Quick start

Check the prerequisites

Check these requirements before you install the app. The device runs Mini mPOS; the payment terminal takes the card. They can be the same device.

Choose a device setup

On an Adyen terminal

The complete checkout on one device. Use an Adyen Android payment terminal with Android 9 or later. Check the current models in the Adyen Android terminal guide.

Tablet or phone with a network terminal

Recommended for a counter. An Android 9+ tablet or phone on the same local network as an Adyen terminal. Mini mPOS is not installed on that terminal.

Tablet or phone with a cloud terminal

For a device and terminal on different networks. Both need internet access; payments reach the terminal through Adyen.

Tap to Pay on a phone

No separate terminal. Use a phone with near-field communication (NFC) and the Adyen Payments app, activated by Adyen Support. Check the Adyen phone requirements and Adyen supported countries and payment methods.

Physical-terminal features depend on the terminal, payment method and Adyen configuration. Test the workflows you need. Check Adyen capabilities.

• Printing needs a terminal with a built-in printer. If there is none, you can email or share receipts instead.
• Scanning barcodes, refund QR codes or setup codes needs a camera.

Prepare the network

Ask the site's network administrator to allow the following:

Internet

Outgoing HTTPS on TCP 443 from the device and terminal to *.adyen.com and *.adyenpayments.com. Allow these by domain name, not IP address, because Adyen's IP addresses change.

Local network (for network terminals)

The tablet or phone must reach the terminal's IP address on TCP 8443. Connect both to the same network, and make sure Wi-Fi client isolation (common on guest networks) does not separate them.

Email receipts (optional)

Outgoing access to your SMTP server, usually TCP 587 (STARTTLS) or 465 (SSL/TLS).

Give each network terminal a fixed IP address with a DHCP reservation in your router. Mobile data works for the tablet or phone in cloud and Tap to Pay setups, but not with a network terminal. For the terminal's own requirements, see the Adyen network configuration guide.

Prepare Adyen credentials

To validate with Adyen, you need an active test merchant account with in-person payments enabled and Customer Area access. Start with TEST credentials and a TEST terminal or Adyen Payments Test. For LIVE, use the corresponding live account, credentials and terminal or Payments app.

To create or edit credentials, your Customer Area user needs Manage API credentials or Merchant admin. These are user permissions, not roles for the API key.

Enable the POS payment methods you plan to accept; follow the Adyen payment method setup guide. Mini mPOS uses the terminal's configured methods.

1. In the Customer Area, go to Developers › API credentials. Create a credential for Mini mPOS and generate its API key; see the Adyen API credential guide.
2. For the main API key, enable these additional roles:
   • Management API - Terminal actions read
   • Management API - Terminal settings read and write
   • Management API - Terminal settings Advanced read and write
   • Cloud Device API role
   • API tokenise payment details
   The same roles are required for every setup. The credential must belong to your company account and have access to the destination's merchant account. See the Adyen API role guide.
3. For LIVE, note the Live URL prefix from Developers › API URLs.
4. For Tap to Pay, Mini mPOS automatically creates a separate merchant-scoped credential with the Adyen Payments App role and a client key. Adyen Support must enable Tap to Pay and make this role assignable from your company credential.
5. If you want to configure the device manually:
   • Note the Merchant account.
   • For an Adyen terminal, network terminal or Tap to Pay, find the Shared key (identifier, passphrase and version) under Devices › Device settings › Integrations › Terminal API › Encryption key. Cloud terminals do not use it.

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Install the app

Download the signed minimpos-<version>.apk from the latest release.

Adyen terminal

1. In the Customer Area, upload the APK and deploy it to your terminals; see the Adyen app deployment guide. Your user needs permission to upload and deploy apps.
2. Open Mini mPOS on the terminal, select Connect to Adyen and tap Continue.

Tablet or phone

1. Open the APK on the device and allow installation from your browser or file manager when Android asks.
2. Open Mini mPOS, select Connect to Adyen and tap Continue.

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Connect to Adyen

Connecting pairs Mini mPOS with its terminal or the Adyen Payments app and checks your Adyen API key. Follow only the part for your setup. Each has two options: the setup helper (recommended), or manual entry in Settings › Terminal.

