Place a call with one POST. Know the outcome seconds after hangup.

# Place a call — the agent dials, talks, and reports back
curl -X POST https://api.voicecallingai.com/v1/calls \
  -H "Authorization: Bearer $VCA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "AGENT_UUID",
    "to": "+9198xxxxxxxx",
    "external_ref": "lead-4812"
  }'

# 202 → { "status": "queued", ... }
# DND, consent and calling-hours checks run before dial — and again at dial time.

// Webhooks are signed: X-VCA-Signature: t=<unix>,v1=<hex>
// where v1 = HMAC_SHA256(signing_secret, `${t}.` + raw_body)
const crypto = require("crypto");

function verifyVcaSignature(sigHeader, rawBody, secret) {
  const { t, v1 } = Object.fromEntries(
    sigHeader.split(",").map((p) => p.split("="))
  );
  const expected = crypto.createHmac("sha256", secret) // secret = "whsec_..."
    .update(`${t}.`).update(rawBody).digest("hex");
  const a = Buffer.from(expected), b = Buffer.from(v1 || "");
  return a.length === b.length && crypto.timingSafeEqual(a, b)
    && Math.abs(Date.now() / 1000 - Number(t)) <= 300; // reject stale timestamps
}

// seconds after hangup:
// { "type": "call.completed", "data": { "outcome": "...", "summary": "...", ... } }