You may want to give memberships to all contacts in a group. This example creates memberships for a Paid group.

First, get the source group by searching for it. In this example, the group named Paid.

const groups = await THQ.Groups.getGroups({search_terms: "Paid"});
const groupId = groups.data[0].id; // Get the id of the first group

Next, get the contacts in the source group.

const contacts = await THQ.Contacts.getContactsInGroup(groupId);

Now that we have our contacts, let's work out what membership level/s we would like to give them. In this example, we have two separate membership levels, 2024 Member and 2024 Member - Voucher. Each member also has a custom field with how they paid, although you don't need to have this extra step if you only want to add to one membership level.

The dropdown custom field Payment Method has the following options: Voucher, Cash or Card. We will create a map of these values to valid payment methods for TidyHQ (cash, card, cheque, bank or other).

const paymentMethodMap = {
    "Voucher": "other", // Arguably this is not needed as the fallback value is "other", but it's here for completeness
    "Cash": "cash",
    "Card": "card"
};

Let's get the membership levels.

const levels = await THQ.V2.MembershipLevels.getMembershipLevels();
const voucherLevel = levels.data.find(level => level.name === "2024 Member - Voucher");
const otherLevel = levels.data.find(level => level.name === "2024 Member");

Now we can loop through the contacts and create memberships for them.

for (let i = 0; i < contacts.data.length; i++) {
    // Get the contact
    const contact = contacts.data[i];

    // Get the payment method from the custom field, default to "other" if not found/set
    const paymentMethod = contact.custom_fields.find(field => field.title === "Payment Method")?.value?.title;
    const tidyPaymentMethod = paymentMethodMap[paymentMethod] || "other";

    // Get the membership level based on the payment method
    const membershipLevel = paymentMethod === "Voucher" ? voucherLevel : otherLevel;

    // Create the membership
    const res = await THQ.V2.MembershipLevels.createMembership(targetLevel.id, {
        member: { contact_id: contact.id },
        payment_type: 'paid',
        payment_method: tidyPaymentMethod,
        send_welcome_email: true // This is true by default, and will queue welcome emails to be sent
    });

    // Log progress
    if (res.success) {
        console.log(`Created membership for contact ${contact.display_name}`);
    } else {
        console.log(`Failed to create membership for contact ${contact.display_name}`);
        console.log(res.data); // Contains the error message from TidyHQ
    }
}

Note that creating a membership will take a moment. Also, if the membership is not free, financial transactions will be created.