Opencode Anthropic Login Via CLI — Development skill for Claude Code

OpenCode Anthropic Auth

[OpenCode](https://github.com/sst/opencode) plugin that lets you use Anthropic models with your Claude Pro/Max subscription. No API key required.

Features

Binary Introspection

Reads the Claude CLI binary to extract current beta headers, OAuth scopes, and version info. Stays in sync with Anthropic's API automatically instead of relying on hardcoded values.

Cross-Platform Support

Works on **macOS**, **Linux**, and **Windows**.

Auto Login

If you have Claude CLI installed and logged in, the plugin picks up your credentials automatically:

• macOS: System Keychain
• Linux / Windows: ~/.claude/.credentials.json

CCS Support

If you use [CCS](https://github.com/kaitranntt/ccs) for multiple Claude Code instances, each instance in `~/.ccs/instances/` is detected and shows up as a separate auth method.

Browser Login

Opens an OAuth flow through `claude.com` for users without the CLI. Log in, paste the code, done.

Token Refresh

Handles expired tokens automatically. Falls back to the CLI if the standard refresh fails.

Request Patching

Patches requests so OpenCode talks to Anthropic's API the same way Claude Code does.

Install

Add to your `opencode.json`:

{
  "plugin": ["opencode-anthropic-login-via-cli@latest"]
}

Then open OpenCode and go to **Connect Provider > Anthropic**.

Updating

OpenCode caches plugin packages in `~/.cache/opencode/node_modules/`. If you pin to a specific version and later bump it (or re-install the same version after a patch), OpenCode may keep loading the cached copy. If requests still behave like the old version after an update, clear the cache:

rm -rf ~/.cache/opencode/node_modules/

Then restart OpenCode — it will re-download the plugin on next launch.

Auth Methods

Method	Label	How it works