feat(tui): autocomplete skill references

tui/src/app.test.ts

@@ -10,6 +10,7 @@ import { NanobotTui, sessionExitMessage, type AppOptions } from "./app"
 import type {
   MessageOptions,
   RecoveryState,
+  SkillCandidate,
   SlashCommand,
   WorkspaceScopePayload,
 } from "./protocol"
@@ -513,6 +514,69 @@ describe("NanobotTui layout", () => {
     expect(sent).toEqual([])
   })
 
+  test("completes available skills with arrows, Enter, Tab, and Escape", async () => {
+    setup = await createRenderer({ width: 80, height: 24, screenMode: "alternate-screen" })
+    const sent: string[] = []
+    const app = mount(setup, sent)
+    const ui = app as unknown as {
+      ready: boolean
+      composer: TextareaRenderable
+      skillCandidates: SkillCandidate[]
+      skillMenu: { visible: boolean }
+    }
+    app.accept({ event: "attached", chat_id: "chat" })
+    await waitUntil(() => ui.ready)
+    ui.skillCandidates = [
+      { name: "simplify", description: "Simplify code", source: "workspace" },
+      { name: "verify", description: "Verify public behavior", source: "builtin" },
+    ]
+
+    await setup.mockInput.typeText("$")
+    expect(ui.skillMenu.visible).toBe(true)
+    setup.mockInput.pressArrow("down")
+    setup.mockInput.pressEnter()
+    await waitUntil(() => ui.composer.plainText === "$verify ")
+    expect(ui.skillMenu.visible).toBe(false)
+    expect(sent).toEqual([])
+
+    ui.composer.setText("")
+    await setup.mockInput.typeText("please $sim")
+    expect(ui.skillMenu.visible).toBe(true)
+    setup.mockInput.pressTab()
+    expect(ui.composer.plainText).toBe("please $simplify ")
+    expect(ui.skillMenu.visible).toBe(false)
+
+    ui.composer.setText("")
+    await setup.mockInput.typeText("$")
+    expect(ui.skillMenu.visible).toBe(true)
+    setup.mockInput.pressEscape()
+    await waitUntil(() => !ui.skillMenu.visible)
+    expect(ui.skillMenu.visible).toBe(false)
+    expect(ui.composer.plainText).toBe("$")
+
+    ui.composer.setText("")
+    await setup.mockInput.typeText("请用 $ver")
+    expect(ui.skillMenu.visible).toBe(true)
+    setup.mockInput.pressTab()
+    expect(ui.composer.plainText).toBe("请用 $verify ")
+    await setup.mockInput.typeText("now")
+    expect(ui.composer.plainText).toBe("请用 $verify now")
+
+    ui.composer.setText("use $verify later")
+    ui.composer.cursorOffset = 8
+    await waitUntil(() => ui.skillMenu.visible)
+    ui.composer.cursorOffset = ui.composer.plainText.length
+    await waitUntil(() => !ui.skillMenu.visible)
+
+    ui.composer.setText("")
+    await setup.mockInput.typeText("$missing")
+    expect(ui.skillMenu.visible).toBe(true)
+    ui.composer.submit()
+    await waitUntil(() => sent.length === 1)
+    expect(sent).toEqual(["$missing"])
+    expect(ui.skillMenu.visible).toBe(false)
+  })
+
   test("runs bang commands through the gateway without steering the agent", async () => {
     setup = await createRenderer({ width: 80, height: 24, screenMode: "alternate-screen" })
     const sent: string[] = []

