How do you run several coding agents in parallel without them breaking each other?
parallel-coding-agents.answer
Give each agent its own ticket and its own branch, so no two agents edit the same files at the same time. Separate branches don't stop two changes that each look fine from breaking each other, so niwa runs the check on the combined result before main moves, and sends the work back with the log if it fails.
One ticket, one branch
Each agent takes a ticket from a board and works on its own branch. A half-finished change never lands under another agent's feet.
Check the combined result
Two changes can each pass their own tests and still break each other once merged. The check that counts runs on the merged result, before main moves. If it fails, main stays where it was and the ticket goes back with the log.
Another agent decides
The agent that wrote a change never merges it. An independent reviewer checks the exact commit against the ticket's criteria, and niwa merges only when the gate passes.
The record
niwa is built by its own crew. From 29 August to 28 September 2026, its git history shows 441 changes merged, 436 of them approved by a reviewer that wasn't the author.