diff --git a/docs/tui-capabilities.md b/docs/tui-capabilities.md
index a67fb9f2..2306cb99 100644
--- a/docs/tui-capabilities.md
+++ b/docs/tui-capabilities.md
@@ -132,3 +132,26 @@ existing diagnostic-counts projection; raw error text, stacks and session IDs
 are not added to the uploaded ZIP. Offline tests cover persisted tool histories,
 archives, concurrent parent output, side-session cleanup and local diagnostics;
 this does not establish native-terminal or live-model acceptance.
+
+## Select a plugin for a message
+
+Type `@` in the Composer to search files and installed, enabled plugins. Plugin
+candidates show their source so packages with the same display name can be
+selected independently. Choose a plugin with Tab or Enter, then describe the task.
+The Composer shows `@Name` and retains the plugin identity through editing, undo,
+prompt history, queued-message recovery, saved drafts, and `/edit` after a
+message is sent. Ctrl+C clearing/restoration and external-editor edits retain
+unchanged plugin bindings. If external edits make duplicate labels ambiguous,
+reselect those plugins in the Composer. Displayed messages remain readable; Runtime retains
+the original input separately when needed to recover the plugin identity for editing.
+
+Selection applies to that message. Runtime checks the plugin's effective Skills,
+MCP tools, and App tools again for the turn and asks the Agent to prefer relevant
+capabilities. Selecting a plugin does not install or enable it. An unavailable
+selection is reported to the Agent rather than redirected to a same-named package.
+
+Exec and ACP text prompts can use the durable linked form, for example
+`[@Notes](plugin://notes%40local) summarize these files`. The ID is the package
+name plus its `local` or `official` source; display labels do not determine the
+selection. Legacy whitespace-delimited `@package-name` text remains supported
+when it identifies exactly one effective plugin.
diff --git a/packages/agent-modules/system-reminder/package.json b/packages/agent-modules/system-reminder/package.json
index 1ee0840c..0ddefcd9 100644
--- a/packages/agent-modules/system-reminder/package.json
+++ b/packages/agent-modules/system-reminder/package.json
@@ -14,7 +14,8 @@
     "@mavis/config": "workspace:^",
     "@types/node": "^20",
     "typescript": "^5",
-    "vitest": "^2"
+    "vitest": "^2",
+    "@mavis/shared": "workspace:^"
   },
   "private": true,
   "license": "MIT"
diff --git a/packages/agent-modules/system-reminder/src/plugin-reference.ts b/packages/agent-modules/system-reminder/src/plugin-reference.ts
index 5878a928..2ad38865 100644
--- a/packages/agent-modules/system-reminder/src/plugin-reference.ts
+++ b/packages/agent-modules/system-reminder/src/plugin-reference.ts
@@ -1,12 +1,15 @@
+import { parsePluginMentions } from '@mavis/shared/plugin-mention';
+
 export interface EffectivePluginToolGroup {
   readonly source: string;
   readonly tools: readonly string[];
-  /** Deferred App tools must be discovered before they can be invoked. */
+  /** Deferred tools must be discovered before they can be invoked. */
   readonly access?: 'direct' | 'tool_search';
 }
 
 export interface EffectivePluginCapabilityInventory {
   readonly name: string;
+  readonly pluginId?: string;
   readonly appTools: readonly EffectivePluginToolGroup[];
   readonly mcpTools: readonly EffectivePluginToolGroup[];
   readonly skills: readonly string[];
@@ -33,7 +36,7 @@ export function detectPluginReferencesForMessages<T extends EffectivePluginCapab
 
   for (const text of texts) {
     for (const match of detectReferencesInText(text, plugins)) {
-      const key = normalizedName(match.name);
+      const key = match.pluginId ?? normalizedName(match.name);
       if (seen.has(key)) continue;
       seen.add(key);
       selected.push(match);
@@ -45,11 +48,12 @@ export function detectPluginReferencesForMessages<T extends EffectivePluginCapab
 /** Render one self-contained reminder for every Plugin selected in this turn. */
 export function buildPluginReferenceReminder(
   plugins: readonly EffectivePluginCapabilityInventory[],
+  unavailablePluginIds: readonly string[] = [],
 ): string | undefined {
-  if (plugins.length === 0) return undefined;
-  const blocks = plugins.map((plugin) => {
+  if (plugins.length === 0 && unavailablePluginIds.length === 0) return undefined;
+  const blocks = plugins.slice(0, 8).map((plugin) => {
     const name = inlineCode(plugin.name);
-    return [
+    const detail = [
       `<selected-plugin name="${escapeXml(plugin.name)}">`,
       `Referenced as \`@${name}\`.`,
       '',
@@ -66,20 +70,46 @@ export function buildPluginReferenceReminder(
       '</plugin-skills>',
       '</selected-plugin>',
     ].join('\n');
+    return detail.length <= 4096
+      ? detail
+      : `<selected-plugin name="${escapeXml(plugin.name).slice(0, 512)}">\nCapability details omitted to fit the context limit. Use this Plugin's tool provenance and Skill namespace in the available catalogs.\n</selected-plugin>`;
   });
 
+  const bounded: string[] = [];
+  let remaining = 12_288;
+  let omitted = plugins.length > 8 || unavailablePluginIds.length > 8;
+  for (const block of [
+    ...blocks,
+    ...unavailablePluginIds
+      .slice(0, 8)
+      .map(
+        (id) =>
+          `Selected Plugin \`${inlineCode(id)}\` is unavailable for this turn. Tell the user it could not be used; do not substitute a same-named Plugin or enable/install it automatically.`,
+      ),
+  ]) {
+    if (block.length + 2 > remaining) {
+      omitted = true;
+      continue;
+    }
+    bounded.push(block);
+    remaining -= block.length + 2;
+  }
+
   return [
     '<system-reminder>',
     'The user explicitly selected the following Plugin capabilities for this request.',
     'Prefer them when relevant; other tools remain available if needed.',
     '',
-    blocks.join('\n\n'),
+    bounded.join('\n\n'),
+    ...(omitted ? ['Additional selected capabilities omitted to fit the context limit.'] : []),
     '',
-    'Only the capabilities listed above are effective for this turn.',
+    'The listed capabilities are drawn from the effective inventory for this turn; lists may be truncated.',
     'Do not invent or claim unavailable Plugin capabilities.',
-    ...(plugins.some((plugin) => plugin.appTools.some((group) => group.access === 'tool_search'))
+    ...(plugins.some((plugin) =>
+      [...plugin.appTools, ...plugin.mcpTools].some((group) => group.access === 'tool_search'),
+    )
       ? [
-          'For App tools marked `via tool_search + mcp_invoke`, discover the exact tool with `tool_search` before calling it through `mcp_invoke`.',
+          'For tools marked `via tool_search + mcp_invoke`, discover the exact tool with `tool_search` before calling it through `mcp_invoke`.',
         ]
       : []),
     'Before following a listed Skill, call the `skill` tool with its exact name.',
@@ -91,6 +121,7 @@ export function buildPluginReferenceReminder(
 function formatAppToolGroups(groups: readonly EffectivePluginToolGroup[]): string {
   if (groups.length === 0) return 'none';
   return [...groups]
+    .slice(0, 16)
     .sort((left, right) => {
       const sourceOrder = normalizedName(left.source).localeCompare(normalizedName(right.source));
       if (sourceOrder !== 0) return sourceOrder;
@@ -108,11 +139,24 @@ function detectReferencesInText<T extends EffectivePluginCapabilityInventory>(
   text: string,
   plugins: readonly T[],
 ): T[] {
-  const normalizedText = text.normalize('NFKC');
+  const linked = parsePluginMentions(text);
+  let plainText = text;
+  for (const mention of [...linked].reverse())
+    plainText = `${plainText.slice(0, mention.start)}${' '.repeat(mention.end - mention.start)}${plainText.slice(mention.end)}`;
+  const normalizedText = plainText.normalize('NFKC');
   const matches: Array<{ index: number; plugin: T }> = [];
   for (const plugin of plugins) {
+    const explicit = linked.find((mention) => mention.pluginId === plugin.pluginId);
+    if (explicit) {
+      matches.push({ index: explicit.start, plugin });
+      continue;
+    }
     const name = normalizedName(plugin.name);
-    if (!name) continue;
+    if (
+      !name ||
+      plugins.filter((candidate) => normalizedName(candidate.name) === name).length !== 1
+    )
+      continue;
     const pattern = new RegExp(`(^|\\s)@${escapeRegExp(name)}(?=\\s|$)`, 'giu');
     const match = pattern.exec(normalizedText);
     if (!match) continue;
@@ -128,16 +172,19 @@ function formatToolGroups(
 ): string {
   if (groups.length === 0) return 'none';
   return [...groups]
+    .slice(0, 16)
     .sort((left, right) => normalizedName(left.source).localeCompare(normalizedName(right.source)))
     .map((group) => {
       const tools = formatToolNames(group.tools);
-      return `- ${label} \`${inlineCode(group.source)}\`: ${tools || 'none'}`;
+      const access = group.access === 'tool_search' ? ' via `tool_search` + `mcp_invoke`' : '';
+      return `- ${label} \`${inlineCode(group.source)}\`${access}: ${tools || 'none'}`;
     })
     .join('\n');
 }
 
 function formatToolNames(tools: readonly string[]): string {
   return [...new Set(tools)]
+    .slice(0, 32)
     .sort((left, right) => normalizedName(left).localeCompare(normalizedName(right)))
     .map((tool) => `\`${inlineCode(tool)}\``)
     .join(', ');
@@ -146,6 +193,7 @@ function formatToolNames(tools: readonly string[]): string {
 function formatSkills(skills: readonly string[]): string {
   if (skills.length === 0) return 'none';
   return [...new Set(skills)]
+    .slice(0, 32)
     .sort((left, right) => normalizedName(left).localeCompare(normalizedName(right)))
     .map((skill) => `- \`${inlineCode(skill)}\``)
     .join('\n');
diff --git a/packages/local-runtime-v2/src/application/conversation/conversation-application.ts b/packages/local-runtime-v2/src/application/conversation/conversation-application.ts
index c7be0ea1..1f7c92f8 100644
--- a/packages/local-runtime-v2/src/application/conversation/conversation-application.ts
+++ b/packages/local-runtime-v2/src/application/conversation/conversation-application.ts
@@ -70,6 +70,8 @@ import {
 } from "./session-stream-delivery.js";
 
 export interface ConversationSendMessageRequest extends SendMessageReq {
+  /** Readable projection supplied by the process-local composer; content retains transport identity. */
+  readonly displayContent?: string;
   /** Process-local caller's Unix-ms deadline; its cancellation owner still enforces it. */
   readonly executionDeadlineAtMs?: number;
   /** Process-local opt-in; emits metadata only, never provider payloads. */
@@ -575,6 +577,9 @@ async function toDirectSendInput(
       input: toAgentHostUserInput(req, text, attachments),
       ...executionOptions,
       provenance: messageProvenance(req),
+      ...(req.displayContent !== undefined
+        ? { displayContent: req.displayContent }
+        : {}),
       ...(materialized.displayAttachments.length > 0
         ? { displayAttachments: materialized.displayAttachments }
         : {}),
diff --git a/packages/local-runtime-v2/src/application/conversation/direct-send-delivery.ts b/packages/local-runtime-v2/src/application/conversation/direct-send-delivery.ts
index 28f3e872..3c2a6e91 100644
--- a/packages/local-runtime-v2/src/application/conversation/direct-send-delivery.ts
+++ b/packages/local-runtime-v2/src/application/conversation/direct-send-delivery.ts
@@ -26,6 +26,7 @@ export interface DirectSendInput {
   readonly outputContract?: SubmitTurnSubmission['outputContract'];
   readonly executionDeadlineAtMs?: SubmitTurnSubmission['executionDeadlineAtMs'];
   readonly provenance: SubmitTurnSubmission['provenance'];
+  readonly displayContent?: string;
   readonly displayAttachments?: readonly UserMessageAttachment[];
   readonly requestedTurnId?: string;
   readonly hideUserMessage?: boolean;
@@ -388,8 +389,12 @@ async function completeAfterSettlement(
 
 function directSendDisplayOptions(
   input: DirectSendInput,
-): Pick<NonNullable<SubmitTurnSubmission['delivery']>, 'displayAttachments' | 'hideUserMessage'> {
+): Pick<
+  NonNullable<SubmitTurnSubmission['delivery']>,
+  'displayContent' | 'displayAttachments' | 'hideUserMessage'
+> {
   return {
+    ...(input.displayContent !== undefined ? { displayContent: input.displayContent } : {}),
     ...(input.displayAttachments
       ? { displayAttachments: input.displayAttachments.map((attachment) => ({ ...attachment })) }
       : {}),
diff --git a/packages/local-runtime-v2/src/application/conversation/user-message-turn-delivery.ts b/packages/local-runtime-v2/src/application/conversation/user-message-turn-delivery.ts
index 22fb114c..c4aa266b 100644
--- a/packages/local-runtime-v2/src/application/conversation/user-message-turn-delivery.ts
+++ b/packages/local-runtime-v2/src/application/conversation/user-message-turn-delivery.ts
@@ -1,3 +1,4 @@
+import { parsePluginMentions } from '@mavis/shared/plugin-mention';
 import { randomUUID } from 'node:crypto';
 
 import {
@@ -126,6 +127,7 @@ export class UserMessageTurnDeliveryService implements UserMessageTurnDelivery {
       ...(input.message.userMessageId ? { userMessageId: input.message.userMessageId } : {}),
       unstartedFromTurnIds: input.message.unstartedFromTurnIds,
       content: projectedMessageContent(delivery, input.message.message.text),
+      inputContent: input.message.message.text,
       ...(attachments ? { attachments } : {}),
       ...(input.message.sourceMessageId ? { sourceMessageId: input.message.sourceMessageId } : {}),
       provenance: input.message.provenance,
@@ -295,6 +297,7 @@ async function commitTurnMessages(
       messageKey: member.messageKey,
       userMessageId: member.userMessageId,
       content: projectedMessageContent(member.message, member.message.content),
+      inputContent: member.message.content,
       timestamp: member.createdAt,
       ...(member.unconsumedFromTurnIds
         ? { unconsumedFromTurnIds: member.unconsumedFromTurnIds }
@@ -323,6 +326,7 @@ async function commitTurnMessage(
     messageKey: input.messageKey ?? `turn:${turnId}`,
     ...(input.userMessageId ? { userMessageId: input.userMessageId } : {}),
     content: projectedMessageContent(input, input.input.text),
+    inputContent: input.input.text,
     ...(queryKey ? { queryKey } : {}),
     ...(attachments ? { attachments } : {}),
     ...(input.sourceMessageId ? { sourceMessageId: input.sourceMessageId } : {}),
@@ -340,6 +344,7 @@ function commitMessage(
     readonly messageKey: string;
     readonly userMessageId?: UserMessageId;
     readonly content: string;
+    readonly inputContent: string;
     readonly timestamp?: number;
     readonly unconsumedFromTurnIds?: readonly string[];
     readonly unstartedFromTurnIds?: readonly string[];
@@ -360,6 +365,9 @@ function commitMessage(
       messageKey: input.messageKey,
       ...(input.userMessageId ? { userMessageId: input.userMessageId } : {}),
       content: input.content,
+      ...(input.inputContent !== input.content && parsePluginMentions(input.inputContent).length > 0
+        ? { editContent: input.inputContent }
+        : {}),
       ...(input.timestamp !== undefined ? { timestamp: input.timestamp } : {}),
       ...(input.unconsumedFromTurnIds
         ? { unconsumedFromTurnIds: input.unconsumedFromTurnIds }
diff --git a/packages/local-runtime-v2/src/application/session/content-application.ts b/packages/local-runtime-v2/src/application/session/content-application.ts
index 81e295e4..27b69097 100644
--- a/packages/local-runtime-v2/src/application/session/content-application.ts
+++ b/packages/local-runtime-v2/src/application/session/content-application.ts
@@ -481,6 +481,7 @@ export function toSessionMessageView(
   );
   return {
     msgId: maybeString(firstDefined([message.msgId, message.msg_id])) ?? "",
+    ...(typeof message.editContent === "string" ? { editContent: message.editContent } : {}),
     parentMsgId: maybeString(
       firstDefined([message.parentMsgId, message.parent_msg_id]),
     ),
diff --git a/packages/local-runtime-v2/src/service/session-system/messages/repo/contract.ts b/packages/local-runtime-v2/src/service/session-system/messages/repo/contract.ts
index 197c3f35..f2b38fc5 100644
--- a/packages/local-runtime-v2/src/service/session-system/messages/repo/contract.ts
+++ b/packages/local-runtime-v2/src/service/session-system/messages/repo/contract.ts
@@ -2,6 +2,8 @@ import type { AppDb } from '../../../../infra/db/client.js';
 