tui/src/app.ts

@@ -20,6 +20,7 @@ import {
 
 import {
   NanobotClient,
+  fetchAvailableSkills,
   fetchHistory,
   fetchGatewayConnection,
   fetchMentionCandidates,
@@ -35,6 +36,7 @@ import {
   type MentionCandidate,
   type MessageOptions,
   type RecoveryState,
+  type SkillCandidate,
   type SlashCommand,
   type SessionSummary,
   type TokenUsage,
@@ -69,6 +71,12 @@ import {
   mentionQuery,
   type MentionQuery,
 } from "./mention-menu"
+import {
+  insertSkill,
+  SkillMenu,
+  skillQuery,
+  type SkillQuery,
+} from "./skill-menu"
 import { PromptQueue, type QueuedPrompt } from "./prompt-queue"
 import { QueuePreview, type QueuePreviewTheme } from "./queue-preview"
 import { RecoveryNotice, type RecoveryNoticeTheme } from "./recovery-notice"
@@ -399,6 +407,7 @@ export class NanobotTui {
   private readonly commandMenu: CommandMenu
   private readonly sessionMenu: SessionMenu
   private readonly mentionMenu: MentionMenu
+  private readonly skillMenu: SkillMenu
   private readonly branchMenu: BranchMenu
   private readonly runtimeControls: RuntimeControls
   private readonly contextPanel: ContextPanel
@@ -455,6 +464,8 @@ export class NanobotTui {
   private readyDetail = ""
   private mentionCandidates: MentionCandidate[] = []
   private activeMentionQuery: MentionQuery | null = null
+  private skillCandidates: SkillCandidate[] = []
+  private activeSkillQuery: SkillQuery | null = null
   private transcriptNavigation: TranscriptNavigation = {
     awayFromBottom: false,
     unseenOutput: false,
@@ -478,6 +489,7 @@ export class NanobotTui {
   private hostBranch: string
   private readonly apiReauthenticator: ApiReauthenticator | undefined
   private apiRefreshPromise: Promise<GatewayApiConnection> | null = null
+  private skillLoadId = 0
 
   private constructor(
     renderer: CliRenderer,
@@ -517,6 +529,7 @@ export class NanobotTui {
       (session) => this.switchSession(session),
     )
     this.mentionMenu = new MentionMenu(renderer, commandMenuTheme(this.palette))
+    this.skillMenu = new SkillMenu(renderer, commandMenuTheme(this.palette))
     this.branchMenu = new BranchMenu(renderer, commandMenuTheme(this.palette))
     this.contextPanel = new ContextPanel(renderer, contextPanelTheme(this.palette))
     this.diffViewer = new DiffViewer(
@@ -704,6 +717,9 @@ export class NanobotTui {
         { name: "linefeed", action: "newline" },
         { name: "return", action: "submit" },
       ],
+      onCursorChange: () => {
+        if (!this.sessionMenu.visible && !this.branchMenu.visible) this.syncComposerMenus()
+      },
       onContentChange: () => {
         this.draft.prune(this.composer.plainText)
         this.runtimeControls.hide()
@@ -756,6 +772,7 @@ export class NanobotTui {
     this.shell.add(this.commandMenu.root)
     this.shell.add(this.sessionMenu.root)
     this.shell.add(this.mentionMenu.root)
+    this.shell.add(this.skillMenu.root)
     this.shell.add(this.branchMenu.root)
     this.shell.add(this.contextPanel.root)
     this.shell.add(this.runtimeControls.menuRoot)
@@ -810,6 +827,7 @@ export class NanobotTui {
     this.client.connect()
     void this.loadCommands()
     void this.loadMentions()
+    void this.loadSkills()
     this.runtimeControls.preload()
     this.renderer.start()
     // OpenTUI learns the real terminal background through OSC 10/11. Wait for
@@ -865,6 +883,15 @@ export class NanobotTui {
       if (candidate) this.chooseMention(candidate, this.activeMentionQuery)
       return
     }
+    if (this.skillMenu.visible && this.activeSkillQuery) {
+      const candidate = this.skillMenu.choose()
+      if (candidate) {
+        this.chooseSkill(candidate, this.activeSkillQuery)
+        return
+      }
+      this.skillMenu.hide()
+      this.activeSkillQuery = null
+    }
     if (!visibleContent) return
     if (["exit", "quit", "/quit", ":q"].includes(visibleContent.toLowerCase())) {
       this.quit()
@@ -926,6 +953,7 @@ export class NanobotTui {
     this.clearComposer()
     this.commandMenu.hide()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.recordPrompt(prompt.content)
     this.transcript.user(prompt.content, turnId)
     this.hostBlocked = false
@@ -1336,6 +1364,7 @@ export class NanobotTui {
     this.updateGatewayApiConnection(apiUrl, apiToken)
     void this.loadCommands()
     void this.loadMentions()
+    void this.loadSkills()
   }
 
