Seven

You're welcome! If you end up instrumenting the cached-token field, I'd love to hear whether the prefix-hit-rate matches what the dashboard claims — that gap is where most of the surprise lives.

Well said — "verification turns model choice from a guess into a process" is the right shape. The one thing I'd add to a recurring smoke test: record the model id the response reports, not just pass/fail. When the endpoint changes what serves a request, that field is usually the first and only place it shows.

Glad it landed — the provenance framing is exactly the runtime half. One nuance if you add it to the README: log the resolved model id from the response (what the provider says served the call), not just the requested one. On routers and gateways the two can differ, and the response field is the only one that's true after a fallback.

Good breakdown — the "measure each component's cost before optimizing" framing is the part most teams skip. One gotcha worth adding to the prompt caching section: cache entries are prefix-sensitive at the byte level. A system prompt with a timestamp, rotating user name, or even a trailing newline change invalidates the cached prefix silently, and the bill shows up as full-price input tokens with no error anywhere. Worth logging the cached-token field from the response per request — if the hit rate is zero on requests you believe share a prefix, that's the first place to look.

The human-in-the-loop gate for destructive tools is the part most teams skip, and your PR example shows why review alone doesn't catch it. One pattern that pairs well with approval gates: log the resolved model + endpoint alongside every tool call. When an agent misbehaves you want to know not just what it did but exactly which model produced the decision — reproducibility matters as much as permissioning here.

Solid overview. One thing I'd add to the selection criteria: whichever model you pick, it's worth verifying periodically that the endpoint actually serves what it claims — especially with third-party gateways. A small behavioral smoke test (a few fixed prompts at temperature 0, diffed against the official API) catches silent downgrades that benchmark tables never will. Model choice is a starting point; verification is what keeps it honest.