--- title: "Connect PostStack and Stax - APIANT.ai" description: "When \"Contact Updated (instant)\" fires in PostStack, your agent runs \"Create Customer\" in Stax, or \"List Payment\" in Stax to \"Add a contact\" in PostStack." canonical: "https://apiant.ai/connect/poststack-to-stax" --- # Connect PostStack and Stax When **Contact Updated (instant)** fires in [PostStack](https://apiant.ai/connections/poststack), your agent runs **Create Customer** in [Stax](https://apiant.ai/connections/stax), or **List Payment** in Stax 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 Stax **1** trigger Stax **17** 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 Stax 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 Stax can do together ### From PostStack to Stax - When **Contact Updated (instant)** in PostStack then **Create Customer** in Stax - When **New Contact (instant)** in PostStack then **Create Scheduled Invoice** in Stax ### From Stax to PostStack - When **List Payment** in Stax then **Add a contact** in PostStack - When **List Payment** in Stax 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 Stax ## Triggers and actions 8 triggers · 48 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 **List Payment** Triggers when a new payment transaction is recorded in Stax. - Action **Capture payment** Captures funds from a pre-authorized Stax transaction, turning the pre-authorization into a completed charge. Returns the updated transaction. - Action **Create Customer** Creates a customer record on the Stax merchant account and returns the new customer. - Action **Create Item** Creates an item in the merchant's Stax catalog and returns the new catalog item. - Action **Create Scheduled Invoice** Creates a scheduled invoice that automatically generates invoices for a customer on a one-time or recurring schedule, with optional autopay. Returns the new schedule. - Action **Delete Catalog Item** Deletes a catalog item from Stax. - Action **Delete payment method** Deletes a customer's saved payment method in Stax and returns the deleted payment method. - Action **Delete Scheduled Invoice** Deletes a recurring invoice schedule so it stops generating invoices. - Action **Find Customers** Searches your Stax customers by name, email, company, phone, address or other details and returns the matching customers. - Action **Find Invoices** Returns the invoices on the Stax merchant account that match the search criteria you supply, such as keywords, customer name, company, email, price, schedule or payment method. - Action **Find Items** Searches the merchant's catalog for items matching a name, code, price or other criteria and returns the matching items. - Action **Find Payment Methods** Returns all saved payment methods (cards and bank accounts) for a Stax customer. - Action **Find Payments** Returns the payments and other transactions on the merchant account that match the search criteria, such as keywords, customer, date range, amount, type or status. - Action **Make a Payment** Charges a customer's saved payment method for the amount you specify, or places a pre-authorization to capture later. Returns the resulting transaction. - Action **Refund payment** Refunds all or part of a settled Stax payment transaction back to the customer. - Action **Update customer** Updates an existing customer's contact details, address, notes and options in Stax, and returns the updated customer. - Action **Update invoice** Updates an existing unpaid invoice's customer, amounts, line items, memos and payment options, and returns the updated invoice. Fully paid invoices cannot be edited. - Action **Void payment** Voids a payment transaction in Stax before it settles, cancelling the charge. ## 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) - [ **Stax** Stax makes it easy to accept payments in-person and online and provides businesses with the tools they need...](https://apiant.ai/connections/stax) 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 Stax - [ **HubSpot to Stax** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-stax) - [ **Salesforce to Stax** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/salesforce-to-stax) - [ **Slack to Stax** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/slack-to-stax) - [ **Google Sheets to Stax** Google Sheets is Google's online spreadsheet app for creating, editing and sharing spreadsheets.](https://apiant.ai/connect/google-sheets-to-stax) - [ **Gmail to Stax** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-stax) - [ **Google Calendar to Stax** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/google-calendar-to-stax) Questions ## PostStack and Stax, 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 Stax when something happens in PostStack? Any of Stax's 17 actions, including Create Customer, Create Item, Create Scheduled Invoice and Update customer. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from Stax to PostStack? Yes. When something happens in Stax, your agent can act in PostStack too. This page covers both directions: Stax's triggers and PostStack's actions are listed here as well. ### ### Do I have to build a connector for PostStack or Stax? 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 Stax 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.