Library

Transaction enrichment library for FastAPI

Use TxnKit as a transaction enrichment API from FastAPI. This page shows the safe request shape, a short code snippet, and the boundary for keeping sensitive data out of the integration.

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Target intent

FastAPI apps adding a safe one-descriptor enrichment endpoint.

TxnKit should sit behind your FastAPI route and should not accept full statement uploads.

Raw descriptor

TST*MAIN ST CAFE

Short FastAPI API snippet

@app.post("/api/enrich-transaction")
async def enrich_transaction(payload: dict):
    async with httpx.AsyncClient(timeout=1.0) as client:
        response = await client.post(
            "https://api.txnkit.dev/v1/enrich",
            headers={"Authorization": f"Bearer {os.environ['TXNKIT_API_KEY']}"},
            json={"raw_description": payload["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

{
  "normalized_merchant": "main st cafe",
  "display_name": "Main St Cafe",
  "category": null,
  "subcategory": null,
  "website": null,
  "logos": {
    "preferred": null,
    "variants": [],
    "warnings": [
      "no_verified_logo_for_local_merchant"
    ]
  },
  "confidence": 0.56,
  "recurring_hint": false,
  "processor_hint": "toast",
  "location_hint": null,
  "signals": [
    "removed_toast_prefix"
  ],
  "warnings": [
    "local_merchant_identity_not_verified"
  ]
}

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 FastAPI 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 should sit behind your FastAPI route and should not accept full statement uploads.
  • 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.

OpenAPI · Benchmark · Security · Pricing

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