   private async refreshApiConnection(
@@ -1477,6 +1506,7 @@ export class NanobotTui {
     this.clearComposer()
     this.commandMenu.hide()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.recordPrompt(content)
     this.syncQueuePreview()
     this.renderActiveStatus()
@@ -1581,6 +1611,31 @@ export class NanobotTui {
         return
       }
     }
+    if (this.skillMenu.visible) {
+      if (!key.ctrl && !key.meta && (key.name === "up" || key.name === "down")) {
+        this.skillMenu.move(key.name === "up" ? -1 : 1)
+        key.preventDefault()
+        return
+      }
+      if (!key.ctrl && !key.meta && key.name === "tab" && this.activeSkillQuery) {
+        const candidate = this.skillMenu.choose()
+        if (candidate) {
+          this.chooseSkill(candidate, this.activeSkillQuery)
+          key.preventDefault()
+          return
+        }
+        this.skillMenu.hide()
+        this.activeSkillQuery = null
+        this.updateMeta()
+      }
+      if (key.name === "escape") {
+        this.skillMenu.hide()
+        this.activeSkillQuery = null
+        this.updateMeta()
+        key.preventDefault()
+        return
+      }
+    }
     if (this.commandMenu.visible) {
       if (!key.ctrl && !key.meta && (key.name === "up" || key.name === "down")) {
         this.commandMenu.move(key.name === "up" ? -1 : 1)
@@ -1720,6 +1775,7 @@ export class NanobotTui {
     this.commandMenu.setTheme(commandMenuTheme(this.palette))
     this.sessionMenu.setTheme(commandMenuTheme(this.palette))
     this.mentionMenu.setTheme(commandMenuTheme(this.palette))
+    this.skillMenu.setTheme(commandMenuTheme(this.palette))
     this.branchMenu.setTheme(commandMenuTheme(this.palette))
     this.runtimeControls.setTheme(runtimeControlsTheme(this.palette))
     this.contextPanel.setTheme(contextPanelTheme(this.palette))
@@ -1749,6 +1805,7 @@ export class NanobotTui {
   private updateMeta(): void {
     const mode: FooterMode = this.runtimeControls.visible ? "runtime"
       : this.mentionMenu.visible ? "mention"
+      : this.skillMenu.visible ? "skill"
       : this.activeTurn ? "active"
       : this.branchMenu.visible ? "branch"
       : this.commandMenu.visible ? "command"
@@ -1932,17 +1989,30 @@ export class NanobotTui {
   }
 
   private syncComposerMenus(): void {
-    this.activeMentionQuery = mentionQuery(this.composer.plainText, this.composer.cursorOffset)
-    const candidates = this.availableMentions()
-    if (this.activeMentionQuery && candidates.length) {
+    const value = this.composer.plainText
+    const cursor = this.composerStringCursor()
+    this.activeMentionQuery = mentionQuery(value, cursor)
+    this.activeSkillQuery = skillQuery(value, cursor)
+    const mentionCandidates = this.availableMentions()
+    if (this.activeMentionQuery && mentionCandidates.length) {
       this.commandMenu.hide()
+      this.skillMenu.hide()
       const limit = this.renderer.height >= 20 ? 7 : 4
       if (this.mentionMenu.visible) this.mentionMenu.update(this.activeMentionQuery.query, limit)
-      else this.mentionMenu.show(candidates, this.activeMentionQuery.query, limit)
+      else this.mentionMenu.show(mentionCandidates, this.activeMentionQuery.query, limit)
       this.updateMeta()
       return
     }
     this.mentionMenu.hide()
+    if (this.activeSkillQuery && this.skillCandidates.length) {
+      this.commandMenu.hide()
+      const limit = this.renderer.height >= 20 ? 7 : 4
+      if (this.skillMenu.visible) this.skillMenu.update(this.activeSkillQuery.query, limit)
+      else this.skillMenu.show(this.skillCandidates, this.activeSkillQuery.query, limit)
+      this.updateMeta()
+      return
+    }
+    this.skillMenu.hide()
     this.syncCommandMenu()
   }
 
