Google Gemini API Error RESOURCE_EXHAUSTED: Quota exceeded (429)

Identify: does your log match?

{
  "error": {
    "code": 429,
    "message": "You exceeded your current quota, please check your plan and billing details.",
    "status": "RESOURCE_EXHAUSTED"
  }
}

1. High

   Free-tier limits

   Free tier limits per model are low and include a daily request cap that resets at midnight Pacific time.

2. Medium

   Bursts above requests per minute

   Parallel calls from a batch job exceed the per-minute limit even when the daily total is small.

3. Low

   Shared project quota

   Several apps use keys from the same Google Cloud project and share its quota.

Fix

const res = await ai.models.generateContent({ model: "gemini-2.5-flash", contents });

import { GoogleGenAI } from "@google/genai";
const ai = new GoogleGenAI({});

async function generate(contents, tries = 5) {
  for (let i = 0; ; i++) {
    try { return await ai.models.generateContent({ model: "gemini-2.5-flash", contents }); }
    catch (e) {
      if (e.status !== 429 || i === tries - 1) throw e;
      await new Promise(r => setTimeout(r, Math.random() * 1000 * 2 ** i));
    }
  }
}

Verify: reproduce it on purpose

$ for i in $(seq 1 40); do curl -s -o /dev/null -w "%{http_code}\n" \
  "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
  -H "x-goog-api-key: $GEMINI_API_KEY" -H "Content-Type: application/json" \
  -d '{"contents":[{"parts":[{"text":"hi"}]}]}' & done | sort | uniq -c

Prevent

• Check your tier’s limits per model in Google AI Studio.
• Enable billing on the project for production traffic.
• Use the Batch API for large offline jobs.