@rigline/plugin-api

What a Rigline plugin is written against: the plugin context, the manifest type and its JSON schema, definePlugin, and the anchor names.

A plugin is one browser ES module and a rigline.json. This package is a devDependency — the build bundles everything the entry imports, so a published plugin has no runtime dependency to resolve, which is what lets rigline add install one without running a package manager.

npm install -D @rigline/plugin-api

What you write runs inside a modification of Anthropic's extension, so the plugin policy applies to it, published or not. Most of it is not left to you — the webview has no network egress, no filesystem and no route into the extension host — and the page is explicit about which half is which.

A plugin

import { definePlugin, type PluginContext, type Teardown } from "@rigline/plugin-api";

export default definePlugin({
  setup(ctx: PluginContext): Teardown {
    const stop = ctx.watch("footerSpacer", (spacer) =>
      ctx.mountBefore(spacer, () => {
        const badge = document.createElement("span");
        badge.textContent = "hello";
        return badge;
      }),
    );
    return stop;
  },
});

{
  "$schema": "node_modules/@rigline/plugin-api/schema/manifest.json",
  "api": 1,
  "name": "hello",
  "description": "A badge in the composer footer.",
  "entry": "dist/index.js",
  "surfaces": ["editor", "sidebar"],
  "uses": { "anchors": ["footerSpacer"], "mount": true }
}

What ctx carries

Every capability is declared in the manifest and granted from the declaration, so a plugin reaching for something it did not declare finds nothing there, and a plugin whose declaration no longer holds against the installed extension is refused by name rather than failing at runtime.

cls and anchor for class names; onMessage for the bus; mount, mountAfter, mountBefore and watch for the DOM; style; rewrite and resend for outbound messages; onToolUse and onToolResult; onSessionId; decorateTranscript; and surface. Anything declared under uses.optional arrives on ctx.optional instead, returning null where this extension version does not have it — so losing a borrowed class to an upstream change costs a plugin some polish rather than its load.

Never name a minified identifier. Class names are <local>_<hash> CSS-modules output and the hash is rebuilt on every upstream build, so reach for a curated anchor name, or cls(module, local) where the table has no entry yet.

Identifier types

rigline codegen --out generated.ts writes the identifiers harvested from your installed extension and augments this package's types with them, so the anchors and message types your editor actually has are the ones your editor offers you. No published type union doubles as a version pin.

Authoring guide · anchors

Changelog — every package in this workspace shares it, and one version number.

MIT.