name a published extension for itself, not "extension.zip"

extension.zip says nothing once it is in a Downloads folder — not what it is, not which server it came
from, and not which of two it is. The name comes from the extension's own manifest.json, which already
carries what a browser will show: "Officer Browser Relay" becomes officer-browser-relay.zip.

Generic, since extensions are meant to be a marketplace of them: any plugin shipping extension/ gets a
file named after its own manifest, falling back to <appName>-extension.zip when that cannot be read —
still better than extension.zip, and it never throws, because a broken extension manifest should fail
the install for its own reason rather than because a file could not be named.

Uninstall removes both names. An install from earlier today published extension.zip, and leaving that
behind would serve a stale extension for a plugin that is gone.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/servers/plugins/install.ts

@@ -1,3 +1,4 @@
+import { join } from 'node:path';
 import {
   deleteScreenForAllUsers,
   getDockPaths,
@@ -20,7 +21,7 @@ import { publishAffordances, unpublishAffordances } from '../affordances/publish
 import { publishNotifications, unpublishNotifications } from '../notifications/publish';
 import { publishSkills, unpublishSkills } from '../skills/publish';
 import { refreshPluginMounts, snapshotPlugins } from './mount';
-import { publishExtension, unpublishExtension } from './zip';
+import { publishExtension, unpublishExtension, extensionFileName } from './zip';
 import { generatePluginSchemas, pushPluginSchema } from './schema';
 import { declaredTables, dropTables, existingTables } from './tables';
 import type { OnLog } from './run-logged';
@@ -397,7 +398,8 @@ export async function installPlugin(
     // A browser extension, zipped from `extension/` and served UNAUTHENTICATED — see zip.ts. Built here
     // rather than committed, so it cannot fall behind the directory it is made from.
     if (await publishExtension(appName, plugin.dir).catch(() => false)) {
-      await step(steps, onStep, `extension: published to /plugins/${appName}/extension.zip`);
+      const file = extensionFileName(appName, join(plugin.dir, 'extension'));
+      await step(steps, onStep, `extension: published to /plugins/${appName}/${file}`);
     }
 
     // What this plugin needs an AGENT to know about itself. A plugin is a new surface arriving at
@@ -529,7 +531,7 @@ export async function uninstallPlugin(appName: string, onStep?: OnStep, onLog?:
   }
 
   await unpublishAssets(appName);
-  await unpublishExtension(appName).catch(() => {});
+  await unpublishExtension(appName, plugin?.dir).catch(() => {});
   // Same reasoning: a copy, with the original still in the plugin's directory. Removed so an agent stops
   // being told about a surface that is no longer there — an affordance for an uninstalled plugin is
   // worse than none, because it reads as true.

src/servers/plugins/zip.ts

@@ -146,11 +146,41 @@ export async function publishExtension(appName: string, pluginDir: string): Prom
 
   const target = join(process.cwd(), 'public', 'plugins', appName);
   mkdirSync(target, { recursive: true });
-  await Bun.write(join(target, 'extension.zip'), zipDirectory(source));
+  await Bun.write(join(target, extensionFileName(appName, source)), zipDirectory(source));
   return true;
 }
 
+/**
+ * What the download is called, from the extension's OWN name.
+ *
+ * `extension.zip` is what this shipped as first, and it is the wrong name the moment it reaches a
+ * Downloads folder: it says nothing about what it is or which server it came from. The extension's
+ * `manifest.json` already carries the name a browser will show — "Officer Browser Relay" — so the file is
+ * named for that and a person can tell two of them apart.
+ *
+ * Falls back to `<appName>-extension.zip` when the manifest cannot be read, which is still better than
+ * `extension.zip` and never throws: a plugin that ships a broken extension manifest should fail at
+ * install for that reason, not because the zip could not be named.
+ */
+export function extensionFileName(appName: string, extensionDir: string): string {
+  try {
+    const raw = JSON.parse(readFileSync(join(extensionDir, 'manifest.json'), 'utf8')) as { name?: string };
+    const slug = String(raw.name ?? '')
+      .toLowerCase()
+      .replace(/[^a-z0-9]+/g, '-')
+      .replace(/^-|-$/g, '');
+    if (slug) return `${slug}.zip`;
+  } catch {
+    /* fall through */
+  }
+  return `${appName}-extension.zip`;
+}
+
 /** Remove it when the plugin goes. A copy, like the assets beside it — the source is in the plugin. */
-export async function unpublishExtension(appName: string): Promise<void> {
-  rmSync(join(process.cwd(), 'public', 'plugins', appName, 'extension.zip'), { force: true });
+export async function unpublishExtension(appName: string, pluginDir?: string): Promise<void> {
+  const dir = join(process.cwd(), 'public', 'plugins', appName);
+  // Both names: an install from before the naming change published `extension.zip`, and leaving that
+  // behind would serve a stale copy of an uninstalled plugin's extension for ever.
+  rmSync(join(dir, 'extension.zip'), { force: true });
+  if (pluginDir) rmSync(join(dir, extensionFileName(appName, join(pluginDir, 'extension'))), { force: true });
 }