Idempotency (safe retries)

Networks fail. If a request times out, you can't tell whether we received it. Send an Idempotency-Key header and retrying is always safe:

• The first request with a key runs the check and charges credits.
• Any retry with the same key and the same body, within 24 hours, returns the original response and charges nothing. The response has the header Idempotent-Replayed: true.
• The same key with a different body returns idempotency_key_reused (HTTP 422).

curl https://veqen-app.com/v1/signup/check \
  -H "Authorization: Bearer $VEQEN_API_KEY" \
  -H "Idempotency-Key: signup-7f3e2a91" \
  -H "Content-Type: application/json" \
  -d '{"email": "jane@example.com", "ip": "203.0.113.7"}'

Choosing a key

Use something unique to the action, such as your signup's database ID or a UUID you generate once and reuse for every retry of that action. Keys can be up to 255 characters.

We keep idempotent responses for 24 hours so retries can be answered. Requests without a key aren't stored.