Read and write Square payments, refunds, orders, customers, catalog items, locations and invoices via the Square Connect v2 API.
Square ships in the w6w first-party pack. It declares 17 actions, 2 health checks, and the host runs its code in a sandbox that never sees the credential.
io.w6w.squareSquare runs payments and point-of-sale for a huge range of in-person and online sellers, and this app lets a workflow act on that transaction data directly. Create a payment and, when something needs to be undone, refund it, then list and look up individual payments and refunds to reconcile what actually happened. Search and read orders, and look up a seller’s locations to know where a sale took place.
On the customer and catalog side, create, update, list and look up customers, and browse the whole catalog or search it for a specific item. List invoices to see what has been billed.
Every write is idempotent by default — a retried call reuses the same id rather than creating a second charge or a second refund — and this app talks to whichever of Square’s production or sandbox environments the connected token belongs to.
Three routes to the same 17 actions. The Workflow tab is generated from Square's own manifest and carries its real ids, so it is copy-pasteable; the Code and CLI examples are the same call for any action on any app, so every app-specific value in them is a blank you fill in.
catalog-get-many List catalog objects — items, variations, categories, taxes, discounts, modifiers. Page size is fixed at 100.
catalog-search-items Search catalog items and variations by free text, category, location, product type or archived state.
customer-create Create a customer profile. Needs at least one of given name, family name, company name, email or phone.
customer-get-many List customer profiles on the account. Eventually consistent — a just-created profile may lag.
customer-update Sparsely update a customer profile — only the fields you fill in are changed. Optionally version-checked.
invoice-get-many List invoices for one location. Square requires the location id here.
location-get Retrieve one business location — its address, timezone, currency, capabilities and status.
location-get-many List every business location on the account. Unpaginated — Square returns them all at once.
order-search Search orders by location, state and time window. Square has no plain list-orders endpoint; this is it.
payment-create Charge a payment token, a card on file, or record a cash/external payment. Deduplicated on Square's idempotency key.
payment-get-many List payments taken by the seller, newest first. Defaults to the last year of the default location.
refund-create Refund all or part of a Square payment. Deduplicated on Square's idempotency key.
refund-get Retrieve one payment refund — its status, amount, reason and originating payment.
refund-get-many List payment refunds across the seller's locations, newest first. Defaults to the last year.
A workflow step names the app and the action, and the editor fills in the
connection when you pick one. This is the Step shape from the
workflow spec, carrying Square's real ids.
{
"manifestVersion": "2",
"name": "square-example",
"steps": [
{
"id": "customer-get",
"uses": {
"app": "io.w6w.square",
"action": "customer-get",
"connection": "conn_YOUR_CONNECTION_ID"
},
"with": {
"customerId": "<customerId>"
}
}
]
}customer-get catalog-get-many catalog-search-items customer-create customer-get-many +12 more actions available
Every app-specific value here is a blank you have to fill in. An
app action is reached through the connection that authenticates it, so the
address is a connection id, not the app id — and connections belong to your account,
so a public page cannot know yours. Create one for Square, then fill in
the three blanks: conn_YOUR_CONNECTION_ID, the action key, and the
parameters that action declares. The call itself is real — the shape is transcribed
from the studio's own snippet builder, which prints the same kind of blanks — but
nothing in it is specific to Square. The Workflow tab is where this app's
real ids are.
npm install @w6w/sdkyarn add @w6w/sdkpnpm add @w6w/sdkdeno add npm:@w6w/sdkimport { W6wClient, isActionRun } from "@w6w/sdk";
// Reads W6W_BASE_URL and W6W_TOKEN from the environment when omitted.
const client = new W6wClient();
const envelope = await client.run({
urn: "conn_YOUR_CONNECTION_ID",
action: "payment-create",
payload: {
sourceId: "<value>",
amount: "<value>",
currency: "<value>",
// tipAmount: "<value>",
// locationId: "<value>",
// customerId: "<value>",
// orderId: "<value>",
// autocomplete: "<value>",
// buyerEmailAddress: "<value>",
// referenceId: "<value>",
// note: "<value>",
// statementDescriptionIdentifier: "<value>",
// idempotencyKey: "<value>",
},
});
if (isActionRun(envelope)) console.log(envelope.value); npm install -g @w6w/cli w6w run conn_YOUR_CONNECTION_ID --action payment-create --payload '{"sourceId":"<value>","amount":"<value>","currency":"<value>"}' Give an AI agent Square — without giving it Square's credentials. One MCP endpoint exposes every app, function and workflow the caller is entitled to, as tools it can discover and run. Access is granted per team while we onboard.
One tool call{
"name": "w6w_invoke",
"arguments": {
"ref": "app:io.w6w.square#customer-get",
"input": {
"customerId": "<customerId>"
}
}
}
Every tool names its target with a single ref. The
app: form above doesn't name a connection at all — the
host resolves which of the caller's Square connections to sign
with, and refuses rather than guesses when the answer is ambiguous.
The token is attached host-side, at the moment of the call. It is never a tool argument, never in the model's context, and never in a transcript — so a prompt injection has nothing to exfiltrate.
Tools are derived per end user from what that person has actually connected and is entitled to — not one shared bot identity carrying the union of everyone's access.
Multi-step work runs on the workflow engine and returns a run handle the agent can poll — retries, branching and state survive the conversation that started them.
Square's declared health checks are on the surface too, so an agent can tell "the vendor is down" from "your credential expired" before it burns a retry on either.
The MCP surface is part of the hosted platform. Square itself is MIT, and the runtime that executes it is source-available (FSL).
Square declares its own checks, so its health is a property of the app rather than something the host guesses at.
Rollup indicator from Square's own status page at issquareup.com. Unauthenticated and unsigned; covers both the production and sandbox hosts.