Connect Square to Store MCP
Checked against official docs on .
Connect the seller first, then select the variation and location when interpreting stock.
Platform summary
Supported work
- Read and edit supported listings
- Read and set inventory
- Read orders (read-only)
Not supported
- Fulfillment and tracking changes
- Refunds
- Cancellations
Writes need a paid plan, permission and provider support. Actual grants may be narrower.
Prerequisites
You need authority to authorize the Square seller and a Store MCP account. A catalog item and its variation are different records. Begin with a known item and location visible in the Square dashboard.
Steps
- In Stores, choose Square and follow the Square authorization screen for the intended seller.
- Return to Store MCP and check connection health and identity. Authorize an AI client for View only access to that store.
- List catalog listings and read one item. Record the returned variation IDs.
- Use locations.list and inventory.get for that listing; compare the selected variation and location with Square.
Safe example
The example uses synthetic names. Select your own authorized store and verify every identifier before a write.
Read my selected Square store and a known catalog item. Show each variation and its location-specific inventory. Keep unknown quantities unknown; do not make a physical-count change.You’re done when…
Expect separate inventory rows for variation/location pairs. Confirm the seller, variation and location all match before treating a quantity as the stock you wanted. A catalog record alone is not proof of tracked stock.
Limitations
Square order writes and order events are unavailable. Catalog creation is not a Store MCP publish operation. Sandbox physical-count acceptance does not establish production write acceptance.
Variations, locations and physical counts
A Square item groups variations; inventory belongs to a variation at a location. Catalog or sales totals can differ from inventory counts because they describe different states and locations. Do not sum duplicate pools.
inventory.set records a physical count using provider idempotency. Square does not supply the same atomic expected-quantity guarantee as Shopify. Re-read immediately before and after a deliberate count and avoid competing dashboard edits. inventory.adjust is unavailable.
Supported seller work
Catalog items become listings and variations retain separate IDs. Supported writes create or update catalog records and set physical-count inventory at a location. Square does not expose Store MCP media upload, publication-state changes, inventory adjustment, payment creation, cancellation, refund or fulfillment writes.
Orders are read across active locations. Order lines reference a variation; their listingId is null, so join using variantId. Catalog images are returned as provider IDs without downloadable URLs.
Availability and verification
The connector has deterministic fixtures. Scoped sandbox acceptance on September 17, 2026 verified OAuth, identity, catalog create/read and inventory set/read-back. A production connection exists, but controlled production read/write acceptance remains outstanding. No marketplace listing approval is claimed.
Notifications
Square order-event ingestion is not implemented. Use an on-demand order read; adding a destination or sending a test does not create a Square order stream.
Sources and verification
Official documentation checked 2026-09-21. This is a documentation review, not a new live provider or client acceptance run.