Idempotency

• POST /v1/calls
• POST /v1/campaigns/{id}/start
• POST /v1/contacts/imports

curl https://api-us.larynth.com/v1/calls \
  -H "Authorization: Bearer $LARYNTH_API_KEY" \
  -H "Idempotency-Key: 6f1c2f6e-8f0b-4d57-b4c5-3a5e8c1d9a10" \
  -H "Content-Type: application/json" \
  -d '{
    "assistant_id": "3f1c6e0a-5b1d-4c3e-9a57-2d0f4c8d1e11",
    "from_e164": "+14155550100",
    "to_e164": "+14155550123",
    "purpose": "informational"
  }'

​

Behavior

• Send the same key and the same body again within 24 hours and you get the stored response. No second call is placed.
• Send the same key with a different body and you get 409 with idempotency.key_reused.
• Send the same key while the first request is still running and you get 409 with idempotency.in_progress. Wait a moment and retry.
• Leave the header out on an endpoint that requires it and you get 400 with idempotency.key_required.