Need Oauth to test reimplmentation of Claude code to submit PR.

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I've built a complete native reimplementation of Claude Code in a non-JS
language (~3,200 LOC, six tools, IPC dispatch, full streaming Messages API
support). Before drafting a PR I'd like guidance on the supported OAuth
path soI can test the API and MAX PRO Subscription capability. The API credit system is tested and working.

## What I tried

I want to be transparent about exactly what I did and where I got stuck —
this is a request for the right path, not an FYI.

1. Discovered the Client ID Metadata Document at

redacted

1. Discovered RFC 8414 metadata at

redacted

1. Captured the official claude CLI's OAuth flow. It uses:

redacted

## Questions

1. Is there a documented or planned third-party path for obtaining a

subscription-scoped OAuth client_id? The DCR endpoint at
api.anthropic.com/register clearly works for some flows but not for
claude.ai-based auth. What about non windows, Linux or FOSS non stand operating systems that need to access Claude Code ? This is a feature alike rebuild it extended nothing the existing NodeJS system doesn't.

1. Until such a path exists, would Anthropic accept a PR (separate

repo, opt-in, prominent attribution) that uses the official claude-cli
client_id? The end user is signing in to their own claude.ai
account with the same scopes; only the binary requesting consent
differs.

1. **Is /v1/messages with Authorization: Bearer <subscription-token>

the supported subscription-billing path**, or do third-party clients
need to use /v1/sessions/*? I noticed both URL families in the
official binary.

## What this would unlock

A clean, auditable, single-binary Claude Code reimplementation that runs
without Node/Bun/JS, lives in a shippable ~800KB ELF, and works out of
the box for Pro/Max/Team users on their existing subscription. Happy to
share the full source privately with the Anthropic team if useful — just
need a contact (email or Slack channel works).

## Environment

• WSL2 / Ubuntu 24.04
• Official claude CLI: 2.1.121
• HTTP transport: curl --no-buffer -N (subprocess-pipe, not native TLS)
• Discovery: strings + /.well-known probes only; no binary modification

Proposed Solution

access to Oauth, can sign NDA , Also can encrypt tightly the Oauth path as well. Unlike the existing NodeJS version I can easily penetrate with a bit of effort and time.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_