QSign API

Embed signing into your product with one API.

A white-label REST API for e-signature, Aadhaar eSign and DSC. Ship signing without building a signing stack.

curl https://app.qsig.in/othercompanyapi/v1/documents/sign \
  -H "X-Api-Key: qsk_live_…" \
  -d '{
    "file_url": "https://…/nda.pdf",
    "method": "aadhaar_esign",
    "signers": [{ "email": "a@co.in" }]
  }'

{ "status": "sent", "id": "doc_8Kd…", "mode": "live" }

Everything you need to ship signing

Built for production from day one — keys, webhooks, sandbox, metering and every signing method.

One REST API

Create, send and finalize documents over a clean JSON API. e-Signature, Aadhaar eSign and DSC behind a single integration.

Opaque API keys

Live and test keys (qsk_live_ / qsk_test_), hashed at rest. Rotate, suspend and scope per account from the dashboard.

Signed webhooks

HMAC-signed delivery for sent, signed and completed events, with automatic retries and a delivery log.

Sandbox & live modes

Build against a sandbox with test keys, then flip to live — same API surface, isolated data and billing.

Usage metering & quotas

Per-plan monthly call limits with usage headers and 80% quota alerts, so you never get surprised.

DSC over the API

Prepare/finalize a PKI digital signature with tamper-evident sealing and trusted timestamps on Enterprise.

API pricing

Self-serve plans from 1,000 calls/month. Billed in ₹ for India and $ internationally.

API Starter

Programmatic e-signing for a single product.

₹2,999/mo

or $49/mo international

✓1,000 API calls / month
✓e-Signature API
✓API key + webhooks
✓Email-driven Aadhaar

Choose API Starter

API Pro

Popular

Higher volume with Aadhaar eSign over the API.

₹4,999/mo

or $99/mo international

✓10,000 API calls / month
✓Everything in Starter, plus:
✓Aadhaar eSign via API
✓Priority support

Start free

API Enterprise

Maximum scale with every signing method.

₹9,999/mo

or $199/mo international

✓100,000 API calls / month
✓Everything in Pro, plus:
✓DSC signing
✓Highest rate limits

Choose API Enterprise

Start building with QSign

Create an API account, grab a sandbox key, and send your first signing request in minutes.

Start free Talk to sales