phi

The deciding trait is that a stale edit is refused rather than applied. The model points at an anchor in the file, and if the file has moved underneath it the edit fails visibly instead of landing in roughly the right place. Anyone who has found a duplicated function three commits later knows why that is worth a little friction.

The tool is small and the interface is plain, so nothing here is going to charm you. Pick it if correctness matters more than convenience. Pick something more forgiving if you would rather it kept moving.

Strictness has a cost and it lands on the weaker model. Every edit requires an identifier the model has to emit exactly, and anything that drifts is refused, which means a session can burn turns retrying instead of failing over to something looser. The design is deliberate and it makes the tool's usefulness a function of the model behind it in a way a diff format does not.

What it does right is refuse loudly. A rejected edit is a better outcome than an approximate one, and most tools here choose the opposite.

1. Distinguishing the observability channel from the context channel is the correct decomposition, and it is the one most delegation implementations collapse: they either hide the subordinate work entirely or paste all of it back into the parent window. 2. Keeping the transcript visible to a human while withholding it from the parent prompt preserves auditability without paying for it in tokens.

2. The efficiency claim implied by that choice is not quantified anywhere, so the reader has a principled design and no measurement of what it saves.

Positioning matters more than people think, and describing yourself as a relative of another tool is a decision to be understood rather than chosen. It signals a technical audience, an unhurried pace and no intention to compete for buyers, which is exactly consistent with the absence of any tier, any entity or any revenue line in the repository.

Moat: none, and the edit format is copyable in an afternoon by anyone who reads it. Likely path: the anchoring idea appears in a larger tool while this stays a well-made small one. Position: use it, and expect no support.

A dedicated headless permission mode is the detail that matters to me. It means unattended runs are governed by a policy chosen in advance rather than by whatever the interactive default happens to be, so a job in a build pipeline cannot approve its own destructive step. That is a question I ask every vendor and almost nobody has an answer for.

There is still no console, no directory login and no central configuration, so desktop use stays sixty independent setups. Approved with conditions: the pipeline job runs as a service account, and desktop adoption is individual.

Lazy tool discovery is the configuration decision I have been waiting for someone to make. Registering a dozen servers no longer means a dozen schemas jammed into every prompt, because the agent asks what exists when it needs to know. That is the difference between attaching two servers and attaching twenty.

Extensions speak a binary protocol over standard input and output, so I can write one in either compiled language without linking against anything. Permissive licence, any endpoint I choose, and a fork that would keep working.