Editing files while it works

You can keep working in your own editor while a turn runs. Your changes are never overwritten by an older copy.

Before the agent overwrites or edits a file, Houston checks two things:

1. the agent has read the file in this conversation
2. the file still says what the agent last saw

If you changed it in the meantime (or a shell command, a formatter, or a subagent did), the write is refused and the agent reads the file again first.

• Creating a new file needs no read.
• Reads carry over between messages of one conversation for files nobody has changed since. After the app restarts, or once a read has been compacted out of the conversation, the agent reads a file again before changing it.
• Changes Houston makes on the agent's behalf right after a write (format-on-save, a PostToolUse hook) don't count as yours.

Precise edits. The agent sees files with line numbers, so it can cite exact lines and page through a large file by them.

• When an edit lands somewhere the agent didn't spell out exactly (its snippet had drifted from the file, or carried copied line numbers), the result shows the edited lines so it can check them.
• An edit whose snippet matches nothing points the agent at the closest part of the file instead of only failing.