grok2cc

Run Grok with Claude Code in two ways:

Mode	What	Harness	Entry
B (recommended)	Grok is the model; Claude Code is the agent	Claude Code	harness-proxy.mjs + claude-with-grok.sh
A	Claude Code delegates to Grok Build CLI	Grok Build (nested)	server.mjs (MCP)

Mode B is a thin local proxy in front of xAI’s native Anthropic-compatible POST /v1/messages API (tools + streaming). It does not start the Grok Build CLI harness.

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Mode B — Claude Code harness + Grok model

Why a proxy?

1. xAI expects Authorization: Bearer; Claude Code’s ANTHROPIC_API_KEY is sent as x-api-key
2. xAI tool JSON Schema requires required to be an array ([] if empty); Claude often omits it
3. Auth can reuse ~/.grok/auth.json from grok login (or XAI_API_KEY)

Prerequisites

• Node.js 18+
• Claude Code CLI (claude)
• Grok auth: grok login or export XAI_API_KEY=...

Quick start

git clone https://github.com/Dremig/grok2cc.git
cd grok2cc
npm install   # only needed for Mode A (MCP); Mode B is zero-deps

# Interactive Claude Code, model = Grok
./claude-with-grok.sh

# Headless
./claude-with-grok.sh -p "hello" --dangerously-skip-permissions

# Coding model
GROK_HARNESS_DEFAULT_MODEL=grok-build-0.1 ./claude-with-grok.sh

The launcher starts harness-proxy.mjs on 127.0.0.1:8790 if it is not already up.

Manual proxy:

node harness-proxy.mjs
# or: npm run proxy

Health: curl http://127.0.0.1:8790/health

VS Code official Claude Code extension

Yes — same Mode B path works. Use the installer:

git clone https://github.com/Dremig/grok2cc.git
cd grok2cc
./install-vscode.sh
# optional model:
# MODEL=grok-build-0.1 ./install-vscode.sh

What it does:

1. Patches VS Code / Cursor / Insiders settings.json (claudeCode.environmentVariables + disableLoginPrompt)
2. Patches ~/.claude/settings.json (gateway env; backs up previous file)
3. Approves the dummy key grok-harness in ~/.claude.json
4. Starts harness-proxy.mjs and installs a macOS LaunchAgent so it survives reboot

Then: Developer: Reload Window → open Claude Code panel.

./install-vscode.sh --uninstall   # restore latest backups, stop LaunchAgent
./install-vscode.sh --no-launchd  # config only; no LaunchAgent

Manual JSON (if you prefer): vscode-settings.example.json.

Notes:

• Real auth: grok login (~/.grok/auth.json) or XAI_API_KEY
• Extension gateway vars: LLM gateway connect
• Still Claude Code harness; only the model is Grok

Verified

• Plain text reply via Claude Code → Grok
• Full tool loop (e.g. Bash) inside Claude Code harness with model grok-4.5

Environment (Mode B)

Variable	Meaning
GROK_HARNESS_PORT	Proxy port (default 8790)
GROK_HARNESS_HOST	Bind host (default 127.0.0.1)
GROK_HARNESS_DEFAULT_MODEL	Default model (default grok-4.5)
GROK_HARNESS_UPSTREAM	Upstream base (default https://api.x.ai)
GROK_AUTH_JSON	Path to Grok auth file
XAI_API_KEY / GROK_HARNESS_TOKEN	Override token instead of auth.json
GROK_HARNESS_LOG=1	Log each proxied request (LaunchAgent already sets this)

Logs & debugging

Path	What
~/Library/Logs/grok2cc/harness-proxy.err.log	Request log: method, path, status, latency, 4xx error body
/tmp/grok2cc-last-request.json	Last rewritten body sent upstream
/tmp/grok2cc-last-raw-request.json	Last raw Claude request (on 4xx)
/tmp/grok2cc-last-error.json	Last upstream error body (on 4xx)

tail -f ~/Library/Logs/grok2cc/harness-proxy.err.log
curl -s http://127.0.0.1:8790/health

Known Claude Code + Grok quirks (handled by proxy):

• stop / stop_sequences — auto-mode Bash safety classifier sends these; xAI rejects → Claude may say “model temporarily unavailable”
• invalid roles (system/tool in messages) — normalized
• tool JSON Schema required must be an array

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Mode A — MCP nested agent

Exposes grok_delegate / grok_ask / grok_review by wrapping grok -p.

npm install

claude mcp add --scope user grok \
  --env GROK_BIN="$HOME/.grok/bin/grok" \
  -- node "$(pwd)/server.mjs"

claude mcp list   # should show grok ✓ Connected

Optional reverse direction (Grok Build → Claude tools):

# ~/.grok/config.toml
[mcp_servers.claude-code]
command = "claude"
args = ["mcp", "serve"]
enabled = true

Set [compat.claude] mcps = false on the Grok side if Claude’s user config also registers this MCP (avoids recursion).

MCP tools

Tool	Purpose
grok_delegate	Agentic coding (--always-approve)
grok_ask	Consult / second opinion (plan mode)
grok_review	Code review focus

Env (Mode A)

Variable	Meaning
GROK_BIN	Path to grok
GROK_DEFAULT_MODEL	Default -m
GROK_DEFAULT_CWD	Default working directory
GROK_TIMEOUT_MS	Subprocess timeout (default 600000)

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Layout

grok2cc/
  harness-proxy.mjs    # Mode B: Anthropic→xAI local proxy
  claude-with-grok.sh  # Mode B: launch Claude Code through the proxy
  server.mjs           # Mode A: MCP server wrapping grok CLI
  scripts/probe.mjs    # list MCP tools

License

MIT