@@ -1961,13 +2031,44 @@ export class NanobotTui {
   private chooseMention(candidate: MentionCandidate, query: MentionQuery): void {
     const inserted = insertMention(this.composer.plainText, candidate, query)
     this.composer.setText(inserted.value)
-    this.composer.cursorOffset = inserted.cursor
+    this.setComposerStringCursor(inserted.value, inserted.cursor)
     this.mentionMenu.hide()
     this.activeMentionQuery = null
     this.syncComposerPlaceholder()
     this.updateMeta()
   }
 
+  private chooseSkill(candidate: SkillCandidate, query: SkillQuery): void {
+    const inserted = insertSkill(this.composer.plainText, candidate, query)
+    this.composer.setText(inserted.value)
+    this.setComposerStringCursor(inserted.value, inserted.cursor)
+    this.skillMenu.hide()
+    this.activeSkillQuery = null
+    this.syncComposerPlaceholder()
+    this.updateMeta()
+  }
+
+  private composerStringCursor(): number {
+    return this.composer.editBuffer.getTextRange(0, this.composer.cursorOffset).length
+  }
+
+  private setComposerStringCursor(value: string, cursor: number): void {
+    const target = Math.min(Math.max(cursor, 0), value.length)
+    const before = value.slice(0, target)
+    const row = before.split("\n").length - 1
+    const line = before.slice(before.lastIndexOf("\n") + 1)
+    let offset = row === 0 ? 0 : this.composer.editBuffer.getLineStartOffset(row)
+    const maxColumn = Math.max(8, line.length * 8 + 8)
+    for (let column = 0; column <= maxColumn; column += 1) {
+      const candidate = this.composer.editBuffer.positionToOffset(row, column)
+      if (candidate === 0 && (row !== 0 || column !== 0)) break
+      const candidateLength = this.composer.editBuffer.getTextRange(0, candidate).length
+      if (candidateLength > target) break
+      if (candidateLength === target) offset = candidate
+    }
+    this.composer.cursorOffset = offset
+  }
+
   private setComposer(content: string): void {
     this.draft.clear()
     this.composer.setText(content)
@@ -2010,9 +2111,11 @@ export class NanobotTui {
     this.commandMenu.hide()
     this.hideSessionMenu()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.branchMenu.hide()
     this.contextPanel.hide()
     this.activeMentionQuery = null
+    this.activeSkillQuery = null
   }
 
   private dismissRuntimeControls(): void {
@@ -2043,6 +2146,25 @@ export class NanobotTui {
     }
   }
 
+  private async loadSkills(): Promise<void> {
+    const loadId = ++this.skillLoadId
+    try {
+      const candidates = await fetchAvailableSkills(
+        this.options.apiUrl,
+        this.options.apiToken,
+        this.apiReauthenticator,
+      )
+      if (loadId !== this.skillLoadId) return
+      this.skillCandidates = candidates
+      if (this.activeSkillQuery) {
+        this.skillMenu.hide()
+        this.syncComposerMenus()
+      }
+    } catch {
+      // Skill completion is additive; explicit $skill-name input still works.
+    }
+  }
+
   private availableMentions(): MentionCandidate[] {
     const currentKey = this.client.activeChatId
       ? `websocket:${this.client.activeChatId}`
@@ -2127,6 +2249,7 @@ export class NanobotTui {
     this.commandMenu.hide()
     this.dismissRuntimeControls()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.branchMenu.hide()
     this.contextPanel.hide()
     this.clearComposer()
@@ -2221,6 +2344,7 @@ export class NanobotTui {
     this.commandMenu.hide()
     this.hideSessionMenu()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.branchMenu.hide()
     this.contextPanel.hide()
     this.clearComposer()
@@ -2387,6 +2511,7 @@ export class NanobotTui {
     this.commandMenu.hide()
     this.hideSessionMenu()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.branchMenu.hide()
     this.clearComposer()
     this.status.content = "Reading agent context…"
@@ -2459,6 +2584,7 @@ export class NanobotTui {
     this.commandMenu.hide()
     this.hideSessionMenu()
     this.mentionMenu.hide()
+    this.skillMenu.hide()
     this.branchMenu.hide()
     this.contextPanel.hide()
     this.clearComposer()

