Quickstart: Your first Blink PDF call

Blink PDF has two verbs: render Markdown to PDF, and fill an AcroForm by name. This guide gets you a working bp_ key and a PDF on disk in about five minutes. The same key does both.

Create your account and get an API key

Sign up for a free account at app.blinkpdf.io/login. The free tier includes 250 units per month with no credit card required. Fill and render share that allowance.Once you’re logged in:

Open the API Keys section of your dashboard.
Click Create new key.
Copy the key — it starts with bp_ and is shown only once.

A key that can render can fill. Do not mint a second key for fill.

Store your API key somewhere safe immediately. For security reasons, the dashboard will not show the full key again after you navigate away. If you lose it, you’ll need to rotate it and update any services using the old key.

Make your first API call

Replace bp_xxxxxxxxxxxxxxxxxxxx with your actual API key. Pick a verb.

Fill a form
Render Markdown

Inspect lists the field names. Fill writes appearances and returns a PDF. This synthetic intake has givenName (text) and agree (checkbox). It is not a real-world form.Inspect spends no unit. Fill spends 1 unit.

INTAKE_PDF='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'

curl https://api.blinkpdf.io/v1/inspect \
  --request POST \
  --header 'Accept: application/json' \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: bp_xxxxxxxxxxxxxxxxxxxx' \
  --data "{\"pdf\":\"${INTAKE_PDF}\"}"

curl https://api.blinkpdf.io/v1/fill \
  --request POST \
  --header 'Accept: application/pdf' \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: bp_xxxxxxxxxxxxxxxxxxxx' \
  --data "{\"pdf\":\"${INTAKE_PDF}\",\"values\":{\"givenName\":\"Ada\",\"agree\":true}}" \
  --output intake-filled.pdf

import json
import requests

INTAKE_PDF = "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"

headers = {
    "x-api-key": "bp_xxxxxxxxxxxxxxxxxxxx",
    "Content-Type": "application/json",
}

inspected = requests.post(
    "https://api.blinkpdf.io/v1/inspect",
    headers={**headers, "Accept": "application/json"},
    json={"pdf": INTAKE_PDF},
)
inspected.raise_for_status()
print(json.dumps(inspected.json(), indent=2))

filled = requests.post(
    "https://api.blinkpdf.io/v1/fill",
    headers={**headers, "Accept": "application/pdf"},
    json={"pdf": INTAKE_PDF, "values": {"givenName": "Ada", "agree": True}},
)
filled.raise_for_status()

with open("intake-filled.pdf", "wb") as f:
    f.write(filled.content)

print("PDF saved to intake-filled.pdf")
print(f"Request ID: {filled.headers['X-Request-Id']}")

import fs from "fs";

const INTAKE_PDF =
  "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";

const key = "bp_xxxxxxxxxxxxxxxxxxxx";

const inspected = await fetch("https://api.blinkpdf.io/v1/inspect", {
  method: "POST",
  headers: {
    "x-api-key": key,
    Accept: "application/json",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ pdf: INTAKE_PDF }),
});

if (!inspected.ok) {
  throw new Error(`Inspect failed: ${inspected.status} ${inspected.statusText}`);
}

console.log(await inspected.json());

const filled = await fetch("https://api.blinkpdf.io/v1/fill", {
  method: "POST",
  headers: {
    "x-api-key": key,
    Accept: "application/pdf",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    pdf: INTAKE_PDF,
    values: { givenName: "Ada", agree: true },
  }),
});

if (!filled.ok) {
  throw new Error(`Fill failed: ${filled.status} ${filled.statusText}`);
}

fs.writeFileSync("intake-filled.pdf", Buffer.from(await filled.arrayBuffer()));
console.log("PDF saved to intake-filled.pdf");
console.log(`Request ID: ${filled.headers.get("X-Request-Id")}`);

Inspect returns JSON. You should see givenName (Tx) and agree (checkbox). Fill returns application/pdf. Open intake-filled.pdf — Ada already shows in the text field. Do not set /NeedAppearances.A successful fill includes X-BlinkPDF-Billing: counted (1 unit) and X-Fill-Warnings (empty when every appearance fit). See Fill.

