Signable PDF API

# 1. Get a token
TOKEN=$(curl -s -X POST https://api.getsigned.app/oauth/token \
  -d "grant_type=client_credentials&client_id=$ID&client_secret=$SECRET" \
  | jq -r .access_token)

# 2. Upload any PDF + declare signers + place a signature field
ENV_ID=$(curl -s -X POST https://api.getsigned.app/v1/envelopes \
  -H "Authorization: Bearer $TOKEN" \
  -F "document=@contract.pdf;type=application/pdf" \
  -F 'signers=[{"name":"Alex","email":"alex@client.io"}]' \
  -F 'fields=[{"type":"signature","page":1,"x":300,"y":120,"w":200,"h":60}]' \
  | jq -r .id)

# 3. Send — Alex gets an email with a unique signing link
curl -s -X POST https://api.getsigned.app/v1/envelopes/$ENV_ID/send \
  -H "Authorization: Bearer $TOKEN"

# When Alex signs → webhook fires → download sealed PDF:
# GET /v1/envelopes/$ENV_ID/document

What is a signable PDF API?

A signable PDF API takes any standard PDF document and enables it to be electronically signed via a REST interface. You upload the PDF, declare who should sign it and where their signature fields should appear, then send it. Each signer receives a unique signing link, signs on a hosted or embedded page, and the completed document is returned as a sealed PDF with a tamper-evident audit trail. The original document does not need any special preparation — any PDF works.

Do I need to prepare the PDF before uploading it?

No. Upload the PDF as-is — contracts, agreements, forms, or any other standard PDF. The API accepts the document, stores its SHA-256 hash as the integrity baseline, and applies signature fields at the coordinates you specify. No special PDF preparation, form field tagging, or pre-processing is required.

How do I position signature fields on the PDF?

Two methods: (1) API coordinates — specify page number, x, y, width, and height in points in the fields array of your POST /v1/envelopes request. PDF coordinate space has the origin at the bottom-left of the page. (2) Drag-drop placer — use the GetSigned field placer UI to visually position fields on a rendered PDF preview, then save the template for reuse. The placer outputs the same coordinate format as the API.

What does the sealed PDF contain?

The sealed PDF contains: all original content from the uploaded document, signature fields flattened with each signer's captured signature, an audit certificate page listing every event (view, consent, OTP verification, signature, seal) with timestamps and IP addresses, and a PKCS#7 digital signature over the entire file using a CA-issued certificate. Any modification to the sealed PDF invalidates the digital signature.

What PDF size and page limits does the API support?

GetSigned accepts PDFs up to 25MB and 500 pages. For documents larger than 25MB — which may occur with high-resolution scans — consider optimizing the PDF before upload (reduce image DPI, flatten layers). Contact support for higher limits on enterprise plans.

Can I make a PDF signable without coding?

Yes. The GetSigned console includes a document uploader and drag-drop field placer. You upload the PDF, drag signature, initial, date, and text fields onto each page, assign them to signers, and click send — no code required. For recurring documents, save the layout as a template and send subsequent envelopes from the console or via the API.