Sub-Nebula

Reduce Claude Code token costs by routing subagents to cheaper models.

Paid Claude Code accounts burn tokens fast. This proxy cuts costs by keeping your main Claude interactions on Anthropic while routing subagent tasks to Kimi (significantly cheaper).

Quick Start

# 1. Configure - copy .env.example to .env and edit
cp .env.example .env
# Edit .env: KIMI_API_KEY=sk-kimi-xxx

# 2. Start proxy
go run .

# 3. Configure Claude Code
cat > ~/.claude/settings.json << 'EOF'
{
  "env": {
    "ANTHROPIC_BASE_URL": "http://localhost:4242",
    "ANTHROPIC_AUTH_TOKEN": "dummy",
    "CLAUDE_CODE_SUBAGENT_MODEL": "kimi-for-coding"
  }
}
EOF

# 4. Run with proxy
claude

How It Works

flowchart LR
    A[Claude Code] --> B[SubNebula]

    B --> C{Is Subagent Task?}

    C -->|No| D[Claude Models]
    C -->|Yes| E[Kimi Model API]

    D --> F[Response]
    E --> F

    F --> A

Loading

Routing logic:

• claude-* models → Anthropic API (your OAuth session)
• kimi-* models → Kimi API (your API key)

Features

• Transparent proxy - No payload modification
• OAuth auto-auth - Reads Claude token from system credentials (macOS Keychain / ~/.claude/.credentials.json)
• Token caching - Avoids repeated credential reads
• /v1/models endpoint - Lists available models from both providers
• Concurrent fetching - Aggregates models from Anthropic + Kimi in parallel

Endpoints

Endpoint	Description
GET /health	Proxy health check
GET /v1/models	List all available models
POST /v1/messages	Proxy messages to appropriate provider

Environment Variables

Variable	Default	Description
PORT	4242	Proxy port
KIMI_API_KEY	-	Kimi API key
KIMI_BASE_URL	https://api.kimi.com/coding	Kimi endpoint
SUBAGENT_MODEL	kimi-for-coding	Default subagent model

Troubleshooting

"failed to read Claude credentials"

• Ensure you've logged into Claude Code at least once
• macOS: verify security find-generic-password -s "Claude Code-credentials" -w works
• Linux: verify ~/.claude/.credentials.json exists

"401 Unauthorized"

• Check your OAuth session is valid: claude login
• Verify KIMI_API_KEY is set correctly

License

MIT