eSignature API

Send envelopes in minutes. Pay per use.

Developer-first e-signatures. Upload a PDF, place fields, and LimeSign emails each signer a secure link to review and sign — with a tamper-evident Certificate of Completion.

● Sandbox free ESIGN / UETA ready $0.65 / envelope
cURLPythonNode copy
# Create & send an envelope
curl -X POST https://api.lime-sign.com/v1/envelopes \
  -H "Authorization: Bearer lsk_test_…" \
  -d '{
    "title": "NDA",
    "documents": [{ "file_id": "file_01H…" }],
    "signers": [{
      "name": "Ada Lovelace",
      "email": "ada@example.com"
    }]
  }'
Built for teams shipping signature flows
ESIGN / UETA readyCertificate of CompletionWebhooks + MCPWhite-label
How it works

From document to signed in three steps.

01

Prepare

Upload a PDF, drop signature, date, and text fields exactly where they belong, and add your signers.

02

Send

LimeSign emails each signer a secure, single-use link (SMS optional). No account needed to sign.

03

Sign & seal

They review and sign on any device. You get the sealed PDF and a tamper-evident Certificate of Completion.

Features

Everything you need to ship signing.

Developer-first API

Create and send an envelope in a single call. Clean REST, versioned, documented.

Fields, your way

Signature, initials, date, and text — placed by anchor tags, coordinates, or drag-and-drop.

Tamper-evident audit

Hash-chained events and a human-readable Certificate of Completion for every envelope.

Webhooks

HMAC-signed, fixed-schema events with retries — know the moment an envelope completes.

Your brand

Logo, colors, and sender name on the emails and the signing experience.

Secure by default

Encryption in transit and at rest, DKIM-signed email, and single-use signing links.

Pricing

Simple, usage-based pricing.

Free
$0
sandbox & testing
  • 3 envelopes / mo
  • Full API access
  • Community support
Pay as you go
$0.65
per envelope sent
  • Unlimited envelopes
  • Webhooks & branding
  • Email support
Business
Volume
discounts at scale
  • SMS delivery
  • Delivery inspector
  • Priority support
Enterprise
Custom
let's talk
  • SSO / SAML
  • SOC 2 & DPA
  • SLA
Ready when you are

Start sending documents for signature today.