Send a POST request to https://api.blinkpdf.io/v1/render with your Markdown content in the request body.

curl https://api.blinkpdf.io/v1/render \
  --request POST \
  --header 'Accept: application/pdf' \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: bp_xxxxxxxxxxxxxxxxxxxx' \
  --data '{
    "markdown": "# Invoice 0042\n\nHi Jane, thanks for your business!\n\n## What'\''s included\n\n- **Pro plan** subscription\n- Priority support\n\n**Total: $39** — paid on May 23, 2026.",
    "metadata": { "title": "Invoice 0042" }
  }' \
  --output invoice.pdf

import requests

response = requests.post(
    "https://api.blinkpdf.io/v1/render",
    headers={
        "x-api-key": "bp_xxxxxxxxxxxxxxxxxxxx",
        "Accept": "application/pdf",
        "Content-Type": "application/json",
    },
    json={
        "markdown": (
            "# Invoice 0042\n\n"
            "Hi Jane, thanks for your business!\n\n"
            "## What's included\n\n"
            "- **Pro plan** subscription\n"
            "- Priority support\n\n"
            "**Total: $39** — paid on May 23, 2026."
        ),
        "metadata": {"title": "Invoice 0042"},
    },
)

response.raise_for_status()

with open("invoice.pdf", "wb") as f:
    f.write(response.content)

print("PDF saved to invoice.pdf")
print(f"Request ID: {response.headers['X-Request-Id']}")

import fs from "fs";

const response = await fetch("https://api.blinkpdf.io/v1/render", {
  method: "POST",
  headers: {
    "x-api-key": "bp_xxxxxxxxxxxxxxxxxxxx",
    Accept: "application/pdf",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    markdown:
      "# Invoice 0042\n\n" +
      "Hi Jane, thanks for your business!\n\n" +
      "## What's included\n\n" +
      "- **Pro plan** subscription\n" +
      "- Priority support\n\n" +
      "**Total: $39** — paid on May 23, 2026.",
    metadata: { title: "Invoice 0042" },
  }),
});

if (!response.ok) {
  throw new Error(`Render failed: ${response.status} ${response.statusText}`);
}

const buffer = Buffer.from(await response.arrayBuffer());
fs.writeFileSync("invoice.pdf", buffer);

console.log("PDF saved to invoice.pdf");
console.log(`Request ID: ${response.headers.get("X-Request-Id")}`);

A successful render looks like this:

HTTP/1.1 200 OK
Content-Type: application/pdf
X-Request-Id: 4dcbe381-c0e8-4832-9a2f-1b7c0e9d2f5a
X-Render-Status: ok
X-Render-Rendered-As-Requested: true
X-BlinkPDF-Billing: counted
X-BlinkPDF-Usage-PDFs-This-Period: 4

The body is a raw PDF binary. See the API reference for the full header list.

Simple Markdown renders are designed to complete quickly. Remote images, large documents, and network distance can add latency.

Save and verify the PDF

If you used curl, --output writes the file directly. Python and Node.js examples write to the current working directory.Open the file in any PDF viewer. A fill should already show Ada in the text field (appearances are written — do not rely on /NeedAppearances). A render should show the heading Invoice 0042, a bullet list, and the total line.

Every PDF rendered from Markdown is PDF/UA-1 compliant. Filled AcroForms keep the template’s own accessibility tags; overlay is the default (flatten: true stamps and strips widgets).

Move your API key to an environment variable

Before you ship any code, move your API key out of your source files and into an environment variable. Hardcoded keys are a common source of credential leaks.

export BLINKPDF_API_KEY="bp_xxxxxxxxxxxxxxxxxxxx"

Then reference it in your code:

import os, requests

response = requests.post(
    "https://api.blinkpdf.io/v1/render",
    headers={"x-api-key": os.environ["BLINKPDF_API_KEY"]},
    json={"markdown": "# Hello, world!"},
)

const response = await fetch("https://api.blinkpdf.io/v1/render", {
  method: "POST",
  headers: {
    "x-api-key": process.env.BLINKPDF_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ markdown: "# Hello, world!" }),
});

See the Authentication guide for a full security checklist and details on key rotation.

What to explore next

Fill a form

Inspect, validate-fill, fill, and stored templates.

API Reference

Render, fill, inspect, templates, response headers, and error codes.

MCP fill

inspect_form → validate_fill → fill_form for agents.

Plans & Pricing

Compare tiers from Free (250 units/mo) to Enterprise. Fill is 1 unit on the same allowance.

Get Started

Fill a form

Core Concepts

Guides

MCP Server

Configuration

Plans & Limits

Help

Quickstart: Your first Blink PDF call

What to explore next

Fill a form

API Reference

MCP fill

Plans & Pricing

​What to explore next

Fill a form

API Reference

MCP fill

Plans & Pricing

What to explore next