tui/src/footer-hints.ts

@@ -17,6 +17,7 @@ export interface FooterHintTheme {
 
 export type FooterMode =
   | "mention"
+  | "skill"
   | "runtime"
   | "active"
   | "branch"
@@ -117,7 +118,7 @@ function hintsFor(
   if (mode === "runtime") return width >= 64
     ? [hint("↑↓/click", "choose"), hint("enter", "apply"), hint("esc", "close")]
     : [hint("enter", "apply"), hint("esc", "close")]
-  if (mode === "mention") return width >= 64
+  if (mode === "mention" || mode === "skill") return width >= 64
     ? [hint("↑↓", "choose"), hint("tab/enter", "insert"), hint("esc", "close")]
     : [hint("enter", "insert"), hint("esc", "close")]
   if (mode === "active") return []

tui/src/protocol.test.ts

@@ -3,6 +3,7 @@ import { describe, expect, test } from "bun:test"
 import {
   NanobotClient,
   GatewayConnectionError,
+  fetchAvailableSkills,
   fetchGatewayConnection,
   fetchHistory,
   fetchMentionCandidates,
@@ -805,6 +806,53 @@ describe("gateway protocol", () => {
     }
   })
 
+  test("loads only enabled and available skills", async () => {
+    const original = globalThis.fetch
+    let authorization = ""
+    globalThis.fetch = ((_: string | URL | Request, init?: RequestInit) => {
+      authorization = new Headers(init?.headers).get("Authorization") || ""
+      return Promise.resolve(new Response(JSON.stringify({
+        skills: [
+          {
+            name: "verify",
+            description: "Verify public behavior",
+            source: "builtin",
+            enabled: true,
+            available: true,
+          },
+          {
+            name: "disabled",
+            description: "Disabled skill",
+            source: "workspace",
+            enabled: false,
+            available: true,
+          },
+          {
+            name: "unavailable",
+            description: "Missing dependency",
+            source: "builtin",
+            enabled: true,
+            available: false,
+          },
+          { name: "my skill", enabled: true, available: true },
+          { name: "技能", enabled: true, available: true },
+          { enabled: true, available: true },
+        ],
+      })))
+    }) as typeof fetch
+
+    try {
+      expect(await fetchAvailableSkills("http://nanobot.test", "secret")).toEqual([{
+        name: "verify",
+        description: "Verify public behavior",
+        source: "builtin",
+      }])
+      expect(authorization).toBe("Bearer secret")
+    } finally {
+      globalThis.fetch = original
+    }
+  })
+
   test("drops slash commands with unknown lifecycle metadata", async () => {
     const original = globalThis.fetch
     globalThis.fetch = (() => Promise.resolve(new Response(JSON.stringify({

tui/src/protocol.ts

@@ -262,6 +262,12 @@ export interface MentionCandidate {
   session?: SessionMention
 }
 
+export interface SkillCandidate {
+  name: string
+  description: string
+  source: string
+}
+
 export interface MessageOptions {
   cliApps?: Array<{ name: string }>
   mcpPresets?: Array<{ name: string }>
@@ -299,6 +305,8 @@ export interface SessionSummary {
   archived: boolean
 }
 
