What is low-code?

With low-code, applications can be developed faster because applications are built from (visual) blocks. Of course, every application is unique, but often applications contain a large overlap in functionalities. By reusing these functionalities as building block, these blocks only need to be put in the right grouping. Of course, new building blocks can also be realized for that one truly unique piece of functionality.

Why low-code?

There is a high demand for developers, which means that many companies have shortages. Low code allows developers to develop web apps faster. It is often possible to build an application within a few days that solves a problem. This minimal viable product is quickly deployable, provides feedback for future further development and can ultimately be further refined.

What is PWA?

The progressive web app (PWA) is one of the newest developments in the field of apps. A PWA connects the properties of a website with many features of native mobile apps. As a result, the application functions independently of the operating system and at the same time as a website and app.

Why PWA?

  • A PWA works on any browser and any device, regardless of screen size.
  • The technology is universal and not controlled by one supplier.
  • You can also use a PWA offline or with a bad connection (ok, this doesn’t happen automatically, but it is possible).
  • A PWA, unlike a native app, can simply be found by Google or other search engines.
  • You do not have to download a PWA from the app store, which makes it easy to use. The app can also be added to a phone’s home screen. The PWA is then simply placed between the other native apps.
  • A PWA can simply be shared via a link (URL) and is secured via HTTPS.

Any downsides to PWA compared with native apps?

There are limitations to the PWA technology comparing it to native apps. For most use-cases the benefits outweigh the downsides but this is the list:

  • Apps are not available in the Android Play store or IOS App store. Depending on your goals that’s a benefit but can have drawbacks as well.
  • No push notification support on iOS yet. Apple announced it’s supported in iOS 16, coming in 2023.
  • Limited support yet for Bluetooth communication.

What is Open Source?

The source code of open source software is free. This means that it is available and adaptable. Open source software is attractive for developers and system administrators around the world. They can make improvements to the source code of open source or work on all kinds of extensions that benefit the community.

Why Open Source?

The first advantage of open source is that anyone can copy, adapt, supplement and distribute this software without having to pay copyright.

In addition, the open source software is free. There are no costs associated with using the software.

There is better and faster access to the latest innovations. Developers from all over the world are active who write additional software to be applied to open source solutions.

With Open Source you are not tied to one supplier.

What is vendor lock-in?

Vendor lock-in makes a customer dependent on a supplier for products and services because he is unable to change suppliers without substantial switching costs or inconvenience. Appsemble does not apply this way of doing business and deliberately does not create a vendor lock-in. We want customers to choose us as long as we continue to add value. With the maturing of the Appsemble ecosystem there will undoubtedly be several providers offering services.


What is Appsemble?

Appsemble is a platform with which (PWA) apps can easily be developed. Someone with little technical knowledge should be able to easily create apps with this. Someone with a lot of technical knowledge can create complex apps and therefore saves time by reusing building blocks. Appsemble is:

● is open source.
● is built with modern standards (PWA, ReactJS / Node.js, Docker, Kubernetes, Oauth2, JWT)
● App development possible in a pleasant style low-code format (YAML). Building blocks are selected and configured here.
● makes apps easy to share, copy and edit.

What’s the mission of Appsemble?

Our mission is to transform the way IT projects are done in the public sector, by enabling reuse, cooperation and innovation. We started with a joint plan with the municipality of Amsterdam, and now we have a growing team of smart software developers and a growing number of municipalities joining us. We believe in the power of open source to make a positive impact on society.

Is there a roadmap?

The roadmap containing major upcoming features is published here. For more detail on each topic, see the epics page. Keep in mind that any dates mentioned are not final. More urgent issues can come up at any time, but at least it shows which direction in which we’re going.

In case you’re interesting in finding out what we’re doing from sprint to sprint (planned every 2 weeks), here’s the planning board.

Feel free to put topics on the agenda via the issue tracker or Discord!

What is Appsemble SAAS?

Appsemble SAAS (Software as a Service) is the possibility to use Appsemble without having to set up your own hosting.
In addition to hosting with an SLA, support is also provided.
There is also access to a partner network (for example for logging in to DigiD, eHerkenning or certified hosting)

What does Appsemble SAAS cost?

The costs for a basic per app are €5 excl. VAT per month. This includes:

  • Hosting in the European (GDPR compatible) cloud.
  • Standard Appsemble backend.
  • 1 GB data storage.
  • 50 notifications per day.
  • Unlimited users (FUP).
  • Appsemble supported basic blocks.
  • Basic email support.
  • Basic SLA.

The costs for a standard app are €25 excl. VAT per month. This contains the above features of the basic app, plus:

  • 50 GB storage.
  • 5000 notifications per day.
  • Standard SLA.

The costs for an extensive app are €50 excl. VAT per month. This includes the above features of the standard app, plus:

  • Customized backend containers possible.
  • 200 GB storage.
  • Unlimited number of notifications per day (FUP).
  • Email and telephone support.
  • 3rd party building blocks.
  • Extensive SLA.

Are there SAAS options for organisations?

SAAS hosting with an Enterprise SLA is gets you the following extras compared to the standard app costs:

  • Faster response time for support.
  • Technical support for developers.
  • Greater amounts of users or data.
  • Additional hosting of custom backends.
  • Support in connection with single-sign-on setup.

Costs are € 100 ex. VAT per app.

What are the available SLA forms?

Various forms of a Service Level Agreement (SLA) can be concluded for an app.
What are the differences?

