opencode-claude-bridge

Use your Claude Pro/Max subscription in OpenCode. If you're logged into the Claude CLI, it just works — no extra setup.

Install

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

{
  "plugin": ["opencode-claude-bridge"]
}

OpenCode auto-installs the plugin from npm on next launch.

If you're logged into the Claude CLI (claude login), the plugin auto-syncs your credentials — just select an Anthropic model and start chatting. If not, you'll be prompted to authenticate via browser OAuth or enter an API key.

Upgrade:

OpenCode pins the installed version. To upgrade to the latest:

cd ~/.cache/opencode && npm install opencode-claude-bridge@latest

Then restart OpenCode.

git clone https://github.com/dotCipher/opencode-claude-bridge.git ~/opencode-claude-bridge
cd ~/opencode-claude-bridge && npm install && npm run build

Then reference the full path in your config:

{
  "plugin": ["/Users/YOU/opencode-claude-bridge/dist/index.js"]
}

How the bridge works

The plugin sits between OpenCode and the Anthropic API:

OpenCode → opencode-claude-bridge → Anthropic API

Authentication — Supports both OAuth and API key auth:

• OAuth (Pro/Max) — Auto-reads your Claude CLI's OAuth tokens from macOS Keychain (or ~/.claude/.credentials.json on Linux). No browser flow needed. If Claude CLI isn't available, falls back to browser-based OAuth PKCE.
• API key — Works alongside a standard provider entry in your OpenCode config with an apiKey. The plugin only activates its OAuth handling for the built-in anthropic provider; custom API key providers pass through unchanged.

Token refresh — When tokens expire, three layers are tried: re-read from Keychain, refresh via stored token, refresh via CLI's token.

Request transformation — Every outbound OAuth request is rewritten to match what Claude Code sends: correct headers, ?beta=true URL parameter, thinking body field, mcp_ tool name prefixing, and system prompt sanitization.

Requirements

• OpenCode v1.2+
• For OAuth: Claude CLI installed and logged in (claude login)
• macOS (Keychain) or Linux (~/.claude/.credentials.json fallback)
• For API key: just configure a provider with apiKey in your OpenCode config as usual

Environment overrides

All OAuth and header parameters can be overridden via environment variables (ANTHROPIC_CLIENT_ID, ANTHROPIC_TOKEN_URL, ANTHROPIC_AUTHORIZE_URL, ANTHROPIC_CLI_VERSION, ANTHROPIC_BETA_FLAGS). Defaults match Claude Code 2.1.81 — most users won't need to change these.

Updating for new Claude CLI versions

When Claude Code updates, the required headers or body fields may change. To capture exactly what the latest Claude CLI sends:

./scripts/intercept-claude.sh claude-sonnet-4-6

This starts a local proxy, runs Claude CLI through it with OAuth, and saves the full request headers and body to /tmp/claude-intercept-*. Compare against the plugin's constants and fetch wrapper to spot differences.

Key things that have changed across versions:

• anthropic-beta flags (required set changes)
• Body fields (thinking, metadata, context_management)
• user-agent version string
• x-stainless-package-version

Credits

Combines approaches from shahidshabbir-se/opencode-anthropic-oauth, ex-machina-co/opencode-anthropic-auth, vinzabe/PERMANENT-opencode-anthropic-oauth-fix, and lehdqlsl/opencode-claude-auth-sync.

License

MIT