 export interface DisplayMessageRecord extends Record<string, unknown> {
   readonly msg_id?: string;
+  /** Canonical user input preserved when display text hides plugin identities. */
+  readonly editContent?: string;
   /** Stable canonical identity of this completed assistant message, when known. */
   readonly canonical_message_id?: string;
   readonly role?: string;
diff --git a/packages/local-runtime-v2/src/service/session-system/messages/user-message-commit-service.ts b/packages/local-runtime-v2/src/service/session-system/messages/user-message-commit-service.ts
index d6c54d10..589f0796 100644
--- a/packages/local-runtime-v2/src/service/session-system/messages/user-message-commit-service.ts
+++ b/packages/local-runtime-v2/src/service/session-system/messages/user-message-commit-service.ts
@@ -47,6 +47,8 @@ export interface CommitUserMessageInput {
   /** Pre-generated identity shared by Queue, Display and canonical history. */
   readonly userMessageId?: UserMessageId;
   readonly content?: string;
+  /** Canonical input retained when readable display text hides explicit plugin identities. */
+  readonly editContent?: string;
   /** Display classification independent from Turn/query identity. */
   readonly kind?: string;
   /** Query sidecar identity; absent only for legacy or non-query user Messages. */
@@ -118,6 +120,7 @@ export class UserMessageCommitService {
         msg_id: messageId,
         role: 'user',
         msg_content: input.content ?? '',
+        ...(input.editContent !== undefined ? { editContent: input.editContent } : {}),
         msg_type: 1,
         timestamp: input.timestamp ?? this.nowMs(),
         kind: input.kind,
diff --git a/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.test.ts b/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.test.ts
new file mode 100644
index 00000000..28432121
--- /dev/null
+++ b/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.test.ts
@@ -0,0 +1,169 @@
+import { buildLocalTurnToolCatalog } from './local-turn-tool-catalog.js';
+import { Type } from '@sinclair/typebox';
+import { describe, expect, it, vi } from 'vitest';
+import type { RuntimeTool } from '@mavis/agent-core/tools';
+import {
+  detectPluginReferencesForMessages,
+  buildPluginReferenceReminder,
+} from '@mavis/system-reminder';
+import {
+  mergeAgentHostTurnCapabilities,
+  type MergeAgentHostTurnCapabilitiesInput,
+} from './local-turn-plugin-capabilities.js';
+
+function tool(name: string): RuntimeTool {
+  return {
+    def: { name, description: 'Synthetic test tool', schema: Type.Object({}) },
+    impl: {
+      execute: vi.fn(async () => ({
+        tool_name: name,
+        text: 'ok',
+        content: [{ type: 'text' as const, text: 'ok' }],
+      })),
+    },
+  };
+}
+function input(
+  userText = '[@My Notes](plugin://notes%40local) summarize',
+): MergeAgentHostTurnCapabilitiesInput {
+  const mcp = tool('mcp__notes__read');
+  const app = tool('app_notes_search');
+  return {
+    tools: [],
+    plan: { deferred: false, inlineTools: [] },
+    model: { provider: 'synthetic', id: 'offline', contextWindow: 128000 },
+    options: {
+      enabled: true,
+      modelWhitelist: [],
+      thresholdPct: 10,
+      minDeferCount: 1,
+      topKDefault: 5,
+      topKMax: 10,
+      systemHint: true,
+      maxSchemaTextLen: 1000,
+    },
+    effectivePluginSkills: [{ pluginName: 'notes', name: 'notes:organize' }],
+    capabilities: {
+      revision: 'r1',
+      plugins: [{ name: 'notes', source: 'local', appProviders: ['notes-app'] }],
+      skills: [],
+      runtimeTools: [mcp, app],
+      runtimeToolBindings: [
+        { kind: 'mcp', source: 'notes-server', pluginName: 'notes', tool: mcp },
+        { kind: 'app', source: 'notes-app', toolMode: 'tool_search', tool: app },
+      ],
+    },
+    userText,
+  };
+}
+
+describe('Plugin identity selection at the final Runtime capability boundary', () => {
+  it('selects exact IDs independently of aliases and never substitutes a same-named source', () => {
+    const local = {
+      name: 'notes',
+      pluginId: 'notes@local',
+      skills: ['notes:organize'],
+      appTools: [],
+      mcpTools: [],
+    };
+    const official = { ...local, pluginId: 'notes@official' };
+    expect(
+      detectPluginReferencesForMessages([], '[@Alias](plugin://notes%40local)', [official, local]),
+    ).toEqual([local]);
+    expect(
+      detectPluginReferencesForMessages([], '[@notes](plugin://notes%40missing)', [local]),
+    ).toEqual([]);
+    expect(detectPluginReferencesForMessages([], '@notes summarize', [official, local])).toEqual(
+      [],
+    );
+    expect(detectPluginReferencesForMessages([], '@notes summarize', [local])).toEqual([local]);
+  });
+
+  it('advertises only effective skills, direct MCP and searchable App tools, preserving callable implementations', async () => {
+    const request = input();
+    const result = mergeAgentHostTurnCapabilities(request);
+    expect(result.reminder).toContain('notes:organize');
+    expect(result.reminder).toContain('mcp__notes__read');
+    expect(result.reminder).toContain('app_notes_search');
+    expect(result.reminder).toContain('tool_search');
+    expect(result.plan.deferred).toBe(true);
+    const mcp = result.tools.find((tool) => tool.def.name === 'mcp__notes__read')!;
+    await expect(mcp.impl.execute({ sessionId: 's', turnId: 't' }, {})).resolves.toMatchObject({
+      text: 'ok',
+    });
+    expect(mcp.toolCallProvenanceResolver?.({ phase: 'start', toolName: mcp.def.name })).toEqual([
+      expect.objectContaining({ plugin_name: 'notes' }),
+    ]);
+  });
+
+  it('discovers and invokes deferred MCP and App tools through the final catalog', async () => {
+    const request = input();
+    const mcp = request.capabilities!.runtimeTools[0]!;
+    const result = buildLocalTurnToolCatalog({
+      sessionId: 's',
+      llmModel: request.model,
+      sources: {
+        nativeTools: [],
+        mcpEntries: [{ tool: mcp, source: 'configured', serverName: 'notes-server' }],
+        threadGoalTools: [],
+        cuRuntimeAvailable: false,
+      },
+      config: { ...request.options, modelWhitelist: ['*'], thresholdPct: 0 },
+      desktopCapabilities: request.capabilities,
+      effectivePluginSkills: request.effectivePluginSkills,
+      userText: request.userText,
+    });
+    expect(result.tools.map((tool) => tool.def.name)).not.toContain(mcp.def.name);
+    expect(result.userPromptPrefix).toContain(
+      'server `notes-server` via `tool_search` + `mcp_invoke`',
+    );
+    const search = result.tools.find((tool) => tool.def.name === 'tool_search')!;
+    const invoke = result.tools.find((tool) => tool.def.name === 'mcp_invoke')!;
+    for (const name of ['mcp__notes__read', 'app_notes_search']) {
+      const found = await search.impl.execute({ sessionId: 's', turnId: 't' }, { query: name });
+      expect(JSON.stringify(found)).toContain(name);
+      await expect(
+        invoke.impl.execute({ sessionId: 's', turnId: 't' }, { tool_name: name, arguments: {} }),
+      ).resolves.toMatchObject({ text: 'ok' });
+    }
+  });
+
+  it('reports a plugin disabled before this turn and does not activate it or use another source', () => {
+    const request = input();
+    const result = mergeAgentHostTurnCapabilities({
+      ...request,
+      effectivePluginSkills: [],
+      capabilities: {
+        revision: 'r2',
+        plugins: [],
+        runtimeTools: [],
+        runtimeToolBindings: [],
+        skills: [],
+      },
+    });
+    expect(result.reminder).toContain('notes@local');
+    expect(result.reminder).toContain('unavailable for this turn');
+    expect(result.tools).toEqual([]);
+    expect(
+      mergeAgentHostTurnCapabilities({ ...request, capabilities: undefined }).reminder,
+    ).toContain('unavailable');
+    expect(
+      mergeAgentHostTurnCapabilities(input('[@notes](plugin://notes%40official)')).reminder,
+    ).toContain('notes@official` is unavailable');
+  });
+
+  it('bounds capability instructions even for large inventories', () => {
+    const result = buildPluginReferenceReminder(
+      Array.from({ length: 40 }, (_, index) => ({
+        name: `plugin-${index}`,
+        pluginId: `plugin-${index}@local`,
+        skills: Array.from({ length: 200 }, (_, i) => `plugin-${index}:skill-${i}`),
+        appTools: [],
+        mcpTools: [],
+      })),
+    );
+    expect(result!.length).toBeLessThan(16384);
+    expect(result).toContain('omitted');
+    expect(result).toContain('</system-reminder>');
+  });
+});
diff --git a/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.ts b/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.ts
index 6d7656a1..0f956f1c 100644
--- a/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.ts
+++ b/packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.ts
@@ -1,3 +1,4 @@
+import { buildPluginId, parsePluginMentions } from '@mavis/shared/plugin-mention';
 import type { RuntimeTool } from '@mavis/agent-core/tools';
 import {
   attachPluginCapabilityAttribution,
@@ -66,7 +67,10 @@ export interface MergeAgentHostTurnCapabilitiesInput {
   readonly capabilities?: AgentHostTurnCapabilityView;
   readonly model: McpModelIdentity;
   readonly options: McpDisclosureOptions;
-  readonly effectivePluginSkills: readonly { readonly pluginName: string; readonly name: string }[];
+  readonly effectivePluginSkills: readonly {
+    readonly pluginName: string;
+    readonly name: string;
+  }[];
   readonly hostCapabilityRegistry?: HostCapabilityResolver;
   readonly surface?: HostCapabilitySurface;
   readonly userText?: string;
@@ -84,7 +88,13 @@ export function mergeAgentHostTurnCapabilities(
 ): MergedAgentHostTurnCapabilities {
   const merged = mergeTools(input);
   const capabilities = input.capabilities;
-  if (!capabilities) return merged;
+  if (!capabilities) {
+    const reminder = buildPluginReferenceReminder(
+      [],
+      parsePluginMentions(input.userText ?? '').map((mention) => mention.pluginId),
+    );
+    return { ...merged, ...(reminder ? { reminder } : {}) };
+  }
   const attributed = {
     ...merged,
     tools: attachPluginCapabilityAttribution(
@@ -98,29 +108,38 @@ export function mergeAgentHostTurnCapabilities(
     ),
   };
   if (input.userText === undefined) return attributed;
-  const reminder = buildPluginReferenceReminder(
-    detectPluginReferencesForMessages(
-      [{ content: input.userText }],
-      input.userText,
-      buildCapabilityInventory({
-        capabilities,
-        effectivePluginSkills: input.effectivePluginSkills,
-        // Attribution decorates relevant tools with cloned wrapper objects.
-        // Inventory filtering must retain the pre-decoration identities used
-        // by runtimeToolBindings and the deferred registry.
-        finalTools: merged.tools,
-        deferredToolNames: new Set(
-          attributed.plan.deferred ? attributed.plan.deferredRegistry.keys() : [],
-        ),
-      }),
+  const inventory = buildCapabilityInventory({
+    capabilities,
+    effectivePluginSkills: input.effectivePluginSkills,
+    // Inventory filtering uses the pre-attribution tool identities.
+    finalTools: merged.tools,
+    deferredToolNames: new Set(
+      attributed.plan.deferred ? attributed.plan.deferredRegistry.keys() : [],
     ),
+  });
+  const unavailable = [
+    ...new Set(parsePluginMentions(input.userText).map((mention) => mention.pluginId)),
+  ].filter(
+    (id) =>
+      !inventory.some(
+        (plugin) =>
+          plugin.pluginId === id &&
+          (plugin.skills.length > 0 || plugin.appTools.length > 0 || plugin.mcpTools.length > 0),
+      ),
+  );
+  const reminder = buildPluginReferenceReminder(
+    detectPluginReferencesForMessages([{ content: input.userText }], input.userText, inventory),
+    unavailable,
   );
   return { ...attributed, ...(reminder ? { reminder } : {}) };
 }
 
 function buildAttributionIndex(input: {
   readonly capabilities: AgentHostTurnCapabilityView;
-  readonly effectivePluginSkills: readonly { readonly pluginName: string; readonly name: string }[];
+  readonly effectivePluginSkills: readonly {
+    readonly pluginName: string;
+    readonly name: string;
+  }[];
   readonly finalTools: readonly RuntimeTool[];
   readonly plan: McpDisclosurePlan;
 }): PluginCapabilityAttributionIndex {
@@ -273,7 +292,10 @@ function mergeSearchableTools(
   );
   for (const tool of selected.searchable) deferredRegistry.set(tool.def.name, tool);
   const index = buildOrReuseIndex(
-    [...deferredRegistry.values()].map((tool) => ({ tool, source: 'configured' as const })),
+    [...deferredRegistry.values()].map((tool) => ({
+      tool,
+      source: 'configured' as const,
+    })),
     { maxSchemaTextLen: input.options.maxSchemaTextLen },
   );
   const estimate = input.options.estimateTokens ?? estimateToolTokens;
@@ -312,16 +334,20 @@ function mergeSearchableTools(
 
 function buildCapabilityInventory(input: {
   readonly capabilities: AgentHostTurnCapabilityView;
-  readonly effectivePluginSkills: readonly { readonly pluginName: string; readonly name: string }[];
+  readonly effectivePluginSkills: readonly {
+    readonly pluginName: string;
+    readonly name: string;
+  }[];
   readonly finalTools: readonly RuntimeTool[];
   readonly deferredToolNames: ReadonlySet<string>;
 }): EffectivePluginCapabilityInventory[] {
   const finalTools = new Set(input.finalTools);
-  const searchableAppToolsAvailable =
+  const searchableToolsAvailable =
     input.finalTools.some((tool) => tool.def.name === 'tool_search') &&
     input.finalTools.some((tool) => tool.def.name === 'mcp_invoke');
   return input.capabilities.plugins.map((plugin) => ({
     name: plugin.name,
+    pluginId: buildPluginId(plugin.name, plugin.source),
     appTools: plugin.appProviders.flatMap((provider) => {
       const bindings = input.capabilities.runtimeToolBindings.filter(
         (binding) => binding.kind === 'app' && binding.source === provider,
@@ -333,7 +359,7 @@ function buildCapabilityInventory(input: {
           ? [binding.tool.def.name]
           : [],
       );
-      const searchable = searchableAppToolsAvailable
+      const searchable = searchableToolsAvailable
         ? bindings.flatMap((binding) =>
             binding.toolMode === 'tool_search' && input.deferredToolNames.has(binding.tool.def.name)
               ? [binding.tool.def.name]
@@ -343,18 +369,37 @@ function buildCapabilityInventory(input: {
       return [
         ...(direct.length > 0 ? [{ source: provider, tools: direct }] : []),
         ...(searchable.length > 0
-          ? [{ source: provider, tools: searchable, access: 'tool_search' as const }]
+          ? [
+              {
+                source: provider,
+                tools: searchable,
+                access: 'tool_search' as const,
+              },
+            ]
           : []),
       ];
     }),
-    mcpTools: groupMcpTools(
-      input.capabilities.runtimeToolBindings.filter(
-        (binding) =>
-          binding.kind === 'mcp' &&
-          binding.pluginName === plugin.name &&
-          finalTools.has(binding.tool),
+    mcpTools: [
+      ...groupMcpTools(
+        input.capabilities.runtimeToolBindings.filter(
+          (binding) =>
+            binding.kind === 'mcp' &&
+            binding.pluginName === plugin.name &&
+            finalTools.has(binding.tool),
+        ),
       ),
-    ),
+      ...(searchableToolsAvailable
+        ? groupMcpTools(
+            input.capabilities.runtimeToolBindings.filter(
+              (binding) =>
+                binding.kind === 'mcp' &&
+                binding.pluginName === plugin.name &&
+                !finalTools.has(binding.tool) &&
+                input.deferredToolNames.has(binding.tool.def.name),
+            ),
+          ).map((group) => ({ ...group, access: 'tool_search' as const }))
+        : []),
+    ],
     skills: input.effectivePluginSkills.flatMap((skill) =>
       skill.pluginName === plugin.name ? [skill.name] : [],
     ),
diff --git a/packages/protocol/src/local.ts b/packages/protocol/src/local.ts
index c313e961..10c8268f 100644
--- a/packages/protocol/src/local.ts
+++ b/packages/protocol/src/local.ts
@@ -339,6 +339,8 @@ export interface MemoryReferenceView {
 
 export interface SessionMessageView {
   msgId: string;
+  /** Canonical user text for editing when display text omits plugin identities. */
+  editContent?: string;
   parentMsgId?: string;
   timestamp?: number;
   msgContent?: string;
diff --git a/packages/shared/package.json b/packages/shared/package.json
index 57e7636a..456b4e3a 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -191,6 +191,10 @@
     "./safety-check-v2": {
       "types": "./src/safety-check-v2.ts",
       "import": "./dist/safety-check-v2.js"
+    },
+    "./plugin-mention": {
+      "types": "./src/plugin-mention.ts",
+      "import": "./dist/plugin-mention.js"
     }
   },
   "types": "./src/index.ts",
diff --git a/packages/shared/src/plugin-mention.ts b/packages/shared/src/plugin-mention.ts
new file mode 100644
index 00000000..d738380b
--- /dev/null
+++ b/packages/shared/src/plugin-mention.ts
@@ -0,0 +1,40 @@
+/** Durable plugin identity shared by Composer history and Runtime selection. */
+export function buildPluginId(name: string, source: 'official' | 'local'): string {
+  return `${name.trim()}@${source}`;
+}
+
+export interface PluginMention {
+  readonly pluginId: string;
+  readonly label: string;
+  readonly start: number;
+  readonly end: number;
+}
+
+export function serializePluginMention(pluginId: string, label: string): string {
+  const name = label
+    .replace(/^@/u, '')
+    .replace(/[\[\]\r\n\\]/gu, ' ')
+    .slice(0, 256);
+  return `[@${name}](plugin://${encodeURIComponent(pluginId)})`;
+}
+
+/** Linked references also work in exec and ACP text inputs. Display names never select identity. */
+export function parsePluginMentions(text: string): PluginMention[] {
+  const result: PluginMention[] = [];
+  for (const match of text.matchAll(/\[@([^\]\r\n]{1,256})\]\(plugin:\/\/([^\s()]{1,768})\)/gu)) {
+    let pluginId: string;
+    try {
+      pluginId = decodeURIComponent(match[2]!);
+    } catch {
+      continue;
+    }
+    if (!pluginId || pluginId.length > 512 || /[\u0000-\u001f\u007f]/u.test(pluginId)) continue;
+    result.push({
+      pluginId,
+      label: `@${match[1]}`,
+      start: match.index,
+      end: match.index + match[0].length,
+    });
+  }
+  return result;
+}
diff --git a/packages/tui/src/application/run-coordinator.ts b/packages/tui/src/application/run-coordinator.ts
index bfdcda4e..211a1eb2 100644
--- a/packages/tui/src/application/run-coordinator.ts
+++ b/packages/tui/src/application/run-coordinator.ts
@@ -28,6 +28,7 @@ export interface TuiRunRequest {
   turnId: string;
   session: Promise<TuiSession>;
   content: string;
+  displayContent?: string;
   workspace: string;
   version: string;
   attachments?: readonly TuiTransportAttachment[];
@@ -406,6 +407,7 @@ function toSendMessageRequest(
     id: session.sessionId,
     turnId: request.turnId,
     content: request.content,
+    ...(request.displayContent !== undefined ? { displayContent: request.displayContent } : {}),
     ...(executionDeadlineAtMs !== undefined ? { executionDeadlineAtMs } : {}),
     ...(request.executionDiagnostics ? { executionDiagnostics: true } : {}),
     ...(request.clientIntent ? { clientIntent: request.clientIntent } : {}),
diff --git a/packages/tui/src/runtime/adapters/plugin-access.ts b/packages/tui/src/runtime/adapters/plugin-access.ts
index 3b857017..035ec738 100644
--- a/packages/tui/src/runtime/adapters/plugin-access.ts
+++ b/packages/tui/src/runtime/adapters/plugin-access.ts
@@ -1,3 +1,4 @@
+import { buildPluginId } from '@mavis/shared/plugin-mention';
 import type {
   CliService,
   InstalledPluginSummary,
@@ -124,7 +125,7 @@ function toPluginView(
   const name = plugin.name.trim();
   if (!name) return undefined;
   return {
-    pluginId: `${name}@${marketplace}`,
+    pluginId: buildPluginId(name, marketplace),
     name,
     displayName: plugin.displayName?.trim() || name,
     marketplace,
diff --git a/packages/tui/src/runtime/stream-events.ts b/packages/tui/src/runtime/stream-events.ts
index 5644b107..55ca8996 100644
--- a/packages/tui/src/runtime/stream-events.ts
+++ b/packages/tui/src/runtime/stream-events.ts
@@ -44,6 +44,7 @@ export type TuiMessagePart =
     };
 
