What is the Addo Sign API?

The Addo Sign API allows organisations and software developers to integrate Addo Sign with other applications. It can be used to create signing processes, send documents and recipient information, follow signing progress and retrieve completed documents.

What systems can Addo Sign integrate with?

The API can be used with systems capable of communicating with a REST API. Typical examples include ERP systems, CRM platforms, HR solutions, case management systems, document management solutions, property management platforms and custom applications.

Can signing processes be automated?

Yes. Your application can initiate signing processes through the API, while status information, callbacks and webhooks can be used to automate what happens as the signing progresses.

Can we use Addo Sign without employees manually creating every transaction?

Yes. One of the primary reasons for using the API is to allow another application to create and manage signing processes automatically instead of requiring users to manually create each transaction in Addo Sign.

Can we create signing processes with multiple recipients?

Yes. The API supports signing processes involving multiple recipients as well as more advanced workflows using recipient groups and signing stages.

Can our system know when a document has been signed?

Yes. Webhooks and signing status information can be used to notify your application about events in the signing process, allowing your system to react automatically.

Can signed documents be returned to our own system?

Yes. Completed documents can be retrieved through the API so they can continue into your own document management, archiving or business processes.

Where can developers find the technical documentation?

Developers can find endpoints, authentication information, examples and implementation guidance in the Addo Sign API documentation.

Addo API

Build digital signing workflows into your own business applications. Create signing workflows, send documents for signature, manage recipients, track progress and bring completed documents back into your systems – without unnecessary manual steps.

Get started Documentation

Build signing workflows automatacilly on the go

Create signing processes dynamically through the Addo API without relying on predefined templates. Define recipients, documents and signing settings for each individual process – giving your integration greater flexibility.

Explore the Addo API

Create even more advanced business workflows

Control how related document groups behave when something is rejected. Rejection dependencies make it possible to build more sophisticated multi-document signing and approval processes with the Addo API.

Talk to us about your integration

Create signing Ready

POST /api/v1/groups/{groupId}/signings

Response 201 Created

{
  "id": "8f32a7...",
  "status": "created",
  "message": "Signing created successfully"
}

FROM CODE TO SIGNING

Ready when you are.

The fastest way to understand an API is to start building with it. Add digital signing to your application, automate your first workflow and see how Addo Sign fits into the systems you already use.

Start in our demo environment
Build and test your integration before moving into production.
Follow practical API examples
Use the documentation to create your first signing and build from there.
Build the workflow you need
Connect documents, recipients, signing events and your own business logic.

Get access to API

REAL-TIME EVENTS

Let your systems know when something happens.

Use webhooks to react to events throughout the signing process. When a document is opened, signed or completed, Addo Sign can notify your application so the next step can happen automatically.

Document opened Document signed Signing completed Rejected Cancelled

Get access to API

Signing events LIVE

Addo Sign Signing transaction

Document opened DocumentOpened

EVENT

Document signed DocumentSigned

EVENT

Signing completed Completed

EVENT

POST Webhook

Sending...

yourapp.com/webhooks/addo

{
  "event": "Completed",
  "signingId": "8f32a7..."
}

HTTPS

</>

Your application Webhook received

200 OK

ADDO SIGN API

What can you build with the Addo Sign API?

Integrate digital signing directly into your own systems and automate the entire process – from documents and recipients to signing, status updates and completed documents.

Automate signing

Create signings automatically

Start a signing process directly from your own system without manually creating transactions in Addo Sign.

Send documents for signing

Transfer documents from your system and send them directly to the people who need to sign.

Add recipients dynamically

Use data from your own applications to determine who should receive and sign each document.

Use signing templates

Standardise recurring signing processes and reuse predefined configurations across transactions.

Handle multiple documents

Include the documents required for a process and manage them as part of the same signing workflow.

Retrieve completed documents

Bring signed documents back into your own system, document management solution or archive.

Build advanced signing flows

Work with multiple recipients

Create signing processes involving several people, organisations or other parties.

Control the signing sequence

Structure the order in which recipients take part in the signing process.

Organise recipient groups

Group recipients and build signing flows that reflect the way your business processes work.

Create dynamic workflows

Build signing processes programmatically when documents, recipients or workflow requirements vary.

Track signing status

Let your application follow a signing process from creation through signing to completion.

