Analyze transaction velocity API

Identify abnormal transaction frequency and amount velocity from caller-supplied histories. Velocity spikes alone are never labeled confirmed fraud.

The Analyze transaction velocity operation is part of the Fraud & Transaction Security API on BRAINIAC.software. Identify abnormal transaction frequency and amount velocity from caller-supplied histories. Velocity spikes alone are never labeled confirmed fraud. It is exposed as POST /api/v1/fraud-signals/transaction-velocity-analyze and priced at $0.04 USDC on Base. Payment uses the x402 exact scheme: an unpaid call returns HTTP 402 with payment requirements; after paying the exact USDC amount, retry the same request with a payment-signature header and Idempotency-Key. No account and no API key are required. Data sources for this product: Caller-supplied payment records, transaction histories, invoices, and identity records processed locally Limitations: Payment processors and financial accounts are never contacted. Statistical anomalies alone are never labeled confirmed fraud. Personal and financial identifiers are masked in responses (last4 / redacted email). Observed facts are separated from inferred risk hypotheses. Missing amounts or identity fields are reported as missing, not invented. Outputs are compliance prechecks, drafts, or data lookups for human review. They are not official determinations, legal advice, identity confirmation, or certified filings. Related operations in this group include Detect payment fraud patterns, Detect synthetic-identity signals, Detect invoice fraud signals, Assess supplier bank-change risk. Open the group documentation for the full request schema, field notes, and response examples before integrating.

POST$0.04 USDC
/api/v1/fraud-signals/transaction-velocity-analyze

Example request

curl -i -X POST "https://www.brainiac.software/api/v1/fraud-signals/transaction-velocity-analyze" \
  -H 'content-type: application/json' \
  -H 'Idempotency-Key: <fresh-64-character-random-hex-key>' \
  --data-binary @- <<'JSON'
{
  "asOf": "2026-11-04T21:00:00.000Z",
  "velocityWindowMinutes": 30,
  "velocityCountThreshold": 5,
  "velocityAmountThreshold": 1000,
  "transactions": [
    {
      "id": "T1",
      "at": "2026-11-04T20:00:00.000Z",
      "customerId": "C2",
      "eventType": "purchase",
      "status": "completed",
      "amount": 250,
      "currency": "USD",
      "source": "Caller-supplied"
    },
    {
      "id": "T2",
      "at": "2026-11-04T20:02:00.000Z",
      "customerId": "C2",
      "eventType": "purchase",
      "status": "completed",
      "amount": 250,
      "currency": "USD",
      "source": "Caller-supplied"
    },
    {
      "id": "T3",
      "at": "2026-11-04T20:04:00.000Z",
      "customerId": "C2",
      "eventType": "purchase",
      "status": "completed",
      "amount": 250,
      "currency": "USD",
      "source": "Caller-supplied"
    },
    {
      "id": "T4",
      "at": "2026-11-04T20:06:00.000Z",
      "customerId": "C2",
      "eventType": "purchase",
      "status": "completed",
      "amount": 250,
      "currency": "USD",
      "source": "Caller-supplied"
    },
    {
      "id": "T5",
      "at": "2026-11-04T20:08:00.000Z",
      "customerId": "C2",
      "eventType": "purchase",
      "status": "completed",
      "amount": 250,
      "currency": "USD",
      "source": "Caller-supplied"
    }
  ]
}
JSON

An unpaid probe returns HTTP 402 with x402 payment requirements. After paying the exact USDC amount on Base, retry the identical request with a payment-signature header.

FAQ

  • Do I need an API key? No. Pay the listed USDC amount with x402.
  • What network? Base (eip155:8453), USDC.
  • Is this an official determination? No. Results are for human review against the cited sources.

Related APIs

Fraud & Transaction Security APIFull docsHow it works