agent caught its own broken fix before it merged

agent caught its own broken fix before it merged, a gate that can actually say no gave the agent one vague prompt: "users noticing a billing issue on prod, find fix and prove." it audited the service, found 22 bugs ranked by blast radius, wrote a fix, then ran it through the sandbox. its own SQL-injection fix failed the proof. so it diagnosed it, stripped the over-engineering, and re-proved green. no human in the loop, no prod creds, no "trust me it compiles." that last part is what fetchsandbox is actually for. your agent writes the stripe/webhook/auth integration, it looks fine, returns 200, passes review, then breaks on duplicate webhooks or out-of-order events in prod. the sandbox reproduces those scenarios against your actual code before anything merges. bug reproduced, fix verified, receipt url, not a vibe. full 4-min demo in comments. wondering if anyone else has a setup where the agent can actually fail its own fix. submitted by /u/Common_Dream9420 [link] [comments]