Handle rejections and events

Let your workflow respond when a recipient rejects a signing request or the transaction changes state.

Connect signing to your systems

Use webhooks and callbacks

Notify your applications automatically when important events occur during the signing process.

React to completed signatures

Trigger the next step in your process automatically when recipients have signed.

Update your business systems

Use signing status to update processes in your CRM, ERP, HR platform or other business applications.

Automate document archiving

Use completed documents in automated workflows that move them into your DMS, archive or other storage.

Integrate signing into your applications

Make digital signing part of your own software, platform or self-service solution.

Build end-to-end workflows

Combine the API with events and callbacks to move documents from your system to signing and back again.

ONE CONTINUOUS WORKFLOW

From document to signed. Automatically.

Let your application handle the entire document lifecycle. Upload a document, create the signing, send it to the recipient and bring the completed document back into your own workflow.

Start the process from your own application
Follow signing status as the process progresses
Retrieve the completed document automatically

Get access to API

Signing workflow Ready

employment-contract.pdf Ready to upload

✓

Upload document POST /api/v1/uploads

Waiting

Create signing Configure document and recipients

Waiting

Send to recipient Jane Doe · jane@example.com

Waiting

Document signed Recipient completes the signing

Waiting

Retrieve document Return the completed file to your system

Waiting

✓

Signing completed employment-contract-signed.pdf is ready

COMPLETED

Addo Sign API

POST /api/v1/uploads

Authorization: Bearer YOUR_ACCESS_TOKEN
Content-Type: multipart/form-data

formfile: contract.pdf

Response

{
  "storageId": "20f913b9-f113-...",
  "name": "contract.pdf",
  "contentType": "application/pdf"
}

POST /api/v1/groups/{groupId}/signings

{
  "fileGroups": [
    {
      "id": 1,
      "name": "Contracts"
    }
  ],

  "files": [
    {
      "storageId": "20f913b9-f113-...",
      "isSigningRequired": true,
      "fileGroupId": 1
    }
  ],

  "recipients": [
    {
      "name": "Jane Doe",
      "email": "jane@example.com",
      "recipientGroupId": 1
    }
  ]
}

EVENT Completed signing

{
  "callbacks": [
    {
      "url": "https://your-domain.com/signing-completed",
      "type": 1
    }
  ]
}

Completed · Type 1 Trigger your workflow when the signing is completed and the signed documents are ready.

GET /api/v1/signings/{signingId}/files

[
  {
    "id": 80260,
    "name": "contract.pdf",
    "isCompleted": true,
    "requireSigning": true
  }
]

GET /api/v1/signings/{signingId}/files/{fileId}/data

READY TO BUILD?

Start integrating with the Addo Sign API

Build digital signing directly into your applications and workflows. Use our REST API to create signings, manage recipients, react to events and retrieve completed documents.

REST API Webhooks Bearer authentication Signing templates Demo environment

View API documentation

Get API access

The Addo Sign API lets you trigger, manage, and track signing processes directly from your own systems. Because it gives direct programmatic access to your signing environment, API access is a controlled feature in Addo Sign — it must be requested and enabled by our team before you can start integrating.

Access to Addo API
Access is granted after a short conversation with our team about your use case
Test enviroment
A dedicated test environment can be provided to validate your integration
Production access
Access to production is enabled once your integration is ready to go live

Contact us through our contact form to request API access. We'll help you scope the right setup, including a test environment if you need one.

Request API access

Addo API

Digital signing, built into your business

Build signing workflows automatacilly on the go

Create even more advanced business workflows

Build your own signing applications and bring your business to the next level

Ready when you are.

Let your systems know when something happens.

What can you build with the Addo Sign API?

Automate signing

Create signings automatically

Send documents for signing

Add recipients dynamically

Use signing templates

Handle multiple documents

Retrieve completed documents

Build advanced signing flows

Work with multiple recipients

Control the signing sequence

Organise recipient groups

Create dynamic workflows

Track signing status

Handle rejections and events

Connect signing to your systems

Use webhooks and callbacks

React to completed signatures

Update your business systems

Automate document archiving

Integrate signing into your applications

Build end-to-end workflows

From document to signed. Automatically.

Start integrating with the Addo Sign API

Get API access

Questions & answers