Create an Extension

Create an extension

Use this guide when you want to add general host-aware behavior to Cove, not only one metadata source.

What an extension is for

A Cove extension can contribute more than one narrow hook. Depending on the design, it can add:

• UI pages or panels
• backend APIs
• settings
• background jobs
• themes
• installable tools such as downloaders or scrapers

Build approach

Think about the extension in two parts:

• frontend contribution when users need a page, panel, settings surface, or visual integration
• backend contribution when you need APIs, jobs, events, storage, or other server-side behavior

Not every extension needs both, but many serious ones do.

Recommended implementation flow

1. Define the user-facing behavior first.
2. Decide which parts belong in the UI and which belong in the backend.
3. Keep permissions narrow and explicit.
4. Build and test locally against a running Cove dev environment.
5. Package the extension in the layout Cove expects before testing install flow.

Packaging expectations

The host expects pre-built extension artifacts. That means:

• backend pieces should already be compiled
• frontend pieces should already be bundled
• install should not depend on runtime package restores

See Packaging for the detailed constraints.

Good first checks

Before calling an extension ready:

• confirm it loads into a normal local Cove run
• confirm permission failures are understandable
• confirm any UI additions feel native to Cove instead of visually detached
• confirm any user-visible metadata changes preserve provenance