{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "#/components/schemas/UsageMetadata", "title": "UsageMetadata", "type": "object", "description": "Metadata on the generation request's token usage.", "properties": { "promptTokenCount": { "type": "integer", "format": "int32", "description": "Number of tokens in the prompt." }, "candidatesTokenCount": { "type": "integer", "format": "int32", "description": "Total number of tokens across all the generated response candidates." }, "totalTokenCount": { "type": "integer", "format": "int32", "description": "Total token count for the generation request (prompt + response candidates)." }, "cachedContentTokenCount": { "type": "integer", "format": "int32", "description": "Number of tokens in the cached part of the prompt (the cached content)." } } }