 export interface TuiMessage {
+  editContent?: string;
   id?: string;
   turnId?: string;
   role: TuiMessageRole;
@@ -333,6 +334,7 @@ function normalizeMessage(message: Record<string, unknown>, fallbackTurnId?: str
     tokensBefore: readNumber(message, ['tokensBefore', 'tokens_before']),
     tokensAfter: readNumber(message, ['tokensAfter', 'tokens_after']),
     content: readString(message, ['msg_content', 'msgContent', 'content']),
+    editContent: readString(message, ['editContent']),
     thinking: readString(message, ['thinking_content', 'thinkingContent', 'thinking']),
     thinkingDurationMs: readNumber(message, ['thinking_duration_ms', 'thinkingDurationMs']),
     toolCalls: normalizeToolCalls(readArray(message, ['tool_calls', 'toolCalls'])),
diff --git a/packages/tui/src/tui/commands/plugin-autocomplete.ts b/packages/tui/src/tui/commands/plugin-autocomplete.ts
new file mode 100644
index 00000000..abe63065
--- /dev/null
+++ b/packages/tui/src/tui/commands/plugin-autocomplete.ts
@@ -0,0 +1,113 @@
+import type { McodePluginRuntimeAccess } from '../../plugin/contract.js';
+import type { AutocompleteItem, AutocompleteProvider } from '../widgets/autocomplete.js';
+import { truncateToWidth } from '../engine/public.js';
+import { sanitizeTerminalText } from '../rendering/terminal-text.js';
+
+export interface PluginAutocompleteItem extends AutocompleteItem {
+  readonly pluginId: string;
+  readonly groupLabel: string;
+}
+
+/** Product-level plugin candidates share @ with files; plugin state stays in Runtime. */
+export class TuiPluginAutocomplete implements AutocompleteProvider {
+  readonly triggerCharacters = ['@'];
+
+  constructor(
+    private readonly base: AutocompleteProvider,
+    private readonly plugins?: Partial<Pick<McodePluginRuntimeAccess, 'listInstalledPlugins'>>,
+  ) {}
+
+  async getSuggestions(
+    lines: string[],
+    cursorLine: number,
+    cursorCol: number,
+    options: { signal: AbortSignal; force?: boolean },
+  ) {
+    const before = (lines[cursorLine] ?? '').slice(0, cursorCol);
+    const prefix = /(?:^|\s)(@[^\s"/]*)$/u.exec(before)?.[1];
+    if (
+      !prefix ||
+      lines.join('\n').trimStart().startsWith('!') ||
+      !this.plugins?.listInstalledPlugins
+    ) {
+      return this.base.getSuggestions(lines, cursorLine, cursorCol, options);
+    }
+    const [files, plugins] = await Promise.allSettled([
+      this.base.getSuggestions(lines, cursorLine, cursorCol, options),
+      this.plugins.listInstalledPlugins(),
+    ]);
+    if (options.signal.aborted) return null;
+    const fileSuggestions = files.status === 'fulfilled' ? files.value : null;
+    const query = prefix.slice(1).normalize('NFKC').toLocaleLowerCase();
+    const items: PluginAutocompleteItem[] =
+      plugins.status === 'fulfilled'
+        ? plugins.value
+            .filter(
+              (plugin) =>
+                plugin.installed &&
+                plugin.enabled &&
+                [plugin.name, plugin.displayName, plugin.pluginId].some((text) =>
+                  text.normalize('NFKC').toLocaleLowerCase().includes(query),
+                ),
+            )
+            .sort(
+              (a, b) =>
+                a.displayName.localeCompare(b.displayName) || a.pluginId.localeCompare(b.pluginId),
+            )
+            .map((plugin) => {
+              const name =
+                sanitizeTerminalText(plugin.displayName)
+                  .replace(/[\[\]\\]/gu, ' ')
+                  .replace(/\s+/gu, ' ')
+                  .trim()
+                  .slice(0, 256) || plugin.name;
+              return {
+                value: `@${name}`,
+                label: `@${name}`,
+                pluginId: plugin.pluginId,
+                groupLabel: '  Plugins',
+                description: `${plugin.marketplace} · ${truncateToWidth(
+                  sanitizeTerminalText(plugin.description ?? plugin.name)
+                    .replace(/\s+/gu, ' ')
+                    .trim(),
+                  64,
+                  '…',
+                )}`,
+              };
+            })
+        : [];
+    const combined = [
+      ...items,
+      ...(fileSuggestions?.items ?? []).map((item) => ({
+        ...item,
+        ...(items.length > 0 ? { groupLabel: '  Files' } : {}),
+      })),
+    ];
+    return combined.length ? { prefix, items: combined } : null;
+  }
+
+  applyCompletion(
+    lines: string[],
+    cursorLine: number,
+    cursorCol: number,
+    item: AutocompleteItem,
+    prefix: string,
+  ) {
+    if (!('pluginId' in item))
+      return this.base.applyCompletion(lines, cursorLine, cursorCol, item, prefix);
+    const line = lines[cursorLine] ?? '';
+    const start = cursorCol - prefix.length;
+    const insertion = `${item.value} `;
+    const next = [...lines];
+    next[cursorLine] = line.slice(0, start) + insertion + line.slice(cursorCol);
+    return { lines: next, cursorLine, cursorCol: start + insertion.length };
+  }
+
+  shouldAutoTriggerCompletion(lines: string[], cursorLine: number, cursorCol: number) {
+    return this.base.shouldAutoTriggerCompletion?.(lines, cursorLine, cursorCol);
+  }
+
+  shouldTriggerFileCompletion(lines: string[], cursorLine: number, cursorCol: number) {
+    return this.base.shouldTriggerFileCompletion?.(lines, cursorLine, cursorCol) ?? false;
+  }
+}
diff --git a/packages/tui/src/tui/controller/chat-controller.ts b/packages/tui/src/tui/controller/chat-controller.ts
index abd1b851..f7724640 100644
--- a/packages/tui/src/tui/controller/chat-controller.ts
+++ b/packages/tui/src/tui/controller/chat-controller.ts
@@ -435,6 +435,7 @@ export class TuiChatController {
           turnId,
           session,
           content,
+          ...(options.displayContent !== undefined ? { displayContent } : {}),
           workspace: this.workspaceDir,
           version: this.version,
           ...(attachments.length > 0 ? { attachments } : {}),
diff --git a/packages/tui/src/tui/controller/interaction/input-flow.ts b/packages/tui/src/tui/controller/interaction/input-flow.ts
index 75509bb3..612196e7 100644
--- a/packages/tui/src/tui/controller/interaction/input-flow.ts
+++ b/packages/tui/src/tui/controller/interaction/input-flow.ts
@@ -109,6 +109,7 @@ export class TuiInputFlow {
       item,
     ) => {
       previousAutocompleteSelect?.(suggestions, item);
+      if ('pluginId' in item) return;
       const imageReference = selectedImageMentionReference(item.value, suggestions.prefix);
       if (!imageReference) return;
       void this.options.composerDraft.queueAttachment(imageReference).catch((error: unknown) =>
@@ -505,6 +506,7 @@ export class TuiInputFlow {
       this.options.editor.restoreDraft({
         ...this.clearedEditorDraft,
         text: '',
+        pluginMentions: [],
         cursor: 0,
         pastes: [],
         attachmentPlaceholders: [],
diff --git a/packages/tui/src/tui/controller/product/command-flow.ts b/packages/tui/src/tui/controller/product/command-flow.ts
index 43b93fdc..1b00837f 100644
--- a/packages/tui/src/tui/controller/product/command-flow.ts
+++ b/packages/tui/src/tui/controller/product/command-flow.ts
@@ -1,3 +1,4 @@
+import { parsePluginMentions } from '@mavis/shared/plugin-mention';
 import {
   createTuiCommandCatalog,
   matchTuiCommandInput,
@@ -12,7 +13,7 @@ import { TuiLoginRegionPicker } from '../../features/auth/login-region-picker.js
 import { TuiPermissionModePicker } from '../../features/interaction/permission-mode-picker.js';
 import { TuiSettingsPicker } from '../../features/settings/picker.js';
 import { TuiHotkeysPicker } from '../../features/settings/hotkeys-picker.js';
-import { submittedEditorContent, type Editor } from '../../widgets/editor/editor.js';
+import { submittedEditorContent, submittedEditorTransport, type Editor } from '../../widgets/editor/editor.js';
 import type { TuiInteractionSurface } from '../../shell/interaction-surface.js';
 import type { TuiSurfaceHost } from '../../shell/surface-host.js';
 import type { TuiRunProjection } from '../../state/run-projection.js';
@@ -226,10 +227,14 @@ export class TuiCommandFlow {
     // Hidden context may be rebuilt for an edited session-mutation message.
     // Other opaque transport (including /review) belongs to the old text and
     // must not override the user's correction.
-    const transportContent = recoverable?.transportContent &&
+    const pluginTransport = recoverable?.transportContent && parsePluginMentions(recoverable.transportContent).length > 0
+      ? rebuildSessionMutationTransport(recoverable.transportContent, submittedEditorTransport(editor) ?? visibleContent)
+      : undefined;
+    const transportContent = pluginTransport ?? (recoverable?.transportContent &&
+      parsePluginMentions(recoverable.transportContent).length === 0 &&
       (unchangedText || rebuildSessionMutationTransport(recoverable.transportContent, visibleContent))
       ? recoverable.transportContent
-      : undefined;
+      : undefined);
     const transportAttachments = recoverable?.transportAttachments
       ? reconcileRecoveredTransportAttachments(recoverable, resources.attachments)
       : undefined;
@@ -273,7 +278,7 @@ export class TuiCommandFlow {
           requireRuntimeAcceptance: true,
           transportContent:
             options.transportContent ??
-            rebuildSessionMutationTransport(recoveryTransport, input) ??
+            rebuildSessionMutationTransport(recoveryTransport, seed ? submittedEditorTransport(seed.editor) ?? input : input) ??
             recoveryTransport,
           ...(seed?.reviewRequest && !options.reviewRequest
             ? { reviewRequest: seed.reviewRequest }
@@ -507,9 +512,11 @@ export class TuiCommandFlow {
         const bashContext = this.options.bashFlow?.takeContext(
           seed ? seed.sessionId : this.options.controller.snapshot().session?.sessionId,
         );
+        const boundContent = seed ? submittedEditorTransport(seed.editor) : undefined;
+        const messageContent = options.transportContent ?? boundContent;
         const transportContent = bashContext
-          ? `${bashContext}\n\n${options.transportContent ?? command}`
-          : options.transportContent;
+          ? `${bashContext}\n\n${messageContent ?? command}`
+          : messageContent;
         let submission = createTuiSubmissionSnapshot({
           submissionId,
           sessionId: seed ? seed.sessionId : this.options.controller.snapshot().session?.sessionId,
diff --git a/packages/tui/src/tui/controller/product/session-mutation-flow.ts b/packages/tui/src/tui/controller/product/session-mutation-flow.ts
index 10f95a6e..9ffc66d3 100644
--- a/packages/tui/src/tui/controller/product/session-mutation-flow.ts
+++ b/packages/tui/src/tui/controller/product/session-mutation-flow.ts
@@ -1,3 +1,4 @@
+import { submittedEditorTransport } from '../../widgets/editor/editor.js';
 import type { TuiChatController } from '../chat-controller.js';
 import type { Component, Focusable } from '../../rendering/component.js';
 import { matchesKey } from '../../engine/public.js';
@@ -415,8 +416,12 @@ export class TuiSessionMutationFlow {
       this.options.onChanged();
       return 'retained';
     }
+    const boundContent = draft ? submittedEditorTransport(draft) ?? content : content;
     const transportContent =
-      rebuildSessionMutationTransport(invocation.targetMessage?.content, content) ?? content;
+      rebuildSessionMutationTransport(
+        invocation.targetMessage?.editContent ?? invocation.targetMessage?.content,
+        boundContent,
+      ) ?? boundContent;
     if (invocation.phase === 'resubmit') {
       this.invocations.set(invocation.sequence, { ...invocation, phase: 'resubmitting' });
       this.options.setHint(sessionMutationText('sessionMutation.hint.editSubmitting'));
@@ -658,7 +663,9 @@ export class TuiSessionMutationFlow {
     this.closeHistoryScreen();
     this.options.setEditTranscriptBoundary?.(targetMessage.id);
     this.invocations.set(sequence, { ...invocation, targetMessage, phase: 'editing' });
-    const content = visibleSessionMutationContent(targetMessage.content);
+    const content = visibleSessionMutationContent(
+      targetMessage.editContent ?? targetMessage.content,
+    );
     const placeholders = this.editAttachmentEntries();
     if (placeholders.length > 0) this.options.editor.restoreMessageDraft(content, placeholders);
     else this.options.editor.setText(content);
diff --git a/packages/tui/src/tui/controller/projection/turn-user-projection.ts b/packages/tui/src/tui/controller/projection/turn-user-projection.ts
index 7bf3910c..957d0c1c 100644
--- a/packages/tui/src/tui/controller/projection/turn-user-projection.ts
+++ b/packages/tui/src/tui/controller/projection/turn-user-projection.ts
@@ -1,3 +1,4 @@
+import { parsePluginMentions } from '@mavis/shared/plugin-mention';
 import type { TuiMessage } from '../../../runtime/port.js';
 import {
   formatTuiHistorySubmission,
@@ -34,7 +35,7 @@ export class TuiUserProjection {
       return;
     }
     const visibleContent =
-      message.source === 'code_review' ? '/review' : visibleSessionMutationContent(content);
+      message.source === 'code_review' ? '/review' : visibleUserContent(content);
     this.transcript.upsert({
       id: `history:user:${messageId}`,
       kind: 'user',
@@ -69,7 +70,7 @@ export class TuiUserProjection {
       return false;
     }
     const formatted = formatTuiHistorySubmission(
-      message.source === 'code_review' ? '/review' : visibleSessionMutationContent(content),
+      message.source === 'code_review' ? '/review' : visibleUserContent(content),
       message.attachments ?? [],
     );
     const attachments = toTuiTranscriptAttachments(message.attachments ?? []);
@@ -187,3 +188,12 @@ function mergeTranscriptAttachments(
     ...attachment,
   }));
 }
+
+/** Older persisted rows may still contain the durable plugin transport links. */
+function visibleUserContent(content: string): string {
+  let visible = visibleSessionMutationContent(content);
+  for (const mention of parsePluginMentions(visible).reverse()) {
+    visible = visible.slice(0, mention.start) + mention.label + visible.slice(mention.end);
+  }
+  return visible;
+}
diff --git a/packages/tui/src/tui/controller/run/active-run-flow.ts b/packages/tui/src/tui/controller/run/active-run-flow.ts
index 2604786d..333083bb 100644
--- a/packages/tui/src/tui/controller/run/active-run-flow.ts
+++ b/packages/tui/src/tui/controller/run/active-run-flow.ts
@@ -1,3 +1,5 @@
+import { TuiPluginAutocomplete } from '../../commands/plugin-autocomplete.js';
+import type { McodePluginRuntimeAccess } from '../../../plugin/contract.js';
 import type { Component } from '../../rendering/component.js';
 import type { Terminal } from '../../engine/public.js';
 import {
@@ -57,7 +59,9 @@ export interface TuiSteerOptions {
 
 export function createTuiInitialAutocomplete(
   workspace: string | readonly TuiWorkspaceRoot[],
-  workspaceFiles?: Partial<TuiWorkspaceFilePort>,
+  workspaceFiles?: Partial<
+    TuiWorkspaceFilePort & Pick<McodePluginRuntimeAccess, 'listInstalledPlugins'>
+  >,
   builtInCommands: readonly TuiCommand[] = MINIMAX_CODE_DISCOVERABLE_COMMANDS,
 ) {
   return createTuiAutocomplete(builtInCommands, [], workspace, workspaceFiles);
@@ -67,15 +71,20 @@ export function createTuiAutocomplete(
   builtInCommands: readonly TuiCommand[],
   skillCommands: readonly TuiCommand[],
   workspace: string | readonly TuiWorkspaceRoot[],
-  workspaceFiles?: Partial<TuiWorkspaceFilePort>,
+  workspaceFiles?: Partial<
+    TuiWorkspaceFilePort & Pick<McodePluginRuntimeAccess, 'listInstalledPlugins'>
+  >,
   shellCwd?: () => string,
 ): AutocompleteProvider {
-  return new TuiAutocompleteProvider(
-    builtInCommands,
-    skillCommands,
-    workspace,
+  return new TuiPluginAutocomplete(
+    new TuiAutocompleteProvider(
+      builtInCommands,
+      skillCommands,
+      workspace,
+      workspaceFiles,
+      shellCwd,
+    ),
     workspaceFiles,
-    shellCwd,
   );
 }
 
