# POS Integration Learn how to accept payments at the point of sale using the Finix API. ## POS Integration Overview Follow these six steps to integrate your POS system with Finix: div div | **Step** | **Description** | | --- | --- | | [Provision a Merchant](#step-1-onboard-a-seller-optional) | Onboard merchants and set up their payment terminals to accept in-person payments. | | [Set up the Payment Terminal](#step-2-set-up-the-payment-terminal) | Configure the payment terminal by connecting it to Wi-Fi and installing required updates to prepare it for processing payments. | | [Create a Device](#step-3-create-a-device) | Create a `Device` resource and connect your payment terminal to Finix's API. | | [Activate the Payment Terminal](#step-4-activate-the-payment-terminal) | Activate the payment terminal to begin setup. | | [Check Connection](#step-5-check-connection) | Check connection to the payment terminal to ensure it is ready to process payments. | | [Create a Sale](#step-6-create-a-sale) | Create a sale to debit a buyer for an in-person transaction. | | [Cancelling a Transaction](#step-7-cancelling-a-transaction) | Learn how to cancel a transaction. | div img ## Step 1: Onboard a Seller (Optional) This step is not required if you are only processing payments for yourself. Your Finix Point of Contact will provide you with a `Merchant` resource to use for payments. To process in-person transactions with our API first, you must have an approved seller. If you are a Software Platform or Marketplace that is onboarding sellers, please see our [Platform Quickstart](/guides/platform-payments/platform-quickstart) to learn how to quickly onboard sellers. ## Step 2: Set up the Payment Terminal Place the payment terminal where you'll use it to process the majority of payments. To set up the payment terminal, you'll need: - A Wi-Fi network and router. - The Wi-Fi network's name and password. - Physical access to the payment terminal being activated. ## Step 3: Create a Device Create a `Device` under the `Merchant` provisioned to process In-Person Payments. Include the `Device.model` of the payment terminal you'll be using to process cards. For more details about the payment terminals available, see our [available devices](/guides/in-person-payments/select-your-device). Pax A800 Model PAX_A800 Device ```json Model PAX_A800 Device { "id": "DVoDo7F6yYCnX2d6Fj9hvsd", "created_at": "2025-11-14T19:01:04.638451Z", "updated_at": "2025-11-14T19:01:04.638451Z", "configuration_details": { "allow_debit": true, "check_for_duplicate_transactions": true, "prompt_amount_confirmation": true, "prompt_manual_entry": false, "signature_threshold_amount": 10000, "bypass_device_on_capture": true, "prompt_receipt_confirmation": true, "display_tip_on_receipt": false, "prompt_tip_on_screen": false, "allow_standalone_authorizations": false, "allow_standalone_sales": false, "allow_standalone_refunds": false, "tipping_details": { "percent_tipping_threshold": 0, "percent_options": [ 18, 20, 22 ], "fixed_options": [ 100, 150, 200 ] }, "idle_message": null, "idle_image_file_id": null, "automatic_receipt_delivery_methods": null, "available_receipt_methods": null, "prompt_for_signature": "NEVER", "surcharge_basis_points": null }, "description": "Cashier One", "enabled": false, "idle_message": null, "merchant": "MUsMvN47nRtdgUkE23SRHDC6", "model": "PAX_A800", "name": "My PAX_A800 Finix Device", "serial_number": "1234567891", "tags": {}, "_links": { "self": { "href": "https://finix.sandbox-payments-api.com/devices/DVoDo7F6yYCnX2d6Fj9hvsd" }, "merchant": { "href": "https://finix.sandbox-payments-api.com/merchants/MUsMvN47nRtdgUkE23SRHDC6" }, "transfers": { "href": "https://finix.sandbox-payments-api.com/transfers" }, "authorizations": { "href": "https://finix.sandbox-payments-api.com/authorizations" } } } ``` Pax A920 Pro Model PAX_A920PRO Device ```json Model PAX_A920PRO Device { "id": "DV5znKhAQZs6J7rfXqYnr86F", "created_at": "2025-05-21T19:02:11.141785Z", "updated_at": "2025-05-21T19:02:11.141785Z", "configuration_details": { "allow_debit": true, "check_for_duplicate_transactions": true, "prompt_amount_confirmation": true, "prompt_manual_entry": false, "signature_threshold_amount": 