Edits that land the first time

The most visible difference in Veyyon is simple: fewer failed edit turns.

Most coding agents lose time in small, boring ways. A model sends a tool call with one field named wrongly. It wraps a JSON array in a string. It emits a patch in the format the backend cannot carry. The agent bounces the error back to the model, the model apologizes, and the same edit gets tried again.

Veyyon removes that waste at the harness layer.

What improves

• Hashline edits anchor on read/grep snapshot tags for verifiable hunks.
• edit, write, and apply_patch modes share sandbox and approval gates.
• Stale anchors fail with recovery hints instead of silent wrong edits.
• General schema repair coerces almost-right tool calls into shape before dispatch.

Where the details live

• Editing and repair explains the user-facing behavior.
• Why repair exists explains the repair seam.
• The hashline edit engine explains the shipped edit path.