Messages API with Tool Use
LunoGen uses Anthropic's Messages API with tool use for structured agent actions. Claude decides which tool to call, and the agent executes HTTP requests, sends WhatsApp messages, or writes files in one loop.
Conversation example
Check the weather in Tokyo and if it's raining, reschedule my 3 PM walk to tomorrow
Calling Messages API with tool use (weather + calendar tools)...
Tool use trace (Claude Sonnet) 1. weather.get(location='Tokyo') → 'heavy rain, 16C, 90% humidity' 2. calendar.get_event(title='walk', time='3 PM today') → found 3. calendar.move(event_id='abc', new_time='tomorrow 3 PM') → success Done. It's raining in Tokyo so I moved your 3 PM walk to tomorrow 3 PM. Weather tomorrow: partly cloudy, 19C. Your calendar is updated.
More Anthropic use cases
Bring Your Own Anthropic Key
Connect your Anthropic API key and LunoGen uses your account for all Claude calls. You control billing, model access, and rate limits — and gain access to the latest Claude releases as soon as they ship.
Claude Opus for Complex Reasoning
Route your hardest tasks — deep research, multi-step tool use, long planning — to Claude Opus. The agent detects complexity and automatically uses Opus when the prompt needs it.
Claude Haiku for Fast, Cheap Replies
Quick user messages — greetings, simple questions, intent checks — get routed to Claude Haiku for near-instant, low-cost replies. Opus handles the thinking, Haiku handles the talking.
Prompt Caching for Cost Savings
LunoGen caches your long system prompt, memory context, and knowledge base on Anthropic's side. Repeated calls hit the cache and cost a fraction of normal tokens — often cutting bills by 70% or more.
Vision Tasks on WhatsApp Images
Send an image to the agent on WhatsApp and it runs Claude vision — reading receipts, describing screenshots, extracting handwritten notes, or checking a product photo for defects.
Deploy this in minutes
Create a LunoGen agent, connect Anthropic, and start running this workflow from WhatsApp today.