Request details
/api/usage/requests/{request_id}Fetch the reconciliation record for one completed request. Use this when response usage is not enough, especially for cache write tokens, provider raw usage fields, billing line items and routing metadata.
Path parameters
request_idstringRequest ID for a request made by the same API key. Lazu rejects attempts to read another key's request details.
Response fields
request_idstringThe requested request ID.
modelstringRequested model or route name.
resolved_modelstringActual upstream model after routing and model mapping.
usage.dimensionsobject[]Normalized dimensions such as input, output,
cache_read, cache_write_5m,
cache_write_1h, cache_miss, audio and image
dimensions.
billing.line_itemsobject[]Billable usage lines with price, quantity and total charge.
provider_usage.raw_fieldsobjectCompact provider-native usage fields retained for reconciliation.
routingobjectRoute decision metadata when the request used routing.
Cache field guidance
OpenAI-compatible responses may show cache reads as
usage.prompt_tokens_details.cached_tokens or
usage.input_tokens_details.cached_tokens. Cache writes may appear
as cache_write_tokens, cache_write_5m_tokens or
cache_write_1h_tokens only when the upstream reports them.
For billing and reconciliation, this endpoint is the more complete source.