--- title: "Connect PostStack and Returnless - APIANT.ai" description: "When \"Contact Updated (instant)\" fires in PostStack, your agent runs \"Find customers\" in Returnless." canonical: "https://apiant.ai/connect/poststack-to-returnless" --- # Connect PostStack and Returnless When **Contact Updated (instant)** fires in [PostStack](https://apiant.ai/connections/poststack), your agent runs **Find customers** in [Returnless](https://apiant.ai/connections/returnless), or **Request Created** in Returnless 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 Returnless **2** triggers Returnless **16** 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 Returnless 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 Returnless can do together ### From PostStack to Returnless - When **Contact Updated (instant)** in PostStack then **Find customers** in Returnless - When **New Contact (instant)** in PostStack then **Add note** in Returnless ### From Returnless to PostStack - When **Request Created** in Returnless then **Add a contact** in PostStack - When **Return Created** in Returnless 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 Returnless ## Triggers and actions 9 triggers · 47 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 **Request Created** Triggers when a customer creates a new return request that needs approval. - Trigger **Return Created** Triggers when a new return is created, including a request once it is approved. - Action **Add note** Adds an internal note to a return or return request. - Action **Add Request** Creates a return request in Returnless for items from an existing sales order. - Action **Approve a Request** Approves a return request in Returnless so the customer can send the items back. - Action **Approve a Request Without Shipment** Approves a pending return request without a return shipment, so the customer keeps the items. - Action **Find customers** Returns the customers in your Returnless account that match an email address. - Action **Find products** Returns the products in your Returnless account that match a SKU. - Action **Find Requests** Finds a Request in your Returnless account. - Action **Find Returns** Finds returns (return orders) in Returnless by return number. - Action **Find sales orders** Finds sales orders in Returnless by order number. - Action **Get customer** Returns a single Returnless customer by its id. - Action **Get Request (By Request ID)** Returns a single return request (return order) from Returnless by its ID. - Action **Get Return (By Return ID)** Returns a single return in Returnless, with all of its details, by its return ID. - Action **Get sales order** Returns a single sales order by its ID, including its customer, address and order details. - Action **List return reasons** Returns the return reasons configured in your Returnless account. - Action **Reject Request** Rejects a pending return request in Returnless. - Action **Update return** Changes the status of a return, such as Checked, Approved or Resolved. ## 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) - [ **Returnless** Returnless gives e-commerce businesses a way to get their returns in check.](https://apiant.ai/connections/returnless) 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 Returnless - [ **HubSpot to Returnless** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-returnless) - [ **Google Sheets to Returnless** Google Sheets is Google's online spreadsheet app for creating, editing and sharing spreadsheets.](https://apiant.ai/connect/google-sheets-to-returnless) - [ **Gmail to Returnless** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-returnless) - [ **Google Calendar to Returnless** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/google-calendar-to-returnless) - [ **Google Drive to Returnless** Google Drive is a cloud storage solution for uploading, sharing, and collaborating on files across devices...](https://apiant.ai/connect/google-drive-to-returnless) - [ **Mailchimp to Returnless** Mailchimp marketing automation and email platform.](https://apiant.ai/connect/mailchimp-to-returnless) Questions ## PostStack and Returnless, 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 Returnless when something happens in PostStack? Any of Returnless's 16 actions, including Update return, Add note, Add Request and Approve a Request. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from Returnless to PostStack? Yes. When something happens in Returnless, your agent can act in PostStack too. This page covers both directions: Returnless's triggers and PostStack's actions are listed here as well. ### ### Do I have to build a connector for PostStack or Returnless? 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 Returnless 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.