Chat Threads: Token and Cost Fields Replaced with BCU

Token counts and cost fields have been removed from the Chat Threads API and replaced with BCU (Bobsled Compute Units) — a normalized compute metric that provides a consistent measure of AI resource usage regardless of the underlying model.

What Changed

totalTokens replaced with totalBCU on both list and detail endpoints
totalCost removed from the list response and stats
sortBy=totalTokens replaced with sortBy=totalBCU for server-side sorting
Turn-level token/cost breakdown removed from thread detail; replaced with a single totalBCU per turn

Modified Endpoints

GET /api/v1/accounts/{accountId}/chat-threads — list endpoint
GET /api/v1/accounts/{accountId}/chat-threads/{threadId} — detail endpoint

List Endpoint: Response Changes

Thread items

Removed Field	Replacement Field	Type
`totalTokens`	`totalBCU`	`number \| null` (non-negative)
`totalCost`	—	Removed

Stats object

Removed Field	Replacement
`totalCost`	Removed

Sort parameter

Old Value	New Value
`totalTokens`	`totalBCU`

Detail Endpoint: Response Changes

Thread metrics

Removed Field	Replacement Field	Type
`totalTokens`	`totalBCU`	`number` (non-negative)

Turn-level `agentMetadata.usage`

Removed Fields	Replacement Field
`inputTokens`, `outputTokens`, `totalTokens`, `inputCost`, `outputCost`, `totalCost`	`totalBCU`

Updated Response Examples

List thread item

{
  "id": "550e8400-...",
  "title": "Revenue by region",
  "totalBCU": 0.42,
  "turnCount": 3,
  "avgLatencyMs": 1250
}

Detail turn usage

{
  "agentMetadata": {
    "usage": {
      "totalBCU": 0.15
    }
  }
}

Migration Notes

Replace all references to totalTokens with totalBCU in your integration code
Remove any logic that reads totalCost, inputCost, outputCost, inputTokens, or outputTokens from API responses
Update sort parameters: change sortBy=totalTokens to sortBy=totalBCU
BCU values are decimal numbers (e.g., 0.42), not integer token counts — adjust formatting accordingly