Architecture Decision Record: Package Structure dart, flutter

Title: Package Structure dart, flutter

status

In progress

Updated on 11-04-2026

contributors

• Main contributor(s): 1leo

• Reviewer(s): frnandu, nogringo

• final decision made by: frnandu, 1leo, nogringo

Context and Problem Statement

The 0.8.0 release was not streamlined. The goal of this ADR is to find out a suitable solution for the future. We decided that we want to make it easier for developers to use ndk in their environment, reducing the decision down to dart required, flutter required.

Main Proposal

The big changes are two main packages, ndk and ndk_flutter. The ndk package supports dart/flutter the ndk_flutter package only flutter. This makes it easier for the developer to decide. e.g.

running on server? => ndk running in a app? => ndk + ndk_flutter

Consequences

There are several ways this could be implemented. Right now we embedded other packages into ndk, ndk_flutter.

previous package	operation	new structure
ndk_amber	embedded =>	ndk_flutter
drift_cache_manager	renamed	ndk_drift
isar	removed	discontinued
ndk	--	ndk
ndk_cache_manager_test_suite	--	ndk_cache_manager_test_suite
ndk_flutter	--	ndk_flutter
nip07_event_signer	--	nip07_event_signer
ndk_objectbox	--	ndk_objectbox
ndk_rust_verifier	embedded =>	ndk (native assets)
ndk_demo	--	ndk_demo
sembast_cache_manager	embedded =>	ndk
--	new package	ndk_bip32_keys

However the embeddings could lead to blurry lines in terms of seperation. Breaking change for developers (changing the import structure).

Pro: Ideally there is no further setup required from the developer. Assuming we choose good defaults.

Alternative proposals

A alternative could be leaving the package structure, enforcing clear seperation. This would also allow the flexibility reusing and switching out storage dependencies separately for ndk ndk_flutter. To make the storage decision explicit for the developers the cache manager argument on the NDKConfig could be required with explanations on what to do like: use MemCacheManger() to get started long term options are ObjectboxCacheManger import via ... etc.

Another benefit is that we can prescreen db packages for their web compatibility and other potential changes in an isolated way.

previous package	operation	new structure
ndk_amber	dependency of	ndk_flutter
drift_cache_manager	renamed	ndk_drift
isar	removed	discontinued
ndk	--	ndk
ndk_cache_manager_test_suite	--	ndk_cache_manager_test_suite
ndk_flutter	--	ndk_flutter
nip07_event_signer	--	nip07_event_signer
ndk_objectbox	--	ndk_objectbox
ndk_rust_verifier	embedded =>	ndk (native assets)
ndk_demo	--	ndk_demo
sembast_cache_manager	dependency of	ndk, ndk_flutter
bip32_keys	embedded =>	ndk

Final Notes

accepted:

previous package	operation	new structure
ndk_amber	embedded =>	ndk_flutter
drift_cache_manager	renamed	ndk_drift
isar	removed	discontinued
ndk	--	ndk
ndk_cache_manager_test_suite	--	ndk_cache_manager_test_suite
ndk_flutter	--	ndk_flutter
nip07_event_signer	--	nip07_event_signer
ndk_objectbox	--	ndk_objectbox
ndk_rust_verifier	embedded =>	ndk (native assets)
ndk_demo	--	ndk_demo
sembast_cache_manager	embedded =>	ndk
ndk_bip32_keys	embedded =>	ndk

changes:

previous package	operation	new structure
ndk_bip32_keys	embedded =>	ndk

=> clear seperation for sembast issue