---
title: "Validate Payment & Generate QR API"
slug: validate-standard-payload
url: https://apyhub.com/callable-labs/service/validate-standard-payload
provider: Callable Labs
categories: [Data Validation, Developer Tools, Finance]
tags: [qr-validation, payment-validation, gs1-digital-link, swiss-qr-bill, upi, EVMCo, Pix-BR-Code, SEPA, GS1]
auth: api_key
version: 1.0.0
service_type: sync
endpoints: 3
atoms: 1-20
mcp: true
---

# Validate Payment & Generate QR API

Validate GS1 and payment QR payloads, inspect parsed fields, and render scannable QR codes in common formats. Useful for checkout, invoicing, and test automation.

## Endpoints

| Method | URL | Description | Atoms |
| --- | --- | --- | --- |
| POST | `https://api.eu.apyhub.com/callable-labs/validate-standard-payload/validate` | What it does Validates a single QR payment or GS1 payload against the selected standard and returns… | 10 |
| POST | `https://api.eu.apyhub.com/callable-labs/validate-standard-payload/render` | What it does Validates a complete GS1 or payment payload against the selected standard and renders… | 20 |
| GET | `https://api.eu.apyhub.com/callable-labs/validate-standard-payload/fixtures` | What it does Returns a list of official-source reference fixtures for the requested QR payment stan… | 1 |

## Endpoint reference

### Validate one GS1 or payment QR payload

`POST https://api.eu.apyhub.com/callable-labs/validate-standard-payload/validate` · 10 atoms · accepts `application/json` · returns `application/json`

| Parameter | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `payload` | body | string | yes | Complete raw payload to validate, exactly as encoded in the QR symbol or URI, 1 to 10,000 characters. Preserve newlines for EPC/SEPA and Swiss QR-bill payloads; whitespace and case are significant fo… |
| `standard` | body | string | yes | Standard to validate the payload against. Only the selected scheme's rules run. Choose `gs1-digital-link`, `epc-sepa`, `swiss-qr-bill`, `pix-br-code`, `upi` or `emvco-mpm`. One of: gs1-digital-link,… |

#### Quickstart

Validate a QR payment payload by sending the standard and raw encoded payload in a JSON body.

```bash
curl -X POST "https://api.eu.apyhub.com/callable-labs/validate-standard-payload/validate" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "standard": "gs1-digital-link",
    "payload": "https://id.gs1.org/01/09506000134352/21/ABC123"
  }'
```

#### What you'll get back

Returns a JSON object with `standard` and `specification` strings, a `valid` boolean, and optional `errors`, `warnings`, `fields`, and `normalized` fields. `valid` is `true` when no blocking validation errors were found.

```json
{
  "standard": "gs1-digital-link",
  "valid": true,
  "normalized": "https://id.gs1.org/01/09506000134352/21/ABC123",
  "fields": {
    "domain": "id.gs1.org",
    "primary_ai": "01",
    "path_ais": {
      "21": "ABC123",
      "01": "09506000134352"
    },
    "query_ais": {}
  },
  "errors": [],
  "warnings": [],
  "specification": "GS1 Digital Link URI Syntax 1.7.0 (August 2026)"
}
```

### Generate a QR code from a validated payload

`POST https://api.eu.apyhub.com/callable-labs/validate-standard-payload/render` · 20 atoms · accepts `application/json` · returns `application/json`

| Parameter | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `dark` | body | string | no | Colour of the dark modules: a hex value such as `#1d4ed8`, an `rgb()` value or a CSS colour name. Default: `#000000`. Example: `#1d4ed8`. |
| `size` | body | integer | no | Exact output width in pixels, 32 to 2048. Omit to use eight pixels per QR module. Example: `300`. |
| `light` | body | string | no | Background colour. Use `transparent` or null for no background; some scanners rely on a light quiet zone, so verify transparent output. Default: `#ffffff`. |
| `format` | body | string | no | Output format. `json` (default) returns a data URI plus metadata; `png`, `svg`, `jpeg`, `webp` and `pdf` return the image or document bytes with the matching content type. One of: json, png, svg, jpe… |
| `payload` | body | string | yes | Complete raw payload exactly as encoded, 1 to 10,000 characters. EPC/SEPA and Swiss QR-bill are line-delimited: separate lines with a line feed inside the JSON string. Literal `\n` sequences are deco… |
| `standard` | body | string | yes | Standard the payload must satisfy before it is rendered. Only the selected scheme's rules run, the same checks as `POST /v1/standards/validate`. If the payload fails, the response is `422 invalid_pay… |

