CumulativeTokenUsage

Session running totals of counted-once usage.

The cache splits and server-computed cost join the counters. The counters stay accumulate-only; cost is the documented exception — it may move either way on price re-adoption and is labeled estimate. Copy was dropped for the cost member.

Fields and variants

• cacheReadTokens
• cacheWriteTokens
• cost
• outputTokens
• promptTokens
• totalTokens

Source

schema/msp/experimental/msp.schema.json#/types/CumulativeTokenUsage

{
  "description": "Session running totals of counted-once usage.\n\nThe cache splits and server-computed `cost` join the counters. The counters\nstay accumulate-only; `cost` is the documented exception — it may move\neither way on price re-adoption and is labeled estimate. `Copy` was dropped\nfor the `cost` member.",
  "properties": {
    "cacheReadTokens": {
      "description": "Cache-read tokens, session total: saturating sum of\nthe per-completion splits; an absent split contributes 0.\nAdditive-optional: absent on the wire reads as 0 and zero totals\nare omitted, so pre-feature bytes decode and re-encode identically.",
      "type": "integer"
    },
    "cacheWriteTokens": {
      "description": "Cache-write tokens, session total. Additive-optional\nlike the read split.",
      "type": "integer"
    },
    "cost": {
      "$ref": "#/$defs/CumulativeCost",
      "description": "Server-computed session cost: `None` (wire-absent)\nwhen no leg is priced — clients omit the row. Additive-optional:\nabsent reads as unpriced."
    },
    "outputTokens": {
      "description": "Output tokens, session total.",
      "type": "integer"
    },
    "promptTokens": {
      "description": "Counted-once prompt tokens, session total.",
      "type": "integer"
    },
    "totalTokens": {
      "description": "Counted-once totals, session total.",
      "type": "integer"
    }
  },
  "required": [
    "outputTokens",
    "promptTokens",
    "totalTokens"
  ],
  "type": "object"
}