opencode-claude-auth

Self-contained Anthropic auth provider for OpenCode 2 using your Claude Code subscription credentials — no separate login or API key needed.

3.0.0 and later require OpenCode 2.0+ and will not load on OpenCode 1.x. The last version that supports OpenCode 1.x is 2.2.1 — see Migrating from OpenCode 1.

Compatibility

How it works

The plugin registers a Claude Code subscription auth method on OpenCode's built-in Anthropic provider. Run /connect, choose Anthropic, then Import Claude Code subscription — it reads OAuth tokens directly from the macOS Keychain (or ~/.claude/.credentials.json — or $CLAUDE_CONFIG_DIR/.credentials.json if that env var is set — on other platforms) and hands them to OpenCode.

OpenCode's native Anthropic provider handles prompt conversion and streaming. Session hooks add the Claude Code identity and adjust subscription requests to set Authorization: Bearer with the current access token (and strip x-api-key), translate tool names, and process responses. OpenCode owns the credential's lifecycle from there and calls back into the plugin to refresh it as needed. Refreshes go directly to Anthropic's OAuth endpoint (zero LLM tokens consumed); the plugin always checks the keychain first and adopts whatever is there if it differs from what OpenCode handed back, so an independent claude re-login or refresh doesn't leave OpenCode stuck retrying a dead token. It falls back to the claude CLI only in the narrow window where Claude Code will actually rotate the token.

Alternative: CLIProxyAPI (plugin not required)

If you run CLIProxyAPI, you don't need this plugin. CLIProxyAPI logs in to your Claude Code account with OAuth, handles token refresh, and exposes a Claude-compatible API on http://localhost:8317 by default. Point OpenCode's built-in Anthropic provider at it:

1. Log in with your Claude Code account (via the proxy's -claude-login flag) and set an api-keys entry in its config.yaml.

2. Configure the Anthropic provider in ~/.config/opencode/opencode.json:

   {
     "provider": {
       "anthropic": {
         "options": {
           "baseURL": "http://localhost:8317",
           "apiKey": "your-api-key-1"
         }
       }
     }
   }
   

Remove opencode-claude-auth from your plugins list when using this setup — the two approaches shouldn't be combined. CLIProxyAPI also supports multi-account load balancing and other providers (Codex, Gemini, Grok). This plugin remains the lighter option if you only need Claude Code credentials in OpenCode with no extra service running.

Prerequisites

• OpenCode 2 installed — see the OpenCode 2 migration guide for installation instructions
• Claude Code installed and authenticated (run claude at least once)

macOS is preferred (uses Keychain). Linux and Windows work via the credentials file fallback.

Installation

For Humans

Option A: Let an LLM do it

Paste this into any LLM agent (Claude Code, OpenCode, Cursor, etc.):

Install the opencode-claude-auth plugin and configure it by following: https://raw.githubusercontent.com/griffinmartin/opencode-claude-auth/main/installation.md

Option B: Manual setup

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

   {
     "plugins": ["opencode-claude-auth@latest"]
   }
   

   OpenCode 2 uses the plugins key (plural) — OpenCode 1 used plugin (singular). The @latest tag ensures OpenCode always pulls the newest version on startup. No manual npm install is needed — OpenCode automatically installs npm plugins using Bun at startup.

2. Connect it — restart OpenCode, run /connect, choose Anthropic, then Import Claude Code subscription. Use /models and pick a model under Anthropic.

For LLM Agents

See installation.md for step-by-step agent instructions.

Usage

Run /connect once to import your Claude Code subscription, then use OpenCode normally — the plugin refreshes credentials automatically and provides them to the Anthropic API. If your credentials aren't OAuth-based, the connection falls through to standard API key auth.

Migrating from OpenCode 1

OpenCode 2 replaced the plugin and auth APIs this plugin used under OpenCode 1, so 3.0.0 and later only load on OpenCode 2.

1. Upgrade OpenCode — see the OpenCode 2 migration guide.

2. In ~/.config/opencode/opencode.json, move the plugin from the plugin key (OpenCode 1) to plugins (OpenCode 2):

   {
     "plugins": ["opencode-claude-auth@latest"]
   }
   

3. Restart OpenCode, run /connect, choose Anthropic, then Import Claude Code subscription. The OpenCode 1 connection isn't carried over.

Staying on OpenCode 1

2.2.1 is the last release that supports OpenCode 1. Pin it instead of tracking @latest:

{
  "plugin": ["opencode-claude-auth@2.2.1"]
}

Supported models

14 supported models. Run pnpm run test:models to verify against your account.

Credential sources

The plugin checks these in order:

1. macOS Keychain (all Claude Code-credentials* entries — multiple accounts are detected automatically)
2. ~/.claude/.credentials.json (fallback, works on all platforms; if CLAUDE_CONFIG_DIR is set, reads $CLAUDE_CONFIG_DIR/.credentials.json instead)

Multiple accounts (macOS)

If you have multiple Claude Code accounts authenticated on macOS, they're all detected from the Keychain automatically and offered as a selection prompt when you run /connect. Each account is labeled by its subscription tier (Claude Pro, Claude Max, etc.).

To switch accounts, re-run /connect and pick a different one. Your selection is persisted across sessions.

If only one account is found, the selection prompt is skipped and the plugin uses it directly.

Troubleshooting