@@ -132,11 +141,9 @@ export class TuiActiveRunFlow {
   private autocompleteHasLiveRun: boolean | undefined;
   private autocompleteSignature: string | undefined;
   private pendingAutocomplete:
-    | { readonly provider: AutocompleteProvider; readonly signature: string }
-    | undefined;
+    { readonly provider: AutocompleteProvider; readonly signature: string } | undefined;
   private contextInspection:
-    | { readonly sessionId: string; readonly panel: TuiReportInspectionPanel }
-    | undefined;
+    { readonly sessionId: string; readonly panel: TuiReportInspectionPanel } | undefined;
 
   constructor(
     private readonly options: {
@@ -569,7 +576,9 @@ class TuiAutocompleteProvider implements AutocompleteProvider {
     builtInCommands: readonly TuiCommand[],
     skillCommands: readonly TuiCommand[],
     workspace: string | readonly TuiWorkspaceRoot[],
-    private readonly workspaceFiles?: Partial<TuiWorkspaceFilePort>,
+    private readonly workspaceFiles?: Partial<
+      TuiWorkspaceFilePort & Pick<McodePluginRuntimeAccess, 'listInstalledPlugins'>
+    >,
     shellCwd?: () => string,
   ) {
     this.workspaceRoots = normalizeAutocompleteRoots(workspace);
@@ -732,7 +741,10 @@ class TuiAutocompleteProvider implements AutocompleteProvider {
     const directory = query ? query.slice(0, -1) : undefined;
     if (this.workspaceFiles?.listWorkspaceFileTreeCandidates) {
       const entries = await this.workspaceFiles.listWorkspaceFileTreeCandidates(
-        { roots: this.workspaceRoots, ...(directory ? { path: directory } : {}) },
+        {
+          roots: this.workspaceRoots,
+          ...(directory ? { path: directory } : {}),
+        },
         signal,
       );
       return entries.flatMap((entry) => this.toMultiRootTreeItem(entry));
diff --git a/packages/tui/src/tui/controller/run/queue-flow.ts b/packages/tui/src/tui/controller/run/queue-flow.ts
index 7632f22b..3a87c34f 100644
--- a/packages/tui/src/tui/controller/run/queue-flow.ts
+++ b/packages/tui/src/tui/controller/run/queue-flow.ts
@@ -1,3 +1,4 @@
+import { decodePluginMentions, encodePluginMentions, transformPluginMentions } from '../../widgets/editor/plugin-mentions.js';
 import type {
   TuiModelSelection,
   TuiQueuePort,
@@ -301,6 +302,12 @@ export class TuiQueueFlow {
         ? (submission?.transportContent ?? rememberedTransport)
         : (item.content ?? submission?.transportContent ?? rememberedTransport);
     if (!transportContent) return item;
+    const decoded = decodePluginMentions(visibleSessionMutationContent(transportContent));
+    if (decoded.mentions.length) {
+      this.queuedTransportContents.set(item.itemId, transportContent);
+      return { ...item, content: decoded.text };
+    }
+    if (rememberedTransport && decodePluginMentions(visibleSessionMutationContent(rememberedTransport)).text === item.content) return item;
     if (item.reviewRequest) {
       this.queuedTransportContents.set(item.itemId, transportContent);
       return { ...item, content: '/review' };
@@ -575,8 +582,11 @@ export class TuiQueueFlow {
     }
     const sessionId = this.options.controller.snapshot().session?.sessionId;
     if (!sessionId) return false;
-    const transportContent =
-      rebuildSessionMutationTransport(this.queuedTransportContents.get(itemId), content) ?? content;
+    const previousTransport = this.queuedTransportContents.get(itemId);
+    const previous = decodePluginMentions(visibleSessionMutationContent(previousTransport ?? cached?.content));
+    const mentions = transformPluginMentions(previous.text, content, previous.mentions);
+    const boundContent = encodePluginMentions(content, mentions);
+    const transportContent = rebuildSessionMutationTransport(previousTransport, boundContent) ?? boundContent;
     const updated = await this.options.runtime.updateQueuedMessageContent(
       sessionId,
       itemId,
@@ -588,6 +598,8 @@ export class TuiQueueFlow {
       await this.refresh(sessionId);
       return false;
     }
+    if (transportContent !== content) this.queuedTransportContents.set(itemId, transportContent);
+    else this.queuedTransportContents.delete(itemId);
     const captured = this.queuedSubmissions.get(itemId);
     if (captured) {
       this.queuedSubmissions.set(itemId, {
@@ -596,6 +608,7 @@ export class TuiQueueFlow {
           schemaVersion: 1,
           text: content,
           cursor: content.length,
+          pluginMentions: mentions,
           pastes: [],
           pasteCounter: 0,
         },
@@ -792,7 +805,8 @@ function createSubmissionFromQueuedMessage(
   submissionId: string,
   transportContent?: string,
 ): TuiSubmissionSnapshot {
-  const content = item.content ?? '';
+  const decoded = decodePluginMentions(visibleSessionMutationContent(transportContent ?? item.content));
+  const content = decoded.text;
   const transportAttachments = (item.attachments ?? []).flatMap<TuiTransportAttachment>(
     (attachment) => {
       const filePath = attachment.local?.filePath;
@@ -816,12 +830,13 @@ function createSubmissionFromQueuedMessage(
     editor: {
       schemaVersion: 1,
       text: content,
+      pluginMentions: decoded.mentions,
       cursor: content.length,
       pastes: [],
       pasteCounter: 0,
     },
     content,
-    ...(transportContent ? { transportContent } : {}),
+    ...(transportContent || decoded.mentions.length ? { transportContent: transportContent ?? item.content } : {}),
     attachments: (item.attachments ?? []).flatMap((attachment) => {
       const filePath = attachment.local?.filePath;
       if (!filePath) return [];
diff --git a/packages/tui/src/tui/engine/LOCAL_CHANGES.json b/packages/tui/src/tui/engine/LOCAL_CHANGES.json
index f39b20b7..690550ab 100644
--- a/packages/tui/src/tui/engine/LOCAL_CHANGES.json
+++ b/packages/tui/src/tui/engine/LOCAL_CHANGES.json
@@ -21,9 +21,9 @@
     },
     {
       "path": "components/editor.ts",
-      "currentSha256": "0775a490df136d1083738cce649e026d6153ecb5480715b2c1104d51051968c5",
-      "changeIds": ["L005", "L009", "L022", "L030", "L032"],
-      "reason": "Keep strict TypeScript fixes and add the smallest generic snapshot, paste, telemetry, programmatic submission, undo-extension and empty-placeholder hooks needed by the MCode product wrapper. 提供方通过上下文回调控制自动触发，并通过 applyOnEnter 控制 Enter 是否填入候选。 强制补全上下文失效时立即取消请求并清空菜单。 支持单帧 placeholder 覆盖，由 Editor 统一保留 padding、可见光标和 IME 定位标记。 命令参数候选标记阶段，接受命令后续查参数，并隔离参数回调失败。",
+      "currentSha256": "55d313e4f7f5760212e0ff397cb7a599c52d42a90df8c0014f25cf4652897d20",
+      "changeIds": ["L005", "L009", "L022", "L030", "L032", "L042"],
+      "reason": "Preserve product history metadata through a generic text transform and draft extension state. Keep strict TypeScript fixes and add the smallest generic snapshot, paste, telemetry, programmatic submission, undo-extension and empty-placeholder hooks needed by the MCode product wrapper. 提供方通过上下文回调控制自动触发，并通过 applyOnEnter 控制 Enter 是否填入候选。 强制补全上下文失效时立即取消请求并清空菜单。 支持单帧 placeholder 覆盖，由 Editor 统一保留 padding、可见光标和 IME 定位标记。 命令参数候选标记阶段，接受命令后续查参数，并隔离参数回调失败。",
       "behaviorImpact": "MCode Draft, attachment, product-level submission-intent and empty-input guidance semantics use the canonical Pi Editor cursor, width, padding, history, undo, paste-marker and autocomplete behavior. Shell 补全只由 Tab 打开，菜单内输入继续过滤；Enter 执行当前输入，Tab 填入选中项。其他提供方沿用默认行为。 删除 Shell 标记或命令名前缀后立即关闭候选；已取消请求的延迟结果无法恢复旧菜单。 带参数候选的命令支持连续补全，参数 Enter 仅填入，Esc 保留草稿；无参数命令保持原行为。"
     },
     {
diff --git a/packages/tui/src/tui/engine/LOCAL_CHANGES.md b/packages/tui/src/tui/engine/LOCAL_CHANGES.md
index 50b72941..b240a9f3 100644
--- a/packages/tui/src/tui/engine/LOCAL_CHANGES.md
+++ b/packages/tui/src/tui/engine/LOCAL_CHANGES.md
@@ -170,3 +170,10 @@ Remove `L024` when the selected Pi baseline natively matches legacy-terminal `Ct
 - Evidence: application tests replay `/theme`, `/settings`, prompt-history search, image-preview dismissal, multi-line draft clearing and completion filtering. Engine tests repeatedly expand/shrink each transient section under xterm and an ED 2 clear-to-scrollback model, compare the complete viewport, verify unique history, and retain positive background-activity scroll preservation. Short documents avoid unnecessary clearing.
 - Boundary: full history reconstruction retains L034's shell-scrollback tradeoff. Emulator tests do not establish native terminal or live-service acceptance.
 - Removal condition: the selected Pi baseline distinguishes transient UI layout shrink from ordinary background content shrink.
+
+## L042: Preserve product mention bindings in prompt history
+
+- Product contract: plugin labels retain their exact identities while browsing history, including restoration of the working draft.
+- Minimal difference: expose a generic history-text decoder and capture/restore the existing undo extension state alongside the history draft. Plugin parsing and identity ownership stay in the product Editor.
+- Evidence: `tui-plugin-mentions.test.ts` covers repeated history navigation, identical display labels with different IDs, working-draft restoration, atomic deletion and undo.
+- Removal condition: the selected Pi baseline supports durable history decoding and draft extension state.
diff --git a/packages/tui/src/tui/engine/components/editor.ts b/packages/tui/src/tui/engine/components/editor.ts
index 999096c7..5c8a5657 100644
--- a/packages/tui/src/tui/engine/components/editor.ts
+++ b/packages/tui/src/tui/engine/components/editor.ts
@@ -356,6 +356,7 @@ export class Editor implements Component, Focusable {
   private history: string[] = [];
   private historyIndex: number = -1; // -1 = not browsing, 0 = most recent, 1 = older, etc.
   private historyDraft: EditorState | null = null;
+  private historyDraftExtensionState: unknown;
 
   // Kill ring for Emacs-style kill/yank operations
   private killRing = new KillRing();
@@ -377,6 +378,8 @@ export class Editor implements Component, Focusable {
   // Undo support
   private undoStack = new UndoStack<EditorSnapshot>();
 
+  /** Decode a durable history entry before restoring its editable text. */
+  public transformHistoryText?: (text: string) => string;
   public onSubmit?: (text: string, snapshot: EditorStateSnapshot) => void;
   public onChange?: (text: string) => void;
   public onPaste?: (text: string) => boolean;
@@ -496,6 +499,7 @@ export class Editor implements Component, Focusable {
     if (this.historyIndex === -1 && newIndex >= 0) {
       this.pushUndoSnapshot();
       this.historyDraft = structuredClone(this.state);
+      this.historyDraftExtensionState = this.captureUndoExtensionState?.();
     }
 
     this.historyIndex = newIndex;
@@ -505,6 +509,8 @@ export class Editor implements Component, Focusable {
       this.historyDraft = null;
       if (draft) {
         this.state = draft;
+        this.restoreUndoExtensionState?.(this.historyDraftExtensionState);
+        this.historyDraftExtensionState = undefined;
         this.preferredVisualCol = null;
         this.snappedFromCursorCol = null;
         this.scrollOffset = 0;
@@ -514,7 +520,7 @@ export class Editor implements Component, Focusable {
       }
     } else {
       this.setTextInternal(
-        this.history[this.historyIndex] || '',
+        this.transformHistoryText?.(this.history[this.historyIndex] || '') ?? this.history[this.historyIndex] ?? '',
         direction === -1 ? 'start' : 'end',
       );
     }
@@ -523,6 +529,7 @@ export class Editor implements Component, Focusable {
   private exitHistoryBrowsing(): void {
     this.historyIndex = -1;
     this.historyDraft = null;
+    this.historyDraftExtensionState = undefined;
   }
 
   /** Internal setText that doesn't reset history state - used by navigateHistory */
@@ -1221,6 +1228,8 @@ export class Editor implements Component, Focusable {
     this.onAutocompleteSelect = undefined;
     this.captureUndoExtensionState = undefined;
     this.restoreUndoExtensionState = undefined;
+    this.transformHistoryText = undefined;
+    this.historyDraftExtensionState = undefined;
   }
 
   /**
diff --git a/packages/tui/src/tui/features/composer/draft-recovery.ts b/packages/tui/src/tui/features/composer/draft-recovery.ts
index 0e8a829e..505198dd 100644
--- a/packages/tui/src/tui/features/composer/draft-recovery.ts
+++ b/packages/tui/src/tui/features/composer/draft-recovery.ts
@@ -1,3 +1,4 @@
+import { validPluginMentions } from '../../widgets/editor/plugin-mentions.js';
 import { createHash } from 'node:crypto';
 import {
   chmod,
@@ -431,7 +432,10 @@ export class TuiDraftRecovery {
               const relocatedPath = attachment.filePath
                 ? relocatedPaths.get(attachment.filePath)
                 : undefined;
-              return { ...attachment, ...(relocatedPath ? { filePath: relocatedPath } : {}) };
+              return {
+                ...attachment,
+                ...(relocatedPath ? { filePath: relocatedPath } : {}),
+              };
             }),
           }
         : {}),
@@ -450,7 +454,9 @@ export class TuiDraftRecovery {
         .map((attachment) => resolve(attachment.filePath))
         .filter((filePath) => dirname(filePath) === resolve(this.assetsDirectory)),
     );
-    const entries = await readdir(this.assetsDirectory, { withFileTypes: true }).catch(() => []);
+    const entries = await readdir(this.assetsDirectory, {
+      withFileTypes: true,
+    }).catch(() => []);
     await Promise.all(
       entries.map(async (entry) => {
         if (!entry.isFile()) return;
@@ -509,6 +515,7 @@ function cloneDraft(draft: TuiRecoverableDraft): TuiRecoverableDraft {
   return {
     editor: {
       ...draft.editor,
+      pluginMentions: draft.editor.pluginMentions?.map((mention) => ({ ...mention })),
       pastes: draft.editor.pastes.map((paste) => ({ ...paste })),
       ...(draft.editor.attachmentPlaceholders
         ? {
@@ -538,7 +545,9 @@ function cloneRetrySubmission(retry: TuiRetrySubmission): TuiRetrySubmission {
       ...(retry.snapshot.transportContent
         ? { transportContent: retry.snapshot.transportContent }
         : {}),
-      attachments: retry.snapshot.attachments.map((attachment) => ({ ...attachment })),
+      attachments: retry.snapshot.attachments.map((attachment) => ({
+        ...attachment,
+      })),
       ...(retry.snapshot.transportAttachments
         ? {
             transportAttachments: retry.snapshot.transportAttachments.map((attachment) => ({
@@ -556,6 +565,7 @@ function cloneRetrySubmission(retry: TuiRetrySubmission): TuiRetrySubmission {
 function cloneEditorDraft(editor: EditorDraftSnapshot): EditorDraftSnapshot {
   return {
     ...editor,
+    pluginMentions: editor.pluginMentions?.map((mention) => ({ ...mention })),
     pastes: editor.pastes.map((paste) => ({ ...paste })),
     ...(editor.attachmentPlaceholders
       ? {
@@ -749,6 +759,7 @@ function isEditorDraft(value: unknown): value is EditorDraftSnapshot {
     !isRecord(value) ||
     value.schemaVersion !== 1 ||
     typeof value.text !== 'string' ||
+    !validPluginMentions(value.text, value.pluginMentions) ||
     !Number.isInteger(value.cursor) ||
     (value.cursor as number) < 0 ||
     (value.cursor as number) > value.text.length ||
diff --git a/packages/tui/src/tui/features/composer/submission.ts b/packages/tui/src/tui/features/composer/submission.ts
index 85075427..5f904fb8 100644
--- a/packages/tui/src/tui/features/composer/submission.ts
+++ b/packages/tui/src/tui/features/composer/submission.ts
@@ -51,7 +51,9 @@ export function createTuiSubmissionSnapshot(options: {
     editor: cloneEditorDraft(options.editor),
     content: options.content,
     ...(options.transportContent ? { transportContent: options.transportContent } : {}),
-    attachments: options.resources.attachments.map((attachment) => ({ ...attachment })),
+    attachments: options.resources.attachments.map((attachment) => ({
+      ...attachment,
+    })),
     transportAttachments: (options.transportAttachments ?? options.resources.attachments).map(
       (attachment) => ({ ...attachment }),
     ),
@@ -64,6 +66,7 @@ export function createTuiSubmissionSnapshot(options: {
 function cloneEditorDraft(editor: EditorDraftSnapshot): EditorDraftSnapshot {
   return {
     ...editor,
+    pluginMentions: editor.pluginMentions?.map((mention) => ({ ...mention })),
     pastes: editor.pastes.map((paste) => ({ ...paste })),
     ...(editor.attachmentPlaceholders
       ? {
diff --git a/packages/tui/src/tui/features/history/search-panel.ts b/packages/tui/src/tui/features/history/search-panel.ts
index 0a568d69..cc2aad2e 100644
--- a/packages/tui/src/tui/features/history/search-panel.ts
+++ b/packages/tui/src/tui/features/history/search-panel.ts
@@ -1,3 +1,4 @@
+import { decodePluginMentions } from '../../widgets/editor/plugin-mentions.js';
 import { Input, matchesKey } from '../../engine/public.js';
 import type { Component, Focusable } from '../../rendering/component.js';
 import { truncateToWidth, visibleWidth } from '../../rendering/text.js';
@@ -67,8 +68,8 @@ export class TuiHistorySearchPanel implements Component, Focusable {
           const selected = index === this.selectedIndex;
           const prefix = selected ? chalk.bold.hex(colors.signal)('› ') : '  ';
           const value = selected
-            ? chalk.bold.hex(colors.text)(sanitizeTerminalText(entry))
-            : chalk.hex(colors.muted)(sanitizeTerminalText(entry));
+            ? chalk.bold.hex(colors.text)(sanitizeTerminalText(decodePluginMentions(entry).text))
+            : chalk.hex(colors.muted)(sanitizeTerminalText(decodePluginMentions(entry).text));
           return fit(`${prefix}${value}`, safeWidth);
         })
       : [fit(chalk.hex(colors.muted)('  No matching prompts'), safeWidth)];
@@ -82,7 +83,7 @@ export class TuiHistorySearchPanel implements Component, Focusable {
   private matches(): string[] {
     const query = this.searchInput.getValue().trim().toLocaleLowerCase();
     if (!query) return [...this.options.entries];
-    return this.options.entries.filter((entry) => entry.toLocaleLowerCase().includes(query));
+    return this.options.entries.filter((entry) => decodePluginMentions(entry).text.toLocaleLowerCase().includes(query));
   }
 