10000, "bypass_device_on_capture": true, "prompt_receipt_confirmation": true, "display_tip_on_receipt": false, "prompt_tip_on_screen": false, "allow_standalone_authorizations": false, "allow_standalone_sales": false, "allow_standalone_refunds": false, "tipping_details": { "percent_tipping_threshold": 0, "percent_options": [ 18, 20, 22 ], "fixed_options": [ 100, 150, 200 ] }, "idle_message": null, "idle_image_file_id": null, "automatic_receipt_delivery_methods": null, "available_receipt_methods": null, "prompt_for_signature": "NEVER", "surcharge_basis_points": null }, "description": "Cashier Two", "enabled": false, "idle_message": null, "merchant": "MU7noQ1wdgdAeAfymw2rfBMq", "model": "PAX_A920PRO", "name": "My PAX_A920PRO Finix Device", "serial_number": "1234567892", "tags": {}, "_links": { "self": { "href": "https://finix.sandbox-payments-api.com/devices/DV5znKhAQZs6J7rfXqYnr86F" }, "merchant": { "href": "https://finix.sandbox-payments-api.com/merchants/MU7noQ1wdgdAeAfymw2rfBMq" }, "transfers": { "href": "https://finix.sandbox-payments-api.com/transfers" }, "authorizations": { "href": "https://finix.sandbox-payments-api.com/authorizations" } } } ``` Pax IM30 Model PAX_IM30 Device ```json Model PAX_IM30 Device { "id" : "DVfeMQJxpXaYkvBskg2VdZsh", "created_at" : "2026-04-11T02:30:15.941482Z", "updated_at" : "2026-04-11T02:30:15.941482Z", "configuration_details" : { "allow_debit" : false, "check_for_duplicate_transactions" : false, "prompt_amount_confirmation" : false, "prompt_manual_entry" : false, "signature_threshold_amount" : 10000, "bypass_device_on_capture" : false, "prompt_receipt_confirmation" : false, "display_tip_on_receipt" : false, "prompt_tip_on_screen" : false, "allow_standalone_authorizations" : false, "allow_standalone_sales" : false, "allow_standalone_refunds" : false, "tipping_details" : { "percent_tipping_threshold" : 0, "percent_options" : [ 18, 20, 22 ], "fixed_options" : [ 100, 150, 200 ] }, "idle_message" : null, "idle_image_file_id" : null, "automatic_receipt_delivery_methods" : null, "available_receipt_methods" : null, "prompt_for_signature" : "NEVER", "surcharge_basis_points" : null }, "description" : "Kiosk Three", "enabled" : false, "idle_message" : null, "merchant" : "MUwfZPNW3r4EqLMzwgr6txw4", "model" : "PAX_IM30", "name" : "My PAX_IM30 Finix Device", "serial_number" : "1234567890", "tags" : { }, "_links" : { "self" : { "href" : "https://finix.sandbox-payments-api.com/devices/DVfeMQJxpXaYkvBskg2VdZsh" }, "merchant" : { "href" : "https://finix.sandbox-payments-api.com/merchants/MUwfZPNW3r4EqLMzwgr6txw4" }, "transfers" : { "href" : "https://finix.sandbox-payments-api.com/transfers" }, "authorizations" : { "href" : "https://finix.sandbox-payments-api.com/authorizations" } } } ``` ## Step 4: Activate the Payment Terminal Once the `Device` is created and the `serial_number` is set, you can link the `Device` resource with the payment terminal you'll use by sending an activation request to the payment terminal. A successful request returns `Device.enabled: true`. The device must be online and connected to the network with the app in the front in order for the request to succeed. ```shell Activate Device curl -i -X PUT \ -u USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e \ https://finix.sandbox-payments-api.com/devices/DV7DvjGoZ2AEdhAKhtKXVv4b \ -H 'Accept: application/hal+json' \ -H 'Content-Type: application/json' \ -H 'Finix-Version: 2022-02-01' \ -d '{ "action": "ACTIVATE" }' ``` ## Step 5: Check Connection Prior to initiating a payment, you can check the connection to verify that the device is ready to process payments. Checking connection will confirm that the: - Device is powered on - Finix Payment App is open - Device is connected to internet - Device was able to connect to the Finix Server Use the `Device` you enabled to check Connection. Below is a sample request and response. - The `connection` field in the response has two