---
title: "Connect PostStack and Square - APIANT.ai"
description: "When \"Contact Updated (instant)\" fires in PostStack, your agent runs \"Add order\" in Square, or \"New order\" in Square to \"Add a contact\" in PostStack."
canonical: "https://apiant.ai/connect/poststack-to-square"
---

# Connect PostStack and Square

When **Contact Updated (instant)** fires in [PostStack](https://apiant.ai/connections/poststack), your agent runs **Add order** in [Square](https://apiant.ai/connections/square), or **New order** in Square to **Add a contact** in PostStack. Describe the whole flow and it is built, tested on every scenario and kept running.

PostStack **7** triggers PostStack **31** actions Square **3** triggers Square **19** actions

What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it.

## What do you want PostStack and Square to do together?

Give your AI client this address.

`https://mcp.apiant.ai`

One connection does both: ask your client to act in an app once, or have it build an automation that keeps running. Any client that takes a remote MCP server. Nothing to install. Create your free account, then sign in once in your browser.

### Set it up in your client

### Claude Code

Run this in the directory you want to work in.

`claude mcp add --transport http -s project apiant-ai https://mcp.apiant.ai`

Start Claude Code there, approve the server, and sign in in the browser page it opens.

[Claude Code guide (opens in a new tab)](https://apiant.ai/docs/mcp/claude-code)

### Claude, web and desktop

Open Customize, then Connectors, then Add custom connector, and paste the address. On Team and Enterprise an owner adds it first.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

### Cursor

Add the address to your MCP configuration as a server URL. Cursor signs you in in your browser.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

### Zed

Open Settings, then AI, then MCP Servers, then Add Server, then Add Remote Server.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

### Codex and the ChatGPT desktop app

Open Settings, then MCP servers, then Add server, and choose Streamable HTTP. From the terminal, Codex takes the address with its own add command and then signs you in.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

### Any other MCP client

Paste the address where the client asks for a remote MCP server URL, and name the server apiant-ai where it lets you. APIANT's skills reach the client over the same connection.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

Example flows

## What PostStack and Square can do together

### From PostStack to Square

- When **Contact Updated (instant)** in PostStack then **Add order** in Square
- When **New Contact (instant)** in PostStack then **Create customer** in Square

### From Square to PostStack

- When **New order** in Square then **Add a contact** in PostStack
- When **New or updated customer** in Square then **Add contacts to segment** in PostStack

Starting points drawn from the triggers and actions in the catalog today. Describe the flow you need, at any depth, and your agent builds it and tests every scenario before it ships.

Everything your agent can do with PostStack and Square

## Triggers and actions 10 triggers · 50 actions

- Trigger

**Contact Deleted (instant)**

Fires when a contact is deleted (event: contact.deleted).

- Trigger

**Contact Updated (instant)**

Fires when a contact is updated (event: contact.updated).

- Trigger

**Email Bounced (instant)**

Fires when an email bounces (event: email.bounced).

- Trigger

**Email Delivered (instant)**

Fires when an email is delivered (event: email.delivered).

- Trigger

**New Contact (instant)**

Fires when a contact is created (event: contact.created).

- Trigger

**New Inbound Email**

Polls for newly received inbound emails.

- Trigger

**New Sent Email (instant)**

Fires when an email is sent (event: email.sent).

- Action

**Add a broadcast**

Create a new marketing broadcast.

- Action

**Add a contact**

Create a new contact.

- Action

**Add a segment**

Create a new manual contact segment.

- Action

**Add a template**

Create a new email template.

- Action

**Add contacts to segment**

Add contacts to an existing segment.

- Action

**Add suppression**

Add an address to the suppression list.

- Action

**Cancel broadcast**

Cancel an in-flight broadcast.

- Action

**Cancel email**

Cancel a scheduled or queued email before it sends.

- Action

**Delete a contact**

Delete a contact.

- Action

**Delete a template**

Delete an email template.

- Action

**Get a contact**

Fetch one contact by ID.

- Action

**Get a template**

Fetch one email template by ID.

- Action

**Get broadcast**

Retrieve one broadcast by its public id, including the HTML and text bodies that the list endpoint omits.

- Action

**Get email**

Fetch one sent or queued email by ID.

- Action

**Get email events**

Get the delivery event timeline for one email.

- Action

**Get inbound email**

Fetch one received inbound email by ID.

- Action

**Import contacts**

Bulk-import a CSV list of contacts.

- Action

**List broadcasts**

List marketing broadcasts.

- Action

**List contacts**

List contacts in the account.

- Action

**List emails**

List sent, queued, and scheduled emails.

- Action

**List inbound emails**

List emails received via inbound parsing.

- Action

**List segments**

List contact segments.

- Action

**List suppressed addresses**

List addresses on the suppression list.

- Action

**List templates**

List email templates.

- Action

**Send an email**

Send a transactional email through PostStack.

- Action

**Send broadcast**

Start sending a broadcast to its recipients.

- Action

**Send emails in batch**

Send up to 100 emails in a single request.

- Action

**Update a contact**

Update an existing contact's fields.

- Action

**Update a template**

Update an email template, creating a new version.

- Action

**Update email**

Reschedule a queued email's send time.