   private move(direction: -1 | 1): void {
diff --git a/packages/tui/src/tui/shell/composer.ts b/packages/tui/src/tui/shell/composer.ts
index 4cb207c2..f6e1fbe3 100644
--- a/packages/tui/src/tui/shell/composer.ts
+++ b/packages/tui/src/tui/shell/composer.ts
@@ -260,7 +260,7 @@ function composerLabels(
     return [`${attachment} · ${submit} send`, attachment, 'Message'];
   }
   if (state.surface === 'welcome') {
-    return ['Start · @ file · / autocomplete', 'Start below'];
+    return ['Start · @ file or Plugin · / autocomplete', 'Start below'];
   }
   const newline = composerNewlineKeybinding(supportsShiftEnter, keybindings);
   return [`Message · ${submit} send · ${newline} newline`, `Message · ${submit} send`, 'Message'];
diff --git a/packages/tui/src/tui/theme/custom-themes.ts b/packages/tui/src/tui/theme/custom-themes.ts
index 453a8c72..afb59ae6 100644
--- a/packages/tui/src/tui/theme/custom-themes.ts
+++ b/packages/tui/src/tui/theme/custom-themes.ts
@@ -288,6 +288,9 @@ export function watchCustomThemes(
   try {
     watcher = watch(directory, { persistent: false }, fire);
     watcher.on('error', () => undefined);
+    // Native watching may miss edits made while it starts (notably on macOS).
+    // Reconcile once after registration, then use the same debounced event path.
+    fire();
   } catch {
     watcher = undefined;
   }
diff --git a/packages/tui/src/tui/widgets/editor/editor.ts b/packages/tui/src/tui/widgets/editor/editor.ts
index f81e3eff..e7ee277f 100644
--- a/packages/tui/src/tui/widgets/editor/editor.ts
+++ b/packages/tui/src/tui/widgets/editor/editor.ts
@@ -1,3 +1,11 @@
+import {
+  decodePluginMentions,
+  encodePluginMentions,
+  transformPluginMentions,
+  transformExternalPluginMentions,
+  validPluginMentions,
+  type EditorPluginMention,
+} from './plugin-mentions.js';
 import type { AutocompleteProvider, AutocompleteSuggestions } from '../autocomplete.js';
 import {
   decodePrintableKey,
@@ -20,6 +28,7 @@ export type { EditorTheme };
 
 export interface EditorDraftSnapshot extends EditorStateSnapshot {
   readonly attachmentPlaceholders?: readonly EditorAttachmentElement[];
+  readonly pluginMentions?: readonly EditorPluginMention[];
 }
 
 export interface EditorAttachmentPlaceholder {
@@ -46,6 +55,11 @@ export class Editor implements Component, Focusable {
   ) => void;
 
   private readonly engine: PiEditor;
+  private pluginMentions: EditorPluginMention[] = [];
+  private pendingPluginMention: EditorPluginMention | undefined;
+  private pendingPluginState: EditorPluginMention[] | undefined;
+  private skipNextPluginTransform = false;
+  private lastPluginSubmission: { content: string; transport: string } | undefined;
   private attachmentPlaceholders = new Map<string, EditorAttachmentElement>();
   private bindLegacyAttachmentPlaceholders = false;
   private lastText = '';
@@ -70,10 +84,39 @@ export class Editor implements Component, Focusable {
     this.engine.onSubmit = (_text, snapshot) => this.handleEngineSubmit(snapshot);
     this.engine.onPaste = (text) => this.onPaste?.(text) ?? false;
     this.engine.onAutocompleteView = (suggestions) => this.onAutocompleteView?.(suggestions);
-    this.engine.onAutocompleteSelect = (suggestions, item) =>
+    this.engine.onAutocompleteSelect = (suggestions, item) => {
+      if ('pluginId' in item && typeof item.pluginId === 'string') {
+        const start = this.engine.captureState().cursor - suggestions.prefix.length;
+        this.pendingPluginMention = {
+          pluginId: item.pluginId,
+          label: item.value,
+          start,
+          end: start + item.value.length,
+        };
+      }
       this.onAutocompleteSelect?.(suggestions, item);
-    this.engine.captureUndoExtensionState = () => [...this.attachmentPlaceholders.values()];
-    this.engine.restoreUndoExtensionState = (state) => this.restoreAttachmentUndoState(state);
+    };
+    this.engine.captureUndoExtensionState = () => ({
+      attachments: [...this.attachmentPlaceholders.values()],
+      plugins: this.pluginMentions.map((mention) => ({ ...mention })),
+    });
+    this.engine.restoreUndoExtensionState = (state) => {
+      if (!state || typeof state !== 'object' || !('attachments' in state) || !('plugins' in state))
+        return;
+      this.restoreAttachmentUndoState(state.attachments);
+      if (validPluginMentions(this.getText(), state.plugins)) {
+        this.pluginMentions = (state.plugins ?? []).map((mention) => ({
+          ...mention,
+        }));
+        this.skipNextPluginTransform = true;
+      }
+    };
+    this.engine.transformHistoryText = (text) => {
+      const decoded = decodePluginMentions(text);
+      this.pluginMentions = decoded.mentions;
+      this.skipNextPluginTransform = true;
+      return decoded.text;
+    };
   }
 
   get focused(): boolean {
@@ -113,7 +156,15 @@ export class Editor implements Component, Focusable {
   }
 
   addToHistory(text: string): void {
-    this.engine.addToHistory(text);
+    const current = this.captureDraft();
+    const transport =
+      this.lastPluginSubmission?.content === text.trim()
+        ? this.lastPluginSubmission.transport
+        : submittedEditorContent(current) === text.trim()
+          ? submittedEditorTransport(current)
+          : undefined;
+    this.engine.addToHistory(transport ?? text);
+    this.lastPluginSubmission = undefined;
   }
 
   getHistoryEntries(): readonly string[] {
@@ -139,6 +190,7 @@ export class Editor implements Component, Focusable {
   captureDraft(): EditorDraftSnapshot {
     return {
       ...this.engine.captureState(),
+      pluginMentions: this.pluginMentions.map((mention) => ({ ...mention })),
       attachmentPlaceholders: [...this.attachmentPlaceholders.values()].map((element) => ({
         ...element,
       })),
@@ -148,6 +200,11 @@ export class Editor implements Component, Focusable {
   restoreDraft(snapshot: EditorDraftSnapshot): boolean {
     if (!isValidEditorDraftSnapshot(snapshot)) return false;
     const previous = this.attachmentPlaceholders;
+    const previousPlugins = this.pluginMentions;
+    this.pluginMentions = (snapshot.pluginMentions ?? []).map((mention) => ({
+      ...mention,
+    }));
+    this.skipNextPluginTransform = true;
     this.attachmentPlaceholders = new Map(
       (snapshot.attachmentPlaceholders ?? []).map((element) => [element.id, { ...element }]),
     );
@@ -157,6 +214,8 @@ export class Editor implements Component, Focusable {
     const restored = this.engine.restoreState(snapshot);
     if (!restored) {
       this.attachmentPlaceholders = previous;
+      this.pluginMentions = previousPlugins;
+      this.skipNextPluginTransform = false;
       this.skipNextAttachmentTransform = false;
     }
     return restored;
@@ -180,8 +239,18 @@ export class Editor implements Component, Focusable {
       cursor: currentOffset + remappedCurrent.cursor,
       pastes: [...snapshot.pastes.map((paste) => ({ ...paste })), ...remappedCurrent.pastes],
       pasteCounter: remappedCurrent.pasteCounter,
+      pluginMentions: [
+        ...(snapshot.pluginMentions ?? []).map((mention) => ({ ...mention })),
+        ...(remappedCurrent.pluginMentions ?? []).map((mention) => ({
+          ...mention,
+          start: mention.start + currentOffset,
+          end: mention.end + currentOffset,
+        })),
+      ],
       attachmentPlaceholders: [
-        ...(snapshot.attachmentPlaceholders ?? []).map((element) => ({ ...element })),
+        ...(snapshot.attachmentPlaceholders ?? []).map((element) => ({
+          ...element,
+        })),
         ...(remappedCurrent.attachmentPlaceholders ?? [])
           .filter(({ id }) => !submittedAttachmentIds.has(id))
           .map((element) => ({
@@ -239,7 +308,10 @@ export class Editor implements Component, Focusable {
   dismissAttachmentPreview(): void {
     const preview = this.getAttachmentPreview();
     if (!preview) return;
-    this.dismissedAttachmentPreview = { id: preview.id, cursor: this.engine.captureState().cursor };
+    this.dismissedAttachmentPreview = {
+      id: preview.id,
+      cursor: this.engine.captureState().cursor,
+    };
     this.freshAttachmentPreview = undefined;
     this.tui.requestRender();
   }
@@ -251,6 +323,7 @@ export class Editor implements Component, Focusable {
     let cursor = this.engine.captureState().cursor;
     let changed = false;
     const elements = cloneAttachmentElements(this.attachmentPlaceholders);
+    let pluginMentions = this.pluginMentions.map((mention) => ({ ...mention }));
     if (this.bindLegacyAttachmentPlaceholders) {
       const claimedRanges: Array<{ start: number; end: number }> = [];
       for (const [id, label] of next) {
@@ -270,7 +343,9 @@ export class Editor implements Component, Focusable {
       replacement: string,
       target?: { id: string; label: string },
     ): void => {
-      text = `${text.slice(0, start)}${replacement}${text.slice(end)}`;
+      const nextText = `${text.slice(0, start)}${replacement}${text.slice(end)}`;
+      pluginMentions = transformPluginMentions(text, nextText, pluginMentions);
+      text = nextText;
       if (cursor > end) cursor += replacement.length - (end - start);
       else if (cursor > start) cursor = start + replacement.length;
       const delta = replacement.length - (end - start);
@@ -342,10 +417,14 @@ export class Editor implements Component, Focusable {
       return;
     }
     this.pendingAttachmentElements = elements;
+    this.pendingPluginState = pluginMentions;
     this.skipNextAttachmentTransform = true;
     this.engine.replaceRange(0, this.getText().length, text, cursor);
     if (added) {
-      this.freshAttachmentPreview = { id: added.id, cursor: this.engine.captureState().cursor };
+      this.freshAttachmentPreview = {
+        id: added.id,
+        cursor: this.engine.captureState().cursor,
+      };
       this.dismissedAttachmentPreview = undefined;
     }
   }
@@ -359,16 +438,32 @@ export class Editor implements Component, Focusable {
   }
 
   setText(text: string): void {
-    const value = text.replace(/\r\n?/gu, '\n');
+    const decoded = decodePluginMentions(text.replace(/\r\n?/gu, '\n'));
+    const value = decoded.text;
     const replaced = appendAttachmentElements(value, this.attachmentPlaceholders);
-    if (replaced.text === this.getText()) return;
+    if (replaced.text === this.getText()) {
+      if (text !== value) {
+        this.pluginMentions = decoded.mentions;
+        this.onChange?.(this.getText());
+      }
+      return;
+    }
+    this.pendingPluginMention = undefined;
+    this.pendingPluginState = decoded.mentions;
     this.pendingAttachmentElements = replaced.elements;
     this.skipNextAttachmentTransform = true;
     this.engine.replaceRange(0, this.getText().length, replaced.text, replaced.cursor);
   }
 
   replaceTextUndoable(text: string): void {
-    this.setText(text);
+    // External editors edit expanded visible text, while setText loads a new draft.
+    const draft = this.captureDraft();
+    const previous = decodePluginMentions(
+      expandDraftPastes(encodePluginMentions(draft.text, this.pluginMentions), draft.pastes),
+    );
+    const normalized = text.replace(/\r\n?/gu, '\n');
+    const mentions = transformExternalPluginMentions(previous.text, normalized, previous.mentions);
+    this.setText(encodePluginMentions(normalized, mentions));
   }
 
   invalidate(): void {
@@ -407,6 +502,7 @@ export class Editor implements Component, Focusable {
   dispose(): void {
     this.engine.dispose();
     this.attachmentPlaceholders.clear();
+    this.pluginMentions = [];
     this.pendingSubmission = undefined;
     this.lastAttachmentSubmission = undefined;
     this.onAttachmentPlaceholderDeleted = undefined;
@@ -414,7 +510,21 @@ export class Editor implements Component, Focusable {
   }
 
   private handleEngineChange(text: string): void {
+    if (this.pendingPluginState) {
+      this.pluginMentions = this.pendingPluginState;
+      this.pendingPluginState = undefined;
+    } else if (this.skipNextPluginTransform) this.skipNextPluginTransform = false;
+    else this.pluginMentions = transformPluginMentions(this.lastText, text, this.pluginMentions);
+    if (this.pendingPluginMention) {
+      if (
+        text.slice(this.pendingPluginMention.start, this.pendingPluginMention.end) ===
+        this.pendingPluginMention.label
+      )
+        this.pluginMentions.push(this.pendingPluginMention);
+      this.pendingPluginMention = undefined;
+    }
     if (this.pendingSubmission && text === '') {
+      this.pluginMentions = [];
       this.attachmentPlaceholders.clear();
       this.lastText = '';
       this.skipNextAttachmentTransform = false;
@@ -445,12 +555,15 @@ export class Editor implements Component, Focusable {
   private handleEngineSubmit(snapshot: EditorStateSnapshot): void {
     const draft: EditorDraftSnapshot = {
       ...snapshot,
+      pluginMentions: this.pendingSubmission?.pluginMentions?.map((mention) => ({ ...mention })),
       attachmentPlaceholders: (this.pendingSubmission?.attachmentPlaceholders ?? []).map(
         (element) => ({ ...element }),
       ),
     };
     this.pendingSubmission = undefined;
     const content = submittedEditorContent(draft);
+    const transport = submittedEditorTransport(draft);
+    this.lastPluginSubmission = transport ? { content, transport } : undefined;
     if (draft.attachmentPlaceholders?.length) this.lastAttachmentSubmission = { content, draft };
     this.onSubmit?.(content, draft);
   }
@@ -474,14 +587,24 @@ export class Editor implements Component, Focusable {
     }
   }
 
