Anthropic Rate Limits

Overview

Anthropic enforces three types of limits: requests per minute (RPM), input tokens per minute (TPM), and output tokens per minute. Limits depend on your spend tier.

Rate Limit Tiers

Tier	Qualification	RPM	Input TPM	Output TPM
Tier 1	Free	50	40,000	8,000
Tier 2	$40+ spend	1,000	80,000	16,000
Tier 3	$200+ spend	2,000	160,000	32,000
Tier 4	$400+ spend	4,000	400,000	80,000
Scale	Custom	Custom	Custom	Custom

Check your tier: console.anthropic.com → Settings → Limits

Response Headers

Every API response includes rate limit headers:

claude-ratelimit-requests-limit: 1000
claude-ratelimit-requests-remaining: 998
claude-ratelimit-requests-reset: 2025-01-01T00:01:00Z
claude-ratelimit-tokens-limit: 80000
claude-ratelimit-tokens-remaining: 79500
claude-ratelimit-tokens-reset: 2025-01-01T00:01:00Z
retry-after: 5

Built-In SDK Retries

The SDK automatically retries 429 and 529 errors with exponential backoff:

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

const client = new Anthropic({
  maxRetries: 3, // default: 2. Set to 0 to disable.
});

Custom Backoff

async function callWithBackoff(params: Anthropic.MessageCreateParams, maxRetries = 5) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await client.messages.create(params);
    } catch (err) {
      if (err instanceof Anthropic.RateLimitError) {
        const retryAfter = Number(err.headers?.['retry-after'] || 2 ** attempt);
        const jitter = Math.random() * 1000;
        console.log(`Rate limited. Retry in ${retryAfter}s (attempt ${attempt + 1})`);
        await new Promise(r => setTimeout(r, retryAfter * 1000 + jitter));
      } else {
        throw err;
      }
    }
  }
  throw new Error('Exceeded max retries');
}