- Action

**Validate email address**

Check whether an email address is valid and deliverable.

- Trigger

**New order**

Triggered when a new order is created at the specified location.

- Trigger

**New or updated customer**

Triggered when a customer is created or updated.

- Trigger

**New payment**

Triggered when a new payment is received.

- Action

**Add catalog object**

Creates a catalog object (item, variation, category, tax, discount, modifier list and more) in the Square catalog.

- Action

**Add order**

Creates a new Square order at a location, with optional line items, taxes, discounts, service charges and a fulfillment.

- Action

**Add payment**

Creates a payment: charges a card or payment token, or records a cash or external payment the seller received outside Square.

- Action

**Add refund**

Refund a payment.

- Action

**Cancel payment**

Cancels (voids) a Square payment that is still in the APPROVED status, i.e. a delayed-capture payment that has not been completed.

- Action

**Create customer**

Creates a new customer profile.

- Action

**Delete catalog object**

Deletes a Square catalog object by ID, along with any objects that depend on it (for example an item's variations).

- Action

**Delete customer**

Deletes a customer profile by ID.

- Action

**Find catalog object**

Retrieves a catalog object (item, variation, etc.) by ID.

- Action

**Find customer**

Returns customer details for the specified customer ID.

- Action

**Find order**

Retrieves an order by ID.

- Action

**Find payment**

Retrieves a payment by ID.

- Action

**List locations**

Lists all business locations for the connected Square account.

- Action

**List payments**

Lists payments for the connected merchant, newest first.

- Action

**Search catalog objects**

Searches catalog objects by type (ITEM, CATEGORY, etc.).

- Action

**Search customers**

Searches customer profiles by email, phone, or reference ID.

- Action

**Search orders**

Searches orders for the specified location(s).

- Action

**Update customer**

Updates an existing customer profile.

- Action

**Update order**

Updates an open Square order by adding or replacing fields, or clearing them. Completed or canceled orders cannot be updated.

## Each app on its own

- [ **PostStack** EU-hosted email API for transactional and marketing email, with contacts, broadcasts, and analytics](https://apiant.ai/connections/poststack)
- [ **Square** Square is a commerce platform for payments, point of sale, orders, customers, catalog, and invoices.](https://apiant.ai/connections/square)

Reviews

## What our customers say

## More from PostStack

- [ **PostStack to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/poststack-to-salesforce)
- [ **PostStack to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/poststack-to-slack)
- [ **PostStack to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/poststack-to-stripe)
- [ **PostStack to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/poststack-to-shopify)
- [ **PostStack to QuickBooks Online** QuickBooks Online accounting — manage customers, invoices, bills, payments, vendors, expenses, and more via...](https://apiant.ai/connect/poststack-to-quickbooks-online)
- [ **PostStack to Trello** Trello is a visual collaboration tool that organizes projects into boards, lists, and cards.](https://apiant.ai/connect/poststack-to-trello)

## More into Square

- [ **Shopify to Square** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/shopify-to-square)
- [ **Intercom to Square** Intercom is a customer communications platform for support, engagement, and marketing.](https://apiant.ai/connect/intercom-to-square)
- [ **JotForm to Square** JotForm is a web-based WYSIWYG form builder. Create forms, integrate them into your site, and collect...](https://apiant.ai/connect/jotform-to-square)
- [ **OpenAI to Square** OpenAI's platform for text generation (Responses + Chat Completions), image generation (gpt-image-1 /...](https://apiant.ai/connect/openai-to-square)
- [ **Capsule CRM to Square** Capsule is an online hosted CRM system for individuals, small businesses and sales teams wanting a simple...](https://apiant.ai/connect/capsule-crm-to-square)
- [ **MINDBODY to Square** MINDBODY is a powerful business management software that combines your scheduling, task automation...](https://apiant.ai/connect/mindbody-to-square)

Questions

## PostStack and Square, answered

###

### What can start an automation from PostStack?

Any of PostStack's 7 triggers in the catalog, including Contact Updated (instant), New Contact (instant), New Inbound Email and New Sent Email (instant). Describe the moment in plain language and your agent picks the right one.

###

### What can your agent do in Square when something happens in PostStack?

Any of Square's 19 actions, including Create customer, Update customer, Update order and Add catalog object. Your agent maps the data both ways and tests every scenario before it ships.

###

### Can it also run from Square to PostStack?

Yes. When something happens in Square, your agent can act in PostStack too. This page covers both directions: Square's triggers and PostStack's actions are listed here as well.

###

### Do I have to build a connector for PostStack or Square?

No. Both are in the catalog with their triggers and actions. You describe the automation; your agent builds it, tests every scenario and keeps it running.

###

### Can my AI client use PostStack and Square without building an automation?

Yes. With your AI client connected to APIANT, ask it to do something in either app once and it runs that action on the spot. Ask for an automation and your agent builds it, tests every scenario and keeps it running. One connection covers both.

###

### What happens when something fails?

Your agent works that out for you. It plans the failure paths along with the happy path, then tests every scenario before it ships.

###

### Is there a free plan?

Yes. Every plan includes the agent, including free, and building from your own AI client spends no assistant credits.
