xyai2claudecode

Use a Codex-compatible Responses API endpoint inside Claude Code via Claude Code Router on Windows.

This repo packages the working adapter setup I built locally:

• Claude Code Router config
• a custom Responses transformer for Codex-style endpoints
• a claude-codex launcher
• background startup scripts
• Windows logon auto-start registration

What this does

Claude Code speaks Anthropic-style APIs.
This project inserts a local bridge:

Claude Code -> local Claude Code Router -> Codex-compatible /responses endpoint

Target endpoint shape:

• OpenAI Responses-compatible
• model: gpt-5.4
• reasoning effort requested as xhigh
• service tier requested as fast
• long-context model family (~1.05M context on GPT-5.4 per OpenAI docs)

Important note about fast

This repo requests:

"service_tier": "fast"

However, the actual upstream provider may still return or use another tier (for example auto).

So there are two different questions:

1. Does this bridge send fast? Yes.
2. Does the upstream honor it? Provider-dependent; verify from the upstream response.

Files

• bin/claude-codex.js - Claude Code launcher that ensures the router is running first
• bin/claude-codex.cmd - Windows wrapper
• bin/ccr-service.ps1 - foreground router service runner
• bin/start-ccr-background.ps1 - background launcher
• router/plugins/codex-cli.js - custom Responses transformer
• scripts/install.ps1 - installer for local use

Prerequisites

• Windows
• Node.js
• Claude Code CLI installed (claude)
• Claude Code Router installed globally (ccr)
• GitHub CLI optional
• Environment variable:
  • CODEX_API_KEY

Install

From PowerShell:

powershell -ExecutionPolicy Bypass -File .\scripts\install.ps1

What the installer does:

• copies launch scripts into ~/.local/bin
• copies the transformer into ~/.claude-code-router/plugins
• generates a random local router API key
• picks a free high port
• writes ~/.claude-code-router/config.json
• registers a ClaudeCodexRouter scheduled task for logon auto-start

Use

claude-codex

Quick test:

claude-codex -p "Reply with exactly: pong"

Verify router health

$cfg = Get-Content -Raw "$HOME/.claude-code-router/config.json" | ConvertFrom-Json
Invoke-WebRequest -UseBasicParsing "http://127.0.0.1:$($cfg.PORT)/health"

Verify whether upstream honored fast

You need to inspect the upstream response.created payload.
If it comes back with "service_tier":"auto", then the bridge requested fast but the provider did not honor it.

Security

This repo does not publish:

• your real local router API key
• your personal CODEX_API_KEY
• your private Claude skills
• your SSH mappings
• your local MCP credentials

Source attribution

The custom transformer is based on community Claude Code Router Responses transformer work and then modified locally for:

• xhigh reasoning support
• service_tier forwarding
• this launcher flow