Anthropic Message Batches & Async Processing

Overview

Anthropic doesn't have traditional webhooks. Instead, use Message Batches for async bulk processing — up to 10,000 requests per batch at 50% off, with a 24-hour processing SLA.

Prerequisites

• Completed clade-install-auth
• Multiple prompts/documents to process in bulk
• Tolerance for async processing (results within 24 hours)

Instructions

Step 1: Create a Batch

import Anthropic from '@claude-ai/sdk';

const client = new Anthropic();

const batch = await client.messages.batches.create({
  requests: documents.map((doc, i) => ({
    custom_id: `doc-${i}`,
    params: {
      model: 'claude-sonnet-4-20250514',
      max_tokens: 1024,
      messages: [{ role: 'user', content: `Summarize: ${doc.text}` }],
    },
  })),
});

console.log(`Batch ${batch.id} created — ${batch.request_counts.processing} processing`);

Step 2: Poll for Completion

async function waitForBatch(batchId: string): Promise<Anthropic.Messages.MessageBatch> {
  while (true) {
    const batch = await client.messages.batches.retrieve(batchId);

    if (batch.processing_status === 'ended') {
      console.log(`Batch complete:
        Succeeded: ${batch.request_counts.succeeded}
        Errored: ${batch.request_counts.errored}
        Expired: ${batch.request_counts.expired}`);
      return batch;
    }

    console.log(`Processing... ${batch.request_counts.processing} remaining`);
    await new Promise(r => setTimeout(r, 30_000)); // Check every 30s
  }
}

Step 3: Retrieve Results

const results = await client.messages.batches.results(batch.id);

for await (const result of results) {
  if (result.result.type === 'succeeded') {
    const text = result.result.message.content[0].text;
    console.log(`${result.custom_id}: ${text.substring(0, 100)}...`);
  } else {
    console.error(`${result.custom_id}: ${result.result.type} — ${result.result.error?.message}`);
  }
}