@kisaki3/extension-sdk

Authoring SDK for Kisaki extensions.

Use this package from extension code. It re-exports the public contracts from @kisaki3/extension-api and adds the small authoring surface that extension entry points use directly.

Exports

• defineExtension(definition).
• kisaki, a lazy bridge to host capabilities such as library, network, notify, events, runtime, scrapers, ingest, commands, background tasks, and webviews.
• createWebviewRpc(transport, functions), a typed bidirectional RPC sugar over one webview session's postMessage/onMessage.
• All public types and validation helpers exported by @kisaki3/extension-api.

@kisaki3/extension-sdk/webview

Browser-side entry imported by webview documents:

• webview, the in-document client: params, theme, typography, onThemeChange, onTypographyChange, postMessage, onMessage, and close. The client mirrors the active app theme as --kisaki-* color/radius variables and the resolved typography as --kisaki-font-* / --kisaki-text-* variables on the document root, injecting the app font stylesheets.
• createWebviewRpc, the same RPC sugar bound to the document side.

@kisaki3/extension-sdk/base.css

Framework-agnostic base layer (reset, typography, selection, scrollbars) built from the mirrored --kisaki-* variables. Pure CSS — works with or without Tailwind; import it in every webview document.

@kisaki3/extension-sdk/tailwind.css

Optional Tailwind v4 convenience layer (only for documents that use Tailwind). It maps the mirrored --kisaki-* variables onto Tailwind color tokens so documents use the same semantic utilities as the app:

@import 'tailwindcss';
@import '@kisaki3/extension-sdk/base.css';
@import '@kisaki3/extension-sdk/tailwind.css';

Example

import { createWebviewRpc, defineExtension, kisaki } from '@kisaki3/extension-sdk'
import type { HostFunctions, UiFunctions } from '../shared/contract'

export default defineExtension({
  activate(context) {
    context.contributions.cardActions.register({
      id: 'open-settings',
      label: 'Settings',
      async run() {
        const webview = await kisaki.webviews.open({
          entry: 'main/index.html',
          title: 'Settings',
          surface: { kind: 'dialog', size: 'md' }
        })

        createWebviewRpc<UiFunctions, HostFunctions>(webview, {
          loadState: async () => ({
            enabled: (await context.storage.get<boolean>('enabled')) ?? true
          }),
          saveState: (state) => context.storage.set('enabled', state.enabled)
        })
      }
    })
  }
})

Inside the webview document:

import { createWebviewRpc, webview } from '@kisaki3/extension-sdk/webview'
import type { HostFunctions } from '../../shared/contract'

const host = createWebviewRpc<HostFunctions>(webview)
const state = await host.loadState()

Boundary

The SDK does not assemble ExtensionContext, configure runtime bridges, or own extension lifecycle cleanup. The shared extension host owns those runtime responsibilities so extension code cannot forge another extension's identity. Webview documents only ever talk to their own extension host code through the message channel; host capabilities stay in the extension entry.