Diagnosing the 1,393-agent run's cache misses took a state.db join and a live
probe because none of the three were on the one line we log per call:
write=<n> cache_creation tokens; a write costs 50x a read, so this is the
money, and "read stuck, write large" on consecutive lines is a
routing miss visible without a probe
id=<id> the provider's response id (Anthropic msg_..., OpenRouter/Nous
gen-...): what a provider needs to look a request up
upstream=<n> who actually served, when the route reports it (OpenRouter's
`provider`); how we learned GMI was not serving
Fields are appended to the existing line and omitted when absent, so every
existing parser (evals/postmortem, the two cache_prefix probes) keeps
matching; the forensics parser reads them when present.
The streamed chat path fabricated `id="stream-<uuid>"` and dropped the
chunks' id/provider on the floor; it now keeps the first chunk's id and
provider, falling back to the fabricated id only when the stream never sent
one. Nothing depended on the prefix.
Live (Nous, Fable 5.1, both wires): chat -> `write=3759
id=gen-1788727882-... upstream=Anthropic`; native -> `id=gen-1788727891-...`
(the Anthropic Message object's id was already real). Tests: fields present
and omitted, prefix unchanged; forensics parser reads new and old lines.
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