Extensions
Bulwark Webmail can be extended with two kinds of third-party add-ons:
- Plugins — add hooks, UI buttons, sidebar apps, keyboard shortcuts, and whole new workflows that integrate with the JMAP client.
- Themes — customize fonts, colors, and layouts to reshape the look and feel of the inbox.
Both are published on the Bulwark Extensions directory, which hosts free and open source extensions that have passed review.
What you'll find in these docs
- manifest.json reference — required fields, permissions, and metadata.
- REST API reference — the public API the directory exposes for querying and installing extensions.
- Submission guidelines — rules, review process, and content policy for getting your extension published.
- Publishing & updates — how the review pipeline works and how to ship new versions.
Getting started
Plugins
Plugins are managed through Bulwark's admin dashboard. A plugin is a small JavaScript module with a declarative configuration schema, an optional set of UI extension points, and a permission manifest. See the plugin system overview for the built-in architecture — the authoring model for third-party plugins follows the same conventions.
Themes
A theme is a bundle of CSS overrides that target Bulwark's design tokens (the --color-* CSS variables defined in app/globals.css). You declare a theme in the same manifest format as a plugin, set "type": "theme", and ship the stylesheet entry point.
Design principles
- Free and open source, always. The directory will never accept paid or closed-source extensions.
- Privacy first. Extensions must not collect user data beyond what their declared permissions allow.
- Minimum permissions. Requesting more capabilities than an extension needs is grounds for rejection.
- Auditable by default. All source code must live in a public GitHub repository under an OSI-approved license.
Ready to ship? Read the submission guidelines first, then submit at extensions.bulwarkmail.org/submit.