The fax API
developers actually like.

# send a fax. idempotent. signed.
curl "https://api.mintfax.com/v1/faxes" \
  -X POST \
  -H "Authorization: Bearer mfx_live_..." \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+15551234567",
    "from_number": "fnum_8KQRm2",
    "document_url": "https://files.example.com/coversheet.pdf",
    "metadata": { "patient_id": "p_19a8c" },
    "webhook_url": "https://app.example.com/webhooks/fax"
  }'

import { Mintfax } from "mintfax";

const mfx = new Mintfax(process.env.MINTFAX_KEY);

const fax = await mfx.faxes.send({
  to: "+15551234567",
  fromNumber: "fnum_8KQRm2",
  documentUrl: "https://files.example.com/coversheet.pdf",
  metadata: { patientId: "p_19a8c" },
  idempotencyKey: crypto.randomUUID(),
});

console.log(fax.id, fax.status); // fax_2K...  queued

from mintfax import Mintfax

mfx = Mintfax(os.environ["MINTFAX_KEY"])

fax = mfx.faxes.send(
    to="+15551234567",
    from_number="fnum_8KQRm2",
    document_url="https://files.example.com/coversheet.pdf",
    metadata={"patient_id": "p_19a8c"},
    idempotency_key=uuid.uuid4().hex,
)

print(fax.id, fax.status)  # fax_2K...  queued

require "mintfax"

mfx = Mintfax::Client.new(ENV.fetch("MINTFAX_KEY"))

fax = mfx.faxes.send(
  to: "+15551234567",
  from_number: "fnum_8KQRm2",
  document_url: "https://files.example.com/coversheet.pdf",
  metadata: { patient_id: "p_19a8c" },
  idempotency_key: SecureRandom.uuid,
)

puts fax.id, fax.status   # fax_2K...  queued