Documentation

Quick start, in four steps.

One API call, a sealed PDF back, and a public verification link your users can share with anyone.

What you need

A Deepstamp API key (starts with dsk_)
A PDF document to certify
Any language that can send HTTP requests (Node.js, Python, Go, curl...)

Get your API key

Sign in to your Deepstamp dashboard and generate an API key under Settings > API Keys. Your key starts with dsk_. Keep it secret, server-side only.

Confirm your key is active:

curl

curl https://deepstamp.fr/api/v1/whoami \
  -H "x-api-key: dsk_YOUR_KEY"

No dashboard access yet? Contact our team to get started.

Certify a document

Send your PDF to the certification endpoint. You get back a certified version of the PDF with an embedded proof, plus a unique verification identifier.

curl

curl -X POST https://deepstamp.fr/api/v1/certify \
  -H "x-api-key: dsk_YOUR_KEY" \
  -F "file=@invoice.pdf" \
  -F "certificationName=Invoice #2026-0504"

node.js

import fs from "fs";
import path from "path";

const file = fs.readFileSync("invoice.pdf");

const form = new FormData();
form.append("file", new File([file], "invoice.pdf", { type: "application/pdf" }));
form.append("certificationName", "Invoice #2026-0504");

const res = await fetch("https://deepstamp.fr/api/v1/certify", {
  method: "POST",
  headers: { "x-api-key": process.env.DEEPSTAMP_API_KEY },
  body: form,
});

const json = await res.json();
const result = json.data;

// Save the certified PDF (includes embedded proof + verification link)
const certifiedPdf = Buffer.from(result.pades.signed_pdf_base64, "base64");
fs.writeFileSync("invoice-certified.pdf", certifiedPdf);

console.log("Done! Cert ID:", result.certif_hash);

Tip: The certificationName field is the human-readable label shown on the verification page. Use something your users will recognize (e.g., "Invoice #2026-0504").

Return the certified PDF

The API returns a JSON response with the certified PDF (base64-encoded) and a unique certif_hash identifier.

response

{
  "success": true,
  "data": {
    "certif_hash": "ctf_9f86d081884c7d659a2f...",
    "pades": {
      "signed_pdf_base64": "JVBERi0xLjQK..."
    },
    "short_link": {
      "id": "abc12xyz",
      "url": "https://deepstamp.fr/v/abc12xyz"
    }
  }
}

signed_pdf_base64

The certified PDF. Decode from base64 and serve it to your user. This PDF contains embedded proof that anyone can verify.

short_link.url

The public verification link. Share it with your users — anyone can verify the document at this URL without an account.

Verification

Anyone who receives the certified PDF can verify its authenticity. Two options:

Public verification page

Share the link with your users. They (or their clients) open it in a browser and see the certification status instantly.

https://deepstamp.fr/v/abc12xyz

Programmatic verification

Upload any document to the verify endpoint to check if it has been certified. Useful for automated workflows.

POST /api/v1/verify

Verification is always free and public. No API key required for the public proof page.

Error handling

All errors follow a standard JSON format:

{
  "success": false,
  "error": {
    "code": "MISSING_FILE",
    "message": "Field 'file' is required"
  }
}

Status	Reason
`401`	Missing or invalid API key
`400`	Missing file or certificationName in request body
`413`	File exceeds 25 MB limit
`415`	Unsupported file type (PDF only)
`429`	Rate limit exceeded — retry after the delay in the response header
`500`	Server error — contact support@deepstamp.fr

Ready to go live?

Get your API key Full API reference