Associates a contact to a custom object. Using Axios library for HTTP requests.

associateContactToCustomObject.js

const axios = require('axios');
axios.defaults.headers.common['authorization'] = `Bearer ${process.env.HUBSPOTTOKEN}`;
axios.defaults.headers.common['Content-Type'] = `application/json`;
axios.defaults.headers.put['Content-Type'] = `application/json`;


exports.main = async (event) => {
    const partner_id = event.inputFields['partner_id'];

    const partnerObjectId = await getPartner(partner_id);
    console.log(partnerObjectId.results[0].id);

    const associateResult = await associateContactToPartner(event["object"]["objectId"], partnerObjectId.results[0].id);
    console.log(associateResult);
}

//1. Get HubSpot Partner using Contact Partner ID value
function getPartner(partner_id) {
    let requestUrl = `https://api.hubapi.com/crm/v3/objects/partners/search`;
    let data = {
        filterGroups: [{
            filters: [{
                propertyName: 'partner_id',
                operator: 'EQ',
                value: partner_id
            }]
        }],
        properties: ['name', 'partner_id'],
    }
    return new Promise((resolve) => {
        axios.post(requestUrl, data).then(res => {
            resolve(res.data);
        }).catch(err => {
            console.log(err.message)
        });
    });
}

//2. Associate Contact to Partner Object
function associateContactToPartner(contact_id, partner_id) {
    let requestUrl = `https://api.hubapi.com/crm/v4/objects/contacts/${contact_id}/associations/default/partners/${partner_id}`;
    console.log(requestUrl);
    return new Promise((resolve) => {
        axios.put(requestUrl).then(res => {
            resolve(res.data);
        }).catch(err => {
            console.log(err.message)
        });
    });
}

This is perfect, thanks a lot for sharing your expertise!