+  private atomicElements(): EditorAttachmentElement[] {
+    return [
+      ...this.attachmentPlaceholders.values(),
+      ...this.pluginMentions.map((mention) => ({
+        ...mention,
+        id: `plugin:${mention.start}`,
+      })),
+    ];
+  }
+
   private handleAtomicAttachmentInput(data: string): boolean {
-    if (this.attachmentPlaceholders.size === 0) return false;
+    if (this.atomicElements().length === 0) return false;
     const command = resolveAttachmentCommand(data);
     if (!command || command === 'jump-forward' || command === 'jump-backward') return false;
     const snapshot = this.engine.captureState();
     const cursor = snapshot.cursor;
     const text = snapshot.text;
-    const elements = [...this.attachmentPlaceholders.values()];
+    const elements = this.atomicElements();
     if (command === 'left' || command === 'word-left') {
       const element = elements.find(
         (candidate) => cursor > candidate.start && cursor <= attachmentElementEnd(text, candidate),
@@ -525,7 +648,7 @@ export class Editor implements Component, Focusable {
       this.jumpOutsideAttachments(printable, direction);
       return true;
     }
-    if (this.attachmentPlaceholders.size === 0) return false;
+    if (this.atomicElements().length === 0) return false;
     const command = resolveAttachmentCommand(data);
     if (command !== 'jump-forward' && command !== 'jump-backward') return false;
     this.attachmentJumpMode = command === 'jump-forward' ? 'forward' : 'backward';
@@ -541,7 +664,7 @@ export class Editor implements Component, Focusable {
           ? snapshot.text.indexOf(character, from)
           : snapshot.text.lastIndexOf(character, from);
       if (target < 0) return;
-      const element = [...this.attachmentPlaceholders.values()].find(
+      const element = this.atomicElements().find(
         (candidate) => target >= candidate.start && target < candidate.end,
       );
       if (!element) {
@@ -555,7 +678,7 @@ export class Editor implements Component, Focusable {
 
   private snapCursorOutsideAttachment(previousCursor: number): void {
     const snapshot = this.engine.captureState();
-    const element = [...this.attachmentPlaceholders.values()].find(
+    const element = this.atomicElements().find(
       (candidate) => snapshot.cursor > candidate.start && snapshot.cursor < candidate.end,
     );
     if (!element) return;
@@ -623,7 +746,10 @@ function editorDeletionRange(
     };
   }
   if (command === 'delete-line-start') {
-    return { start: text.lastIndexOf('\n', Math.max(0, cursor - 1)) + 1, end: cursor };
+    return {
+      start: text.lastIndexOf('\n', Math.max(0, cursor - 1)) + 1,
+      end: cursor,
+    };
   }
   const lineEnd = text.indexOf('\n', cursor);
   return {
@@ -652,6 +778,7 @@ function isValidEditorDraftSnapshot(snapshot: EditorDraftSnapshot): boolean {
     !snapshot ||
     snapshot.schemaVersion !== 1 ||
     typeof snapshot.text !== 'string' ||
+    !validPluginMentions(snapshot.text, snapshot.pluginMentions) ||
     !Number.isInteger(snapshot.cursor) ||
     snapshot.cursor < 0 ||
     snapshot.cursor > snapshot.text.length ||
@@ -698,7 +825,10 @@ function isValidEditorDraftSnapshot(snapshot: EditorDraftSnapshot): boolean {
       return false;
     }
     attachmentIds.add(element.id);
-    ranges.push({ start: attachmentElementStart(snapshot.text, element), end: element.end });
+    ranges.push({
+      start: attachmentElementStart(snapshot.text, element),
+      end: element.end,
+    });
     return true;
   });
 }
@@ -728,7 +858,14 @@ function remapEditorDraftPastes(
       const id = Number(match[1]);
       const paste = draft.pastes.find((candidate) => candidate.id === id);
       if (!paste || match.index === undefined) return [];
-      return [{ start: match.index, end: match.index + match[0].length, paste, marker: match[0] }];
+      return [
+        {
+          start: match.index,
+          end: match.index + match[0].length,
+          paste,
+          marker: match[0],
+        },
+      ];
     })
     .map((replacement, index) => {
       const id = startingCounter + index + 1;
@@ -754,8 +891,16 @@ function remapEditorDraftPastes(
     schemaVersion: 1,
     text,
     cursor: shiftPosition(draft.cursor),
-    pastes: replacements.map(({ id, paste }) => ({ id, content: paste.content })),
+    pastes: replacements.map(({ id, paste }) => ({
+      id,
+      content: paste.content,
+    })),
     pasteCounter: startingCounter + replacements.length,
+    pluginMentions: draft.pluginMentions?.map((mention) => ({
+      ...mention,
+      start: shiftPosition(mention.start),
+      end: shiftPosition(mention.end),
+    })),
     attachmentPlaceholders: (draft.attachmentPlaceholders ?? []).map((element) => ({
       ...element,
       start: shiftPosition(element.start),
@@ -787,7 +932,11 @@ function attachmentElementEnd(text: string, element: EditorAttachmentElement): n
 function appendAttachmentElements(
   text: string,
   elements: ReadonlyMap<string, EditorAttachmentElement>,
-): { text: string; cursor: number; elements: Map<string, EditorAttachmentElement> } {
+): {
+  text: string;
+  cursor: number;
+  elements: Map<string, EditorAttachmentElement>;
+} {
   let output = text;
   let cursor = output.length;
   const appended = new Map<string, EditorAttachmentElement>();
@@ -812,6 +961,29 @@ export function submittedEditorContent(draft: EditorDraftSnapshot): string {
   return expandDraftPastes(visibleText, draft.pastes).trim();
 }
 
+/** Serialize identity bindings into the existing durable user-text transport. */
+export function submittedEditorTransport(draft: EditorDraftSnapshot): string | undefined {
+  if (!draft.pluginMentions?.length) return undefined;
+  let text = draft.text;
+  const replacements = [
+    ...draft.pluginMentions.map((mention) => ({
+      start: mention.start,
+      end: mention.end,
+      text: encodePluginMentions(mention.label, [
+        { ...mention, start: 0, end: mention.label.length },
+      ]),
+    })),
+    ...(draft.attachmentPlaceholders ?? []).map((element) => ({
+      start: attachmentElementStart(text, element),
+      end: attachmentElementEnd(text, element),
+      text: '',
+    })),
+  ].sort((a, b) => b.start - a.start);
+  for (const replacement of replacements)
+    text = text.slice(0, replacement.start) + replacement.text + text.slice(replacement.end);
+  return expandDraftPastes(text, draft.pastes).trim();
+}
+
 function removeAttachmentElements(
   text: string,
   elements: readonly EditorAttachmentElement[],
diff --git a/packages/tui/src/tui/widgets/editor/plugin-mentions.ts b/packages/tui/src/tui/widgets/editor/plugin-mentions.ts
new file mode 100644
index 00000000..ca882832
--- /dev/null
+++ b/packages/tui/src/tui/widgets/editor/plugin-mentions.ts
@@ -0,0 +1,134 @@
+import {
+  parsePluginMentions,
+  serializePluginMention,
+  type PluginMention,
+} from '@mavis/shared/plugin-mention';
+
+export type EditorPluginMention = PluginMention;
+
+/** Decode durable history links into visible labels with exact identity bindings. */
+export function decodePluginMentions(text: string): {
+  text: string;
+  mentions: EditorPluginMention[];
+} {
+  const mentions: EditorPluginMention[] = [];
+  let offset = 0;
+  let previousEnd = 0;
+  let output = '';
+  for (const mention of parsePluginMentions(text)) {
+    output += text.slice(previousEnd, mention.start) + mention.label;
+    const start = mention.start + offset;
+    mentions.push({ ...mention, start, end: start + mention.label.length });
+    offset += mention.label.length - (mention.end - mention.start);
+    previousEnd = mention.end;
+  }
+  return { text: output + text.slice(previousEnd), mentions };
+}
+
+export function encodePluginMentions(
+  text: string,
+  mentions: readonly EditorPluginMention[],
+): string {
+  let output = text;
+  for (const mention of [...mentions].sort((a, b) => b.start - a.start)) {
+    if (text.slice(mention.start, mention.end) !== mention.label) continue;
+    output =
+      output.slice(0, mention.start) +
+      serializePluginMention(mention.pluginId, mention.label) +
+      output.slice(mention.end);
+  }
+  return output;
+}
+
+export function validPluginMentions(
+  text: string,
+  value: unknown,
+): value is readonly EditorPluginMention[] | undefined {
+  if (value === undefined) return true;
+  if (!Array.isArray(value)) return false;
+  const ranges: Array<{ start: number; end: number }> = [];
+  return value.every((item) => {
+    if (
+      !item ||
+      typeof item !== 'object' ||
+      typeof item.pluginId !== 'string' ||
+      !item.pluginId ||
+      item.pluginId.length > 512 ||
+      /[\u0000-\u001f\u007f]/u.test(item.pluginId) ||
+      typeof item.label !== 'string' ||
+      !item.label.startsWith('@') ||
+      item.label.length > 257 ||
+      !Number.isInteger(item.start) ||
+      !Number.isInteger(item.end) ||
+      item.start < 0 ||
+      item.end <= item.start ||
+      item.end > text.length ||
+      text.slice(item.start, item.end) !== item.label ||
+      ranges.some((range) => item.start < range.end && item.end > range.start)
+    )
+      return false;
+    ranges.push(item);
+    return true;
+  });
+}
+
+/** Edits inside a mention remove its binding; edits outside only move its range. */
+export function transformPluginMentions(
+  previous: string,
+  next: string,
+  mentions: readonly EditorPluginMention[],
+): EditorPluginMention[] {
+  let start = 0;
+  while (start < previous.length && start < next.length && previous[start] === next[start]) start++;
+  let oldEnd = previous.length;
+  let newEnd = next.length;
+  while (oldEnd > start && newEnd > start && previous[oldEnd - 1] === next[newEnd - 1]) {
+    oldEnd--;
+    newEnd--;
+  }
+  return mentions.flatMap((mention) => {
+    if (mention.end <= start) return [{ ...mention }];
+    if (mention.start < oldEnd) return [];
+    const delta = newEnd - oldEnd;
+    return [{ ...mention, start: mention.start + delta, end: mention.end + delta }];
+  });
+}
+
+/** External edits can change several ranges at once; only relocate unambiguous labels. */
+export function transformExternalPluginMentions(
+  previous: string,
+  next: string,
+  mentions: readonly EditorPluginMention[],
+): EditorPluginMention[] {
+  const positions = new Map<string, { before: number[]; after: number[] }>();
+  const occurrences = (text: string, label: string): number[] => {
+    const result: number[] = [];
+    for (
+      let start = text.indexOf(label);
+      start >= 0;
+      start = text.indexOf(label, start + label.length)
+    ) {
+      result.push(start);
+    }
+    return result;
+  };
+  return mentions
+    .flatMap((mention) => {
+      let matches = positions.get(mention.label);
+      if (!matches) {
+        matches = {
+          before: occurrences(previous, mention.label),
+          after: occurrences(next, mention.label),
+        };
+        positions.set(mention.label, matches);
+      }
+      // Inserting/removing a duplicate visible label makes its source identity ambiguous.
+      if (matches.before.length !== matches.after.length) return [];
+      if (matches.before.length === 1) {
+        const start = matches.after[0]!;
+        return [{ ...mention, start, end: start + mention.label.length }];
+      }
+      return transformPluginMentions(previous, next, [mention]);
+    })
+    .sort((a, b) => a.start - b.start);
+}
diff --git a/packages/tui/test/unit/tui-app.test.ts b/packages/tui/test/unit/tui-app.test.ts
index fac9a117..e319311d 100644
--- a/packages/tui/test/unit/tui-app.test.ts
+++ b/packages/tui/test/unit/tui-app.test.ts
@@ -1982,7 +1982,7 @@ describe("createTuiApp", () => {
 
       const starting = app.tui.render(80).join("\n");
       expect(starting).toContain("⠋ Starting server...");
-      expect(starting).not.toContain("Start · @ file · / autocomplete");
+      expect(starting).not.toContain("Start · @ file or Plugin · / autocomplete");
       expect(starting).not.toContain("Loading session");
 
       releaseSessions?.();
@@ -1990,7 +1990,7 @@ describe("createTuiApp", () => {
       app.setStartupStatus(undefined);
 
       expect(app.tui.render(80).join("\n")).toContain(
-        "Start · @ file · / autocomplete",
+        "Start · @ file or Plugin · / autocomplete",
       );
     } finally {
       releaseSessions?.();
diff --git a/packages/tui/test/unit/tui-chat-controller.test.ts b/packages/tui/test/unit/tui-chat-controller.test.ts
index 922c4e5f..1d089a2b 100644
--- a/packages/tui/test/unit/tui-chat-controller.test.ts
+++ b/packages/tui/test/unit/tui-chat-controller.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it, vi } from 'vitest';
-import type { SendMessageReq } from '@mavis/local-runtime-v2/cli-service';
+import type { CliSendMessageReq, SendMessageReq } from '@mavis/local-runtime-v2/cli-service';
 import { TuiFailure } from '../../src/failure.js';
 import {
   TuiChatController as ProductionTuiChatController,
@@ -20,6 +20,50 @@ class TuiChatController extends ProductionTuiChatController {
 }
 
 describe('TuiChatController', () => {
+  it.each(['display', 'legacy transport'])(
+    'reconciles plugin mentions using %s without duplicate user cells',
+    async (echo) => {
+      const content = '[@Codex 插件](plugin://codex%40official) 这个插件可以干什么';
+      const displayContent = '@Codex 插件 这个插件可以干什么';
+      let turn = 0;
+      const runtime = {
+        createSession: vi.fn(async () => ({ sessionId: 'plugin-session' })),
+        sendMessage: vi.fn(async function* (
+          request: SendMessageReq,
+        ): AsyncGenerator<TuiStreamEvent> {
+          expect(request).toMatchObject({ content, displayContent });
+          const message = {
+            id: `message-${request.turnId}`,
+            turnId: request.turnId,
+            role: 'user' as const,
+            content: echo === 'display' ? request.displayContent : request.content,
+          };
+          yield { type: 'message', message };
+          yield { type: 'message', message };
+          yield { type: 'done', turnId: request.turnId };
+        }),
+        abortSession: vi.fn(async () => true),
+      };
+      const transcript = new TranscriptStore();
+      const controller = new ProductionTuiChatController({
+        runtime: runtime as never,
+        transcript,
+        workspaceDir: '/workspace',
+        createTurnId: () => `plugin-turn-${++turn}`,
+      });
+      await controller.submit(content, { displayContent });
+      expect(transcript.snapshot().filter((cell) => cell.kind === 'user')).toMatchObject([
+        { content: displayContent, sourceMessageId: 'message-plugin-turn-1' },
+      ]);
+      // An intentional repeat in another turn must remain a separate message.
+      await controller.submit(content, { displayContent });
+      expect(transcript.snapshot().filter((cell) => cell.kind === 'user')).toHaveLength(2);
+      const rendered = new TranscriptView(transcript).render(100).join('\n');
+      expect(rendered).not.toContain('plugin://');
+      expect(rendered).not.toContain('\x1b[4m');
+    },
+  );
+
   it('hides plain and namespaced AskUser protocol tools from the transcript', () => {
     expect(isQuestionnaireTool('ask_user')).toBe(true);
     expect(isQuestionnaireTool('functions.AskUser')).toBe(true);
diff --git a/packages/tui/test/unit/tui-composer.test.ts b/packages/tui/test/unit/tui-composer.test.ts
index 5c6da276..eb7d980a 100644
--- a/packages/tui/test/unit/tui-composer.test.ts
+++ b/packages/tui/test/unit/tui-composer.test.ts
@@ -312,7 +312,7 @@ describe("TuiComposer", () => {
     );
 
