Function fallbackBillFromGeneration

web/src/llm-api/openrouter.ts:934–1078

* Bill a stream that exited before a usage-bearing chunk arrived by looking up * the generation cost from OpenRouter's /generation endpoint. Mutates * `state.billed` on success so callers can tell the gap was filled. * * Never throws — failures are logged and swallowed. The worst case is that we

(params: {
  generationId: string
  openrouterApiKey: string | null
  userId: string
  stripeCustomerId?: string | null
  agentId: string
  clientId: string | null
  clientRequestId: string | null
  costMode: string | undefined
  byok: boolean
  startTime: Date
  state: StreamState
  request: unknown
  fetch: typeof globalThis.fetch
  logger: Logger
  insertMessage: InsertMessageBigqueryFn
})

 * miss this one request, which is still strictly better than the old behavior.
 */
async function fallbackBillFromGeneration(params: {
  generationId: string
  openrouterApiKey: string | null
  userId: string
  stripeCustomerId?: string | null
  agentId: string
  clientId: string | null
  clientRequestId: string | null
  costMode: string | undefined
  byok: boolean
  startTime: Date
  state: StreamState
  request: unknown
  fetch: typeof globalThis.fetch
  logger: Logger
  insertMessage: InsertMessageBigqueryFn
}): Promise<void> {
  const {
    generationId,
    openrouterApiKey,
    userId,
    stripeCustomerId,
    agentId,
    clientId,
    clientRequestId,
    costMode,
    byok,
    startTime,
    state,
    request,
    fetch,
    logger,
    insertMessage,
  } = params

  try {
    const response = await fetch(
      `https://openrouter.ai/api/v1/generation?id=${encodeURIComponent(generationId)}`,
      {
        method: 'GET',
        headers: {
          Authorization: `Bearer ${openrouterApiKey ?? env.OPEN_ROUTER_API_KEY}`,
        },
      },
    )

    if (!response.ok) {
      logger.error(
        {
          generationId,
          status: response.status,
          statusText: response.statusText,
          userId,
          agentId,
          model: state.model,
          responseTextLength: state.responseText.length,
        },
        'fallbackBillFromGeneration: generation lookup failed',