Practical notes: Coding an Agent: Cracking Agent Loops

The following notes reconstruct a practical path around “Coding an Agent: Cracking Agent Loops”. Emphasis stays on contracts, checks, and drop-in code placeholders rather than motivational framing.

struct Latched {
    /// The repeating block, as bytes: a period can split a multi-byte
    /// character, so this is never treated as text.
    block: Vec<u8>,
    /// Stream offset just past the last confirmed copy.
    end: usize,
    /// Copies confirmed so far, counting the ones the warn rung matched.
    cycles: usize,
}

Operational checklist

The hardening note 0 stage works best when treated as a measurable surface. Capture one golden transcript, one failure case, and the rollback note before expanding scope. Prefer small, testable units over sprawling scripts. When a step fails, the failure should point at a single responsibility rather than a tangled pipeline.

Hardening detail 0/911: measure wall time, error class, and token spend for this note, then decide whether to keep the change based on a fixed question set rather than anecdote.

For the hardening note 1 stage, define the inputs, the owner of the step, and the exit criteria before changing code. Operators should be able to re-run the step from a known checkpoint without guessing hidden state. Record timings and token or query cost next to functional results. Cost visibility early prevents surprise bills when the path moves from demo to shared environments.

Hardening detail 1/911: measure wall time, error class, and token spend for this note, then decide whether to keep the change based on a fixed question set rather than anecdote.

For the hardening note 0 stage, define the inputs, the owner of the step, and the exit criteria before changing code. Operators should be able to re-run the step from a known checkpoint without guessing hidden state. Keep configuration outside application code. Environment files, secret stores, and feature flags belong in one place operators can audit without reading the whole graph.

Hardening detail 0/930: measure wall time, error class, and token spend for this note, then decide whether to keep the change based on a fixed question set rather than anecdote.

When working through the hardening note 1 stage, write down the contract first: required inputs, success signal, and what happens on partial failure. That checklist keeps later code changes honest. Prefer small, testable units over sprawling scripts. When a step fails, the failure should point at a single responsibility rather than a tangled pipeline.

Hardening detail 1/930: measure wall time, error class, and token spend for this note, then decide whether to keep the change based on a fixed question set rather than anecdote.