     const firstHeader = stripAnsi(composer.render(120)[0] ?? "");
-    expect(firstHeader).toContain("Start · @ file · / autocomplete");
+    expect(firstHeader).toContain("Start · @ file or Plugin · / autocomplete");
     expect(firstHeader).toContain(
       "Tip: /goal keeps multi-step work focused on a finish line",
     );
@@ -329,7 +329,7 @@ describe("TuiComposer", () => {
       { now: () => 30_000, tips: ordinaryTip ? [ordinaryTip] : [] },
     );
     const nextHeader = stripAnsi(nextComposer.render(120)[0] ?? "");
-    expect(nextHeader).toContain("Start · @ file · / autocomplete");
+    expect(nextHeader).toContain("Start · @ file or Plugin · / autocomplete");
     expect(nextHeader).toContain(
       "Tip: Ctrl+U resumes your recent Codex session",
     );
@@ -459,7 +459,7 @@ describe("TuiComposer", () => {
     ],
     [
       { mode: "message", surface: "welcome" },
-      "Start · @ file · / autocomplete",
+      "Start · @ file or Plugin · / autocomplete",
     ],
   ] satisfies Array<[TuiComposerState, string]>)(
     "explains the %s submission mode before the user presses Enter",
diff --git a/packages/tui/test/unit/tui-plugin-mentions.test.ts b/packages/tui/test/unit/tui-plugin-mentions.test.ts
new file mode 100644
index 00000000..6ddf09f0
--- /dev/null
+++ b/packages/tui/test/unit/tui-plugin-mentions.test.ts
@@ -0,0 +1,677 @@
+import { ConversationApplication } from '../../../local-runtime-v2/src/application/conversation/conversation-application.js';
+import { DirectSendDeliveryService } from '../../../local-runtime-v2/src/application/conversation/direct-send-delivery.js';
+import { TuiUserProjection } from '../../src/tui/controller/projection/turn-user-projection.js';
+import { TranscriptStore } from '../../src/tui/transcript/store.js';
+import { visibleWidth } from '../../src/tui/engine/public.js';
+import { TuiInputFlow } from '../../src/tui/controller/interaction/input-flow.js';
+import { TuiExternalEditorFlow } from '../../src/tui/controller/interaction/external-editor-flow.js';
+import { TuiSessionMutationFlow } from '../../src/tui/controller/product/session-mutation-flow.js';
+import { UserMessageTurnDeliveryService } from '../../../local-runtime-v2/src/application/conversation/user-message-turn-delivery.js';
+import { UserMessageCommitService } from '../../../local-runtime-v2/src/service/session-system/messages/user-message-commit-service.js';
+import {
+  normalizeDisplayMessage,
+  decodeDisplayMessage,
+} from '../../../local-runtime-v2/src/service/session-system/messages/repo/codec.js';
+import { toSessionMessageView } from '../../../local-runtime-v2/src/application/session/content-application.js';
+import { normalizeTuiMessage } from '../../src/runtime/stream-events.js';
+import { TuiHistorySearchPanel } from '../../src/tui/features/history/search-panel.js';
+import { TuiQueueFlow } from '../../src/tui/controller/run/queue-flow.js';
+import { TuiRunProjection } from '../../src/tui/state/run-projection.js';
+import { TuiCommandFlow } from '../../src/tui/controller/product/command-flow.js';
+import { mkdtemp, rm } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { serializePluginMention, parsePluginMentions } from '@mavis/shared/plugin-mention';
+import { createTuiAutocomplete } from '../../src/tui/controller/run/active-run-flow.js';
+import {
+  Editor,
+  submittedEditorTransport,
+  submittedEditorContent,
+} from '../../src/tui/widgets/editor/editor.js';
+import { TuiDraftRecovery } from '../../src/tui/features/composer/draft-recovery.js';
+import { createTuiSubmissionSnapshot } from '../../src/tui/features/composer/submission.js';
+import { stripTerminalSequences } from '../../src/tui/engine/public.js';
+
+const identity = (value: string) => value;
+const makePlugin = (name = 'notes', marketplace: 'local' | 'official' = 'local') => ({
+  pluginId: `${name}@${marketplace}`,
+  name,
+  displayName: 'My Notes',
+  marketplace,
+  installed: true,
+  enabled: true,
+  capabilities: { appCount: 0, mcpServerCount: 0, skillCount: 1 },
+});
+const editors: Editor[] = [];
+afterEach(() => {
+  for (const editor of editors.splice(0)) editor.dispose();
+});
+function createEditor() {
+  const editor = new Editor(
+    { terminal: { rows: 24 }, requestRender: vi.fn() },
+    {
+      borderColor: identity,
+      selectList: {
+        selectedPrefix: identity,
+        selectedText: identity,
+        description: identity,
+        scrollInfo: identity,
+        noMatch: identity,
+      },
+    },
+  );
+  editors.push(editor);
+  editor.focused = true;
+  editor.setAutocompleteProvider(
+    createTuiAutocomplete([], [], '/workspace', {
+      listInstalledPlugins: async () => [makePlugin()],
+      listWorkspaceFileTree: async () => [],
+      searchWorkspaceFiles: async () => [],
+    }),
+  );
+  return editor;
+}
+async function selectPlugin(editor: Editor) {
+  editor.handleInput('@');
+  await vi.waitFor(() =>
+    expect(stripTerminalSequences(editor.render(80).join('\n'))).toContain('local · notes'),
+  );
+  editor.handleInput('\t');
+  expect(editor.getText()).toBe('@My Notes ');
+  expect(editor.captureDraft().pluginMentions).toEqual([
+    { pluginId: 'notes@local', label: '@My Notes', start: 0, end: 9 },
+  ]);
+}
+
+describe('Plugin mentions from Composer to durable text', () => {
+  it('carries the display label through Runtime direct-send admission while preserving execution identity', async () => {
+    const submit = vi.fn(async () => ({ accepted: false, reason: 'invalid-input' }));
+    const directSend = new DirectSendDeliveryService({
+      turns: { submit },
+      stream: { reserve: () => ({ discardIfEmpty: vi.fn() }) },
+    } as never);
+    const application = new ConversationApplication({ directSend } as never);
+    const content = '[@Codex 插件](plugin://codex%40official) hello';
+    const displayContent = '@Codex 插件 hello';
+    await application.sendMessage({}, { id: 's1', content, displayContent });
+    expect(submit).toHaveBeenCalledWith(expect.objectContaining({
+      input: expect.objectContaining({ text: content }),
+      delivery: expect.objectContaining({ displayContent }),
+    }));
+  });
+
+  it('renders legacy plugin history as plain labels without losing editable transport', () => {
+    const transcript = new TranscriptStore();
+    const message = {
+      role: 'user' as const,
+      content: '[@Codex 插件](plugin://codex%40official) hello',
+    };
+    new TuiUserProjection(transcript).hydrate(message, 'message-1', 'turn-1', 1);
+    expect(transcript.snapshot()[0]?.content).toBe('@Codex 插件 hello');
+    expect(message.content).toContain('plugin://');
+  });
+
+  it('groups plugins and files, bounds wide descriptions, and keeps all matching plugins selectable', async () => {
+    const provider = createTuiAutocomplete([], [], '/workspace', {
+      listInstalledPlugins: async () =>
+        Array.from({ length: 10 }, (_, index) => ({
+          ...makePlugin(`notes-${index}`),
+          description: '读取、生成、重排、填写和处理文件。'.repeat(20),
+        })),
+      listWorkspaceFileTree: async () => [
+        { name: 'notes.md', path: 'notes.md', type: 'file' as const },
+      ],
+    });
+    const suggestions = await provider.getSuggestions(['@'], 0, 1, {
+      signal: new AbortController().signal,
+    });
+    expect(suggestions?.items).toHaveLength(11);
+    expect(suggestions?.items[0]).toMatchObject({ groupLabel: '  Plugins' });
+    expect(suggestions?.items[10]).toMatchObject({ groupLabel: '  Files' });
+    for (const item of suggestions!.items.slice(0, 10)) {
+      expect(visibleWidth(item.description!)).toBeLessThanOrEqual(72);
+      expect(item.description).toContain('…');
+    }
+    const editor = createEditor();
+    editor.setAutocompleteProvider(provider);
+    editor.handleInput('@');
+    await vi.waitFor(() => expect(editor.render(180).join('\n')).toContain('Plugins'));
+    expect(editor.render(180).join('\n')).not.toContain('local · notes');
+    for (const width of [40, 80, 180]) {
+      for (const line of editor.render(width))
+        expect(visibleWidth(line)).toBeLessThanOrEqual(width);
+    }
+    for (let index = 0; index < 10; index++) editor.handleInput('\x1b[B');
+    expect(editor.render(80).join('\n')).toContain('Files');
+    editor.handleInput('\t');
+    expect(editor.getText()).toContain('notes.md');
+  });
+
+  it('offers enabled plugins alongside files, refreshes state, and preserves file completion', async () => {
+    const listInstalledPlugins = vi.fn(async () => [
+      makePlugin(),
+      { ...makePlugin('off'), enabled: false },
+    ]);
+    const provider = createTuiAutocomplete([], [], '/workspace', {
+      listInstalledPlugins,
+      listWorkspaceFileTree: async () => [
+        { name: 'notes.md', path: 'notes.md', type: 'file' as const },
+      ],
+    });
+    const request = { signal: new AbortController().signal };
+    const result = await provider.getSuggestions(['@'], 0, 1, request);
+    expect(result?.items).toHaveLength(2);
+    expect(result?.items[0]).toMatchObject({ pluginId: 'notes@local' });
+    expect(result?.items[1]?.value).toContain('notes.md');
+    listInstalledPlugins.mockResolvedValue([{ ...makePlugin(), enabled: false }]);
+    expect((await provider.getSuggestions(['@'], 0, 1, request))?.items).toHaveLength(1);
+    expect(provider.applyCompletion(['see @ suffix'], 0, 5, result!.items[0]!, '@').lines).toEqual([
+      'see @My Notes  suffix',
+    ]);
+  });
+
+  it('renders a label, submits stable identity, and preserves history through multiple recalls', async () => {
+    const editor = createEditor();
+    await selectPlugin(editor);
+    editor.handleInput('整理笔记');
+    const submitted = vi.fn();
+    editor.onSubmit = submitted;
+    editor.handleInput('\r');
+    const [content, draft] = submitted.mock.calls[0]!;
+    expect(content).toBe('@My Notes 整理笔记');
+    const transport = submittedEditorTransport(draft);
+    expect(transport).toBe('[@My Notes](plugin://notes%40local) 整理笔记');
+    editor.addToHistory(content);
+    editor.addToHistory('another prompt');
+    editor.handleInput('\x1b[A');
+    expect(editor.getText()).toBe('another prompt');
+    editor.handleInput('\x1b[A');
+    expect(editor.getText()).toBe(content);
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(transport);
+    editor.handleInput('\x1b[B');
+    expect(editor.getText()).toBe('another prompt');
+    expect(editor.captureDraft().pluginMentions).toEqual([]);
+  });
+
+  it('deletes a selected mention atomically and restores its exact identity with undo', async () => {
+    const editor = createEditor();
+    await selectPlugin(editor);
+    editor.handleInput('\x7f');
+    expect(editor.getText()).toBe('');
+    expect(editor.captureDraft().pluginMentions).toEqual([]);
+    editor.handleInput('\x1f');
+    expect(editor.getText()).toBe('@My Notes ');
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      '[@My Notes](plugin://notes%40local)',
+    );
+  });
+
+  it('restores the working draft identity after browsing history', async () => {
+    const editor = createEditor();
+    await selectPlugin(editor);
+    editor.addToHistory('older');
+    editor.handleInput('\x01');
+    editor.handleInput('\x1b[A');
+    expect(editor.getText()).toBe('older');
+    editor.handleInput('\x1b[B');
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      '[@My Notes](plugin://notes%40local)',
+    );
+  });
+
+  it('keeps identities distinct when history labels are identical', () => {
+    const editor = createEditor();
+    editor.addToHistory(serializePluginMention('notes@local', 'My Notes'));
+    editor.addToHistory(serializePluginMention('notes@official', 'My Notes'));
+    editor.handleInput('\x1b[A');
+    expect(editor.captureDraft().pluginMentions?.[0]?.pluginId).toBe('notes@official');
+    editor.handleInput('\x1b[A');
+    expect(editor.captureDraft().pluginMentions?.[0]?.pluginId).toBe('notes@local');
+  });
+
+  it('preserves mentions with attachments, merged retries and persisted drafts', async () => {
+    const editor = createEditor();
+    await selectPlugin(editor);
+    editor.syncAttachmentPlaceholders([{ id: '/image.png', label: '[Image #1]' }]);
+    editor.handleInput('summarize');
+    const snapshot = editor.captureDraft();
+    expect(submittedEditorTransport(snapshot)).toBe(
+      '[@My Notes](plugin://notes%40local) summarize',
+    );
+    const submission = createTuiSubmissionSnapshot({
+      submissionId: 's1',
+      editor: snapshot,
+      content: submittedEditorContent(snapshot),
+      resources: { attachments: [] },
+    });
+    const directory = await mkdtemp(join(tmpdir(), 'plugin-mention-test-'));
+    try {
+      const store = new TuiDraftRecovery({ dataDir: directory, workspaceDir: '/workspace' });
+      const plain = {
+        ...snapshot,
+        text: '@My Notes summarize',
+        cursor: 19,
+        attachmentPlaceholders: [],
+      };
+      await store.flush({
+        editor: plain,
+        attachments: [],
+        retrySubmissions: [
+          {
+            retryId: 'retry:r1',
+            failedReason: 'offline',
+            snapshot: { ...submission, editor: plain },
+          },
+        ],
+      });
+      const loaded = await new TuiDraftRecovery({
+        dataDir: directory,
+        workspaceDir: '/workspace',
+      }).load();
+      expect(loaded?.editor.pluginMentions).toEqual(snapshot.pluginMentions);
+      expect(loaded?.retrySubmissions?.[0]?.snapshot.editor.pluginMentions).toEqual(
+        snapshot.pluginMentions,
+      );
+      editor.setText('new draft');
+      expect(editor.restoreSubmittedDraft(loaded!.editor)).toBe(true);
+      expect(submittedEditorTransport(editor.captureDraft())).toBe(
+        '[@My Notes](plugin://notes%40local) summarize\nnew draft',
+      );
+    } finally {
+      await rm(directory, { recursive: true, force: true });
+    }
+  });
+
+  it('shows human-readable history search and restores the canonical identity', () => {
+    const entry = serializePluginMention('notes@official', 'My Notes');
+    const editor = createEditor();
+    const panel = new TuiHistorySearchPanel({
+      entries: [entry],
+      initialQuery: 'My Notes',
+      onSelect: (text) => editor.setText(text),
+      onCancel: vi.fn(),
+      requestRender: vi.fn(),
+    });
+    const rendered = stripTerminalSequences(panel.render(100).join('\n'));
+    expect(rendered).toContain('@My Notes');
+    expect(rendered).not.toContain('plugin://');
+    panel.handleInput('\r');
+    expect(editor.captureDraft().pluginMentions?.[0]?.pluginId).toBe('notes@official');
+  });
+
+  it('rejects corrupt restored ranges and malformed IDs without binding another plugin', () => {
+    const editor = createEditor();
+    expect(
+      editor.restoreDraft({
+        schemaVersion: 1,
+        text: '@Notes',
+        cursor: 6,
+        pastes: [],
+        pasteCounter: 0,
+        pluginMentions: [{ pluginId: 'notes@local', label: '@Wrong', start: 0, end: 6 }],
+      }),
+    ).toBe(false);
+    expect(parsePluginMentions('[@Notes](plugin://%ZZ)')).toEqual([]);
+  });
+  it('submits bound text through the real command flow and restores the binding on failure', async () => {
+    const editor = createEditor();
+    await selectPlugin(editor);
+    editor.handleInput('summarize');
+    const draft = editor.captureDraft();
+    const content = submittedEditorContent(draft);
+    const submit = vi.fn(
+      async (
+        _text: string,
+        options: {
+          onSessionResolved?: (id: string) => void;
+          onRuntimeAccepted?: (id: string) => void;
+        },
+      ) => {
+        options.onSessionResolved?.('session-a');
+        options.onRuntimeAccepted?.('session-a');
+        return 'succeeded' as const;
+      },
+    );
+    const flow = new TuiCommandFlow({
+      workspaceDir: '/workspace',
+      controller: {
+        snapshot: () => ({ status: 'idle', sessions: [], session: { sessionId: 'session-a' } }),
+        submit,
+        refreshSessionMetadata: async () => undefined,
+      } as never,
+      activeRunFlow: {} as never,
+      featureFlow: {
+        skillCommands: () => [],
+        waitForWelcomeModelSelection: async () => undefined,
+        applyPendingModelSelection: async () => undefined,
+      } as never,
+      feedbackFlow: {} as never,
+      updateFlow: {} as never,
+      interactionFlow: { handleCommand: async () => false, hasPending: () => false } as never,
+      sessionFlow: {} as never,
+      queueFlow: {} as never,
+      composerDraft: {
+        hasContent: () => false,
+        capture: () => ({ attachments: [] }),
+        reserveSubmission: vi.fn(),
+        restoreSubmission: vi.fn(),
+        completeSubmission: async () => undefined,
+      } as never,
+      workspaceRoots: { additionalDirectories: () => [] } as never,
+      runProjection: new TuiRunProjection(),
+      editor,
+      surface: {} as never,
+      surfaceHost: { setChatFocus: vi.fn() } as never,
+      queueEnabled: true,
+      liveRunId: () => undefined,
+      runtimeStopping: () => false,
+      abortLiveTurn: async () => false,
+      leaveUi: async () => undefined,
+      whenReady: async () => undefined,
+      append: vi.fn(),
+      setHint: vi.fn(),
+      onChanged: vi.fn(),
+    });
+    const seed = flow.captureSubmissionSeed(draft);
+    editor.setText('');
+    await expect(flow.submit(content, seed)).resolves.toBe('consumed');
+    expect(submit).toHaveBeenCalledWith(
+      '[@My Notes](plugin://notes%40local) summarize',
+      expect.objectContaining({ displayContent: content }),
+    );
+    flow.restoreRecoverableSubmission({
+      submissionId: 'recovered',
+      sessionId: 'session-a',
+      editor: draft,
+      content,
+      attachments: [],
+      createdAtMs: 1,
+      transportContent:
+        '<user-provided-context>context</user-provided-context>\n\n[@My Notes](plugin://notes%40local) summarize',
+    });
+    editor.restoreDraft(draft);
+    editor.handleInput(' tomorrow');
+    const retrySeed = flow.captureSubmissionSeed();
+    await flow.submit('@My Notes summarize tomorrow', retrySeed);
+    expect(submit).toHaveBeenLastCalledWith(
+      '<user-provided-context>context</user-provided-context>\n\n[@My Notes](plugin://notes%40local) summarize tomorrow',
+      expect.objectContaining({ displayContent: '@My Notes summarize tomorrow' }),
+    );
+    editor.setText('');
+    await flow.restoreFailedSeed(content, seed);
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      '[@My Notes](plugin://notes%40local) summarize',
+    );
+  });
+
+  it.each(['', '<user-provided-context>synthetic context</user-provided-context>\n\n'])(
+    'reconstructs queued bindings and context after reload: %s',
+    async (context) => {
+      let item = {
+        itemId: 'q1',
+        sessionId: 's1',
+        status: 'queued',
+        source: 'user',
+        content: `${context}[@My Notes](plugin://notes%40local) summarize`,
+        attachments: [],
+      };
+      const projection = new TuiRunProjection();
+      const updateQueuedMessageContent = vi.fn(
+        async (_session: string, _item: string, content: string) => {
+          item = { ...item, content };
+          return item;
+        },
+      );
+      let removed = false;
+      const queue = new TuiQueueFlow({
+        runtime: {
+          getQueueSnapshot: async () => ({
+            items: removed ? [] : [item],
+            paused: true,
+            pendingCount: removed ? 0 : 1,
+          }),
+          deleteQueuedMessage: async () => {
+            removed = true;
+            return true;
+          },
+          updateQueuedMessageContent,
+        } as never,
+        controller: { snapshot: () => ({ session: { sessionId: 's1' } }) } as never,
+        composerDraft: { restoreQueuedSubmission: vi.fn(), releaseQueueItem: vi.fn() } as never,
+        runProjection: projection,
+        transcript: { get: vi.fn(), remove: vi.fn(), upsert: vi.fn() } as never,
+        followUp: { setQueueSummary: vi.fn(), setItems: vi.fn() } as never,
+        surface: {} as never,
+        enabled: true,
+        setHint: vi.fn(),
+        onChanged: vi.fn(),
+        requestRender: vi.fn(),
+      });
+      await queue.refresh('s1');
+      expect(projection.snapshot().queuedItems[0]?.content).toBe('@My Notes summarize');
+      await queue.updateContent('q1', '@My Notes summarize tomorrow');
+      expect(updateQueuedMessageContent).toHaveBeenCalledWith(
+        's1',
+        'q1',
+        `${context}[@My Notes](plugin://notes%40local) summarize tomorrow`,
+      );
+      const restored = await queue.restoreLatest();
+      expect(restored?.content).toBe('@My Notes summarize tomorrow');
+      expect(submittedEditorTransport(restored!.editor)).toBe(
+        '[@My Notes](plugin://notes%40local) summarize tomorrow',
+      );
+    },
+  );
+});
+
+describe('Plugin mention review regressions', () => {
+  it('clears and restores the actual editor binding with Ctrl+C and Ctrl+-', () => {
+    const editor = createEditor();
+    editor.setText('[@My Notes](plugin://notes%40local) summarize');
+    const flow = new TuiInputFlow({
+      editor,
+      tui: { requestRender: vi.fn() },
+      interaction: { isActive: () => false },
+      liveRunId: () => undefined,
+      hasWaitingMessage: () => false,
+      featureFlow: { isFeatureScreenActive: () => false },
+      composerDraft: {
+        abortClipboardRead: () => false,
+        stashForClear: vi.fn(),
+        hasContent: () => false,
+        restoreClearedDraft: vi.fn(),
+      },
+      setHint: vi.fn(),
+      onChanged: vi.fn(),
+      workspaceDir: '/workspace',
+    } as never);
+    flow.handle('\x03');
+    expect(editor.getText()).toBe('');
+    expect(editor.captureDraft().pluginMentions).toEqual([]);
+    flow.handle('\x1f');
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      '[@My Notes](plugin://notes%40local) summarize',
+    );
+  });
+
+  it.each([false, true])(
+    'keeps external edits and undo bound, including expanded paste: %s',
+    async (withPaste) => {
+      const editor = createEditor();
+      editor.setText('[@My Notes](plugin://notes%40local) summarize');
+      if (withPaste) {
+        const draft = editor.captureDraft();
+        const prefix = '[paste #1] ';
+        editor.restoreDraft({
+          ...draft,
+          text: prefix + draft.text,
+          cursor: prefix.length + draft.text.length,
+          pastes: [{ id: 1, content: 'Expanded text before plugin' }],
+          pasteCounter: 1,
+          pluginMentions: draft.pluginMentions!.map((mention) => ({
+            ...mention,
+            start: mention.start + prefix.length,
+            end: mention.end + prefix.length,
+          })),
+        });
+      }
+      const before = editor.captureDraft();
+      const transport = submittedEditorTransport(before);
+      let rename = false;
+      const flow = new TuiExternalEditorFlow({
+        editor,
+        tui: { start: vi.fn(), stop: vi.fn(), requestRender: vi.fn() },
+        workspaceDir: '/workspace',
+        configuredCommand: 'synthetic-editor',
+        editDraft: async ({ draft }) =>
+          rename ? draft.replace('@My Notes', '@Other Notes') : draft + ' tomorrow',
+        isAppStopped: () => false,
+        append: vi.fn(),
+        setHint: vi.fn(),
+        onChanged: vi.fn(),
+      });
+      await flow.open();
+      expect(submittedEditorTransport(editor.captureDraft())).toBe(transport + ' tomorrow');
+      editor.handleInput('\x1f');
+      expect(editor.captureDraft()).toEqual(before);
+      rename = true;
+      await flow.open();
+      expect(editor.captureDraft().pluginMentions).toEqual([]);
+      expect(submittedEditorTransport(editor.captureDraft())).toBeUndefined();
+    },
+  );
+
+  it('retains an unchanged plugin across multiple external edits without guessing duplicate identities', async () => {
+    const editor = createEditor();
+    editor.setText('[@My Notes](plugin://notes%40local) summarize');
+    const flow = new TuiExternalEditorFlow({
+      editor,
+      tui: { start: vi.fn(), stop: vi.fn(), requestRender: vi.fn() },
+      workspaceDir: '/workspace',
+      configuredCommand: 'synthetic-editor',
+      editDraft: async ({ draft }) => 'Please ' + draft + ' tomorrow',
+      isAppStopped: () => false,
+      append: vi.fn(),
+      setHint: vi.fn(),
+      onChanged: vi.fn(),
+    });
+    await flow.open();
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      'Please [@My Notes](plugin://notes%40local) summarize tomorrow',
+    );
+    editor.setText(
+      '[@My Notes](plugin://notes%40local) and [@My Notes](plugin://notes%40official)',
+    );
+    editor.replaceTextUndoable('@My Notes and @My Notes tomorrow');
+    expect(submittedEditorTransport(editor.captureDraft())).toBe(
+      '[@My Notes](plugin://notes%40local) and [@My Notes](plugin://notes%40official) tomorrow',
+    );
+    editor.replaceTextUndoable('@My Notes tomorrow');
+    expect(editor.captureDraft().pluginMentions).toEqual([]);
+  });
+
+  it.each(['ordinary', 'batch', 'steering'] as const)(
+    'preserves %s display-message identity through storage, projection and /edit',
+    async (mode) => {
+      const canonical =
+        '<user-provided-context>synthetic context</user-provided-context>\n\n[@My Notes](plugin://notes%40local) summarize';
+      const display = '@My Notes summarize';
+      let stored: ReturnType<typeof decodeDisplayMessage> | undefined;
+      const commits = new UserMessageCommitService({
+        makeMessageId: () => 'u1',
+        messages: {
+          commitUserMessage: async (input) => {
+            const row = normalizeDisplayMessage(input.message, {
+              turnId: input.turnId,
+              nowMs: () => 1,
+            });
+            stored = decodeDisplayMessage({
+              sessionId: input.sessionId,
+              messageId: row.msgId,
+              dataJson: row.dataJson,
+              source: null,
+              sourceContextJson: null,
+            } as never);
+            return { message: stored, created: true, firstUserMessageForSession: true };
+          },
+        },
+      });
+      const delivery = new UserMessageTurnDeliveryService({
+        messages: commits,
+        stream: { write: vi.fn() },
+        queryCollapse: {
+          resolveQueryKey: async () => 'q1',
+          start: async () => {
+            throw new Error('Synthetic unavailable sidecar');
+          },
+        },
+      });
+      const message = { content: canonical, attachments: [], displayContent: display };
+      if (mode === 'steering') {
+        await delivery.consumeSteering({
+          sessionId: 's1',
+          turnId: 't1',
+          message: {
+            producerId: 'cli',
+            idempotencyKey: 'fixture',
+            provenance: { source: 'cli' },
+            message: { text: canonical, attachments: [] },
+            delivery: { displayContent: display },
+          },
+        } as never);
+      } else {
+        await delivery.deliver({
+          sessionId: 's1',
+          input: { text: canonical, attachments: [] },
+          provenance: { source: 'cli' },
+          displayContent: display,
+          requestedTurnId: 't1',
+          submit: async () => ({ accepted: true, turnId: 't1' }),
+          ...(mode === 'batch'
+            ? {
+                immediateSendBatch: {
+                  members: [
+                    { message, messageKey: 'batch-1', createdAt: 1, provenance: { source: 'cli' } },
+                  ],
+                },
+              }
+            : {}),
+        } as never);
+      }
+      expect(stored?.msg_content).toBe(display);
+      expect(stored?.editContent).toBe(canonical);
+      const reloaded = normalizeTuiMessage(toSessionMessageView(stored!));
+      expect(reloaded.content).toBe(display);
+      expect(reloaded.editContent).toBe(canonical);
+      const editor = createEditor();
+      const editSessionMessage = vi.fn(async () => ({}));
+      const flow = new TuiSessionMutationFlow({
+        editor,
+        controller: {
+          snapshot: () => ({ session: { sessionId: 's1' } }),
+          getTerminalDurationId: () => undefined,
+          dismissTerminalDuration: vi.fn(),
+        },
+        runtime: {
+          listSessionInputSummaries: async () => [{ userMessageId: 'u1', timestamp: 1 }],
+          listMessagePage: async () => ({ messages: [reloaded], hasMore: false }),
+          editSessionMessage,
+        },
+        surfaceHost: { setChatFocus: vi.fn() },
+        setHint: vi.fn(),
+        append: vi.fn(),
+        onChanged: vi.fn(),
+        hasLiveRun: () => false,
+      } as never);
+      flow.startEdit();
+      await vi.waitFor(() => expect(flow.isEditing()).toBe(true));
+      expect(editor.getText()).toBe(display);
+      editor.handleInput(' tomorrow');
+      await flow.submitEdit(editor.getText(), [], editor.captureDraft());
+      expect(editSessionMessage).toHaveBeenCalledWith(
+        expect.objectContaining({ content: canonical + ' tomorrow' }),
+      );
+    },
+  );
+});
diff --git a/packages/tui/test/unit/tui/theme/custom-themes.test.ts b/packages/tui/test/unit/tui/theme/custom-themes.test.ts
index 23020c02..9b48b725 100644
--- a/packages/tui/test/unit/tui/theme/custom-themes.test.ts
+++ b/packages/tui/test/unit/tui/theme/custom-themes.test.ts
@@ -1,10 +1,12 @@
+import { watch as watchFs, writeFileSync } from 'node:fs';
 import { mkdtemp, mkdir, readFile, rm, writeFile } from 'node:fs/promises';
 import { join } from 'node:path';
 import { tmpdir } from 'node:os';
-import { afterEach, describe, expect, it } from 'vitest';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 import {
   customThemesDirectory,
   loadCustomThemes,
+  watchCustomThemes,
 } from '../../../../src/tui/theme/custom-themes.js';
 import { TuiThemeRegistry } from '../../../../src/tui/theme/registry.js';
 import type { TuiThemeDefinition } from '../../../../src/tui/theme/contracts.js';
@@ -14,9 +16,15 @@ import {
   MINIMAX_CODE_LIGHT_THEME,
 } from '../../../../src/tui/theme/palettes.js';
 
