Pabbly Connect

Prerequisites

A PolyDoc account and API key - sign up for free, no credit card required. The free plan includes 150 PDF conversions per month.
A Pabbly Connect account - sign up.

Use Case 1: Invoice PDFs from a Spreadsheet

Generate an invoice PDF for every new row in Google Sheets and email it automatically.
Google Sheets (new row) → Google Sheets (Lookup Spreadsheet Rows V2) → Code (Run JavaScript) → API (Custom Request) → Gmail

Pabbly Connect offers unlimited workflows on every plan, so you can add as many PDF generation flows as you need without hitting a workflow cap. Tasks (executions) are still metered.

We use Google Sheets as the data source here, but any source that can POST JSON to a Pabbly webhook works the same way - Airtable, Notion, PostgreSQL/MySQL, NocoDB/Baserow. Keep one row for the invoice header and a second sheet (or a row child) for the line items, and reshape them with a Code step before the API call.

Prepare your data source

Create two Google Sheets tabs: invoices and invoice_items. Examples below - import via File → Import (CSV/XLSX).

invoice_number	invoice_date	invoice_due_date	invoice_subtotal	invoice_tax_rate	invoice_tax_amount	invoice_total	customer_name	customer_email	customer_street	customer_city	customer_country
INV-2026-001	2026-01-15	2026-02-14	1200	0.1	120	1320	John Doe	john.doe@example.com	456 Customer Avenue	Beautiful City	UK

invoice_number	quantity	name	description	price	original_price
INV-2026-001	1	Web Design Services	Custom website design and development for company homepage	800
INV-2026-001	1	Logo Design	Professional logo design with 3 revision rounds	300
INV-2026-001	1	SEO Optimization	Search engine optimization for 10 target keywords	100	150

Create a workflow and add the trigger

Log in to Pabbly Connect, click Create Workflow, name it something like PolyDoc: Google Sheets → PDF → Gmail, and pick Create from Scratch.

In the Trigger step, pick Google Sheets and choose New or Updated Spreadsheet Row (Pabbly only exposes this single Sheets trigger event). Pabbly then generates a unique Webhook URL and shows the setup steps for the Pabbly Connect Webhooks Google Sheets add-on.

Pabbly's Sheets trigger is webhook-based, not OAuth. You install the Pabbly Connect Webhooks add-on on the spreadsheet (Extensions → Add-ons → Get add-ons), open it, paste this Webhook URL into Initial Setup, and pick the trigger column. The add-on then POSTs each new/updated row to Pabbly. Click Capture Webhook Response in Pabbly and edit a row in the sheet so Pabbly learns the field shape.

Search rows on `invoice_items`

Click + Add Action, choose Google Sheets, and pick Lookup Spreadsheet Rows V2. Select the same spreadsheet, point at the invoice_items tab, and configure:

Lookup Value: map the trigger's invoice_number field
Lookup Column(s): the column letter that holds invoice_number on the invoice_items sheet (e.g. A)
End Column of Data: the last column letter that holds an item field (e.g. F for quantity, name, description, price, original_price)
Use Sheet Headers as Keys in Response: Yes (otherwise rows come back keyed by 0-based column index and the next step has to guess)
Max Length: 100 (default)

Click Save & Send Test Request - the response panel should expand and show every matching row from invoice_items.

Build the `items` array

Add Code (Pabbly) → Run JavaScript after the Lookup step. Pabbly's Code step has no separate "Input Data" section - reference the upstream Lookup output by typing / inside the editor and selecting fields from the mapping picker, or by using {{2.field}} syntax (where 2 is the Lookup step's index in the scenario).

// 'rows' below is the array of matching invoice_items rows from the Lookup step.
// Insert it via the mapping picker (type "/" → pick the Lookup step's response array).

const items = rows.map(row => ({
  quantity: Number(row.quantity),
  name: row.name,
  description: row.description,
  price: Number(row.price),
  ...(row.original_price
    ? { original_price: Number(row.original_price) }
    : {}),
}));

return { items };

Wrap every numeric field in Number(...). Pabbly hands the Lookup output back to the Code step as strings, and PolyDoc renders unquoted numbers right-aligned (and runs arithmetic on subtotals) - quoted numbers render as text and break the totals row.

