opencode-litellm

OpenCode plugin that auto-discovers models from a LiteLLM proxy and makes them available in OpenCode without manual configuration.

Install

opencode plugin opencode-litellm --global

This registers the plugin in ~/.config/opencode/opencode.json for you. Omit --global to install it only in the current project. Pass --force to replace an existing pinned version.

Setup

1. Open OpenCode and run /connect.
2. Select LiteLLM from the provider list.
3. Enter your LiteLLM proxy base URL (e.g., http://localhost:4000).
4. Enter your API key when prompted (leave blank if your proxy has no authentication).
5. Restart OpenCode — your LiteLLM models will appear in the model picker automatically.

How it works

On every startup the plugin calls GET /v1/models on your LiteLLM proxy and injects the results as an OpenAI-compatible provider into OpenCode's runtime config. Models appear in the model picker using the IDs returned by your proxy (e.g. claude-sonnet, deepseek-coder-v2).

If the proxy is unreachable or the API key is missing, the plugin falls back to a placeholder entry so OpenCode starts cleanly and /connect still lists LiteLLM.

Each request also carries OpenCode's session ID as a top-level litellm_session_id field in the request body, so the LiteLLM Admin UI groups every turn of one OpenCode chat into a single session. A new chat session produces a different ID.

Development

Prerequisites

• Bun — runtime, package manager, and test runner. Install from bun.sh.
• OpenCode — install globally: npm install -g opencode-ai

Setup

git clone https://github.com/your-org/opencode-litellm
cd opencode-litellm
bun install

Open the repo in OpenCode. The .opencode/opencode.json in this repo loads the plugin directly from src/index.ts:

{
  "plugin": ["../src/index.ts"]
}

Any changes to src/index.ts take effect the next time you restart OpenCode — no build step required.

Logs

The plugin logs via client.app.log() into OpenCode's standard log file. Use the /read-plugin-logs command inside OpenCode to filter and view plugin-specific output. Log files are at:

• Windows: %USERPROFILE%\.local\share\opencode\log\<timestamp>.log
• macOS/Linux: ~/.local/share/opencode/log/<timestamp>.log

Running tests

bun test                                    # all tests
bun test --watch                            # watch mode
bun test tests/plugin.test.ts              # unit only
bun test tests/integration.test.ts         # integration only
bun test --testNamePattern "config hook"   # filter by name

Project structure

src/index.ts                      # plugin — auth, config, and chat.params hooks
.opencode/opencode.json           # loads plugin from ../src/index.ts for development
tests/plugin.test.ts              # unit tests (mocked fetch)
tests/integration.test.ts         # integration tests (real in-process mock server)
tests/fixtures/litellm-server.ts  # mock LiteLLM HTTP server

Publishing

bun run build   # compiles src/ to dist/
npm publish