retellai-rate-limits

# Retell AI Rate Limits ## Overview Handle Retell AI rate limits gracefully with exponential backoff and idempotency. ## Prerequisites - Retell AI SDK installed - Understanding of async/await patterns - Access to rate limit headers ## Instructions ### Step 1: Understand Rate Limit Tiers | Tier | Requests/min | Requests/day | Burst | |------|-------------|--------------|-------| | Free | 60 | 1,000 | 10 | | Pro | 300 | 10,000 | 50 | | Enterprise | 1,000 | 100,000 | 200 | ### Step 2: Implement Exponential Backoff with Jitter ```typescript async function withExponentialBackoff( operation: () => Promise, config = { maxRetries: 5, baseDelayMs: 1000, maxDelayMs: 32000, jitterMs: 500 } ): Promise { for (let attempt = 0; attempt <= config.maxRetries; attempt++) { try { return await operation(); } catch (error: any) { if (attempt === config.maxRetries) throw error; const status = error.status || error.response?.status; if (status !== 429 && (status < 500 || status >= 600)) throw error; // Exponential delay with jitter to prevent thundering herd const exponentialDelay = config.baseDelayMs * Math.pow(2, attempt); const jitter = Math.random() * config.jitterMs; const delay = Math.min(exponentialDelay + jitter, config.maxDelayMs); console.log(`Rate limited. Retrying in ${delay.toFixed(0)}ms...`); await new Promise(r => setTimeout(r, delay)); } } throw new Error('Unreachable'); } ``` ### Step 3: Add Idempotency Keys ```typescript import { v4 as uuidv4 } from 'uuid'; import crypto from 'crypto'; // Generate deterministic key from operation params (for safe retries) function generateIdempotencyKey(operation: string, params: Record): string { const data = JSON.stringify({ operation, params }); return crypto.createHash('sha256').update(data).digest('hex'); } async function idempotentRequest( client: RetellAIClient, params: Record, idempotencyKey?: string // Pass existing key for retries ): Promise { // Use provided key (for retries) or generate deterministic key from params const key = idempotencyKey || generateIdempotencyKey(params.method || 'POST', params); return client.request({ ...params, headers: { 'Idempotency-Key': key, ...params.headers }, }); } ``` ## Output - Reliable API calls with automatic retry - Idempotent requests preventing duplicates - Rate limit headers properly handled ## Error Handling | Header | Description | Action | |--------|-------------|--------| | X-RateLimit-Limit | Max requests | Monitor usage | | X-RateLimit-Remaining | Remaining requests | Throttle if low | | X-RateLimit-Reset | Reset timestamp | Wait until reset | | Retry-After | Seconds to wait | Honor this value | ## Examples ### Queue-Based Rate Limiting ```typescript import PQueue from 'p-queue'; const queue = new PQueue({ concurrency: 5, interval: 1000, intervalCap: 10, }); async function queuedRequest(operation: () => Promise): Promise { return queue.add(operation); } ``` ### Monitor Rate Limit Usage ```typescript class RateLimitMonitor { private remaining: number = 60; private resetAt: Date = new Date(); updateFromHeaders(headers: Headers) { this.remaining = parseInt(headers.get('X-RateLimit-Remaining') || '60'); const resetTimestamp = headers.get('X-RateLimit-Reset'); if (resetTimestamp) { this.resetAt = new Date(parseInt(resetTimestamp) * 1000); } } shouldThrottle(): boolean { // Only throttle if low remaining AND reset hasn't happened yet return this.remaining < 5 && new Date() < this.resetAt; } getWaitTime(): number { return Math.max(0, this.resetAt.getTime() - Date.now()); } } ``` ## Resources - [Retell AI Rate Limits](https://docs.retellai.com/rate-limits) - [p-queue Documentation](https://github.com/sindresorhus/p-queue) ## Next Steps For security configuration, see `retellai-security-basics`.