@sisu-ai/adapter-anthropic

Anthropic Messages API adapter with tool calling and streaming.

Setup

npm i @sisu-ai/adapter-anthropic

• Env: ANTHROPIC_API_KEY (preferred) or API_KEY required
• Optional base URL: ANTHROPIC_BASE_URL (or BASE_URL)
• Optional debug: DEBUG_LLM=1 to log redacted request/response summaries on errors

Usage

import { anthropicAdapter } from '@sisu-ai/adapter-anthropic';

const model = anthropicAdapter({ model: 'claude-3-5-sonnet-20240620' });
// with a self-hosted proxy
const model = anthropicAdapter({ model: 'claude-3-opus-20240229', baseUrl: 'https://api.anthropic.com' });

Tools

• Sends tools in Anthropic format (name, description, input_schema).
• Sends tool_choice only when tools exist (Anthropic rejects tool_choice without tools).
• Maps assistant tool calls to { id, name, arguments } for the middleware loop.
• Maps tool results into Anthropic tool_result blocks and back.

Streaming

• Supports server‑sent events from the Messages API.
• Emits { type: 'token', token } events for content deltas and a final { type: 'assistant_message', message }.

Options

anthropicAdapter({
  model: 'claude-3-5-sonnet-20240620',
  apiKey?: string,            // default: ANTHROPIC_API_KEY or API_KEY
  baseUrl?: string,           // default: https://api.anthropic.com (or ANTHROPIC_BASE_URL / BASE_URL)
  anthropicVersion?: string,  // default: 2023-06-01
  timeout?: number,           // default: 60000 ms
  maxRetries?: number,        // default: 3 (with backoff; 4xx except 429 are not retried)
});

Message mapping

• System messages → system string (joined if multiple system messages appear)
• User messages → { role: 'user', content: [{ type: 'text', text }] }
• Assistant messages with tool calls → tool_use blocks with { id, name, input }
• Tool messages → user tool_result blocks with { tool_use_id | name, content }

Usage reporting

The adapter maps usage.input_tokens and usage.output_tokens to { promptTokens, completionTokens, totalTokens }.

Debugging

• DEBUG_LLM=1 prints sanitized payloads and error bodies.
• Combine with your app logger’s LOG_LEVEL=debug to see middleware events.

Community & Support

Discover what you can do through examples or documentation. Check it out at https://github.com/finger-gun/sisu. Example projects live under examples/ in the repo.

• Code of Conduct
• Contributing Guide
• License
• Report a Bug
• Request a Feature