Library
Transaction enrichment library for NestJS
Use TxnKit as a transaction enrichment API from NestJS. This page shows the safe request shape, a short code snippet, and the boundary for keeping sensitive data out of the integration.
Target intent
NestJS services adding merchant cleanup through a small enrichment service.
TxnKit does not create NestJS modules, queues, or background processors for you.
Raw descriptor
AMZN MKTP CA*2R41Short NestJS API snippet
@Injectable()
export class EnrichmentService {
async enrich(raw_description: string) {
const response = await fetch("https://api.txnkit.dev/v1/enrich", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.TXNKIT_API_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({ raw_description, country: "CA" })
});
return response.json();
}
}Keep API keys out of browser bundles. For frontend stacks, call a backend route or serverless function that owns the TxnKit request.
API-shaped output
{
"input": {
"descriptor": "AMZN MKTP CA*2R41",
"country": "CA"
},
"output": {
"merchant_name": "Amazon Marketplace",
"category": "Online marketplace",
"confidence": "medium",
"signals": [
"processor_pattern",
"merchant_alias",
"category_hint"
],
"warnings": [
"review_low_confidence_matches_before_showing_logo"
],
"logos": []
}
}Low-confidence results should keep fallback labels and warnings visible instead of forcing a guessed logo or website.
When to use
- You are building in NestJS and need one-descriptor merchant cleanup through an HTTP API.
- Your app can keep the TxnKit API key on the server side or inside a trusted serverless function.
- You need merchant display names, categories, confidence, signals, warnings, and logo-ready metadata.
When not to use
- TxnKit does not create NestJS modules, queues, or background processors for you.
- Do not use TxnKit to process card numbers, account numbers, full statements, bank credentials, emails, phone numbers, addresses, customer names, or customer PII.
- Do not use TxnKit when the product requirement is guaranteed merchant identity, every-merchant resolution, or contracted uptime terms.
Proof surfaces
The public contract is POST /v1/enrich, backed by the OpenAPI file, benchmark examples, privacy rules, and deterministic request-path tests.