Square Point of Sale API
Square POS sits on a first-class developer platform: more than 20 REST APIs plus two POS-specific surfaces, the Point of Sale API for app deep-links and the Terminal API for hardware control. Registration, sandbox, and API access are self-serve and free; merchants pay processing fees.
Frequently asked questions
Square Point of Sale scores A on the API Report Card. Square POS sits on a first-class developer platform: more than 20 REST APIs plus two POS-specific surfaces, the Point of Sale API for app deep-links and the Terminal API for hardware control. Registration, sandbox, and API access are self-serve and free; merchants pay processing fees.
Square Point of Sale has a workable official integration path. Most engineering teams can build against it directly. Open API: self-serve, documented, with SDKs
Square Point of Sale is the flagship SMB POS and payments product from Block, Inc. (NYSE: XYZ; formerly Square, Inc.).
General-purpose POS with vertical-specific editions. A merchant signs up online in minutes, plugs in a Square Reader or buys a Terminal/Register, and begins taking card, tap, and contactless payments the same day.
Very high. Square is one of the two or three best-known POS brands globally, ubiquitous in US small-business retail and hospitality, and one of the standard integrations expected of any commerce/accounting/marketing/data SaaS.
Parent: Block, Inc. (NYSE: XYZ), public, headquartered in Oakland/San Francisco. Founders: Jack Dorsey, Jim McKelvey; founded 2009. Q1 2025 Square ecosystem gross profit: ~$898M (+9% YoY); international GPV +15% YoY; mid-market sellers (>$500K/yr) ~41% of GPV.
Founded 2009 by Jack Dorsey and Jim McKelvey; Square IPO'd 2015 and rebranded the parent company to Block, Inc. in late 2021.
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.