@o-lang/llm-anthropic

O-Lang resolver for Anthropic Claude LLM API

Requirements

• ANTHROPIC_API_KEY environment variable

Usage

Allow resolvers:
- llm-anthropic

Step 1: Ask llm-anthropic "What is the capital of France?"
Save as response

Multi-turn chat (RAG chatbot, governed chatbot)

Allow resolvers:
- llm-anthropic

Step 1: llm_chat
  system_prompt: "You are a helpful support agent."
  history: "{{ session.history }}"
  user_message: "{{ params.user_message }}"
Save as reply

Models

| Constant | Model | Best for | |---|---|---| | FAST | claude-haiku-4-5-20251001 | Classification, short answers, data workflows | | SMART | claude-sonnet-4-6 | RAG, chatbots, document analysis | | POWER | claude-opus-4-6 | Complex reasoning, synthesis |

Default for llm_chat: claude-sonnet-4-6 Default for llm_complete: claude-haiku-4-5-20251001

Actions

llm_chat — multi-turn conversation

{
  "action": "llm_chat",
  "context": {
    "system_prompt": "You are a helpful assistant.",
    "history": [
      { "role": "user",      "content": "Hello" },
      { "role": "assistant", "content": "Hi! How can I help?" }
    ],
    "user_message": "What is your refund policy?",
    "model": "claude-sonnet-4-6",
    "max_tokens": 1024,
    "temperature": 0.7
  }
}

llm_complete — single-turn completion

{
  "action": "llm_complete",
  "context": {
    "prompt": "Summarise this patient data: ...",
    "model": "claude-haiku-4-5-20251001",
    "max_tokens": 250
  }
}

Environment variables

ANTHROPIC_API_KEY=your_key_here

# Optional model overrides
LLM_CHAT_MODEL=claude-sonnet-4-6
LLM_COMPLETE_MODEL=claude-haiku-4-5-20251001
LLM_CHAT_MAX_TOKENS=1024

Important: Anthropic API difference

Unlike Groq and OpenAI, the Anthropic API takes system_prompt as a top-level field — not inside the messages array. This resolver handles that automatically. Your .ol workflows use the same system_prompt field regardless of which LLM resolver is plugged in.

Running tests

npm test                    # Jest suite — no API key required
node test-local-resolver.js # Live smoke test — requires ANTHROPIC_API_KEY

Contact

[email protected]