Write contracts

A contract states what a piece owes, and it is fixed ahead of the build. How the piece works is outside it.

Five fields carry a contract. It names the larger thing it sits under, fixes the vocabulary its terms use, states what is in scope, states what is explicitly out of scope, and states how anyone will know it worked. A piece with no stated promise is unverifiable by anyone who cannot read it.

A contract states what the piece does and leaves how to whoever builds it. It does not select the implementation, the components, or where a setting lives. A contract that chooses the implementation is a violation, because the program has been written twice and neither copy is trustworthy.

The out-of-scope field is a term of the contract. Omitting it is a violation. The field stating how anyone will know it worked is scored by a party that did not write the contract, and a statement only its author scores is a violation.

Trust and verify governs the result once the work exists. This principle fixes what that result is scored against.

A contract is a handoff. The sender owes completeness. The receiver owes acknowledgement before acting. A sender who leaves a field for the receiver to infer is a violation. A receiver who starts before confirming every field is present is a violation.

This holds between agents as it holds between builder and agent. The receiver's obligation does not weaken because the receiver is not a person.

Inspection

Take our last handoff and walk me through it from the receiver's side — what did they need in order to start without asking, and what was not there?

Held this, or broke it? Say which principle and what happened — tell me at /contact, subject Principles. What moves a band is somebody else's experience, and I'll publish what moved and who moved it.