Sayfin API Reference

# pip install sayfin
import hmac, hashlib, time, json

def sign_request(secret: str, body: dict) -> dict:
    ts        = str(int(time.time() * 1000))
    payload   = ts + "." + json.dumps(body, separators=(",", ":"))
    signature = hmac.new(
        secret.encode(), payload.encode(), hashlib.sha256
    ).hexdigest()
    return {
        "X-Sayfin-Key":       "sk_live_...",
        "X-Sayfin-Timestamp": ts,
        "X-Sayfin-Signature": signature,
        "Content-Type":       "application/json",
    }

import crypto from "crypto";

function signRequest(secret: string, body: object) {
  const ts      = Date.now().toString();
  const payload = ts + "." + JSON.stringify(body);
  const sig     = crypto
    .createHmac("sha256", secret)
    .update(payload)
    .digest("hex");
  return {
    "X-Sayfin-Key":       "sk_live_...",
    "X-Sayfin-Timestamp": ts,
    "X-Sayfin-Signature": sig,
  };
}

Production:  https://api.sayfin.ai/v1
Sandbox:      https://sandbox.sayfin.ai/v1

{
  "transaction_id": "txn_8f2k9d",
  "amount": 284700,
  "currency": "GBP",
  "card_bin": "483204",
  "merchant_id": "mer_xyz",
  "cardholder_id": "usr_ab91c",
  "geo": "GB",
  "channel": "web"
}

{
  "route": {
    "acquirer":    "acquirer_b",
    "probability": 0.943,
    "confidence":  "high"
  },
  "alternatives": [
    { "acquirer": "acquirer_a", "probability": 0.871 },
    { "acquirer": "acquirer_c", "probability": 0.714 }
  ],
  "behavioral": {
    "segment":        "high_value",
    "trust_score":    0.91,
    "is_recurring":   true,
    "anomaly_flag":   false
  },
  "latency_ms": 7.2,
  "request_id": "req_4af91b"
}

curl -G https://api.sayfin.ai/v1/recommendations \
  -H "X-Sayfin-Key: sk_live_..." \
  -H "X-Sayfin-Signature: ..." \
  -H "X-Sayfin-Timestamp: 1706188800000" \
  --data-urlencode "merchant_id=mer_xyz" \
  --data-urlencode "granularity=day"

{
  "transaction_id": "txn_cmp_01",
  "amount": 150000,
  "currency": "USD",
  "card_bin": "412345",
  "acquirers": ["acquirer_a", "acquirer_b"]
}

{
  "comparison": [
    { "acquirer": "acquirer_a", "probability": 0.871, "rank": 2 },
    { "acquirer": "acquirer_b", "probability": 0.943, "rank": 1 }
  ],
  "recommended": "acquirer_b",
  "delta": 0.072
}

{
  "error": {
    "code":       "invalid_signature",
    "message":    "HMAC signature does not match",
    "status":     401,
    "request_id": "req_err_7x2"
  }
}

# Install
pip install sayfin

# Usage
from sayfin import Sayfin

client = Sayfin(api_key="sk_live_...", secret="...")

result = await client.route(
    transaction_id="txn_8f2k9d",
    amount=284700,
    currency="GBP",
    card_bin="483204",
    merchant_id="mer_xyz",
)
print(result.route.acquirer)  # "acquirer_b"

// Install
npm install @sayfin/sdk

// Usage
import { Sayfin } from "@sayfin/sdk";

const client = new Sayfin({ apiKey: "sk_live_...", secret: "..." });

const result = await client.route({
  transactionId: "txn_8f2k9d",
  amount: 284700,
  currency: "GBP",
  cardBin: "483204",
  merchantId: "mer_xyz",
});
console.log(result.route.acquirer); // "acquirer_b"