Getting Started

This API reference is your guide to understanding the Extend API and how to embed DailyPay functionality and Earned Wage Access into your application.

For an overview of the Extend API functionality, see the Extend API Introduction.


  • The Extend API is a RESTful API, and HTTPS is required for all requests. All request and response bodies are represented with JSON.
  • OAuth 2.0 is used for authentication and authorization with the Extend API. See the OAuth 2.0 RFC 6749 reference for more information.
  • The DailyPay APIs adhere to OpenAPI 3.1.0 standards. See the OpenAPI Specification for more information.

Understanding Authentication

The Extend API uses OAuth 2.0 for authentication. The Extend API OAuth Overview provides a detailed explanation of the OAuth 2.0 Authorization Code Grant and Client Credentials Flow.

Try It

Code Samples are provided for each endpoint in the Extend API Reference. The Try It feature allows you to test the API endpoints directly from the developer portal and is only available in the UAT environment.

  • When using the Try It feature on an endpoint:
    • Make sure you have proper UAT Credentials.
    • Scrub any data that contains real employee phone, email, or other PII.
    • Use non-production data.

Extend API Changelogs

Check back soon for Extend API Changelogs for a list of changes, features, and updates to the Extend API.

API Status

Make sure you subscribe to or keep an eye on the DailyPay Status Page for the current status of the Extend API.


In general, DailyPay APIs have two environments per API and follow the naming structure of for the Production environment and for the UAT environment.

Table of DailyPay APIs and their respective environments

API Name Production URL UAT URL
Extend API
Data Exchange API
Payments API

Key differences between the Production and UAT environments:

Environment Purpose Access Data
Production Live environment for processing production API Traffic Restricted access for authorized clients and users only Real production data exchanges including money movement
UAT Staging environment for developers to test new features, updates, and changes Less restricted access for both developers and testers Test data and exchanges without money movement


Function UAT Production
Testing user data without PII
Ability to mock transfer of funds
Ability to integrate with custom code
Access to real-world transactions like ACH Deposits
Live customer data
Live transactions moving real funds

DailyPay's API Versioning

  • Each API at DailyPay adheres to semver standards for versioning, represented as MAJOR.MINOR.PATCH:

    • The MAJOR version is incremented for breaking changes.
    • The MINOR version is incremented for backwards compatible changes.
    • The PATCH version is incremented for backwards compatible bug fixes.
  • DailyPay will issue a new major API version when a breaking change occurs.

  • To avoid breaking your code, developers are responsible for updating their API calls to interact with new versions of the DailyPay APIs.

  • Communication about API changes will be in the changelogs for the APIs or available from your DailyPay representatives.

DailyPay views the following items as backwards compatible non-breaking changes:

  • New resources
  • New optional query parameters
  • New optional body properties on PATCH, POST, PUT
  • New properties on existing API responses
  • Property order changes on existing API responses
  • Changes to the content, length, or format of error messages and other human-readable strings

Selecting the API Version

Your API version controls the API behavior, properties in responses, available parameters in requests, and so on.

Specify the major API version in the URL path of your API calls in the request header.

  • For example, if you want to use API version v1 of the Extend API, specify the URL or The same applies to the Data Exchange API and Payments API.