Welcome to the StackOne Unified API docs!

StackOne provides B2B SaaS vendors with a single unified API to add high-quality integrations to their products seamlessly, quickly, safely, and cost-efficiently.

Welcome to the StackOne API! 👋

To use the StackOne API you must first create an API key. Getting Started with StackOne

🔐 Using the APIs

Once you've retrieved a Project API Key, you can start interacting with any linked accounts of that project.

To ease implementation and testing, see more information on how to interact with the API in Libraries & SDKs or use our Postman collection Run in Postman

🎁 What our API offers

Our APIs let you interact with relevant endpoints of the StackOne platform to link and manage Accounts. Additionally, our Unified API lets you interact with category-specific (ie: hris crm ats marketing) resources and sub-resources.

Accounts and Sessions

Unified APIs

The StackOne Unified APIs simplifies the integration process by providing a consistent interface for interacting with multiple ATS, HRIS, CRM and Marketing platforms.


CompaniesRepresents the high-level organizational details of companie(s) present in the underlying system, such as its name.
EmployeesContains comprehensive information about employees, such as contact information, job title and start date
EmploymentsDetails the employments of each employee including job positions, start and end dates, compensation and more
Time OffManages records of employee leave requestsand the approval status of such requests.
LocationsManages information about the company's or employees locations. Location may be specific to an employee or, in the case of work locations be the same for numerous employees. Location may contain a name associated contact details.


ApplicationsManages job applications, including when it was created, its status, linked job and candidates identifier and more.
Application OffersHandles job offers associated with applications. It provides information on offer status and details, and responses, allowing tracking from offer creation to candidate acceptance or rejection.
InterviewsRecords details of candidate interviews. This includes information on interview times, participants (including hiring team) and location of the interview (e.g. meeting URL).
Interview StagesRepresents the different stages in the interview process, such as initial screening, technical rounds, and final interviews.
Rejected ReasonsManages standardized reasons for candidate application rejections, aiding in consistent decision-making and recruitment process analysis.
CandidatesProvides detailed profiles of job candidates. This includes personal information, potential qualifications, application status, and history with the company, offering a comprehensive view of each candidate in the recruitment pipeline.
Candidate NotesManages the notes related to a specific candidate - includes the notes content (usually simple text strings) and author.
UsersManages user accounts within the ATS, typically including recruiters, HR personnel, and hiring managers. This endpoint can be used to access user details, roles, and permissions.
JobsManages job positions within the organization. This includes details like title, location and the job status.
Job PostingsFocuses on the public aspect of the job - specifically its job postings - as such job postings will have a extended job description, compensation ranges and also will return any related questionnaire required for applying via the job postings.
LocationsManages geographical locations associated with a job or job posting


ContactsManages individual contact details, including names, addresses, and communication preferences.
AccountsHandles organizational accounts, encompassing details like account status, associated contacts, and transaction history.
ListsManage lists of contacts and accounts


TemplatesManages individual or organizational contact details, including names, addresses, and communication preferences.
Omni-channel templatesSpecialized templates designed for use across multiple channels, ensuring cohesive messaging and branding across all marketing platforms.
Push templatesTemplates for push notifications, optimized for engagement and reach on mobile and web applications.
Email templatesPre-designed layouts and styles for email campaigns, simplifying the process of creating professional and consistent email communications.
CampaignsManages marketing campaigns, encompassing planning, execution, tracking, and analysis of marketing initiatives across various channels.