opencode-usage-plugin

OpenCode plugin that fetches subscription usage for OpenAI, Google, and z.ai.

Features

• /usage command for all providers
• /usage <provider> for a single provider
• Returns normalized JSON for provider usage
• Reads tokens from OpenCode and auth plugins

Installation in OpenCode

Create or edit ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["[email protected]"]
}

For local development, use a relative path:

{
  "plugin": ["./path/to/opencode-usage-plugin"]
}

Provider Setup

OpenAI

• Install the opencode-openai-codex-auth plugin, or ensure openai auth exists in ~/.local/share/opencode/auth.json (aliases: codex, chatgpt).
• The plugin also checks ~/.opencode/auth/openai.json as a fallback.

Google

• Install an Antigravity auth plugin (for example, opencode-antigravity-auth) or ensure google auth exists in ~/.local/share/opencode/auth.json (alias: antigravity).
• Ensure accounts are stored in ~/.config/opencode/antigravity-accounts.json.
• The activeIndex account is used for usage checks (falls back to the first account).

z.ai

• Add a zai-coding-plan entry in ~/.local/share/opencode/auth.json with the API key (aliases: zai, z.ai), or set ZAI_API_KEY.

Usage

/usage
/usage openai
/usage google
/usage zai-coding-plan

Output

• usage tool returns a JSON array (string) of provider usage results
• command/usage.md formats a human-readable summary

Development

npm install
mise run build
npm test
mise run lint

Testing

Tests use vitest with a provider-specific auth configuration system.

Run all tests (mocks only, default):

npm test

Run tests with real auth:

# Edit .env.test and set desired provider(s) to 1
TEST_REAL_OPENAI_AUTH=1
TEST_REAL_GOOGLE_AUTH=1
TEST_REAL_ZAI_CODING_PLAN_AUTH=1
npm test

Run specific provider tests:

npm test -- src/providers/openai/fetch.test.ts
npm test -- src/providers/google/fetch.test.ts
npm test -- src/providers/zai-coding-plan/fetch.test.ts

Test structure:

• src/providers/common/test-helpers.ts - Shared test utilities and fixtures
• src/providers/*/*.test.ts - Provider-specific tests with mocks and real auth
• .env.test - Auth configuration flags (committed to repo)
• vitest.config.ts - Test configuration

Tests are organized into two categories per provider:

• Mock tests - Run by default, test all edge cases and error handling
• Real auth tests - Skipped by default, enabled via .env.test flags

Adding new providers:

1. Implement provider function in src/providers/
2. Add TEST_REAL_NEWPROVIDER_AUTH=0 to .env.test
3. Create src/providers/newprovider.test.ts following existing patterns
4. Add helpers to src/test-helpers.ts if needed

Author

Nelson Pires [email protected]

Repository

https://github.com/nelsonPires5/opencode-usage-plugin

License

MIT License. See the LICENSE file for details.