Supported Devices/Welock/U81 Electronic Door Lock Cylinder

U81 Electronic Door Lock Cylinder

The U81 Smart Lock is a retrofit smart cylinder lock designed for European-profile doors, allowing users to upgrade existing locks without replacing the full door hardware. The U81 combines biometric and electronic access control with a cylinder-based installation format and supports multiple unlocking methods including fingerprint recognition, PIN codes, RFID cards, smartphone app access, Bluetooth credentials, and mechanical backup keys. Designed for homes, apartments, offices, Airbnb rentals, and holiday properties, the U81 integrates with the WELOCK mobile ecosystem for temporary access sharing, audit logs, remote management via optional Wi-Fi gateway, and app-based credential control. The lock features an IP65-rated weather-resistant design, quick DIY installation, and compatibility with most Euro-profile doors.

VariantDefault Variant
ColorBlack
IDU81Brand
Logo of WelockWelock
Product PageManufacturer's Product PageLock TyperetrofitPhysical keyYesBattery PoweredYesBattery TypeAAABattery Count4
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Automate the Welock U81 Electronic Door Lock Cylinder with Seam and start managing your devices today.

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U81 Electronic Door Lock Cylinder

U81 Electronic Door Lock Cylinder

Control This Device With Seam API and TTLock

Connect your TTLock with Seam API to use these features.

Capabilities

What you can do with this device, using Seam API.

Remote UnlockLive
Remote LockLive
Program Online Access CodesLive
SchedulesLive
Program Offline Access CodesUnavailable
Plastic CardInquire
Wallet KeysUnavailable
Mobile KeysInquire

Device Connectivity

Additional equipment needed to remotely connect to this device.

Device Bridge

Required

To remotely interact with this device, you will need to pair it with a compatible bridge.

Automate Access with Welock U81 Electronic Door Lock Cylinder

Check requirements: Requires connectivity setup

A core use case is syncing access codes with reservations from your booking system. With Seam, you can plug calendar tools like Calendly, Cal.com, Google Calendar, and iCal; e-commerce backends like WooCommerce or Shopify; or even class- or appointment-booking software like Mindbody and Acuity. Every confirmed reservation can be set to automatically create a unique, time-bound code on the U81 Electronic Door Lock Cylinder at check-in and revoke it at check-out—no manual handling, no shared codes.

The U81 Electronic Door Lock Cylinder by Welock can be used to automate secure access for your customers, guests, or users using Seam's self-serve solution.

With support for time-based access codes, you can automatically grant and revoke access based on real-world events like bookings, schedules, or user actions—without manual intervention.

This is especially useful for:

Using Seam, you can connect your U81 Electronic Door Lock Cylinder, listen to events from your booking system or backend, and programmatically create access codes that are valid only during the desired time window.

Control Access Remotely with Welock U81 Electronic Door Lock Cylinder

Check requirements: Requires connectivity setup

The U81 Electronic Door Lock Cylinder by Welock supports remote unlocking via the Seam API.

Beyond admin or staff workflows, you can embed an "Unlock" button directly inside your customer-facing app, allowing authorized end-users to open a door, gate, or locker themselves during their reservation or membership window—no front-desk hand-off required.

This pattern works particularly well for:

You can also trigger unlock actions programmatically—for example:

  • Add a button in your app or admin dashboard to unlock a door or gate
  • Allow staff to remotely grant access during a reservation
  • Enable backup access in case a user cannot use their code
  • Build simple interfaces for operators to manage access live

Combined with scheduling or reservation logic, this allows you to create flexible access experiences—for example, enabling a "Unlock" button that only works during an active booking time window.

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