Scan setup codes from a computer

1. On a trusted computer, open the setup helper. It generates codes locally; see its hosting and privacy note.
2. Choose where Mini mPOS runs and the environment, TEST or LIVE.
3. Choose Automatic (recommended) to enter only the Adyen API key; the device looks up the rest. Choose Manual to enter every connection detail.
4. Enter the requested details.
5. Click Make QR codes. Keep the page open: it shows the 12-character transfer code.
6. In Mini mPOS, open Settings › Terminal and tap Scan setup codes or the QR icon at the top right. Read the guidance, tap I already have codes and scan every code.
7. Check the destination and environment, enter the transfer code and tap Verify and import.
8. If asked, choose your terminal. For Tap to Pay, complete registration when the Payments app opens. Nothing is saved until all checks pass.

Create a missing encryption key

If a physical terminal has no encryption key yet, setup offers Create encryption key after the credential and account checks pass.

1. Check the terminal ID and environment shown, then confirm. Do not change this terminal's settings elsewhere while the key is created.
2. If the connection is not verified yet, update the terminal's configuration; see key setup recovery.
3. If creation is interrupted, tap Resume key setup. For QR setup, scan the same codes again with their transfer code.

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Validate your TEST setup

1. In Settings › Terminal, check that the environment is TEST. Complete the final Test connection step to verify API access and supported connection checks.
   • Physical terminal: run Test connection and check it passes.
   • Tap to Pay: confirm the phone is registered in Adyen Payments Test. The connection check validates setup only: there is no terminal diagnosis. Use the test payment below to check payment behavior.
2. In Settings › Payments, check the currency. In Settings › Tax, check the rates and whether prices include tax.
3. On Home, tap New sale, add a Custom item and tap Charge.
4. Tap Pay and follow the Adyen POS testing guide for a successful payment.
5. Check that the result is approved and the receipt has the correct amount, currency and tax. Open the sale in History. Match its PSP reference to the payment in the TEST Customer Area.
6. Refund the payment and check the final refund outcome in the TEST Customer Area. Refund requested is not final confirmation.
7. Repeat the sale with a refused-payment scenario from the Adyen POS testing guide. Check that Mini mPOS shows a decline, not an approval; see declined payments .

Next, set up products, receipts and staff access in Using Mini mPOS.

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Go live

Before using optional terminal features, review Adyen capabilities and test your actual destination: terminal tipping, partial payments, shopper prompts, Giving and keyed entry, offline processing and terminal reconciliation . Availability depends on Adyen configuration and the payment destination.

1. In TEST, try only the optional workflows you plan to use: deposits, receipt tips, payment links or scanned wallets. Deposits and receipt tips hold funds until capture. Check final capture outcomes in the Customer Area.
2. Test the receipt delivery methods you plan to use: print on a real printer, send a test email or share a receipt.
3. Set an admin PIN and, if needed, a Manager PIN; see staff access.
4. Switch to the LIVE terminal or the LIVE Payments app, with LIVE credentials. For a network/cloud terminal or Tap to Pay, choose LIVE under Environment. Enter the Live URL prefix; see the Adyen live endpoints guide. Tap to Pay needs registration again in the selected environment.
5. In Settings › Terminal, check that the environment is LIVE. Complete the final Test connection step to verify API access and supported connection checks.
   • Physical terminal: run Test connection and check it passes.
   • Tap to Pay: confirm the phone is registered in the LIVE Adyen Payments app. The connection check validates setup only: there is no terminal diagnosis.

For daily checks and reconciliation, see Close the day.

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Try the simulator

Explore Mini mPOS without an Adyen account or terminal. No card is charged.

1. Install the app on an Android 9+ phone or emulator.
2. On the welcome screen, select Try a demo instead of Scan setup codes or Connect to Adyen, and tap Continue.
3. In Settings › Simulator, choose the payment outcome, the delay and whether a printer is available. Turn on Offline approvals to see offline warnings in History and terminal reconciliation.

In Settings › Data and transfer, use Add sample data or Remove sample data. Samples are labeled as demos. Samples count in demo day totals and reports; adding them replaces receipt business details with a fictional café and adds its logo when none is set. Removing them keeps your own products, history, settings and logo.

Payment links work offline without API credentials, and their screens and receipts are labeled as demos. Their QR codes cannot take payments; tap Simulate payment to complete one.

The simulator shows how Mini mPOS behaves, not what your terminal or Adyen account supports. Features such as audio guidance, offline approvals and Adyen capabilities are imitated, so test them on a real TEST terminal before relying on them.

Ready to connect? In Settings › Simulator, tap Set up real payments, then Continue to setup. Confirming TEST or LIVE deletes all local history; sample products and receipt details stay, so remove samples and review the receipt business details before real payments. Start with TEST.

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