GitHub - dwelch2344/docuhog: Like MailHog, but for DocuSign. Mock the DocuSign eSignature API for local development and testing.

Like MailHog, but for DocuSign.

What is DocuHog?

DocuHog is a local mock server for the DocuSign eSignature REST API. If you've ever used MailHog to catch outgoing emails during development, DocuHog does the same thing for DocuSign API calls. Point your app at DocuHog instead of DocuSign's sandbox, and every envelope, template, and signing request is captured locally and viewable in a web UI -- no DocuSign developer account, no internet connection, no rate limits.

Features

• Drop-in replacement -- change one URL and your app talks to DocuHog instead of DocuSign
• Mock OAuth -- POST /oauth/token accepts any credentials and returns a valid-looking JWT
• Envelope capture -- create, send, list, and inspect envelopes via the standard REST API
• Status simulation -- move any envelope to sent, delivered, completed, declined, or voided with one click or one API call
• Template support -- CRUD operations for templates
• Web UI -- browse captured envelopes and trigger status changes at http://localhost:8025
• SMTP integration -- forward signing notification emails to MailHog, Mailtrap, or any SMTP server
• JSON file storage -- data persists to disk (ephemeral by default in Docker, volume-mountable)
• Docker-ready -- single container, or docker compose up with MailHog included
• Zero configuration -- works out of the box with sensible defaults

Quick Start

You can be up and running in under two minutes. Pick whichever method suits you.

Docker Compose (recommended)

This starts DocuHog alongside MailHog so envelope notification emails are captured too.

git clone https://github.com/dwelch2344/docuhog.git
cd docuhog
docker compose up

• DocuHog UI + API: http://localhost:8025
• MailHog Web UI: http://localhost:8026

Docker (standalone)

docker run -p 8025:8025 welch/docuhog

Multi-arch images (amd64 + arm64) are published to Docker Hub on every release.

Or use the standalone compose file (no MailHog):

docker compose -f docker-compose.standalone.yml up

Node.js

Requires Node.js 22 or later.

git clone https://github.com/dwelch2344/docuhog.git
cd docuhog
npm install
npm run dev

Open http://localhost:8025 in your browser.

Pointing Your App at DocuHog

The only change your app needs is to set its DocuSign base URL to http://localhost:8025/restapi. No special credentials are required -- DocuHog's mock OAuth accepts anything.

Node.js (DocuSign SDK)

const docusign = require('docusign-esign');

const apiClient = new docusign.ApiClient();
apiClient.setBasePath('http://localhost:8025/restapi');
apiClient.addDefaultHeader('Authorization', 'Bearer any-token-works');

Python (DocuSign SDK)

from docusign_esign import ApiClient

api_client = ApiClient()
api_client.host = 'http://localhost:8025/restapi'
api_client.set_default_header('Authorization', 'Bearer any-token-works')

Java (DocuSign SDK)

ApiClient apiClient = new ApiClient("http://localhost:8025/restapi");
apiClient.addDefaultHeader("Authorization", "Bearer any-token-works");

C# / .NET (DocuSign SDK)

var config = new Configuration(new ApiClient("http://localhost:8025/restapi"));
config.AddDefaultHeader("Authorization", "Bearer any-token-works");

Generic REST

For any HTTP client, just change the base URL:

# Instead of:
https://demo.docusign.net/restapi/v2.1/accounts/{accountId}/envelopes

# Use:
http://localhost:8025/restapi/v2.1/accounts/{accountId}/envelopes

Getting a Mock Token

You can also obtain a mock JWT from DocuHog's OAuth endpoint. This is useful if your app's auth flow obtains a token before making API calls:

curl -X POST http://localhost:8025/oauth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&assertion=anything"

DocuHog will return a response shaped like a real DocuSign OAuth token. Any credentials are accepted.

Configuration

DocuHog is configured via environment variables. All have sensible defaults -- you can run it with zero configuration.

For detailed configuration examples (SMTP providers, storage options, logging), see docs/CONFIGURATION.md.

API Compatibility

DocuHog mocks the following DocuSign eSignature REST API endpoints:

Authentication

Envelopes

Templates

Recipients

Accounts

Internal / UI API

These endpoints power the DocuHog web UI and are not part of the DocuSign API:

For full request/response examples, see docs/API.md.

A Postman collection is included with 36 pre-built requests covering every endpoint.

Web UI

Open http://localhost:8025 in your browser to see the DocuHog web UI. It shows:

• A list of all captured envelopes with their status, recipients, and timestamps
• Envelope details including the full JSON payload your app sent
• Quick overview of recent activity

The web UI is served directly by the DocuHog Express server -- there is nothing extra to install or configure.

Simulating Envelope Status Changes

Because there is no interactive signing ceremony, DocuHog lets you manually move any envelope to any DocuSign status. This is useful for testing how your application responds to each stage of the signing workflow.

Via the Web UI

Open an envelope in the web UI and look for the Simulate Status Change section. Buttons appear for every valid next status based on the envelope's current state:

Clicking Declined or Voided prompts for an optional reason string.

Via the API

PUT /api/v1/envelopes/{envelopeId}/status
Content-Type: application/json

{
  "status": "completed"
}

For declined or voided, supply an optional reason:

PUT /api/v1/envelopes/{envelopeId}/status
Content-Type: application/json

{
  "status": "declined",
  "reason": "Recipient declined to sign"
}

Response (200):

{
  "envelopeId": "abc-123",
  "status": "completed",
  "statusChangedDateTime": "2025-01-15T12:00:00.000Z"
}

Error responses:

Each status change updates the envelope's timestamps (sentDateTime, deliveredDateTime, completedDateTime, voidedDateTime) and each recipient's status accordingly.

Using with MailHog

When DocuHog "sends" an envelope, it can forward notification emails to an SMTP server. The default docker-compose.yml pairs DocuHog with MailHog so those emails are captured locally too:

• DocuHog captures your API calls at http://localhost:8025
• MailHog captures the notification emails at http://localhost:8026

This gives you a complete local testing loop: your app sends an envelope through DocuHog, DocuHog fires a notification email to MailHog, and you can inspect both the API payload and the email without anything leaving your machine.

To use a different SMTP provider (Mailtrap, SendGrid, Gmail SMTP, etc.), see docs/CONFIGURATION.md.

Limitations

DocuHog is a mock server for testing, not a full DocuSign reimplementation. Be aware of the following:

• No signing ceremony -- there is no interactive signing UI. Envelopes are accepted and their status is updated, but recipients do not actually sign documents.
• No real PDF generation -- DocuHog does not generate, merge, or manipulate PDF documents.
• No webhook/Connect notifications -- DocuSign Connect (webhook callbacks) are not implemented.
• No PowerForms, Notary, or advanced features -- only the core envelope, template, and recipient APIs are mocked.
• No conditional recipients or routing -- envelope routing logic is not simulated.
• No document download -- GET .../documents/{documentId} is not implemented.
• Single-user -- there is no multi-user or permission simulation.
• No rate limiting -- DocuHog does not simulate DocuSign's API rate limits.

If your tests depend on any of these features, you will need the DocuSign developer sandbox for those specific scenarios.

Contributing

Contributions are welcome. Please see CONTRIBUTING.md for development setup, coding standards, and the PR process.

License

MIT