Add the PolyDoc API request

Click + Add Action and pick API (Pabbly) → Execute API Request. Configure:

Action Event Method: Custom Request
Custom Request Method: POST
API Endpoint URL: https://api.polydoc.tech/pdf/convert
Payload Type: JSON
Authentication: Bearer Token, value YOUR_API_KEY (raw key, no Bearer prefix - Pabbly adds it). Get the key from the Dashboard.
Add Headers: enabled, with one row - X-Sandbox = true
Data: the JSON body below, with trigger and Code-step values mapped in via / (avoid quoting numeric mappings)

{
  "source": "[template:jlE-whg]",
  "templateData": {
    "invoice_number": "{{1.invoice_number}}",
    "invoice_date":   "{{1.invoice_date}}",
    "invoice_due_date": "{{1.invoice_due_date}}",
    "invoice_subtotal": {{1.invoice_subtotal}},
    "invoice_tax_rate": {{1.invoice_tax_rate}},
    "invoice_tax_amount": {{1.invoice_tax_amount}},
    "invoice_total": {{1.invoice_total}},
    "customer_name":    "{{1.customer_name}}",
    "customer_email":   "{{1.customer_email}}",
    "customer_street":  "{{1.customer_street}}",
    "customer_city":    "{{1.customer_city}}",
    "customer_country": "{{1.customer_country}}",
    "items": {{3.items}}
  }
}

Pabbly's plain POST method only sends a flat key-value body. To send the nested templateData JSON you must select Custom Request as the Action Event Method and then POST as the Custom Request Method - that unlocks the raw Data body field shown above.

Pabbly substitutes mapping tokens ({{1.field}}) literally. Quote text fields and leave numeric / array fields unquoted in the body editor - "invoice_total": "1320" ships as text and the totals row renders as a string.

Remove the X-Sandbox header when you're ready for production. Sandbox requests return a watermarked PDF and don't count against your quota.

This example uses a template as source, but you can also pass plain HTML or a URL. See the Templates section for details.

Send the generated PDF

Add a final action: Gmail → Send Email. Pabbly's Gmail action uses OAuth - pick an existing connection or add a new one. Map:

To: {{1.customer_email}} from the trigger
Subject: e.g. Invoice {{1.invoice_number}}
Attachment Name: invoice-{{1.invoice_number}}.pdf
Attachment URL: the response body URL from the API step - if PolyDoc returned the PDF inline, use the API step's data field. To get a hosted URL instead, attach a cloud storage target to the PolyDoc request and pass that link to Gmail.

Pabbly's Gmail attachment field expects either a public URL or a base64 payload. The most reliable pattern is to add a cloudStorage object to the PolyDoc body (S3 / R2 / GCS presigned PUT URL) so PolyDoc uploads the PDF for you, then pass the resulting URL through.

Save and test

Once every step shows a successful test response, flip the Disable workflow toggle off (the toggle is checked when the workflow is active) and add a real row in your spreadsheet. Watch Task History in the left nav - a green run means the email landed with the watermarked sandbox PDF attached. Then drop the X-Sandbox header to go to production.

Pabbly sessions expire aggressively (around an hour of idle). If you see a Session Expired dialog or curl returns Workflow deactivated, sign back in and re-toggle the workflow off-disable. Pabbly does not auto-resume mid-edit.

Use Case 2: Webhook-Triggered PDF Generation

Receive data from any external service via webhook, generate a PDF, and deliver it.
Webhook trigger → API (Custom Request) → Gmail

This is the lighter path - skip the Sheets add-on, skip the Lookup and Code steps, and ship the entire body straight from the webhook payload. Use it whenever the source system can already POST a well-shaped JSON (form builders, billing webhooks, custom apps).

