I’ve run into this exact 403 issue a few times when setting up the Indexing API—usually it’s a small permission or configuration detail that gets missed. Let’s break down the most likely fixes based on your setup:

1. Ensure Your Service Account Has GSC Site Permissions #

This is the #1 culprit for 403 errors. Creating the service account in Google Cloud isn’t enough—you need to explicitly grant it access to your Google Search Console (GSC) property:

• Open your GSC site, go to Settings > Users and Permissions
• Click Add User, paste the service account's email (found in your credits-6933.json under the client_email field)
• Assign at least the Owner or Site Manager role (Owner is safest for initial testing)
• Save changes and wait 5-10 minutes for permissions to propagate (Google’s systems can take a bit to update)

2. Match the Request URL to Your Verified GSC Property #

Google treats https://url.com, https://www.url.com, and http://url.com as entirely separate properties. Make sure the URL in your request exactly matches the one you verified in GSC—including HTTPS/HTTP status and www prefixes. Any mismatch will trigger a permission error.

3. Verify the Indexing API is Enabled in Your Cloud Project #

Double-check that you’ve turned on the Indexing API for your Google Cloud project:

• Go to the Google Cloud Console, navigate to APIs & Services > Enabled APIs & Services
• Search for "Google Indexing API"—if it’s not listed, click Enable APIs and Services to activate it
• Without this enabled, even a correctly configured service account will return 403 errors

4. Validate Your Service Account Key File #

Ensure the credits-6933.json file you’re using is the exact, unmodified key downloaded from Google Cloud Console:

• Open the file and confirm the client_email and private_key fields are complete and properly formatted
• Avoid manual edits to the file—even a tiny typo can break authentication
• If you suspect corruption, download a fresh key from the service account’s page in Cloud Console

5. Add the Correct Content-Type Header #

Your code doesn’t explicitly set the Content-Type: application/json header. While httplib2 sometimes infers this, missing it can cause the API to reject your request (which might manifest as a 403). Update your request to include the header:

headers = {'Content-Type': 'application/json'}
response, content = http.request(ENDPOINT, method="POST", body=content, headers=headers)

Quick Test to Isolate the Issue #

If you’re still stuck, use Google’s built-in API testing tool in the Cloud Console to send a test request. If that works, the problem is in your code; if it also returns 403, the issue is definitely in your permission/API setup.

内容的提问来源于stack exchange，提问作者Softwareentwicklung Freelancer