Quick Start

This guide walks you through getting authenticated and sending your first signature request using the Lumin API.

Prerequisites

A Lumin account with Workspace Owner access
curl or an HTTP client of your choice

Get your API key

Go to Settings → Developer settings → API keys in the Lumin app, or click here to go directly to the Developer settings page.
Click Generate key, enter a name for the key, and click Create.
Copy and securely store the key — you won’t be able to see it again.

Treat your API key like a password. Do not commit it to source control or expose it in client-side code.

Verify your credentials

Confirm your API key works by calling GET /user/info:

curl -X GET "https://api.luminpdf.com/v1/user/info" \
  -H "X-API-KEY: YOUR_API_KEY"

import requests

response = requests.get(
    "https://api.luminpdf.com/v1/user/info",
    headers={"X-API-KEY": "YOUR_API_KEY"},
)
print(response.json())

const response = await fetch("https://api.luminpdf.com/v1/user/info", {
  headers: { "X-API-KEY": "YOUR_API_KEY" },
});
const data = await response.json();
console.log(data);

A successful response returns your user details:

{
  "user": {
    "id": "usr_a1b2c3d4",
    "email": "[email protected]",
    "name": "Your Name"
  }
}

If you receive a 401 or 403, double-check that your API key was copied correctly and that you are passing it in the X-API-KEY header.

Send a signature request

Use POST /signature_request/send to send a document to one or more signers.The example below sends a PDF from a public URL to a single signer:

curl -X POST "https://api.luminpdf.com/v1/signature_request/send" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Financial Year-End Report Authorization",
    "file_url": "https://example.com/path/to/document.pdf",
    "signers": [
      {
        "email_address": "[email protected]",
        "name": "John Doe"
      }
    ],
    "expires_at": 1927510980694
  }'

import requests

payload = {
    "title": "Financial Year-End Report Authorization",
    "file_url": "https://example.com/path/to/document.pdf",
    "signers": [
        {
            "email_address": "[email protected]",
            "name": "John Doe",
        }
    ],
    "expires_at": 1927510980694,
}

response = requests.post(
    "https://api.luminpdf.com/v1/signature_request/send",
    headers={
        "X-API-KEY": "YOUR_API_KEY",
        "Content-Type": "application/json",
    },
    json=payload,
)
print(response.json())

const response = await fetch(
  "https://api.luminpdf.com/v1/signature_request/send",
  {
    method: "POST",
    headers: {
      "X-API-KEY": "YOUR_API_KEY",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      title: "Financial Year-End Report Authorization",
      file_url:
        "https://example.com/path/to/document.pdf",
      signers: [{ email_address: "[email protected]", name: "John Doe" }],
      expires_at: 1927510980694,
    }),
  }
);
const data = await response.json();
console.log(data);

A 201 Created response returns the new signature request:

{
  "signature_request": {
    "signature_request_id": "sr_a1b2c3d4e5f6",
    "status": "WAITING_FOR_PROCESSING",
    "created_at": "2026-04-01T10:00:00Z"
  }
}

The signer receives an email with a link to review and sign the document. The status moves from WAITING_FOR_PROCESSING to NEED_TO_SIGN once the document is ready.

The expires_at field is a Unix timestamp in milliseconds. Set it to a date in the future. To send to multiple signers simultaneously, add more objects to the signers array and set signing_type to SAME_TIME. For sequential signing, set signing_type to ORDER and assign a group number to each signer.

Next steps

Authentication overview — learn about API Key and OAuth 2.0 options
API Reference — explore all available endpoints
Webhooks — receive real-time event notifications when signers act

Getting started

Authentication

Webhooks

Walkthroughs

Prerequisites

Next steps

​Prerequisites

​Next steps

Prerequisites

Next steps