Google Gemini API 403 PERMISSION_DENIED: what it means and how to fix it

403 PERMISSION_DENIED: Your API key was reported as leaked. Please use another API key.

How to fix it

1. Create a new key in Google AI Studio.
2. Never ship keys in client-side code or commit them; call the API from your server and keep the key in an env var or secret manager.
3. Check your repo history and rotate any other keys that were committed with it.

Handle it in code

import random, time
from google import genai
from google.genai import errors

client = genai.Client()

def generate(prompt, tries=6):
    for i in range(tries):
        try:
            return client.models.generate_content(model="gemini-flash-latest", contents=prompt)
        except errors.APIError as e:
            # 429 RESOURCE_EXHAUSTED, 503 UNAVAILABLE, 500, 504: transient. 400/402/403: fix, do not retry.
            if e.code not in (429, 500, 503, 504) or i == tries - 1:
                raise
            time.sleep(min(60, 2 ** i) + random.random())  # exponential backoff + jitter

Google lists 429 RESOURCE_EXHAUSTED, 503 UNAVAILABLE, 408 and 5xx as transient: retry with exponential backoff and jitter. 400, 402 and 403 are not.

Same kind of error at other providers

• Anthropic 401 authentication_error
• Anthropic 403 permission_error
• OpenAI 401 invalid_api_key
• OpenAI 401 invalid_authentication

Other Google Gemini API errors

• 429RESOURCE_EXHAUSTEDretry
• 503UNAVAILABLE: The model is overloaded. Please try again later.retry
• 400INVALID_ARGUMENTfix
• 400FAILED_PRECONDITIONfix
• 402payment_requiredfix
• 403PERMISSION_DENIED: Your project has been denied accessfix
• 404NOT_FOUNDfix
• 500INTERNALretry
• 504DEADLINE_EXCEEDEDretry
• -RECITATIONfix
• -SAFETYfix

Source

• Google Gemini API error documentation: ai.google.dev/gemini-api/docs/api-errors (checked Oct 24, 2026)

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