Starcat Developer
Starcat Developer Ultra
The max-power agent mode: parallel writers, end-to-end self-validation, and a spend budget
Ultra in the mode selector is the max-power Agent mode. Use it for a substantial, multi-step change you want built, verified, and handed off in one run.
Info:
Ultra needs the Edit Project Files permission. It isn't available on a fork's chat.
Where to Find Ultra
At the top of the mode selector in an app's Starcat Developer builder. Not in a Starcat chat. Selecting Ultra turns on Agent mode; selecting any other mode turns Ultra off.
What Ultra Does Differently
- Delegates the change to parallel write agents after mapping everything it touches.
- Self-validates: reads back every diff, runs lint, typecheck, and tests on touched code, and fixes what it finds.
- Audits tests when correctness depends on them, and adds a regression test. Skips this for copy or styling.
- Works longer on a turn.
- If it can't finish, it reports what's done, what isn't, and the next step.
This loop is why Ultra costs more and takes longer.
How to Prompt Ultra
A vague prompt spends the budget guessing. Give it:
- Goal and scope: what you're building, and where it starts and stops.
- Architecture: the data model (tables and fields), the pages or routes, the APIs with their inputs and outputs, and any external services or other apps it touches.
- Behavior and rules: the important flows, edge cases, permissions, and validation.
- Acceptance criteria: how you'll know it's done, including what should be tested.
- Constraints: patterns to follow, things not to change, libraries to use or avoid.
Warning:
A one-liner like "build a booking website" wastes an Ultra run. Use plain Agent mode for quick, open-ended edits.
Build a restaurant booking website.The Run Budget
The budget control caps how many credits one run may spend before it stops. It appears in each project's builder.
- Presets: 2.5, 5, 10, 15, 25, 50, 75, 100, 150, 200, 250 credits, or type a value.
- Default: 100 credits.
- Set it low for exploratory runs, higher for a large change you want finished.