mistral-rate-limits

Mistral Rate Limits

Overview

Rate limit management for Mistral AI API. Mistral enforces per-workspace RPM (requests/minute) and TPM (tokens/minute) limits that vary by usage tier (Experiment free tier vs Scale pay-as-you-go). View your workspace limits at admin.mistral.ai/plateforme/limits.

Prerequisites

• Mistral API key configured
• Understanding of workspace tier (Experiment vs Scale)
• Application with retry infrastructure

Mistral Rate Limit Architecture

Limits are set at the workspace level, not per key. All API keys in a workspace share the same RPM/TPM budget.

Endpoint	What's limited
/v1/chat/completions	RPM + TPM (input + output)
/v1/embeddings	RPM + TPM (input only)
/v1/fim/completions	RPM + TPM
/v1/moderations	RPM

Headers returned on every response:

• x-ratelimit-limit-requests — your RPM cap
• x-ratelimit-remaining-requests — remaining RPM
• x-ratelimit-limit-tokens — your TPM cap
• x-ratelimit-remaining-tokens — remaining TPM
• Retry-After — seconds to wait (on 429 only)

Instructions

Step 1: Token-Aware Rate Limiter

class MistralRateLimiter {
  private requestTimes: number[] = [];
  private tokenBuckets: Array<{ time: number; tokens: number }> = [];
  private readonly rpm: number;
  private readonly tpm: number;

  constructor(rpm: number, tpm: number) {
    this.rpm = rpm;
    this.tpm = tpm;
  }

  async waitIfNeeded(estimatedTokens: number): Promise<void> {
    const now = Date.now();
    const windowStart = now - 60_000;

    // Prune old entries
    this.requestTimes = this.requestTimes.filter(t => t > windowStart);
    this.tokenBuckets = this.tokenBuckets.filter(b => b.time > windowStart);

    // Check RPM
    if (this.requestTimes.length >= this.rpm) {
      const waitMs = this.requestTimes[0] - windowStart + 100;
      console.warn(`RPM limit (${this.rpm}), waiting ${waitMs}ms`);
      await new Promise(r => setTimeout(r, waitMs));
    }

    // Check TPM
    const currentTPM = this.tokenBuckets.reduce((sum, b) => sum + b.tokens, 0);
    if (currentTPM + estimatedTokens > this.tpm) {
      const waitMs = this.tokenBuckets[0].time - windowStart + 100;
      console.warn(`TPM limit (${this.tpm}), waiting ${waitMs}ms`);
      await new Promise(r => setTimeout(r, waitMs));
    }

    this.requestTimes.push(Date.now());
  }

  recordUsage(tokens: number): void {
    this.tokenBuckets.push({ time: Date.now(), tokens });
  }
}

Step 2: Retry with Retry-After Header

import { Mistral } from '@mistralai/mistralai';

async function chatWithRetry(
  client: Mistral,
  params: { model: string; messages: any[] },
  maxRetries = 5,
): Promise<any> {
  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      return await client.chat.complete(params);
    } catch (error: any) {
      if (error.status !== 429 || attempt === maxRetries) throw error;

      // Respect Retry-After header from Mistral
      const retryAfter = error.headers?.get?.('retry-after');
      const waitSec = retryAfter ? parseInt(retryAfter) : Math.min(2 ** attempt, 60);
      console.warn(`429 — retrying in ${waitSec}s (attempt ${attempt + 1}/${maxRetries})`);
      await new Promise(r => setTimeout(r, waitSec * 1000));
    }
  }
}

Step 3: Rate-Limited Client Wrapper

const limiter = new MistralRateLimiter(100, 500_000);
const client = new Mistral({ apiKey: process.env.MISTRAL_API_KEY });

async function rateLimitedChat(messages: any[], model = 'mistral-small-latest') {
  const estimatedTokens = messages.reduce(
    (sum, m) => sum + Math.ceil((m.content?.length ?? 0) / 4), 0
  );

  await limiter.waitIfNeeded(estimatedTokens);
  const response = await client.chat.complete({ model, messages });

  if (response.usage) {
    limiter.recordUsage(
      (response.usage.promptTokens ?? 0) + (response.usage.completionTokens ?? 0)
    );
  }
  return response;
}

Step 4: Model Fallback for Throughput

class ModelRouter {
  private limiters: Record<string, MistralRateLimiter>;

  constructor() {
    this.limiters = {
      'mistral-large-latest': new MistralRateLimiter(30, 200_000),
      'mistral-small-latest': new MistralRateLimiter(120, 500_000),
    };
  }

  async chat(messages: any[], preferred = 'mistral-large-latest') {
    try {
      return await rateLimitedChat(messages, preferred);
    } catch (error: any) {
      if (error.status === 429 && preferred !== 'mistral-small-latest') {
        console.warn(`Falling back to mistral-small-latest`);
        return rateLimitedChat(messages, 'mistral-small-latest');
      }
      throw error;
    }
  }
}

Step 5: Batch Embedding with Rate Awareness

import time
from mistralai import Mistral

def batch_embed(client: Mistral, texts: list[str], batch_size: int = 32) -> list:
    """Batch embed with automatic rate limiting."""
    all_embeddings = []
    for i in range(0, len(texts), batch_size):
        batch = texts[i:i + batch_size]
        try:
            response = client.embeddings.create(
                model="mistral-embed", inputs=batch
            )
            all_embeddings.extend([d.embedding for d in response.data])
        except Exception as e:
            if hasattr(e, "status_code") and e.status_code == 429:
                time.sleep(10)
                response = client.embeddings.create(
                    model="mistral-embed", inputs=batch
                )
                all_embeddings.extend([d.embedding for d in response.data])
            else:
                raise
    return all_embeddings

Step 6: Usage Dashboard

function rateLimitStatus(limiter: MistralRateLimiter) {
  const now = Date.now();
  const windowStart = now - 60_000;
  const activeRequests = limiter['requestTimes'].filter(t => t > windowStart).length;
  const activeTokens = limiter['tokenBuckets']
    .filter(b => b.time > windowStart)
    .reduce((sum, b) => sum + b.tokens, 0);

  return {
    rpm: { used: activeRequests, limit: limiter['rpm'], pct: (activeRequests / limiter['rpm'] * 100).toFixed(1) },
    tpm: { used: activeTokens, limit: limiter['tpm'], pct: (activeTokens / limiter['tpm'] * 100).toFixed(1) },
  };
}

Error Handling

Issue	Cause	Solution
429 errors	Exceeded RPM or TPM	Use rate limiter + exponential backoff
Inconsistent limits	All keys share workspace budget	Coordinate across services
Batch failures	Too many tokens per batch	Reduce batch size for embeddings
Spike traffic blocked	No request smoothing	Queue requests, spread over window

Resources

• Rate Limits & Usage Tiers
• Pricing
• Batch Inference — 50% cheaper, no rate limits

Output

• Token-aware rate limiter with RPM + TPM tracking
• Retry logic respecting Retry-After headers
• Model fallback routing for throughput
• Rate limit dashboard for monitoring