+const SKILL_REFERENCE_NAME = /^[A-Za-z0-9_-]+$/u
+
 const SLASH_COMMAND_LIFECYCLES = new Set([
   "side_channel",
   "finalize_active_turn",
@@ -683,6 +691,31 @@ export async function fetchSlashCommands(
   })
 }
 
+export async function fetchAvailableSkills(
+  apiUrl: string,
+  apiToken: string,
+  reauthenticate?: ApiReauthenticator,
+): Promise<SkillCandidate[]> {
+  if (!apiUrl || !apiToken) return []
+  const response = await fetchApi(apiUrl, apiToken, "/api/webui/skills", reauthenticate)
+  if (!response.ok) throw new Error(`skill request failed: HTTP ${response.status}`)
+  const payload = await response.json() as { skills?: unknown[] }
+  return (payload.skills || []).flatMap((value) => {
+    if (
+      !isRecord(value)
+      || typeof value.name !== "string"
+      || !SKILL_REFERENCE_NAME.test(value.name)
+      || value.enabled !== true
+      || value.available !== true
+    ) return []
+    return [{
+      name: value.name,
+      description: typeof value.description === "string" ? value.description : value.name,
+      source: typeof value.source === "string" ? value.source : "unknown",
+    }]
+  })
+}
+
 export async function fetchRuntimeControls(
   apiUrl: string,
   apiToken: string,

tui/src/skill-menu.test.ts

@@ -0,0 +1,72 @@
+import { afterEach, describe, expect, test } from "bun:test"
+import { createTestRenderer, type TestRendererSetup } from "@opentui/core/testing"
+
+import { insertSkill, SkillMenu, skillQuery } from "./skill-menu"
+import type { SkillCandidate } from "./protocol"
+
+const skills: SkillCandidate[] = [
+  { name: "simplify", description: "Simplify code", source: "workspace" },
+  { name: "verify", description: "Verify public behavior", source: "builtin" },
+]
+
+describe("skill completion", () => {
+  let setup: TestRendererSetup | undefined
+
+  afterEach(() => {
+    if (setup && !setup.renderer.isDestroyed) setup.renderer.destroy()
+    setup = undefined
+  })
+
+  test("finds and replaces only the skill reference under the cursor", () => {
+    const value = "use $ver before release"
+    const query = skillQuery(value, 8)
+
+    expect(query).toEqual({ query: "ver", start: 4, end: 8 })
+    expect(insertSkill(value, skills[1]!, query!)).toEqual({
+      value: "use $verify before release",
+      cursor: 11,
+    })
+  })
+
+  test("matches backend token boundaries and replaces a whole token", () => {
+    expect(skillQuery("$", 1)).toEqual({ query: "", start: 0, end: 1 })
+    expect(skillQuery("run ($SIM", 9)).toEqual({ query: "sim", start: 5, end: 9 })
+    expect(skillQuery("price$ver", 9)).toBeNull()
+    expect(skillQuery("文$ver", 5)).toBeNull()
+    expect(skillQuery("$verify done", 12)).toBeNull()
+
+    const midToken = skillQuery("use $verify before release", 8)
+    expect(midToken).toEqual({ query: "ver", start: 4, end: 11 })
+    expect(insertSkill("use $verify before release", skills[1]!, midToken!).value)
+      .toBe("use $verify before release")
+  })
+
+  test("filters, navigates, and chooses available skills", async () => {
+    setup = await createTestRenderer({ width: 72, height: 16, screenMode: "alternate-screen" })
+    const menu = new SkillMenu(setup.renderer, {
+      text: "#FFFFFF",
+      muted: "#999999",
+      border: "#555555",
+    })
+    setup.renderer.root.add(menu.root)
+    menu.show(skills, "", 6)
+    await setup.renderOnce()
+
+    expect(setup.captureCharFrame()).toContain("› $simplify")
+    expect(setup.captureCharFrame()).toContain("$verify")
+    expect(menu.move(1)).toBe(true)
+    expect(menu.choose()).toEqual(skills[1]!)
+
+    menu.update("simp", 6)
+    expect(menu.choose()).toEqual(skills[0]!)
+
+    menu.show([
+      { name: "alpha", description: "Verify workflow", source: "workspace" },
+      skills[1]!,
+    ], "verify", 6)
+    expect(menu.choose()).toEqual(skills[1]!)
+
+    menu.show([skills[0]!], "verify", 6)
+    expect(menu.choose()).toBeNull()
+  })
+})

