engineering 15 Oct 2026 · 1 min read

Big Canvases, Smaller Bills

Building a game or a long document on a canvas used to get slower and more expensive with every turn. We rebuilt how the assistant works with large canvases. What we changed - Piece by piece. The assistant reads and patc…

ToRun Team ToRun Team

Building a game or a long document on a canvas used to get slower and more expensive with every turn. We rebuilt how the assistant works with large canvases.

What we changed

  • Piece by piece. The assistant reads and patches only the files and sections it needs, instead of reading and rewriting the whole canvas each time.
  • Less re-sending. Work already saved on the canvas is not sent back with every step, and the fixed part of the conversation stays cached for an hour.
  • Long work finishes. A reply that keeps making progress is no longer cut off at five minutes, and you see what it is doing as it goes.
  • Costs in Runs. When the assistant estimates the next step, it tells you in Runs, the unit your balance uses.

The result: long canvas sessions that stay quick and cost noticeably less per turn.