Validation agent that stops after three tries
Brex's PR validation agent deploys services, runs integration tests, patches failures up to three times, then leaves a human-readable blocker comment.
- Agent or tool
- Cursor
- Topic
- DevOps & Infra
- Reported on
- Blog
- Added
- 2026-10-15
Why it matters
Keeping servers and pipelines healthy is constant, detail-heavy work. Agents that can read logs and run routine fixes are a big help, as long as a person keeps an eye on what changes. It is one of 40 sightings filed under DevOps & Infra on Agent Sightings (number 22 by interest), and one of 30 involving Cursor.
How you could try it
Here is a reusable prompt, written by us in our own words, that captures the task. Paste it into Cursor or any similar agent and adjust the details to your situation.
Monitor this PR's CI and deploy. If tests fail, apply the matching skill and retry up to three times. If still blocked, comment with root cause and stop. Never merge.
The prompt breaks down into 4 steps you can check as the agent works:
- Monitor this PR's CI and deploy.
- If tests fail, apply the matching skill and retry up to three times.
- If still blocked, comment with root cause and stop.
- Never merge.
Tip: Try it first on a staging system or with read-only credentials, and require approval for anything that changes production.
Source
Read the original first-hand account on Blog: https://www.brex.com/journal/agent-automations-for-big-migrations. Our summary is a paraphrase; details are in the source.