OpenCode Anthropic OAuth

Unofficial Anthropic subscription OAuth for OpenCode V2.

Warning

Anthropic may restrict or suspend subscription accounts that use unofficial clients. Use this plugin at your own risk.

Compatibility

This release is pinned to one OpenCode V2 beta:

Component	Version
OpenCode V2	0.0.0-beta-18743
This plugin	0.0.0-beta-18743
@opencode-ai/plugin	0.0.0-beta-18743
Effect	4.0.0-rc.112

Do not update these independently. A new OpenCode beta needs a new tested plugin release.

Install

Pin the full plugin version in opencode.jsonc:

{
  "plugins": ["@op1/opencode-anthropic-auth@0.0.0-beta-18743"]
}

Then start browser login:

opencode2 auth login anthropic --method oauth

If OpenCode cached an older package, remove ~/.cache/opencode/packages/@op1 and restart it.

Request changes

For the plugin's OAuth connection, it:

• Adds the Anthropic OAuth authorization, beta, and Claude CLI headers.
• Removes x-api-key.
• Prepends this system block:

You are a Claude agent, built on Anthropic's Claude Agent SDK.

The existing OpenCode prompt stays unchanged. The plugin does not rewrite messages, tools, URLs, request bodies, or responses.

Development

bun install --frozen-lockfile
bun test
bun run types
bun run lint
bun run format:check
bun run build

For a local build, point plugins to the absolute dist directory and restart OpenCode.

License

MIT