Card payments
Checkoutcard-not-present
€249.00
Visa •••• 4242 · ES · returning device
0.18risk score
APPROVE38 msreturning_device
Fraud gets cut before the money moves.
One API call scores every payment, payout and withdrawal, and returns approve, review or block in milliseconds.
Real-time fraud checks · Fintech & crypto
- Decide in milliseconds
- Catch more, decline less
- Fiat and crypto, one API
- Every decision explained
SincapByte is a real-time, AI-based fraud check API for fintech and crypto companies.
AboutSincapByte is a fraud check API built by payments engineers. It watches every transaction like a squirrel watches its stash, and it moves faster than the fraud.
Our mission is to let good customers pay without friction and stop bad actors before the money moves.
Read the founder's noteThe problem. Fraud and false declines cost more than you think.
Transaction stream · exampleLive
- 18:24:51Card · ES€42.10APPROVE
- 18:24:51Payout · DE€1,200.00APPROVE
- 18:24:52Withdrawal · ETH0.42APPROVE
- 18:24:52A2A · NL€318.00APPROVE
- 18:24:53Card · new device€2,480.00BLOCK
- 18:24:53Sign-up · GB—APPROVE
- 18:24:54Card · FR€89.90APPROVE
- 18:24:54Refund · IT€24.00APPROVE
—
Global card fraud losses per year
[PLACEHOLDER + SOURCE]—
Share of declined orders that were legitimate
[PLACEHOLDER + SOURCE]—
Average cost to a merchant for every $1 of fraud
[PLACEHOLDER + SOURCE]1%
Chargeback ratio at which card schemes start fines
[PLACEHOLDER + SOURCE]How it works. One call in, one decision out.
// your backend sends the event
{
"amount": 2480.00,
"currency": "EUR",
"payment_method": "card",
"device_id": "dev_93kd...",
"ip": "185.220.101.4",
"user_id": "usr_1042"
}// enriching chk_7Fq2...
device new_device +0.21ip ip_proxy +0.18velocity card_velocity_24h +0.31history first_purchase +0.06rules amount_cap_eur_2000 firedmodel score 0.94{
"id": "chk_7Fq2...",
"decision": "block",
"score": 0.94,
"latency_ms": 38,
"reasons": ["card_velocity_24h", "ip_proxy", "new_device_high_amount"]
}// 21 days later: you send the outcome back
{
"type": "chargeback",
"check_id": "chk_A81k...",
"label": "fraud"
}
// your model gets sharper for the next check- 01
Send
the event from your backend.
- 02
Score
with AI models, signals and your rules.
- 03
Decide
approve, review or block in under [PLACEHOLDER: 50] ms.
- 04
Learn
from chargebacks and analyst feedback.
Use cases. Built for money that moves fast.
EU · UK · 2026
Crypto on-ramps and withdrawals
Withdrawal requestBTC
0.85 BTC
to bc1q8f…x9f2 flagged wallet
- Account age2 days
- Password reset1 h ago
- Devicenew
- Wallet riskhigh
REVIEWrisk 0.67account_takeover_pattern
Payouts and marketplaces
Payouts · today5 checks
- Seller #1042€1,180.00APPROVE
- Seller #2210€640.50APPROVE
- Seller #3307€9,900.00BLOCK
- Seller #1188€212.00APPROVE
- Seller #4520€75.00APPROVE
reasonsvelocity_payouts_1hnew_bank_account
ProductThe product. Everything you need to stop fraud in real time.
Real-time risk API
One REST call in your payment path.
AI risk scoring
Models on transaction, device, behavior and network signals.
chk_7Fq2...38 ms
score 0.94BLOCK
Rules engine
Add your own velocity limits, country blocks and caps.
Explainable decisions
Every response lists its top reasons.
