Anthropic adapter

@receipta/anthropic wraps the @anthropic-ai/sdk (v0.30+, including current v0.110) so every Messages API call emits a receipt.

How it works

Same no-fork pattern as the OpenAI adapter — both SDKs share the fetchWithTimeout lineage (verified firsthand). The only provider-specific differences:

• the request id header is request-id (Anthropic) vs x-request-id (OpenAI),
• usage is input_tokens / output_tokens (Anthropic) vs prompt_tokens / completion_tokens,
• the response carries stop_reason vs finish_reason.

The fetch layer is the version-stable single integration point.

Usage

import Anthropic from '@anthropic-ai/sdk';
import { withReceipts } from '@receipta/anthropic';
import { openStore, generateKeyPair } from '@receipta/core';

const store = await openStore('./receipts.log.receipta');
const signer = generateKeyPair();

const client = withReceipts(
  Anthropic,
  { apiKey: process.env.ANTHROPIC_API_KEY! },
  {
    store,
    signer,
    actor: { type: 'service', id: 'my-app' },
  },
);

const res = await client.messages.create({
  model: 'claude-3-5-sonnet-20241022',
  max_tokens: 1024,
  messages: [{ role: 'user', content: 'Hello' }],
});

What gets captured

• provider: "anthropic"
• model: from the response body
• usage: input_tokens / output_tokens
• request_id: the request-id header
• attempt_index: best-effort, sourced from the Stainless SDK's x-stainless-retry-count request header (0 on the first attempt, incrementing on retry); omitted when the header is absent
• outcome: success for 2xx, error otherwise
• content: the request + response bodies (when captureMode: "full")