#### Quickstart

Encode a raw GS1 or payment payload into a QR code with the default JSON response.

```bash
curl -X POST "https://api.eu.apyhub.com/callable-labs/validate-standard-payload/render" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "body": {
      "standard": "gs1-digital-link",
      "payload": "https://id.gs1.org/01/09506000134352/21/ABC123",
      "format": "json"
    }
  }'
```

#### What you'll get back

Returns a JSON object containing the rendered QR code as a PNG data URI together with metadata such as `format`, `media_type`, `width`, `height`, `version`, `content`, and `verified`.

```json
{
  "format": "json",
  "image_format": "png",
  "media_type": "image/png",
  "width": 328,
  "height": 328,
  "data_uri": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAUgAAAFICAYAAAAyFGczAAAGPUlEQVR42u3dUYrDOBRE0cng/W/Zs4CB9ocQVU8657+T2HEuanhIv/d9338A+J9/3QIAgQQQSACBBBBIAIEEEEgAgQQQSACBBBBIAIEEQCABBBJAIAEEEkAgAQQSQCABBBJAIAEEEkAgARBIAIEEEEgAgQQQSACBBBBIAIEEOMGT/gC/3+/oG/y+79L1f/396v3d/frp+7f6+qdf//TfjxUkgEACCCSAQAIIJIBAAggkwPWe9g+YnoP6snsOb/ecW/vnT3++1ecv/fye/vuxggQQSACBBBBIAIEEEEgAgQS43jP9AtL78aWlP9/p+0G2z3H6/VhBAggkgEACCCSAQAIIJIBAAlzucQtmW93PcPXvd79+ej/M6XOIWEECCCSAQAIIJIBAAggkgEACHM4cZFj7nGC76XOYWEECCCSAQAIIJIBAAiCQAAIJsGT8HOT0c3e/pPd7bD93Ov3+q89fes7y9N+PFSSAQAIIJIBAAggkgEACCCTA8ernIO13mJ1znD7HuDrnl35/vx8rSACBBBBIAIEEEEgAgQRAIAH+9HttCDf7C9w8hzf99Xff3938PK0gAQQSQCABBBJAIAEEEgCBBPhT/Rzk6fvZ7b797edi7/7+p+/nmP79tD+fVpAAAgkgkAACCSCQAAIJIJAA14vPQU7fD7B9jnD1+tLS+02m/37395c+9zz9/FtBAggkgEACCCSAQAIIJIBAAoxXPwe5Kj3n1T7nNv37bb/++gCUz3laQQIIJIBAAggkgEACCCQAAgnw4fpzsdvntNr3M5x+f6ff//Sc7em/PytIAIEEEEgAgQQQSACBBBBIgHr1c5CfF1B+rvOq9jnF9v08b9/PcPf3d/r9tYIEEEgAgQQQSACBBBBIAIEEqPekP8DqnNTpc3LpOc/0fpLpz9/+/axKX3/7nKQVJIBAAggkgEACCCSAQAIIJEC9+Bzk7jmn1ddvn/NL39/2OcP0nOvtc5bp59MKEkAgAQQSQCABBBJAIAEEEuB49ftBtmvfDzJ9bnX69Z2bffbvwwoSQCABBBJAIAEEEkAgAQQS4Hq/Nzyo1L7fX/sc4e3nfk+/f+nnf/rzawUJIJAAAgkgkAACCSCQAAIJcL3n9AtMn2v8Zfp+mOlzpafP0U4/N/z0c7utIAEEEkAgAQQSQCABBBJAIAHqxfeD/PyA5fs5prWfO9y+39/0/SjT13f6ueFWkAACCSCQAAIJIJAAAgkgkAD14vtBpueopu/nl3796XN66fvbPse7+v7T5yStIAEEEkAgAQQSQCABBBJAIAHqjd8Pcrf2c5Onz2m2z1Hufn7th9l9f6wgAQQSQCABBBJAIAEEEkAgAepdvx/k7s/Xfq53+xzhqvZznafP+ToXG8C/2AAIJIBAAggkgEACCCRA2HP6Ba7Oae2eU9w9J2m/v7Ovb/p+nc7FBvAvNoBAAggkgEACIJAAAgmw6Pg5yN37ATpX+e79PFffP/18t99f52ID+BcbQCABBBJAIAEEEgCBBPjwuAV/m35ucft+e+1zqO3nnqf/Pj2HaQUJIJAAAgkgkAACCSCQAAIJcL34HOT0c5FX7T7Xevq51O3nPk9/PtNznFaQAAIJIJAAAgkgkAAIJIBAAiyKz0GePkfVvl/h9Ovb/fytvn/7udTTn38rSACBBBBIAIEEEEgAgQQQSIDr1Z+LPf1c5/T1756TTM8Jtp873X7/08+3FSSAQAIIJIBAAggkAAIJIJAAi57pF3D6ucnpc4un7yfYvp9j+/u3Px9WkAACCSCQAAIJIJAAAgkgkADXe9yCbqtzjtPnAHe7fU5095xt+vm1ggQQSACBBBBIAIEEEEgAgQQ4njnIctPnENvPzZ7++W+f47SCBBBIAIEEEEgAgQQQSACBBLje+DnI08/lTV//9DnG1dffvV9h+36ft/++rCABBBJAIAEEEkAgAQQSQCAB6v3e8KDT6ecuTz+Xevd+hO33f/X7mT7nePq511aQAAIJIJAAAgkgkAACCSCQAOPF5yABrCABBBJAIAEEEkAgARBIAIEEEEgAgQQQSACBBBBIAIEEEEgAgQQQSAAEEkAgAQQSQCABBBJAIAEEEkAgAQQSQCABBBJAIN0CAIEEEEgAgQTY6D+gk/yG825EywAAAABJRU5ErkJggg==",
  "warnings": [],
  "verified": true,
  "modules": {
    "width": 33,
    "height": 33
  },
  "version": 4,
  "error": "Q",
  "micro": false,
  "designator": "4-Q",
  "content": "https://id.gs1.org/01/09506000134352/21/ABC123"
}
```