tui/src/skill-menu.ts

@@ -0,0 +1,86 @@
+import { type BoxRenderable, type CliRenderer } from "@opentui/core"
+
+import { PickerMenu, type PickerMenuTheme } from "./picker-menu"
+import type { SkillCandidate } from "./protocol"
+
+export interface SkillQuery {
+  query: string
+  start: number
+  end: number
+}
+
+export function skillQuery(value: string, cursor: number): SkillQuery | null {
+  const cursorAt = Math.min(Math.max(cursor, 0), value.length)
+  const match = /(?:^|[^\p{L}\p{N}\p{M}\p{Pc}$])\$([A-Za-z0-9_-]*)$/u.exec(
+    value.slice(0, cursorAt),
+  )
+  if (!match) return null
+  const valueQuery = match[1] ?? ""
+  const start = cursorAt - valueQuery.length - 1
+  const remainder = /^[A-Za-z0-9_-]*/u.exec(value.slice(cursorAt))?.[0] || ""
+  return {
+    query: valueQuery.toLocaleLowerCase(),
+    start,
+    end: cursorAt + remainder.length,
+  }
+}
+
+export function insertSkill(
+  value: string,
+  candidate: SkillCandidate,
+  query: SkillQuery,
+): { value: string; cursor: number } {
+  const suffix = value.slice(query.end)
+  const tail = /^\s/u.test(suffix) ? "" : " "
+  const inserted = `$${candidate.name}${tail}`
+  return {
+    value: `${value.slice(0, query.start)}${inserted}${suffix}`,
+    cursor: query.start + inserted.length,
+  }
+}
+
+export class SkillMenu {
+  readonly root: BoxRenderable
+  private readonly picker: PickerMenu<SkillCandidate>
+  private items: SkillCandidate[] = []
+
+  constructor(renderer: CliRenderer, theme: PickerMenuTheme) {
+    this.picker = new PickerMenu(renderer, theme, {
+      id: "nanobot-tui-skill-menu",
+      key: (item) => item.name,
+      searchText: (item) => `${item.name} ${item.description}`,
+      render: (item) => `$${item.name}  ${item.description.replace(/\s+/gu, " ")}`,
+      emptyText: "No matching skills",
+    })
+    this.root = this.picker.root
+  }
+
+  get visible(): boolean { return this.picker.visible }
+  show(items: SkillCandidate[], query: string, limit: number): void {
+    this.items = items
+    this.picker.show(this.ranked(query), query, limit)
+  }
+  update(query: string, limit: number): void {
+    this.picker.show(this.ranked(query), query, limit)
+  }
+  move(direction: -1 | 1): boolean { return this.picker.move(direction) }
+  choose(): SkillCandidate | null { return this.picker.current() }
+  hide(): void { this.picker.hide() }
+  setTheme(theme: PickerMenuTheme): void { this.picker.setTheme(theme) }
+
+  private ranked(query: string): SkillCandidate[] {
+    const needle = query.toLocaleLowerCase()
+    if (!needle) return this.items
+    const score = (item: SkillCandidate): number => {
+      const name = item.name.toLocaleLowerCase()
+      if (name === needle) return 0
+      if (name.startsWith(needle)) return 1
+      if (name.includes(needle)) return 2
+      return 3
+    }
+    return this.items
+      .map((item, index) => ({ item, index, score: score(item) }))
+      .sort((left, right) => left.score - right.score || left.index - right.index)
+      .map(({ item }) => item)
+  }
+}