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How to generate a PDF from a template in Python

Q: Do Jinja2 filters work?

Yes — standard filters such as |round, |upper, and |default are available for formatting values inside the template.

Most documents are one layout rendered against changing data: the same invoice for a thousand customers, the same certificate for every course completion. The /v1/generate/template endpoint separates those concerns — you POST a Jinja2 template plus a JSON data object, and Inkspan renders the template and converts the result to PDF in one request.

Keeping the template in the request rather than in your codebase means non-engineers can change document layout without a deploy, and you can store templates in your own database per tenant.

Also in: cURL · Node.js

Python example

import requests

r = requests.post(
    'https://api.inkspan.dev/v1/generate/template',
    headers={'X-API-Key': 'ink_live_...'},
    json={
        "template": "<h1>Invoice {{ number }}</h1>{% for i in items %}<p>{{ i.desc }}: ${{ i.amt }}</p>{% endfor %}<h3>Total: ${{ total }}</h3>",
        "data": {
            "number": "INV-1042",
            "items": [
                {
                    "desc": "Pro Plan",
                    "amt": 49
                }
            ],
            "total": 49
        }
    },
)
r.raise_for_status()
with open('document.pdf', 'wb') as f:
    f.write(r.content)

Request parameters

Name	Type	Required	Description
`template`	string	yes	A Jinja2 template. Supports `{{ variables }}`, `{% for %}` loops, `{% if %}` conditionals, and filters.
`data`	object	yes	JSON object whose top-level keys become template variables.
`filename`	string	no	Filename in the response's Content-Disposition.

Response

Returns a PDF as a binary stream with Content-Type: application/pdf and Content-Disposition: attachment; filename=document.pdf. Write the response body straight to disk — do not parse it as JSON.

Things that catch people out

Template syntax is Jinja2, not Handlebars or Mustache. Loops are {% for i in items %}…{% endfor %}, not {{#each}}.
Only top-level keys in data become variables. Passing {"data": {"invoice": {...}}} means you reference {{ invoice.number }}, not {{ number }}.
Undefined variables render as empty rather than raising. Validate your data server-side if a missing field should be an error.
Escape user-supplied values with the |e filter if they may contain HTML, or they will be interpreted as markup.

Errors

Status	Meaning	Fix
`401`	Invalid or missing API key	Send your key in the `X-API-Key` header.
`402`	Monthly quota exceeded	The response reports used/quota. Upgrade at inkspan.dev/#pricing.
`422`	Missing or invalid parameter	Check required fields in the table above — the body names the offending field.

Failed requests do not count against your quota; only successful ones are metered.

Frequently asked questions

Can I reuse a stored template?

Templates are sent per request, so store yours in your own database or object storage and send it with each call. This keeps tenant-specific layouts under your control.

Do Jinja2 filters work?

Yes — standard filters such as |round, |upper, and |default are available for formatting values inside the template.

How do I format currency?

Format on your side before sending, or use a filter in the template. Sending pre-formatted strings is the more predictable option for money.

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