SLA formBasicStandardExtended
SupportVia emailVia emailVia email and phone
Service windowMonday to Friday
9:00 am to 5:00 pm
Monday to Friday
9:00 am to 5:00 pm
Monday to Sunday
7:00 am to 10:00 pm
Average time to answer
Prio: critical
Prio: important
Prio: normal

2 days
2 days
5 days

24 hours
24 hours
2 days

2 hours
2 hours
8 hours
Average time to repair
Prio: kritisch
Prio: belangrijk
Prio: normaal

Next version
Next version
Next version

5 days
10 days
Next version

24 hours
24 hours
Next version

Explanation of urgency levels:

  • Critically, the service is unavailable
  • Importantly, the service contains a bug that prevents normal operation
  • Normally, some functionality does not work correctly or parts of the service are not

What is a building block?

Building blocks are pre-programmed functionality blocks, with which you build your own application. Because you use pre-programmed blocks you do not have to be able to program yourself to make the app.
Depending on the building block, a number of simple settings can be made per building block.

What does it cost to make a building block?

Making a building block yourself naturally costs nothing. Technical knowledge is required. Appsemble B.V. can develop building blocks at the following target prices:

● Small block (no external dependencies): from € 1000,-
● Large block (link with external services): from € 2500, –

The blocks will be published open source and maintained for at least 6 months by Appsemble B.V. If the blocks are not interesting enough for the community to maintain, a maintenance agreement will have to be concluded after that time, prices on request.
If the blocks must remain the private property of the client, the prices are on request.

What does it cost to make an App?

Creating an app yourself based on our standard building blocks costs nothing. If the desired app requires additional building blocks that have not yet been developed, these are the target prices to be used by Appsemble B.V. to make:

● Small app (incl. 1 or 2 extra building blocks): from € 5000, –
● Medium-sized app (about 4 extra building blocks): from € 10,000
● Large app (more than 4 extra building blocks and a customized backend): from € 25,000

The app recipes will be published open source and maintained for at least 6 months by Appsemble B.V. If the app recipes are not interesting enough for the community to maintain, a maintenance agreement must be concluded after that time, prices on request.
If the apps must remain the private property of the client, the prices are on request.

Can I keep my app closed?

Sure. Even though the Appsemble platform itself is open source, it’s allowed to create your own blocks or app and keep it private (closed).

Hybrid models are also possible. For example, develop new blocks as open source, but keep the app built with those blocks closed. These aspects can be closed:
– Specific combination/configurations of blocks in your app (the app recipe)
– Specific branding (theme) of the app
– The data/contact of the app

This balance should result in a health ecosystem with shared blocks even though it can result in unique apps.

Terms and Conditions

Our standard terms and conditions.

For governmental bodies, we’re open to work with adapted terms and conditions.


The availability (actual and historic) of the Appsemble platform can be viewed on the status page.

Municipalities and Common Ground

What is the relationship between Appsemble and OpenApps?

The apps that are initiated by OpenApps have been provided to Appsemble B.V. as a commercial order to date. The end result is open source and will be added to Appsemble CE.
This is a pragmatic choice because Appsemble is the co-founder of OpenApps and has the necessary expertise in-house.

How do OpenApps and Appsemble relate to the VNG Common Ground?

At the beginning of 2020, the CTO of the Municipality of Amsterdam and the IT strategist common ground of VNG realization independently of supplier Appsemble held consultations about Appsemble compatibility with common ground. The verdict was positive. We continue to follow the basic principles of Common Ground and investigate where we fit in the “CG layer architecture”.
Appsemble provides a solution for all layers as described in the common ground layer architecture and can therefore also offer a standalone total solution. However, the Appsemble architecture is set up in such a way that we can relatively easily exchange layers for layers hosted or developed outside of Appsemble. We are an open platform anyway and work easily with external APIs.


Becoming a partner

The best Apps are created by a local partner that understands the Appsemble low code platform and can implement custom solutions when needed.
The concept is pretty simple: you help Appsemble to become the no. 1 open source, low code platform, we help you in becoming a successful app builder for your local community.

The advantages:

  • Access to an Appsemble account manager.
  • Obtain local leads.
  • 100% commission on hosted services.
  • Free technical support when you’re building open source components.
  • Discounted fee on technical support when you’re building close source components.


How to enable webcam recordings in iOS Safari or Chrome?

Open the Settings app. Navigate to Safari → Advanced → Experimental Features. Make sure the MediaRecorder feature is enabled.
This feature is available from iOS 12.4 and up.

Which browsers and smartphones are supported by Appsemble?

We are actively working to support the latest 2 versions of Chrome, Safari, Edge, Firefox and Samsung Internet.
That doesn’t mean it won’t work in other versions/browsers by definition, but may not work completely.

Apple iPhone: at the time of writing (November 2021), iPhone8 (tested on iOS 15) is the oldest Apple smartphone on which Appsemble works correctly.

Security and privacy

I discovered a security issue, what’s the process?

Vulnerabilities can be reported in our issue tracker. These issues will be marked as sensitive information, so that only the Appsemble team can see this issue. This issue has high priority and we will issue a repair to our SAAS as soon as possible. If we receive a notification via another medium, such as an e-mail, we will proceed in the same way.

We will provide the users with whom we have an SLA agreement with information and, if necessary, a repair in the application. All other users can stay informed about (security) updates via the changelog .

How does Appsemble deal with privacy and GDPR?

For a detailed description, see our privacy policy.

Of course we try to comply with the new privacy law (GDPR) as fully as possible. This is a process that we take steps in, for example::

  • Our servers are located in the Netherlands.
  • We draw up processing agreements.
  • We adhere to the data breach notification obligation.
  • We try as quickly may respond to security vulnerabilities should they become known to us.


Where can I ask questions?

Everyone can join our public Discord channels for community support. Also the core team is active here. Together we’ll try to answer questions quickly.

When an organisation has a SLA, questions can also be asked through email: (in Dutch or English). The response times are agreed upon in the SLA.