Generate PDF Invoices in PHP (Yii2 / Laravel) via REST API

Prerequisites

• PHP 7.4+ or 8.x
• A QuartzAPI account and API key
• An active template code created in the QuartzAPI Visual Builder (e.g. INVOICE_V1)
• Optional: Laravel HTTP client, or Yii2 yiisoft/yii2-httpclient

Step 1: prepare your JSON payload data

Whether you fetch invoice data from Eloquent (Laravel) or Active Record (Yii2), structure it as a clean associative array that matches your template placeholders. QuartzAPI expects document data under data, typically with a master object and line items in master.items.

<?php

$invoiceData = [
    'templateCode' => 'INVOICE_V1',
    'outputFormat' => 'pdf',
    'externalId' => 'INV-2026-0042',
    'data' => [
        'master' => [
            'invoice_number' => 'INV-2026-0042',
            'date' => date('Y-m-d'),
            'customer_name' => 'Acme Corporation',
            'customer_vat' => 'US123456789',
            'customer_email' => 'billing@acme.com',
            'subtotal' => 1090.00,
            'tax' => 239.80,
            'grand_total' => 1329.80,
            'items' => [
                [
                    'description' => 'Web Development Services',
                    'quantity' => 10,
                    'price' => 85.00,
                    'total' => 850.00,
                ],
                [
                    'description' => 'Cloud Hosting (Annual)',
                    'quantity' => 1,
                    'price' => 240.00,
                    'total' => 240.00,
                ],
            ],
        ],
    ],
];

Field names must match the bindings in your template. For a deeper walkthrough of the JSON-to-PDF pattern, see How to generate PDF invoices from JSON.

Step 2: implementation in Laravel

Use Laravel’s HTTP client (Illuminate\Support\Facades\Http) to call generate-document, then download the PDF binary and return it to the browser. Store the API key in config/services.php (e.g. services.quartzapi.key).

Controller example (InvoiceController.php):

<?php

namespace App\Http\Controllers;

use Illuminate\Support\Facades\Http;

class InvoiceController extends Controller
{
    public function downloadPdf(int $invoiceId)
    {
        // 1. Build payload from your Eloquent model (simplified here)
        $payload = [
            'templateCode' => 'INVOICE_V1',
            'outputFormat' => 'pdf',
            'externalId' => 'INV-2026-0042',
            'data' => [
                'master' => [
                    'invoice_number' => 'INV-2026-0042',
                    'grand_total' => 1329.80,
                    // … remaining attributes / items …
                    'items' => [],
                ],
            ],
        ];

        // 2. Generate document
        $generate = Http::withHeaders([
            'Authorization' => 'Bearer ' . config('services.quartzapi.key'),
            'Content-Type' => 'application/json',
        ])->post('https://backend.quartzapi.com/index.php?r=api/v1-jobs/generate-document', $payload);

        if ($generate->failed()) {
            return back()->with('error', 'Failed to generate PDF invoice.');
        }

        $documentId = $generate->json('result.documentId');
        $downloadUrl = $generate->json('result.downloadUrl')
            ?: 'https://backend.quartzapi.com/index.php?r=api/v1-documents/download&uid=' . urlencode((string) $documentId);

        // 3. Fetch PDF bytes
        $pdf = Http::withHeaders([
            'Authorization' => 'Bearer ' . config('services.quartzapi.key'),
        ])->get($downloadUrl);

        if ($pdf->failed()) {
            return back()->with('error', 'Failed to download PDF invoice.');
        }

        // 4. Browser download
        return response($pdf->body(), 200, [
            'Content-Type' => 'application/pdf',
            'Content-Disposition' => 'attachment; filename="Invoice-2026-0042.pdf"',
        ]);
    }
}

Step 3: implementation in Yii2

In Yii2 you can use yii\httpclient\Client (or cURL) inside a controller action. Keep the API key in params (e.g. Yii::$app->params['quartzApiKey']).

Controller example (InvoiceController.php):

<?php

namespace app\controllers;

use Yii;
use yii\httpclient\Client;
use yii\web\Controller;
use yii\web\ServerErrorHttpException;

class InvoiceController extends Controller
{
    public function actionDownloadPdf($id)
    {
        $payload = [
            'templateCode' => 'INVOICE_V1',
            'outputFormat' => 'pdf',
            'externalId' => 'INV-2026-0042',
            'data' => [
                'master' => [
                    'invoice_number' => 'INV-2026-0042',
                    'grand_total' => 1329.80,
                    'items' => [],
                ],
            ],
        ];

        $client = new Client();
        $generate = $client->createRequest()
            ->setMethod('POST')
            ->setUrl('https://backend.quartzapi.com/index.php?r=api/v1-jobs/generate-document')
            ->addHeaders([
                'Authorization' => 'Bearer ' . Yii::$app->params['quartzApiKey'],
                'Content-Type' => 'application/json',
            ])
            ->setContent(json_encode($payload))
            ->send();

        if (!$generate->isOk) {
            throw new ServerErrorHttpException('PDF rendering service unavailable.');
        }

        $body = $generate->data;
        $documentId = $body['result']['documentId'] ?? '';
        $downloadUrl = $body['result']['downloadUrl']
            ?? ('https://backend.quartzapi.com/index.php?r=api/v1-documents/download&uid=' . rawurlencode($documentId));

        $pdf = $client->createRequest()
            ->setMethod('GET')
            ->setUrl($downloadUrl)
            ->addHeaders([
                'Authorization' => 'Bearer ' . Yii::$app->params['quartzApiKey'],
            ])
            ->send();

        if (!$pdf->isOk) {
            throw new ServerErrorHttpException('PDF download failed.');
        }

        return Yii::$app->response->sendContentAsFile(
            $pdf->content,
            'Invoice-2026-0042.pdf',
            ['mimeType' => 'application/pdf', 'inline' => true]
        );
    }
}

Key benefits over mPDF / Dompdf

• Zero RAM overhead on your app servers: memory stays predictable regardless of document size — rendering runs on QuartzAPI.
• No CSS workarounds: layout is maintained in the visual drag-and-drop editor, not in PHP HTML strings.
• Instant design updates: change headers, fonts, or columns without pushing code or running deployments.

Conclusions

For Yii2 and Laravel teams, PDF invoices should be a data problem, not a layout problem. Call generate-document, download the file, and ship the PDF — while designers iterate templates in the portal.

Ready to drop mPDF from your stack? QuartzAPI is in public Beta: create a free account, grab an API key, and wire the examples above into your invoice controller.

👉 Start free with the QuartzAPI Beta