Setup script for running Gemini through Claude Code Router

setup-gemini-claude.sh

#!/bin/bash
# Setup script for running Gemini through Claude Code Router (macOS)
# https://github.com/wbern/claude-code-router

set -e

echo "🚀 Setting up Gemini for Claude Code..."

# Check if CCR is installed
if ! command -v ccr &> /dev/null; then
  echo "❌ Claude Code Router (ccr) is not installed."
  echo ""
  echo "Install it first:"
  echo "  git clone https://github.com/wbern/claude-code-router.git ~/.claude-code-router/fork"
  echo "  cd ~/.claude-code-router/fork && pnpm install && pnpm build && pnpm link --global"
  exit 1
fi

# Backup existing configs
backup_if_exists() {
  if [ -f "$1" ]; then
    BACKUP="$1.backup.$(date +%Y%m%d_%H%M%S)"
    cp "$1" "$BACKUP"
    echo "⚠️  Backed up existing $1 to $BACKUP"
  fi
}

backup_if_exists ~/.claude-code-router/config.json
backup_if_exists ~/.claude-code-router/custom-router.js
backup_if_exists ~/.claude-gemini/settings.json

# Generate random API key for local router
APIKEY="ccr-local-$(openssl rand -hex 8)"

# Create directories
mkdir -p ~/.claude-gemini
mkdir -p ~/.claude-code-router/logs

# 1. Router config
cat > ~/.claude-code-router/config.json << EOF
{
  "HOST": "127.0.0.1",
  "PORT": 3456,
  "APIKEY": "$APIKEY",
  "CUSTOM_ROUTER_PATH": "$HOME/.claude-code-router/custom-router.js",
  "Providers": [
    {
      "name": "gemini",
      "api_base_url": "https://generativelanguage.googleapis.com/v1beta/models/",
      "api_key": "FROM_KEYCHAIN",
      "models": ["gemini-3-pro-preview", "gemini-3-flash-preview", "gemini-2.5-flash", "gemini-2.5-pro"],
      "transformer": { "use": ["gemini"] }
    }
  ],
  "Router": {
    "default": "gemini,gemini-3-pro-preview",
    "background": "gemini,gemini-3-flash-preview",
    "think": "gemini,gemini-3-pro-preview"
  }
}
EOF
echo "✓ Created ~/.claude-code-router/config.json"

# 2. Custom router for summarization (fixes Gemini 3 Pro empty response issue)
# Gemini 3 Pro can return thinking-only responses during compaction, causing failures.
# This routes summarization requests to Flash which handles them reliably.
# See: https://discuss.ai.google.dev/t/gemini-3-0-pro-preview-with-empty-response-text/109818
cat > ~/.claude-code-router/custom-router.js << 'EOF'
// Custom router for claude-code-router
// Routes summarization/compaction requests to Gemini 2.5 Flash
// Gemini 3 Pro can return thinking-only responses (no text output) during summarization,
// causing Claude Code's compaction to fail. Flash handles these reliably.
// See: https://discuss.ai.google.dev/t/gemini-3-0-pro-preview-with-empty-response-text/109818

module.exports = async function router(req, config) {
  const system = req.body.system || [];
  const systemText = Array.isArray(system)
    ? system.map(s => s.text || "").join(" ")
    : system;

  // Detect Claude Code's summarization/compaction requests
  // These prompts contain specific markers from the compact system prompt
  const summarizationMarkers = [
    "create a detailed summary",
    "summarize this coding conversation",
    "Primary Request and Intent",
    "Key Technical Concepts",
    "conversation so far"
  ];

  const isSummarization = summarizationMarkers.some(marker =>
    systemText.toLowerCase().includes(marker.toLowerCase())
  );

  if (isSummarization) {
    console.log("[Custom Router] Detected summarization request, routing to Gemini 2.5 Flash");
    return "gemini,gemini-2.5-flash";
  }

  // Return null to use default routing
  return null;
};
EOF
echo "✓ Created ~/.claude-code-router/custom-router.js (routes summarization to Flash)"

