4. Making it visible

At this point your module works. The tables exist, the API answers, the screens are declared.

And it is invisible.

Open the app launcher: library is not there. No error, no message, no log line. The module works perfectly and nobody can reach it.

Why

Every installation decides which modules it switches on. This is not a code question: the registry is global to the process, so activation is a visibility filter per installation.

A module that has not been switched on appears neither in the launcher nor in the menus, and its screens answer 404 for that installation. Its tables are still there.

Why this is not automatic

Because installing and switching on are two different decisions. You can drop ten modules on a server and open only three to your users, without touching a file.

And switching off destroys nothing: the screens disappear, the data stays.

Switching your module on

From the interface: Settings → Modules, then switch on Library.

From the command line, while developing:

from sqlalchemy import create_engine
from kewos.tenant_modules import set_module_active, list_module_states

engine = create_engine(DATABASE_URL)
with engine.begin() as connection:
    set_module_active(connection, module="library", active=True)

print(list_module_states(engine))
# {'core': True, 'pipeline': True, 'support': True, 'audit': True, 'library': True}

Reload the launcher:

Library is there, filed in the aisle declared by category in the manifest.

The icon

In the screenshot, Library shows its initials, “LI”: that is what the launcher does when a module has no icon.

Add icon.svg at the module’s root. A simple, monochrome path that inherits the current colour:

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none"
     stroke="currentColor" stroke-width="1.7" stroke-linecap="round"
     stroke-linejoin="round">
  <path d="M4 5h6a2 2 0 0 1 2 2v12a2 2 0 0 0-2-2H4z M20 5h-6a2 2 0 0 0-2 2v12a2 2 0 0 1 2-2h6z"/>
</svg>

currentColor, never a fixed colour

An icon that hard-codes its colour ignores the customer’s theme, and turns up bright blue on a green brand. stroke="currentColor" lets it follow the theme.

Checking you have not forgotten anything

Symptom	Cause
The module is not in the launcher	It is not switched on for this installation.
It is there but has no screen	No view declared, or views/ is not loaded by register().
It is there, with screens, but they are empty	A rights question: see The rights.
It shows its initials	No icon.svg.
It is filed under “Other”	No category in the manifest.

Next

Translating.