Generate Fintech and Banking Test Data with MockHero

The Problem

Fintech applications deal with money, and testing with unrealistic data is dangerous. A payment processing system tested with five transactions will not surface rounding errors, currency conversion bugs, or race conditions that only appear under realistic load. But using real financial data in test environments is a compliance nightmare involving PCI-DSS, SOX, and banking regulations.

Building test data for fintech is also structurally complex. You need accounts that belong to customers, transactions that reference both source and destination accounts, balances that make mathematical sense, and statuses that reflect real-world payment processing flows.

The Solution: MockHero Synthetic Financial Data

MockHero generates realistic financial test data with proper referential integrity across customers, accounts, and transactions. Use ref fields to link records, integer fields for amounts in cents (avoiding floating point issues), and enum fields for statuses and transaction types. The data is completely synthetic, so there are no compliance concerns.

Quick Setup

curl -X POST https://api.mockhero.dev/api/v1/generate \
  -H "x-api-key: mh_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
  "tables": [
    {
      "name": "customers",
      "count": 50,
      "fields": [
        { "name": "id", "type": "uuid" },
        { "name": "full_name", "type": "full_name" },
        { "name": "email", "type": "email" },
        { "name": "phone", "type": "phone" },
        { "name": "kyc_status", "type": "enum", "params": { "values": ["pending","verified","rejected","expired"] } },
        { "name": "created_at", "type": "datetime" }
      ]
    },
    {
      "name": "accounts",
      "count": 80,
      "fields": [
        { "name": "id", "type": "uuid" },
        { "name": "customer_id", "type": "ref", "params": { "ref": "customers.id" } },
        { "name": "account_type", "type": "enum", "params": { "values": ["checking","savings","investment","credit"] } },
        { "name": "currency", "type": "enum", "params": { "values": ["USD","EUR","GBP","CAD","AUD"] } },
        { "name": "balance_cents", "type": "integer", "params": { "min": 0, "max": 5000000 } },
        { "name": "status", "type": "enum", "params": { "values": ["active","frozen","closed"] } }
      ]
    },
    {
      "name": "transactions",
      "count": 1000,
      "fields": [
        { "name": "id", "type": "uuid" },
        { "name": "account_id", "type": "ref", "params": { "ref": "accounts.id" } },
        { "name": "amount_cents", "type": "integer", "params": { "min": -500000, "max": 500000 } },
        { "name": "type", "type": "enum", "params": { "values": ["deposit","withdrawal","transfer","payment","refund","fee","interest"] } },
        { "name": "status", "type": "enum", "params": { "values": ["pending","processing","completed","failed","reversed"] } },
        { "name": "description", "type": "sentence" },
        { "name": "created_at", "type": "datetime" }
      ]
    }
  ],
  "format": "json"
}'

Step-by-Step Guide

1. Map your financial domain model

Identify the core entities in your fintech app: customers, accounts, transactions, payments, transfers. Map each to a MockHero table with the right field types. Use integer for monetary amounts (always in cents to avoid floating point) and enum for statuses and types.

2. Get your MockHero API key

Sign up at mockhero.dev/sign-up and copy your API key.

3. Generate and insert the data

const res = await fetch("https://api.mockhero.dev/api/v1/generate", {
  method: "POST",
  headers: {
    "x-api-key": process.env.MOCKHERO_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    tables: [
      // ... schema from above
    ],
    format: "json",
  }),
});

const { data } = await res.json();
// Insert customers first, then accounts, then transactions
// Foreign keys are guaranteed valid by MockHero's ref fields

4. Test financial logic

With 1,000 transactions across 80 accounts, you can test balance calculations, transaction filtering, statement generation, and reporting dashboards with realistic data volumes.

5. Use deterministic seeds for regression tests

Add a "seed": 42 parameter to your MockHero request to get identical data every run. This makes your financial test assertions stable and reproducible.

Why MockHero vs Manual Financial Test Data

• Compliance-safe — completely synthetic data means no PCI-DSS, SOX, or banking regulation concerns in test environments.
• Integer arithmetic — amounts in cents avoid the floating-point bugs that plague financial systems using decimals.
• Realistic distributions — transaction types and statuses span the full range of your enum values, testing edge cases automatically.
• Referential integrity — every transaction references a valid account, every account references a valid customer.

Get Started

Build your fintech test suite on realistic synthetic data. Sign up free at mockhero.dev and generate 1,000 rows per month.