Troubleshooting GitHub Rate Limit Issues with Stack Triggers

Last updated: September 9, 2025

If your stacks are unexpectedly failing to trigger runs for certain Pull Requests, this may be due to GitHub API rate limiting. When rate limits are hit, Spacelift cannot fetch required PR metadata (like labels and file diffs) from GitHub, which can cause push policies to fail.

Symptoms

The main symptom is inconsistent behavior where some PRs fail to trigger runs while identical PRs do trigger runs as expected. This happens because rate limiting is temporary - once the limit resets, normal operation resumes.

Common Causes of Rate Limiting

  • Heavy use of Pull Request comments (including PR comments, aggregated checks, and notification policies targeting VCS)

  • Large number of stacks reacting to GitHub events through a single integration

How to Resolve

The recommended solution is to distribute API load across multiple GitHub integrations:

  1. Create additional GitHub VCS integrations in Spacelift by following our guide to creating custom GitHub applications

  2. Configure your stacks to use different GitHub integrations, spreading the API load across multiple rate limit quotas

You can verify if rate limiting is the cause by checking your notification inbox for messages containing "API rate limit exceeded" or by adding diagnostic output to your push policies.

Prevention

Monitor your GitHub API usage and consider implementing multiple integrations before hitting rate limits, especially if you have:

  • A large number of stacks

  • Heavy automation around PR comments and notifications

  • Frequent PR activity across multiple repositories