# 3. Gemini settings with sandbox permissions
cat > ~/.claude-gemini/settings.json << EOF
{
  "apiKeyHelper": "echo $APIKEY",
  "includeCoAuthoredBy": false,
  "statusLine": {
    "type": "command",
    "command": "~/.claude-gemini/statusline.sh"
  },
  "permissions": {
    "allow": [],
    "deny": [
      "Read(**/.env)",
      "Read(**/.env.*)",
      "Read(**/secrets/**)",
      "Read(**/*.pem)",
      "Read(**/*.key)",
      "Read(**/*credentials*)",
      "Read(**/*secret*)",
      "Read(**/apikey*)",
      "Read(~/.ssh/**)",
      "Read(~/.aws/**)",
      "Read(~/.gnupg/**)",
      "Read(~/.kube/**)",
      "Read(~/.netrc)",
      "Read(~/.git-credentials)",
      "Read(~/.pypirc)",
      "Read(~/.docker/**)",
      "Read(~/.cargo/credentials*)",
      "Read(~/.m2/**)",
      "Read(~/.claude/**)",
      "Read(~/Library/Keychains/**)",
      "Read(~/Library/Cookies/**)",
      "Read(~/Library/Accounts/**)",
      "Read(~/Library/Mail/**)",
      "Read(~/Library/Messages/**)",
      "Read(~/Library/Preferences/**)",
      "Read(~/Library/Safari/**)",
      "Read(~/Library/Application Support/Google/Chrome/**)",
      "Read(~/Library/Application Support/Firefox/**)",
      "Read(~/Library/Application Support/Microsoft/Edge/**)",
      "Read(~/Library/Application Support/1Password/**)",
      "Read(~/Library/Saved Application State/**)",
      "Bash(rm -rf:*)",
      "Bash(rm -r:*)",
      "Bash(sudo:*)",
      "Bash(su:*)",
      "Bash(chmod 777:*)",
      "Bash(curl|sh)",
      "Bash(wget|sh)",
      "Bash(> /dev:*)",
      "Bash(mkfs:*)",
      "Bash(dd:*)"
    ]
  },
  "sandbox": {
    "enabled": true,
    "allowUnsandboxedCommands": true,
    "network": {
      "allowUnixSockets": ["/private/tmp/com.apple.launchd.*/Listeners"],
      "allowLocalBinding": true
    }
  }
}
EOF
echo "✓ Created ~/.claude-gemini/settings.json"

# 4. Status line script (visual indicator)
cat > ~/.claude-gemini/statusline.sh << 'EOF'
#!/bin/bash
echo -e "\033[48;5;94m\033[97m    🤖 GEMINI MODE    \033[0m"
EOF
chmod +x ~/.claude-gemini/statusline.sh
echo "✓ Created ~/.claude-gemini/statusline.sh"

# 5. Symlink commands and plugins (if they exist)
if [ -d ~/.claude/commands ] && [ ! -e ~/.claude-gemini/commands ]; then
  ln -s ~/.claude/commands ~/.claude-gemini/commands
  echo "✓ Symlinked commands"
fi
if [ -d ~/.claude/plugins ] && [ ! -e ~/.claude-gemini/plugins ]; then
  ln -s ~/.claude/plugins ~/.claude-gemini/plugins
  echo "✓ Symlinked plugins"
fi

echo ""
echo "✅ Setup complete!"
echo ""
echo "Next steps:"
echo ""
echo "1. Store your Gemini API key in macOS Keychain:"
echo "   security add-generic-password -a \"\$USER\" -s gemini-api-key -w 'your-api-key-here'"
echo ""
echo "   Get your key at: https://aistudio.google.com/apikey"
echo ""
echo "2. Add these aliases to your ~/.zshrc:"
echo ""
cat << 'ALIASES'
# Gemini via Claude Code Router
gemini() {
  unset ANTHROPIC_AUTH_TOKEN
  CLAUDE_CONFIG_DIR=~/.claude-gemini ANTHROPIC_BASE_URL=http://127.0.0.1:3456 claude "$@"
}
alias gr='gemini --resume'
alias gyolo='gemini --dangerously-skip-permissions'
alias gyolop='gemini --dangerously-skip-permissions -p'
alias gyolor='gemini --dangerously-skip-permissions --resume'
ALIASES
echo ""
echo "3. Start the router: ccr start &"
echo ""
echo "4. Launch Gemini: gyolo"