iOS集成Square POS API：如何获取异账号Account_B的Location ID？

Let’s break down your problem first: your iOS app is configured with Account_A's client ID, but the Square Point of Sale app on the merchant's device is logged into their own Account_B. The error occurs because the location_id you’re passing in your SCCAPIRequest is tied to Account_A, which doesn’t match any locations under Account_B.

Here are two reliable ways to get the correct Location ID for Account_B:

1. Ask the Merchant to Retrieve It Manually (Quickest for Small-Scale Use) #

Merchants can easily find their Location ID in their Square Dashboard (logged into Account_B):

• Log into Square’s backend with Account_B credentials
• Navigate to Settings > Business Information > Locations
• Locate the relevant physical or virtual location, then copy the Location ID (it’s a string starting with L_)

You can either hardcode this ID for the merchant (not ideal for multiple merchants) or add a field in your app where the merchant can input their Location ID directly.

2. Automate Retrieval via Square OAuth & Locations API (Scalable for Multiple Merchants) #

If you need to support multiple merchants with their own Square accounts, you’ll need to implement Square’s OAuth flow to get permission to access Account_B’s data. Here’s how:

Step 1: Initiate OAuth Authorization for Account_B #

Use your Account_A client ID to redirect the merchant to Square’s OAuth authorization page. Make sure to include the locations_read scope to request access to their location data. When the merchant logs in with Account_B and grants permission, Square will send you an authorization code.

Step 2: Exchange Authorization Code for Account_B’s Access Token #

Use the authorization code to request an access token tied to Account_B:

// Example HTTP request using URLSession
let tokenUrl = URL(string: "https://connect.squareup.com/oauth2/token")!
var tokenRequest = URLRequest(url: tokenUrl)
tokenRequest.httpMethod = "POST"
tokenRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")

let tokenParams = [
    "client_id": "<account_a_client_id>",
    "client_secret": "<account_a_client_secret>",
    "code": "<authorization_code_from_merchant>",
    "grant_type": "authorization_code"
]
tokenRequest.httpBody = try? JSONSerialization.data(withJSONObject: tokenParams)

// Send the request to retrieve Account_B's access token

Step 3: Fetch Account_B’s Location IDs #

With the access token for Account_B, call the Square Locations API to get all their location data:

let locationsUrl = URL(string: "https://connect.squareup.com/v2/locations")!
var locationsRequest = URLRequest(url: locationsUrl)
locationsRequest.httpMethod = "GET"
locationsRequest.setValue("Bearer <account_b_access_token>", forHTTPHeaderField: "Authorization")

// Parse the response to extract Location IDs
// The response includes an array of "locations" objects, each with an "id" field

You can then let the merchant select their preferred location from the list, or auto-select the primary one, and use that location_id in your SCCAPIRequest.

Critical Reminder #

Never share your Account_A client secret with anyone, and ensure all OAuth flow steps are handled securely over HTTPS.

内容的提问来源于stack exchange，提问作者StoneLam