How to build a candidate sourcing or job board app with Unified.to

Updated: October 21, 2026

January 4, 2024

To build a candidate sourcing or job board app with Unified.to's ATS API, read your customer's open jobs, then send candidates to the job's public page or create the candidate and application in the ATS, and attach their resume.

Why build with a unified API?

API integrations are necessary for any modern SaaS app, especially for recruitment solutions like candidate sourcing and job boards that require a high volume of integrations to improve product value and support a broader user base.

Instead of building each ATS integration separately, developers can use a unified API to launch many at once. Unified APIs simplify integration efforts by offering consistent endpoints and data formats that reduce the complexity of managing numerous APIs.

Unified APIs accelerate development cycles, enabling quicker deployment of new features and product updates for your recruitment software. We built Unified.to to make integration development as easy as possible for SaaS developers.

Prerequisites

Before starting, be sure to review our Getting Started with Unified article. It will walk you through registering for a free account and our onboarding. Once you have completed the onboarding steps, go ahead and as you like.

Next, deploy the Unified.to Embedded Authorization widget in your product's user-interface. Check out our to learn more.

Overview

These are main steps that you will need to support to build your candidate sourcing or job board app:

read active jobs to search relevant candidates for
apply a candidate to a job

Let's go into more detail for each.

Step 1: Read Jobs

Before searching or finding relevant candidates, you'll need to know which jobs your customer wants you to search for.

Unified.to reads jobs from your customer's ATS.

To get a list of existing jobs from your end user's ATS, call the List all jobs API endpoint (listAtsJobs in the TypeScript SDK).

import { UnifiedTo } from '@unified-api/typescript-sdk';

const sdk = new UnifiedTo({
    security: {
        jwt: "<YOUR_API_KEY_HERE>",
    },
});

export async function getJobs(connectionId: string) {
    return await sdk.ats.listAtsJobs({
        connectionId,
    });
}

The connection_id comes in from your end user's authorization of their ATS and is stored on your end. You can watch our for more detail.

A Job has fields such as name, description, compensation, addresses and remote that will be relevant to your software. Reference our API docs for more information.

Once you have the list of jobs, ask your customer to identify which jobs your app should identify candidates for.

Step 2: Create an application

Once you have a candidate, there are two ways to create a job application.

Send the interested candidate to the job's public web page to apply directly. Many integrations return public_job_urls, a list of the job's public pages (on Greenhouse it's a slow field: request it with fields). The downside to this method is that you lose control of the candidate's experience and not all ATS providers supply the public website. The upside of this method is that it is very easy to implement.
Create an application and candidate in the ATS directly using our Unified ATS API. This is easily accomplished by using the createCandidate API endpoint and createApplication API endpoint.

import { UnifiedTo } from '@unified-api/typescript-sdk';
import { AtsCandidate } from '@unified-api/typescript-sdk/dist/sdk/models/shared';

const sdk = new UnifiedTo({
    security: {
        jwt: '<YOUR_API_KEY_HERE>',
    },
});

export async function createCandidate(connectionId: string, atsCandidate: AtsCandidate) {
    const result = await sdk.ats.createAtsCandidate({
        atsCandidate,
        connectionId,
    });

    return result.atsCandidate?.id;
}

export async function createApplication(connectionId: string, candidateId: string, jobId: string) {
    const result = await sdk.ats.createAtsApplication({
        atsApplication: {
            candidateId,
            jobId,
        },
        connectionId,
    });

    return result.atsApplication?.id;
}

Step 3: uploading a resume/CV/cover letter (optional)

You can also upload the candidate's documents. Set the Document object fields your customer's ATS requires: usually filename, type (such as RESUME), the file as document_url or base64 document_data, and the record it attaches to. Greenhouse and Workable attach to an application_id and take a URL only; Lever attaches to a candidate_id and also accepts base64.

Some ATS providers may require additional fields to be present. Be sure to check their feature support page for more information.

Are we missing anything? Let us know

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