Add webhook trigger

Create a new workflow, pick Webhook by Pabbly as the trigger app, and choose Catch Webhook (Preferred). Pabbly generates a unique URL - copy it.

The webhook URL is per-workflow - two workflows have URLs that look similar but differ in the trailing segment. Don't reuse them across flows or events will land in the wrong scenario.

Send test data to the webhook

Click Capture Webhook Response in Pabbly (it polls for ~30 seconds), then send a test POST with the canonical body so Pabbly learns every field, including the nested items array:

curl -X POST <YOUR_WEBHOOK_URL> \
  -H "Content-Type: application/json" \
  -d '{
    "invoice_number": "INV-2026-001",
    "invoice_date": "2026-01-15",
    "invoice_due_date": "2026-02-14",
    "invoice_subtotal": 1200,
    "invoice_tax_rate": 0.1,
    "invoice_tax_amount": 120,
    "invoice_total": 1320,
    "customer_name": "John Doe",
    "customer_email": "john.doe@example.com",
    "customer_street": "456 Customer Avenue",
    "customer_city": "Beautiful City",
    "customer_country": "UK",
    "items": [
      {"quantity": 1, "name": "Web Design Services", "description": "Custom website design and development", "price": 800},
      {"quantity": 1, "name": "Logo Design", "description": "Professional logo design with 3 revisions", "price": 300},
      {"quantity": 1, "name": "SEO Optimization", "description": "SEO for 10 target keywords", "price": 100, "original_price": 150}
    ]
  }'

The trigger panel collapses a Response Received section underneath - expand it to confirm every field you mapped (and the items array as a list, not flattened to per-index keys).

A workflow won't accept webhook POSTs until it has at least one action step. If curl returns {"status":"error","message":"Workflow deactivated"}, finish wiring the API + Gmail steps below first, then send your test payload.

Add PolyDoc API request

Add API (Pabbly) → Execute API Request after the webhook trigger. The form is identical to Use Case 1 Step 5 - select Custom Request + POST, set the URL, add Bearer Token, enable Headers and add X-Sandbox = true, and paste the JSON body below into the Data field.

The only difference vs Use Case 1: every mapping token points at the webhook step ({{1.field}}) instead of at the Code step output, and items drops straight in as {{1.items}} because the webhook payload already carries it as an array.

{
  "source": "[template:jlE-whg]",
  "templateData": {
    "invoice_number": "{{1.invoice_number}}",
    "invoice_date":   "{{1.invoice_date}}",
    "invoice_due_date": "{{1.invoice_due_date}}",
    "invoice_subtotal": {{1.invoice_subtotal}},
    "invoice_tax_rate": {{1.invoice_tax_rate}},
    "invoice_tax_amount": {{1.invoice_tax_amount}},
    "invoice_total": {{1.invoice_total}},
    "customer_name":    "{{1.customer_name}}",
    "customer_email":   "{{1.customer_email}}",
    "customer_street":  "{{1.customer_street}}",
    "customer_city":    "{{1.customer_city}}",
    "customer_country": "{{1.customer_country}}",
    "items": {{1.items}}
  }
}

If Pabbly's webhook trigger flattened your items array into items.1.quantity, items.2.quantity, etc., switch the trigger's Response Format from Simple to Advance or Raw so the array stays a JSON array.

Drop the X-Sandbox header when you go live.

Deliver the PDF

Add Gmail → Send Email as the final step. Map the attachment to the PolyDoc API step's response (use a cloud storage target in the PolyDoc body if Gmail rejects raw binary). Toggle the workflow active, send another curl, and confirm the PDF lands in the mailbox. Strip the X-Sandbox header for production runs.

Prerequisites​

Use Case 1: Invoice PDFs from a Spreadsheet​

Prepare your data source​

Create a workflow and add the trigger​

Search rows on invoice_items​

Build the items array​

Add the PolyDoc API request​

Send the generated PDF​

Save and test​

Use Case 2: Webhook-Triggered PDF Generation​

Add webhook trigger​

Send test data to the webhook​

Add PolyDoc API request​

Deliver the PDF​