Your rules3 active
IFcard_velocity_24h > 5REVIEW
IFcountry NOT IN [EU, UK]REVIEW
IFamount > 2000 AND new_deviceBLOCK
reasonscard_velocity_24hip_proxynew_device_high_amount
Fiat and crypto
Cards, transfers, payouts and wallets in one schema.
Feedback loop
Chargeback webhooks make the model sharper over time.
One schemaPOST /v1/checks
cardbank_transferpayoutwallet_withdrawal
- chargebackchk_A81k… → fraud
- review.resolvedchk_Q20p… → legit
- chargebackchk_M7d3… → fraud
For developers. Live in days, not quarters.
[CONFIRM "live in days"]
- One endpoint
POST /v1/checksfor payments, payouts, sign-ups and withdrawals. - Signed webhooksSend chargebacks and analyst labels back to train your model.
- Test modeSandbox keys and test checks before you touch live traffic.
curl https://api.sincapbyte.com/v1/checks \
-H "Authorization: Bearer $SINCAPBYTE_KEY" \
-H "Content-Type: application/json" \
-d '{"amount": 2480.00, "currency": "EUR",
"user_id": "usr_1042", "ip": "185.220.101.4"}'const res = await fetch("https://api.sincapbyte.com/v1/checks", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.SINCAPBYTE_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({ amount: 2480.00, currency: "EUR", user_id: "usr_1042", ip }),
});
const check = await res.json(); // check.decision: "approve" | "review" | "block"import os, requests
check = requests.post(
"https://api.sincapbyte.com/v1/checks",
headers={"Authorization": f"Bearer {os.environ['SINCAPBYTE_KEY']}"},
json={"amount": 2480.00, "currency": "EUR", "user_id": "usr_1042", "ip": ip},
).json() # check["decision"]: "approve" | "review" | "block"Response
{
"id": "chk_7Fq2...",
"decision": "block",
"score": 0.94,
"latency_ms": 38,
"reasons": ["card_velocity_24h", "ip_proxy", "new_device_high_amount"]
}p95 [PLACEHOLDER] ms
Who's behind it. Built by people who have run payments at scale.
[PHOTO NEEDED]
I spent 12 years building payment systems at Square, Glovo, iyzico and Weavr. Every team I worked with fought the same fight: stop fraud without blocking good customers, without waiting months for an enterprise tool. SincapByte is the fraud check I wanted then.
Adnan ÖzdemirFounderLinkedIn[FOUNDER TO APPROVE]
Experience from
Square · Glovo · iyzico · Weavr
We are onboarding a small group of design partners. Early pricing, direct access to the team, and a say in the roadmap.
Become a design partnerPricing. Pay per check. Start small.
Free
Test mode
Sandbox
- Test API keys
- 1,000 test checks a month
- Docs and email support
Per check
Early access pricing
Growth Most popular
- Usage-based, with a monthly minimum
- Real-time API and AI scoring
- Rules engine and dashboard
- Chargeback webhooks
Custom
Volume pricing
Scale
- Volume pricing and custom models
- SLA and dedicated support
- EU data residency options
Billing through Stripe. Prices exclude VAT.
FAQ. Everything you need to know before your first check.
How fast is a check?
Our target is under [PLACEHOLDER] ms at p95, so you can call it inside your payment flow.
Do you support crypto?
Yes. You can send wallet addresses and chains for on-ramps, withdrawals and transfers, next to card and bank payments.
How long does integration take?
Most teams need one endpoint and one webhook. Plan days, not months. [CONFIRM]
Can I add my own rules?
Yes. Your rules run next to our models, and you can see which one fired.
Why was a payment blocked?
Every response includes the top reasons, which you can show to analysts or auditors.
Where is data stored?
SincapByte is an EU company. Data hosting region [CONFIRM: EU]. We sign a DPA with every customer.
How does pricing work?
You pay per check, with volume discounts. Sandbox is free.
Is it live yet?
We are onboarding design partners now. Request early access and we'll be in touch within two working days. [CONFIRM SLA]