potential values: - `open`: the device is ready to process payments. - `closed`: the device has not met the criteria outlined above to process payment. If the `connection` is `closed` and a payment is initiated, the `Transfer` will fail with an error of `DEVICE_UNREACHABLE`. Device ```json Device { "id": "DVoDo7F6yYCnX2d6Fj9hvsd", "created_at": "2025-11-14T19:01:04.638451Z", "updated_at": "2025-11-14T19:01:04.638451Z", "android_version": "10", "configuration_details": { "allow_debit": true, "check_for_duplicate_transactions": true, "prompt_amount_confirmation": true, "prompt_manual_entry": false, "signature_threshold_amount": 10000, "bypass_device_on_capture": true, "prompt_receipt_confirmation": true, "display_tip_on_receipt": false, "prompt_tip_on_screen": false, "allow_standalone_authorizations": false, "allow_standalone_sales": false, "allow_standalone_refunds": false, "tipping_details": { "percent_tipping_threshold": 0, "percent_options": [ 18, 20, 22 ], "fixed_options": [ 100, 150, 200 ] }, "idle_message": null, "idle_image_file_id": null, "automatic_receipt_delivery_methods": null, "available_receipt_methods": null, "prompt_for_signature": "NEVER", "surcharge_basis_points": null }, "connection": "Open", // [!code highlight] "description": "Cashier One", "enabled": false, "firmware_version": "PayDroid_10.0.0_Eucalyptus_V20.1.23_20250108", "idle_message": null, "merchant": "MUsMvN47nRtdgUkE23SRHDC6", "model": "PAX_A800", "name": "My PAX_A800 Finix Device", "payment_app_version": "5.9.0", "serial_number": "2210172205", "tags": {}, "_links": { "self": { "href": "https://finix.sandbox-payments-api.com/devices/DVoDo7F6yYCnX2d6Fj9hvsd" }, "merchant": { "href": "https://finix.sandbox-payments-api.com/merchants/MUsMvN47nRtdgUkE23SRHDC6" }, "transfers": { "href": "https://finix.sandbox-payments-api.com/transfers" }, "authorizations": { "href": "https://finix.sandbox-payments-api.com/authorizations" } } } ``` ## Step 6: Create a Sale With the payment terminal connected, you can begin processing In-Person payments. Use the `Device` you enabled to create a `Sale`. ```shell Sale Request curl -i -X POST \ -u USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e \ https://finix.sandbox-payments-api.com/transfers \ -H 'Accept: application/hal+json' \ -H 'Content-Type: application/json' \ -H 'Finix-Version: 2022-02-01' \ -d '{ "amount": 150, "currency": "USD", "device": "DV7DvjGoZ2AEdhAKhtKXVv4b", "operation_key": "CARD_PRESENT_DEBIT", "tags": { "order_number": "chris123transfer" } }' ``` ```json Sale Response { "id": "TRarp7Pz21Low4u2Urw5Ub4W", "created_at": "2019-04-29T20:44:00.13Z", "updated_at": "2022-10-10T05:59:17.59Z", "3ds_redirect_url": null, "additional_buyer_charges": null, "additional_healthcare_data": null, "address_verification": null, "amount": 3138, "amount_requested": 3138, "application": "APeUbTUjvYb1CdPXvNcwW1wP", "capture_amount": 150, "card_present_details": { "emv_data": { "application_identifier": "A0000001523010", "application_label": "DISCOVER", "application_preferred_name": null, "application_transaction_counter": "0005", "cryptogram": "ARCQ F666F8891F870D33", "issuer_code_table_index": null, "pin_verified": false, "tags": null }, "masked_account_number": "************0059", "name": "Test Card 05", "brand": "DISCOVER", "entry_mode": "CHIP_ENTRY", "payment_type": "CREDIT", "approval_code": "004839" }, "currency": "USD", "device": "DVfKLD9GZtsjcJxLtc2yCcfd", "expires_at": "2019-05-06T20:44:00.13Z", "failure_code": null, "failure_message": null, "idempotency_id": null, "is_void": false, "merchant": "MUeDVrf2ahuKc9Eg5TeZugvs", "merchant_identity": "IDsbTBawhnLBAVeinRb84vFR", "messages": [], "raw": null, "security_code_verification": null, "source": "PImTHaz7XVPx4M7mhu9x8gkU", "state": "SUCCEEDED", "tags": { "TicketNumber": "45878" }, "trace_id": "FNX35FSuraeKKJr65wkGVFJni", "void_state": "UNATTEMPTED", "_links": { "self": { "href": "https://finix.sandbox-payments-api.com/authorizations/AUarp7Pz21Low4u2Urw5Ub4W" }, "application": { "href": "https://finix.sandbox-payments-api.com/applications/APeUbTUjvYb1CdPXvNcwW1wP" }, "transfer": { "href": "https://finix.sandbox-payments-api.com/transfers/TRqQCAX7nYHUnkE5YPFTknqd" }, "device": { "href": "https://finix.sandbox-payments-api.com/devices/DVfKLD9GZtsjcJxLtc2yCcfd" }, "merchant_identity": { "href": "https://finix.sandbox-payments-api.com/identities/IDsbTBawhnLBAVeinRb84vFR" } } } ``` Once