+vi.mock('node:fs', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('node:fs')>();
+  return { ...actual, watch: vi.fn(actual.watch) };
+});
+
 const temporaryDirectories: string[] = [];
 
 afterEach(async () => {
+  vi.useRealTimers();
   await Promise.all(
     temporaryDirectories.splice(0).map((directory) => rm(directory, { recursive: true })),
   );
@@ -42,6 +50,55 @@ function onlyTheme(themes: readonly TuiThemeDefinition[]): TuiThemeDefinition {
 }
 
 describe('custom TUI theme files', () => {
+  it('reconciles edits missed during watcher startup and continues to reload later events', async () => {
+    const dataDir = await themesDataDir({
+      'mine.json': { name: 'mine', appearance: 'dark', colors: { brand: '#112233' } },
+    });
+    const file = join(customThemesDirectory(dataDir), 'mine.json');
+    expect(onlyTheme(loadCustomThemes(dataDir).themes).dark.colors.brand).toBe('#112233');
+    const close = vi.fn();
+    vi.mocked(watchFs).mockReturnValueOnce({ on: vi.fn(), close } as never);
+    vi.useFakeTimers();
+    const onChange = vi.fn();
+    const stop = watchCustomThemes(dataDir, onChange);
+    try {
+      // Model macOS dropping the first edit before native watching is ready.
+      writeFileSync(
+        file,
+        JSON.stringify({ name: 'mine', appearance: 'dark', colors: { brand: '#AABBCC' } }),
+      );
+      await vi.advanceTimersByTimeAsync(150);
+      expect(onChange).toHaveBeenCalledTimes(1);
+      expect(onlyTheme(onChange.mock.calls[0]![0].themes).dark.colors.brand).toBe('#AABBCC');
+
+      writeFileSync(
+        file,
+        JSON.stringify({ name: 'mine', appearance: 'dark', colors: { brand: '#DDEEFF' } }),
+      );
+      const fire = vi.mocked(watchFs).mock.calls.at(-1)![2]!;
+      fire('change', 'mine.json');
+      await vi.advanceTimersByTimeAsync(150);
+      expect(onChange).toHaveBeenCalledTimes(2);
+      expect(onlyTheme(onChange.mock.calls[1]![0].themes).dark.colors.brand).toBe('#DDEEFF');
+    } finally {
+      stop();
+    }
+    expect(close).toHaveBeenCalledOnce();
+  });
+
+  it('cancels the startup reconciliation when disposed', async () => {
+    const dataDir = await themesDataDir({});
+    const close = vi.fn();
+    vi.mocked(watchFs).mockReturnValueOnce({ on: vi.fn(), close } as never);
+    vi.useFakeTimers();
+    const onChange = vi.fn();
+    const stop = watchCustomThemes(dataDir, onChange);
+    stop();
+    await vi.advanceTimersByTimeAsync(1000);
+    expect(onChange).not.toHaveBeenCalled();
+    expect(close).toHaveBeenCalledOnce();
+  });
+
   it('returns no themes when the directory is absent', async () => {
     const dataDir = await mkdtemp(join(tmpdir(), 'mcode-tui-themes-empty-'));
     temporaryDirectories.push(dataDir);
diff --git a/packages/tui/test/unit/tui/theme/runtime.test.ts b/packages/tui/test/unit/tui/theme/runtime.test.ts
index d0da7544..ab9e80a1 100644
--- a/packages/tui/test/unit/tui/theme/runtime.test.ts
+++ b/packages/tui/test/unit/tui/theme/runtime.test.ts
@@ -568,6 +568,7 @@ describe('TuiThemeController theme selection', () => {
     const { tmpdir } = await import('node:os');
     const { join } = await import('node:path');
     const dataDir = await mkdtemp(join(tmpdir(), 'mcode-theme-reload-'));
+    let controller: TuiThemeController | undefined;
     try {
       const themesDir = join(dataDir, 'tui', 'themes');
       await mkdir(themesDir, { recursive: true });
@@ -577,7 +578,7 @@ describe('TuiThemeController theme selection', () => {
 
       await write('#112233');
       const ui = new ThemeUi();
-      const controller = new TuiThemeController({
+      controller = new TuiThemeController({
         ui,
         colorLevel: 3,
         env: { COLORFGBG: '15;0' },
@@ -594,8 +595,8 @@ describe('TuiThemeController theme selection', () => {
 
       expect(controller.selectedThemeId()).toBe('mine');
       expect(onChange).toHaveBeenCalled();
-      controller.dispose();
     } finally {
+      controller?.dispose();
       await rm(dataDir, { recursive: true, force: true });
       restoreTheme();
     }
@@ -606,6 +607,7 @@ describe('TuiThemeController theme selection', () => {
     const { tmpdir } = await import('node:os');
     const { join } = await import('node:path');
     const dataDir = await mkdtemp(join(tmpdir(), 'mcode-theme-noop-'));
+    let controller: TuiThemeController | undefined;
     try {
       const themesDir = join(dataDir, 'tui', 'themes');
       await mkdir(themesDir, { recursive: true });
@@ -619,7 +621,7 @@ describe('TuiThemeController theme selection', () => {
 
       const ui = new ThemeUi();
       const onThemesChanged = vi.fn();
-      const controller = new TuiThemeController({
+      controller = new TuiThemeController({
         ui,
         colorLevel: 3,
         env: { COLORFGBG: '15;0' },
@@ -629,8 +631,11 @@ describe('TuiThemeController theme selection', () => {
       controller.setTheme('mine');
       const onChange = vi.fn();
       controller.onChange(onChange);
-      // The constructor load already fired once; only a watcher-driven reload
-      // may satisfy the wait below.
+      // Let the constructor load and startup reconciliation finish before the
+      // no-op edit, so this assertion still requires a native watcher event.
+      await vi.waitFor(() => expect(onThemesChanged.mock.calls.length).toBeGreaterThanOrEqual(2), {
+        timeout: 4000,
+      });
       onThemesChanged.mockClear();
 
       await writeFile(file, body);
@@ -640,8 +645,8 @@ describe('TuiThemeController theme selection', () => {
 
       expect(tuiColors.brand).toBe('#112233');
       expect(onChange).not.toHaveBeenCalled();
-      controller.dispose();
     } finally {
+      controller?.dispose();
       await rm(dataDir, { recursive: true, force: true });
       restoreTheme();
     }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8014dab7..00246441 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -335,6 +335,9 @@ importers:
 
   packages/agent-modules/system-reminder:
     devDependencies:
+      '@mavis/shared':
+        specifier: workspace:^
+        version: link:../../shared
       '@mavis/config':
         specifier: workspace:^
         version: link:../../config
diff --git a/release/public-source.json b/release/public-source.json
index d795f506..306681e2 100644
--- a/release/public-source.json
+++ b/release/public-source.json
@@ -1278,6 +1278,7 @@
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-execution-preparation.ts",
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-input-preparation.ts",
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-payload-transform.ts",
+    "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.test.ts",
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.ts",
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-hooks.ts",
     "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-tool-catalog-source.ts",
@@ -2763,6 +2764,7 @@
     "packages/shared/src/opencode-go-headers.ts",
     "packages/shared/src/openrouter-attribution.ts",
     "packages/shared/src/outbound-media.ts",
+    "packages/shared/src/plugin-mention.ts",
     "packages/shared/src/plugin-skill-name.ts",
     "packages/shared/src/product-build-identity.ts",
     "packages/shared/src/product-time.ts",
@@ -2951,6 +2953,7 @@
     "packages/tui/src/tui/commands/bash-input.ts",
     "packages/tui/src/tui/commands/catalog.ts",
     "packages/tui/src/tui/commands/input-intent.ts",
+    "packages/tui/src/tui/commands/plugin-autocomplete.ts",
     "packages/tui/src/tui/commands/side-session.ts",
     "packages/tui/src/tui/controller/chat-controller-failure.ts",
     "packages/tui/src/tui/controller/chat-controller-support.ts",
@@ -3202,6 +3205,7 @@
     "packages/tui/src/tui/widgets/autocomplete.ts",
     "packages/tui/src/tui/widgets/editor/editor.ts",
     "packages/tui/src/tui/widgets/editor/paste.ts",
+    "packages/tui/src/tui/widgets/editor/plugin-mentions.ts",
     "packages/tui/src/tui/widgets/input.ts",
     "packages/tui/src/tui/widgets/panel-frame.ts",
     "packages/tui/src/tui/widgets/select-list.ts",
@@ -3271,6 +3275,7 @@
     "packages/tui/test/unit/tui-keybindings.test.ts",
     "packages/tui/test/unit/tui-model-picker.test.ts",
     "packages/tui/test/unit/tui-plugin-manager.test.ts",
+    "packages/tui/test/unit/tui-plugin-mentions.test.ts",
     "packages/tui/test/unit/tui-provider-editor.test.ts",
     "packages/tui/test/unit/tui-provider-manager.test.ts",
     "packages/tui/test/unit/tui-provider-onboarding.test.ts",
diff --git a/test/vitest-suites.json b/test/vitest-suites.json
index 40ae8d55..45b5daa4 100644
--- a/test/vitest-suites.json
+++ b/test/vitest-suites.json
@@ -173,7 +173,9 @@
       "packages/tui/test/unit/tui/features/settings/theme-picker.test.ts",
       "packages/tui/test/unit/tui/theme/custom-themes.test.ts",
       "packages/tui/test/unit/tui/theme/palettes.test.ts",
-      "packages/tui/test/unit/tui/theme/runtime.test.ts"
+      "packages/tui/test/unit/tui/theme/runtime.test.ts",
+      "packages/tui/test/unit/tui-plugin-mentions.test.ts",
+      "packages/local-runtime-v2/src/service/turn-system/agent-host/assembly/local-turn-plugin-capabilities.test.ts"
     ],
     "status-contract": [
       "packages/tui/test/unit/tui-build-mode-contract.test.ts"
diff --git a/tsconfig.standalone.json b/tsconfig.standalone.json
index 1ad29d2b..df4c912a 100644
--- a/tsconfig.standalone.json
+++ b/tsconfig.standalone.json
@@ -328,6 +328,9 @@
       "@mavis/shared/navigation-text": [
         "./packages/shared/src/navigation-text.ts"
       ],
+      "@mavis/shared/plugin-mention": [
+        "./packages/shared/src/plugin-mention.ts"
+      ],
       "@mavis/shared/product-build-identity": [
         "./packages/shared/src/product-build-identity.ts"
       ],