### Get official-source reference fixtures

`GET https://api.eu.apyhub.com/callable-labs/validate-standard-payload/fixtures` · 1 atoms · accepts `application/json` · returns `application/json`

| Parameter | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `standard` | query | string | no | One of: gs1-digital-link, epc-sepa, swiss-qr-bill, pix-br-code, upi, emvco-mpm. |

#### Quickstart

Fetch reference QR payment fixtures for a standard like `upi` or `swiss-qr-bill`.

```bash
curl -X GET "https://api.eu.apyhub.com/callable-labs/validate-standard-payload/fixtures?standard=upi" \
  -H "apy-token: $APY_TOKEN"
```

#### What you'll get back

Returns a JSON array of fixture objects. Each object includes `id`, `standard`, `title`, `payload`, `source`, and `note` fields, and may also include `expected_valid` to indicate the validator should accept the payload.

```json
[
  {
    "id": "upi-pay-basic",
    "standard": "upi",
    "title": "UPI pay deep link",
    "payload": "upi://pay?pa=callablelabs@upi&pn=Callable%20Labs&am=10.00&cu=INR&tn=API%20test",
    "expected_valid": true,
    "source": "https://www.npci.org.in/PDF/npci/upi/circular/2017/Circular%20on%20Non-compliance%20of%20UPI%20apps%20to%20Deeplinking%20specs%20Circular%2037-%201.11.2017.pdf",
    "note": "Conformance fixture derived from NPCI UPI Deep Linking 1.5.1 requirements."
  }
]
```

## About

### What it does

QR Standards Validator checks a raw payment or GS1 payload against a selected
specification, then returns the parsed fields, validity result, and any blocking
errors or non-blocking warnings. Send the exact encoded payload and choose one of
the supported standards: `gs1-digital-link`, `epc-sepa`, `swiss-qr-bill`,
`pix-br-code`, `upi`, or `emvco-mpm`.

Use it when you need to verify a QR payload before you store it, generate it, or
send it to a scanner or payment flow. The validation response includes the applied
`standard`, a boolean `valid`, the exact `specification` version used, `normalized`
output when a canonical form exists, structured `fields` parsed from the payload,
plus `errors` and `warnings` for automation and debugging.

The service also renders validated payloads as scannable QR codes with
`POST /render`. Send the same `standard` and `payload`; the two
endpoints run the same checks, so a payload that fails validation is rejected with
`422 invalid_payload` and nothing is rendered. Rendering is plain and deterministic:
`format` (`json`, `png`, `svg`, `jpeg`, `webp`, `pdf`), `size` (32–2048 px), `dark`
and `light` colours. Error correction is fixed at level M and every code is
scan-verified, so `verified` confirms the symbol decodes back to the payload. For
styled codes, logos or typed content use the Scan-Checked QR & Barcode Studio API.

Use the reference fixtures endpoint, `GET /fixtures`, to fetch
official-source payload examples for testing. That helps you compare your
implementation against published samples and confirm your validator or encoder
behaves as expected.

## Usage

Base URL: `https://api.eu.apyhub.com` (default region — see
`GET https://apyhub.com/api/public/regions` for the rest).

Authenticate with an ApyHub API key in the `apy-token` header.
Full docs and a live playground: https://apyhub.com/callable-labs/service/validate-standard-payload