opencode-librarian

OpenCode plugin that adds a Librarian subagent for remote code research. It is designed for deep source investigation across repositories, with long-form answers that cite evidence and point to permalinks when code details matter.

Inspiration

- Heavily inspired by the Librarian agent in oh-my-opencode.
- Aligned with the Librarian concept described by Ampcode.

Usage

- Install and build the plugin, then enable it in your OpenCode config.
- Ask explicitly for the Librarian when you need remote code research or upstream library internals. This plugin only registers the agent; it does not add auto-routing or keyword triggers, so OpenCode will not invoke it unless you select it or ask for it explicitly.

Default model configuration:
- This plugin ships with a default model defined in src/constants.ts.
- Recommended default: gemini-3-flash.
- To override it, set the agent model in your OpenCode config, for example:

``json
{
"agent": {
"librarian": {
"model": "gemini-3-flash"
}
}
}
`

Example prompts:
- "Use the Librarian to look up how React's useEffect cleanup is implemented."
- "Ask the Librarian to explain why this Zod validation error occurs and show the logic causing it."
- "Use the Librarian to trace how our docs get deployed across the docs and infra repos."

Install

`bash
bun install
bun run build
`

Add the plugin to ~/.config/opencode/opencode.json:

`json
{
"plugin": [
"file:///Users/andrew/dev/opencode-librarian"
]
}
`

Development


`bash
bun install
bun run build
``