Recorded Coroid task · September 25, 2026
Chrono City: from brief to verified pull request
A five-era city scene looked ready after the first build. Browser QA found two unmet criteria, sent the work back and verified the fixes before the pull request was ready. This is the record of that run.
This was Coroid's own production task. The images below are the QA agent's captures from its running browser, not generated illustrations. Run totals come from the execution trail.
- Agent runs
- 6
- Delivery cycles
- 2
- Criteria verified
- 11/11
- Tokens used
- 34.7M tokens
- Model spend
- $1.00
- To pull request
- 1 h 48 min
The brief and its checks
Build an interactive city block that moves between 1945, 1965, 1985, 2005 and 2025. Visitors must be able to select each era and open period-aware details for scene objects.
How Coroid writes acceptance criteria- Criterion 3: every selected era must render its city scene.
- Criterion 6: building, vehicle and pedestrian cards need descriptions for their era.
What browser QA caught
In the first delivery cycle, the year label switched to 1985 but the city did not render. QA reproduced the blank purple viewport three times. It also found empty descriptions in the info cards. Both findings went back to the developer agent before review.
What reached review
The architect planned the work, the developer built it twice, QA ran twice and a reviewer checked the result. All 11 acceptance criteria passed in the second cycle. The pull request was ready 1 hour 48 minutes after the task was created.
The architect estimated 12M tokens. The task used more because the developer checked renders, QA exercised the scene in a browser and the failed checks required a second cycle. 97% of tokens were served from cache; model spend was $1.00.
