Integrate over raw HTTP

const res = await fetch("https://api.senderkit.com/v1/send", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SENDERKIT_API_KEY}`,
    "Content-Type": "application/json",
    // See "Idempotency" below — strongly recommended on every send.
    "Idempotency-Key": "welcome:usr_123",
  },
  body: JSON.stringify({
    template: "welcome",
    to: "user@example.com",
    vars: { name: "Ada" },
    metadata: { userId: "usr_123" },
  }),
});

if (!res.ok) {
  const { error } = await res.json();
  throw new Error(`SenderKit ${res.status}: ${error.code} — ${error.message}`);
}

const result = await res.json();
// { id: "msg_…", status: "queued", livemode: true }

curl -X POST https://api.senderkit.com/v1/send \
  -H "Authorization: Bearer $SENDERKIT_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: welcome:usr_123" \
  -d '{
    "template": "welcome",
    "to": "user@example.com",
    "vars": { "name": "Ada" }
  }'

const url = new URL("https://api.senderkit.com/v1/messages");
url.searchParams.set("status", "failed");
url.searchParams.set("limit", "100");
// Filter by metadata: metadata[key]=value
url.searchParams.set("metadata[userId]", "usr_123");

const res = await fetch(url, {
  headers: { Authorization: `Bearer ${process.env.SENDERKIT_API_KEY}` },
});
const { data, nextCursor } = await res.json();
// data: Message[]; nextCursor: string | null (pass back as ?cursor= to page)

curl -G https://api.senderkit.com/v1/messages \
  -H "Authorization: Bearer $SENDERKIT_API_KEY" \
  --data-urlencode "status=failed" \
  --data-urlencode "limit=100"