Conflict

https://api.quotastack.io/errors/conflict

The request clashed with what QuotaStack already holds. Nothing changed.

Why it happened

You reused an Idempotency-Key with a different body. That cause is by far the most common.
Two calls changed the same customer at once.
You sent stack_after with fallback: reject, and no block matched.
The thing is already there. A second override on one metric does this.

How to fix it

Use a new Idempotency-Key when the body is different. Build the key from the business event.
Send the call again with the same key when two writes raced.
Read the page for that call. Each one says what its own 409 means.

Example response 409

{
  "type": "https://api.quotastack.io/errors/conflict",
  "title": "Conflict",
  "status": 409,
  "detail": "Idempotency-Key has already been used with a different request body."
}

Which calls return this

POST /v1/customers
POST /v1/customers/{customer_id}/credits/grant
POST /v1/customers/{customer_id}/credits/adjust
POST /v1/customer-by-external-id/{external_id}/credits/grant
POST /v1/customer-by-external-id/{external_id}/credits/adjust
POST /v1/customers/{id}/entitlements/{billable_metric_key}/increment
POST /v1/customers/{id}/entitlements/{billable_metric_key}/decrement
POST /v1/customer-by-external-id/{external_id}/entitlements/{billable_metric_key}/increment
POST /v1/customer-by-external-id/{external_id}/entitlements/{billable_metric_key}/decrement
POST /v1/imports/customers
POST /v1/subscriptions/{id}/overrides
POST /v1/reservations/{id}/commit
POST /v1/reservations/{id}/release
POST /v1/plans/{id}/variants/{vid}/entitlements
POST /v1/billable-metrics
POST /v1/webhooks/events/{id}/redeliver
POST /v1/webhooks/test

Conflict

Why it happened

How to fix it

Which calls return this

See also