git clone https://github.com/galElmalah/opencode-metasearch2.git
cd opencode-metasearch2
npm install
npm run build
npx tsx --test test.ts

License

MIT