Idempotency

Networks fail in the middle of requests. If a purchase times out, you cannot tell whether it went through, and retrying blindly could buy twice.

Send an Idempotency-Key header and the retry is safe:

curl -X POST https://resellerhq.com/api/v1/numbers/orders \
  -H "Authorization: Bearer $RHQ_API_KEY" \
  -H "Idempotency-Key: 6f1c2f0e-5b7a-4d0e-9a51-1c2c8a0b7f11" \
  -H "Content-Type: application/json" \
  -d '{"country":"US","duration":"30d","customerId":"cus_01K6XJ4Q8ZT3M9R5V2B7WDHNCA"}'

How it behavesCopy Anchor Link

• The first request with a key runs normally. Its outcome, success or error, is stored for 24 hours.
• A retry with the same key and the same body gets the stored response back. Nothing runs twice.
• The same key with a different body answers 422, because that is a mistake, not a retry.
• A retry that arrives while the first request is still running answers 409. Wait and try again.

RulesCopy Anchor Link

• A key is 8 to 200 characters. A UUID is a good choice.
• Use a new key for each new operation, and reuse it only to retry that operation.
• Keys are scoped to your account, so they cannot collide with anyone else's.

Every route that spends money accepts the header: ordering and renewing numbers, registering and renewing domains, and buying or resizing licences.