Build with the TRUE Sign API.

Send documents, add signers, place fields and collect legally binding signatures through a clean REST API. Every sealed PDF comes back with its Proof of Signing, anchored on public blockchain.

Get a free sandbox API reference

Four calls from PDF to sealed proof

# 1. Create a signing request
curl -X POST https://sign-api.trueoriginal.com/v1/requests \
  -H "Authorization: Bearer $API_KEY" \
  -d '{ "title": "Consulting Agreement", "signingOrder": "parallel" }'

# 2. Add signers
curl -X POST .../v1/requests/{id}/signers \
  -d '{ "signers": [ { "name": "Alice Anderson", "email": "[email protected]" } ] }'

# 3. Place signature fields
curl -X POST .../v1/requests/{id}/fields \
  -d '{ "fields": [ { "type": "signature", "page": 4, "x": 120, "y": 640 } ] }'

# 4. Send. Everyone signs from a link.
curl -X POST .../v1/requests/{id}/send

# Webhook fires when sealed: sealed PDF + Proof of Signing + SHA 256 anchor.

Made for builders, human and machine

REST and webhooks

Predictable JSON endpoints for requests, signers, fields and status. Webhooks on every event from viewed to sealed.

Proof of Signing built in

Every completed request returns a sealed PDF whose evidence and blockchain anchor travel with the file. Nothing extra to build.

Free sandbox

Build and test for free against real endpoints. Keys are issued per organisation, you are up the same day.

AI ready docs

OpenAPI specification plus an llms.txt written for AI agents. Your copilot reads the same reference you do.

Included in Enterprise

API access ships with the Enterprise plan, alongside the full TRUE platform. High volume API pricing is quoted per case. Free and Team users can explore the sandbox.

Talk to us See pricing

Developer questions

Yes. You can build and test against the TRUE Sign API for free. Keys are issued per organisation, talk to us and you are up the same day.

API access is included in the Enterprise plan. High volume API pricing is quoted per case.

Yes. The API ships an OpenAPI specification and an llms.txt written for AI agents, so both humans and machines integrate against the same reference.

The API ships with Enterprise

Read everything for free, build against the sandbox, and talk to us when you are ready for keys.

Talk to us API reference