SignatureAPI

Three ways to send for signature

⌘ API

Integrate electronic signatures into your app or platform. Define the entire signing workflow in one request.

Read the API docs →

⚡ No-code

Automate sending and tracking documents for signature from the tools your team already uses.

Power Automate · Zapier

✦ AI Toolkit

Let your AI agent send and track signed documents through a hosted MCP server and agent skills.

Connect your agent →

Send your first envelope in one request

An envelope holds the documents to sign and the recipients who sign them. Sign up for a free test key, then run:

curl https://api.signatureapi.com/v1/envelopes \
  -H 'X-API-Key: key_test_xxxxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
        "title": "Dummy Consent",
        "documents": [{
          "url": "https://pub-9cb75390636c4a8a83a6f76da33d7f45.r2.dev/privacy-placeholder.pdf",
          "places": [{ "key": "signer_signs_here", "type": "signature", "recipient_key": "visitor" }]
        }],
        "recipients": [{
          "key": "visitor", "type": "signer",
          "name": "Jane Doe", "email": "jane@example.com"
        }]
      }'

Jane gets an email, signs in a clean, focused ceremony, and you get the signed PDF with its audit log, plus a webhook at every step. Test envelopes are free and have no legal effect. Full quickstart →

Built for AI agents

Connect any MCP client to the hosted server. It signs in with OAuth, so no API key ever sits in a config file.

https://mcp.signatureapi.com/mcp

Claude Code: install the plugin (MCP server plus skills that design, build and debug your integration)

/plugin marketplace add signatureapi/skills
/plugin install signatureapi@signatureapi

Any coding agent: configure every agent on your machine at once

npx -y add-mcp https://mcp.signatureapi.com/mcp -g

Codex

codex plugin marketplace add signatureapi/skills
codex plugin add signatureapi@signatureapi
codex mcp login signatureapi

Works with Claude, ChatGPT, Cursor, Codex, VS Code, Gemini CLI and more. Connect your client →

Everything a signing workflow needs

👥 Multiple recipients _{Up to 10 signers per envelope.}	🔀 Parallel or sequential _{Everyone at once, or one after another.}	📚 Bundle documents _{Up to 10 documents in one envelope.}
🧩 Document templates _{Merge your data into DOCX templates.}	🔔 Real-time notifications _{Webhooks for every envelope event.}	🌐 Languages and localization _{Signers see the ceremony in their language.}
🙋 Accountless signing _{Signers never create an account.}	🎨 Your branding _{Your logo and colors in emails and ceremonies.}	🔏 Signed, sealed, delivered _{Sealed PDFs with a complete audit log.}

Legally binding. Built to be trusted.

ESIGN Act · UETA · eIDAS SES · SOC 2 · HIPAA · GDPR · CCPA

Signatures are valid under the US ESIGN Act and UETA, the EU's eIDAS regulation, and recognized internationally.

Simple, usage-based pricing

Test mode: Free, for as long as you want
Standard: $25/month, 100 envelopes included
Each additional envelope: $0.25, and only completed envelopes count
Commitment: None. Cancel anytime

See pricing →

What customers say

We needed a scalable solution for handling digital signatures in our SaaS platform, and SignatureAPI delivered. Their support is responsive, the documentation is solid, and integration was smooth.

Scott Terrell, Founder & CEO, Solvrix

Lien waivers used to be the choke-point in our disbursement process. SignatureAPI dropped straight into our stack and now waivers go out, get signed, and come back automatically in minutes.

Cameron Strong, Co-Founder, Findlan

Open source

Repository	What it is
skills	Agent skills for SignatureAPI: design, build and diagnose e-signature integrations
signatureapi-mobile-integration-demo	Embedded signing in native iOS (SwiftUI) and Android (Compose) apps
signatureapi-web-integration-demo	Embedded signing in a web page with an iframe, plus a live demo

Website · Docs · Blog · Changelog · Support

Navigation Menu