SendGrid compatibility

POST /v3/mail/send with the payload you already build — swap the base URL and the key. Field by field, every input is honored or refused with a reason; nothing is silently dropped.

Swap the base URL

The compatibility port lives at the root — https://api.qsendyx.com/v3/mail/send, not under /api/v1 — so the path is identical to the one your code already calls. Authentication is the same header, Authorization: Bearer, with a qsendyx token carrying the email:send scope. Success is a 202 with an empty body and the id in the X-Message-Id header, as at the origin.

curl -X POST https://api.qsendyx.com/v3/mail/send \
  -H "Authorization: Bearer $QUATHOS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "personalizations": [{ "to": [{ "email": "user@example.com" }] }],
    "from":    { "email": "you@yourcompany.com", "name": "Your Company" },
    "subject": "Your receipt",
    "content": [{ "type": "text/html", "value": "<h1>Thanks!</h1>" }]
  }'

What changes in behaviour

One recipient per message. Each (personalization, to address) pair becomes an independent message with its own id, status, cost and suppression — it is what lets you answer "was this person's email delivered?". Since there are N ids and the origin returns one, the response also carries X-Qsy-Message-Ids with the full list, in envelope order. Each id can be read at GET /api/v1/email/messages/{id}.

The cap is 1000 recipients per request, adding up all personalizations — above that, 400: split the batch. Everything that enters through this port is transactional (the origin's marketing sends live in another API, which has no port here); for marketing, use POST /api/v1/email/messages with type: marketing. Idempotency-Key is accepted, even though the origin has no equivalent. A malformed payload is a 400, not a 422 — as at the origin.

{
  "errors": [
    {
      "message": "The sender is not verified.",
      "field": "sender_not_verified",
      "help": "Verify the domain or sender at /painel/email/dominios, then retry."
    }
  ]
}

Field by field

The matrix below is the contract. A field is honored — and the second column says exactly what happens to it — or it is refused with 400 and a message that says what to use instead. There is no third state.