Rulvar API reference / @rulvar/openai / normalizeOpenAiUsage
Function: normalizeOpenAiUsage()
function normalizeOpenAiUsage(raw): Usage;Defined in: packages/openai/src/wire.ts:295
Normalizes Responses usage into the canonical Usage invariant, where inputTokens is the FULL prompt. On the OpenAI wire input_tokens is ALREADY that full count: input_tokens_details.cached_tokens and input_tokens_details.cache_write_tokens (GPT-5.6 and later families) are priced SUBSETS of it, never additional tokens, so both pass through untouched and nothing is added. Verified on the live wire 2026-07-18: two identical long prompts report the SAME input_tokens while the details flip from write to read, and total_tokens equals input_tokens + output_tokens on both calls. Adding writes on top (the v1.19.0 reading of the field) double-billed every written token at 1x + 1.25x and inflated budget debits (v1.19.0 review P1-1). Contrast with the Anthropic adapter, whose wire genuinely EXCLUDES both cache counts from input_tokens, so that adapter adds them; the two wires differ, the canonical Usage invariant does not.
Numeric hygiene is deliberately NOT this function's job: any number the wire (or an injected client) reports passes through, and the core enforces the full telemetry invariant at the adapter boundary for every adapter uniformly, failing the call loud on non-finite, negative, or fractional counts while accounting only sanitized values (usageViolations/sanitizeUsage in @rulvar/core; v1.20.0 review P1-1). Real wires report whole nonnegative integers; a violation here means a broken transport, never plausible provider data.
Parameters
| Parameter | Type |
|---|---|
raw | Record<string, unknown> | undefined |