Atomic check + increment. Idempotent on (sub, metric, clientReqId).

POST 
/me/agents/:agentId/usage/:metricSlug/consume

Agent backends call this BEFORE running the chargeable action. Returns 429 with code: QUOTA_EXCEEDED when the increment would breach the effective quota (base + addons). 402 when there is no active subscription. 404 when the metric slug is unknown.

Request

Responses

200

402

code: PAYMENT_REQUIRED

429

code: QUOTA_EXCEEDED; details include used, effectiveQuota, remaining, resetsAt