Model Tracker

An OpenCode plugin that records model, agent, token, cost, and quality metrics locally. All data stays on your machine.

What it does

The plugin hooks into the OpenCode event stream and intercepts tool execution to capture:

• Per-task metrics: agent name, model, provider, token counts (input, output, cache read/write), cost, and wall-clock duration.
• Quality signals: retry count, finish reason, and error presence drive an automatic inferred quality score (1–5). You can override it with rate_last_task.
• Composite score: a single 0–1 signal combining quality (50%), token efficiency (30%), and speed (20%).

Metrics are written to a local SQLite database under your OpenCode config directory. A localhost admin dashboard lets you browse records, manage the model registry, and sync agent assignments.

No data is sent to any external service.

Installation

For normal OpenCode usage, add the package name to opencode.json in the next section. OpenCode resolves plugin packages from the config entry, so a separate global install is usually unnecessary.

For local development or explicit installation, install from npm:

npm install -g opencode-model-tracker

Or add it as a project dependency:

npm install opencode-model-tracker

OpenCode configuration

Add the plugin to your opencode.json:

{
  "plugin": ["opencode-model-tracker"]
}

The plugin starts automatically when OpenCode loads. A log line is written to stderr confirming the admin UI address:

[model-tracker] Admin UI: http://127.0.0.1:4747

Dashboard

The admin dashboard is available at http://127.0.0.1:4747 and is bound exclusively to localhost. It is not accessible from other machines.

To retrieve the URL from within an OpenCode session, call the plugin-provided OpenCode tool:

model_tracker_status

The tool returns the current dashboard URL. Open it in a browser to view performance records, inspect per-agent and per-model stats, and manage the model registry.

The dashboard embeds a random admin token in the served HTML at startup. Write endpoints (registry updates, record mutations) require this token via the x-model-tracker-admin-token request header. The token is not persisted and rotates on each service restart.

Model registry and assignment sync

On first run, the plugin seeds a user-local models.json from the bundled models.example.json. This registry maps model IDs to metadata and assigns default models to named agents.

You can edit the registry through the dashboard or by directly modifying the registry file at the path shown in REGISTRY_PATH (see Configuration). The sync function reads agent definitions from your OpenCode config directory and writes model assignments back to opencode.json.

The bundled models.example.json is updated with each package release and is never overwritten once the user registry exists.

Data stored locally

By default the plugin writes to:

Path	Contents
$HOME/.config/opencode/model-tracker/model-performance.sqlite	Performance metrics database
$HOME/.config/opencode/model-tracker/models.json	User model registry

Both paths can be overridden with environment variables (see Configuration).

To purge all metrics:

rm "$HOME/.config/opencode/model-tracker/model-performance.sqlite"

To reset the model registry to the bundled defaults:

rm "$HOME/.config/opencode/model-tracker/models.json"

The registry is reseeded from models.example.json on the next plugin load.

Configuration

All paths are resolved at startup. Override them with environment variables before launching OpenCode.

Variable	Default	Description
OPENCODE_CONFIG_DIR	$HOME/.config/opencode	Root OpenCode config directory. Affects all defaults below.
MODEL_TRACKER_REGISTRY_PATH	$OPENCODE_CONFIG_DIR/model-tracker/models.json	User model registry file.
MODEL_TRACKER_DB_PATH	$OPENCODE_CONFIG_DIR/model-tracker/model-performance.sqlite	SQLite metrics database.
MODEL_TRACKER_AGENT_DIR	$OPENCODE_CONFIG_DIR/agent	Directory scanned for agent definitions during sync.
MODEL_TRACKER_OPENCODE_JSON	$OPENCODE_CONFIG_DIR/opencode.json	OpenCode config file updated by assignment sync.

Example — redirect all plugin data to a project-local directory:

export OPENCODE_CONFIG_DIR="$PWD/.opencode"
opencode

Security and privacy

• Localhost only: the admin service binds to 127.0.0.1:4747. It is not reachable from other network interfaces.
• Random admin token: a cryptographically random token is generated at service startup and embedded in the served HTML. Write endpoints reject requests without this token.
• No remote telemetry: all data is written locally. No metrics, session IDs, or model names leave the machine.
• Text truncation: task descriptions and notes are capped at 200 characters before persistence and at the point of capture.
• Path isolation: health and error responses do not include local filesystem paths.
• Generated files ignored: models.json, *.sqlite, *.sqlite-*, and model-performance.json are listed in .gitignore and excluded from the published npm package.

Development

Requirements: Node.js >=22.5.0.

# Install dependencies
npm install

# Run all tests
npm test

# Fail on high/critical dependency advisories
npm run audit:high

# Scan publication-relevant files for private paths
npm run check:private-paths

# Preview the npm package contents without publishing
npm run pack:dry-run

Tests use the Node.js built-in test runner (node --test). No additional test framework is required.

Publishing

The package is published to npm as opencode-model-tracker.

Releases are automated from Conventional Commits on main using semantic-release. npm publishing runs through GitHub Actions with npm Trusted Publishing, so releases include provenance and do not require long-lived npm tokens.

Maintainers should create release commits using Conventional Commit messages (feat:, fix:, etc.); semantic-release determines the next version and publishes it automatically.

Release status

The package is published on npm as opencode-model-tracker.

Troubleshooting

node:sqlite not found / SQLite backend missing

The plugin uses node:sqlite (available in Node.js from v22.5.0) when running under Node.js, and bun:sqlite when running under Bun. If you see an error about a missing SQLite backend:

• Verify your Node.js version is >=22.5.0: node --version
• If OpenCode runs under a Bun-compatible runtime, the bun:sqlite backend is used automatically.
• Upgrade Node.js or switch to a Bun-backed OpenCode distribution if neither backend is available.

ExperimentalWarning: SQLite is an experimental feature

This warning is expected on Node.js 22 and can be safely ignored. It does not affect functionality. Node.js 24 and later promote node:sqlite to stable.

Plugin not loading

Check that opencode-model-tracker appears in the plugin array in opencode.json and that the package is installed in a location OpenCode can resolve. Run npm list opencode-model-tracker to confirm installation.

Admin UI not reachable

Confirm port 4747 is not in use by another process. The plugin writes the resolved URL to stderr on startup — check OpenCode's log output for the [model-tracker] Admin UI: line.

License

MIT. See LICENSE.