complete, similar to other Finix `Transfers`, you can proceed with managing payouts, and the Post-Payments lifecycle. ## Step 7: Cancelling a Transaction There maybe times when you need to cancel a transaction. For example, if the buyer cancels the transaction or the transaction is declined. To cancel a transaction, send a `CANCEL` request to the `Device` resource. Below is a sample request of the `Device` resource and the response you will receive on the cancelled transaction. ```shell Cancel Transfer Request curl -i -X PUT \ -u USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e \ https://finix.sandbox-payments-api.com/devices/{device_id} \ -H 'Accept: application/hal+json' \ -H 'Content-Type: application/json' \ -H 'Finix-Version: 2022-02-01' \ -d '{ "action": "CANCEL" }' ``` ```json Cancel Transfer Response { "id": "TRt3LfP6ot6s5HG1ZN9QE5qc", "created_at": "2025-07-18T23:20:55.95Z", "updated_at": "2025-07-18T23:20:55.95Z", "additional_buyer_charges": null, "additional_healthcare_data": null, "additional_purchase_data": null, "address_verification": null, "amount": 2000, "amount_requested": 2000, "application": "APc9vhYcPsRuTSpKD9KpMtPe", "card_present_details": { "emv_data": { "application_identifier": null, "application_label": null, "application_preferred_name": null, "application_transaction_counter": null, "cryptogram": null, "issuer_code_table_index": null, "network_emv_response": null, "pin_verified": false, "tags": null }, "masked_account_number": null, "name": null, "brand": "UNKNOWN", "entry_mode": "UNKNOWN", "payment_type": null, "approval_code": null, "digital_signature_file_id": null }, "currency": "USD", "destination": null, "device": "DVae7HFLS7BXNaFpKhdH1K6x", "externally_funded": "UNKNOWN", "failure_code": "CANCELLATION_VIA_API", "failure_message": "The transaction was canceled via API before the transaction was completed. The cardholder needs to attempt the transaction again.", "fee": 0, "fee_profile": "FPuizPqrhzYLbmJm88u7aqfj", "idempotency_id": null, "merchant": "MUmfEGv5bMpSJ9k5TFRUjkmm", "merchant_identity": "ID6UfSm1d4WPiWgLYmbyeo3H", "messages": ["RAW MESSAGE"], "operation_key": "CARD_PRESENT_SALE", "parent_transfer": null, "parent_transfer_trace_id": null, "raw": null, "ready_to_settle_at": null, "receipt_last_printed_at": null, "security_code_verification": null, "source": "PIhGjmMzFiT3oorhhBoMHdKc", "split_transfers": [], "state": "FAILED", "statement_descriptor": "FLX*FINIX FLOWERS", "subtype": "API", "supplemental_fee": null, "tags": { "order_number": "Test Transaction" }, "tip_amount": null, "trace_id": "433ca932-11c4-4667-8a21-90db472b7691", "type": "DEBIT", "_links": { "application": { "href": "https://finix.sandbox-payments-api.com/applications/APc9vhYcPsRuTSpKD9KpMtPe" }, "self": { "href": "https://finix.sandbox-payments-api.com/transfers/TRt3LfP6ot6s5HG1ZN9QE5qc" }, "merchant_identity": { "href": "https://finix.sandbox-payments-api.com/identities/ID6UfSm1d4WPiWgLYmbyeo3H" }, "device": { "href": "https://finix.sandbox-payments-api.com/devices/DVae7HFLS7BXNaFpKhdH1K6x" }, "payment_instruments": { "href": "https://finix.sandbox-payments-api.com/transfers/TRt3LfP6ot6s5HG1ZN9QE5qc/payment_instruments" }, "reversals": { "href": "https://finix.sandbox-payments-api.com/transfers/TRt3LfP6ot6s5HG1ZN9QE5qc/reversals" }, "fees": { "href": "https://finix.sandbox-payments-api.com/transfers/TRt3LfP6ot6s5HG1ZN9QE5qc/fees" }, "disputes": { "href": "https://finix.sandbox-payments-api.com/transfers/TRt3LfP6ot6s5HG1ZN9QE5qc/disputes" }, "fee_profile": { "href": "https://finix.sandbox-payments-api.com/fee_profiles/FPuizPqrhzYLbmJm88u7aqfj" } } } ``` ## Next Steps Testing Your Integration Learn how to test your In-Person Payments integration.