agent: TermInput — composer + slash commands

Ported from app.js's `renderTermInput`/`handleSlashCommand`/
`completeSlash`: prompt + auto-growing textarea, Enter sends (Shift+Enter
newline), Tab cycles slash-command completion. Same command set
(/help, /clear, /cancel, /compact, /model, /effort, /new-session,
/logout), same routes (`api/cancel`, `api/compact`, `api/new-session`,
`api/logout`, `send`) via new `lib/termActions.ts` (same `{ok, detail}`
shape as modelEffort.ts's POST helper).

One deliberate UX change: `/new-session` and `/logout` used to pop the
old shadow-DOM `themedConfirm` modal before firing — this rewrite's
destructive actions all avoid that widget family already (SidePanel,
useConfirmClick), and a modal doesn't fit a text-input flow anyway.
Typing the command once arms it (a local note explains what confirming
does); typing it again fires it — a keyboard-native two-step confirm.

`/help`/`/clear` need to reach into LiveStream's row list (local-only
echo rows, never sent anywhere) without lifting that state up to Root —
`useLiveStream` gained `pushLocalNote`/`clearLocal`, exposed off
`LiveStream` via `forwardRef`+`useImperativeHandle` (preact/compat),
same shape as app.js's old `termAPI` object but scoped as a ref handle
instead of a module-level variable.

Screenshot-verified end to end: typed "/help" + Enter into a real
mounted composer, confirmed the textarea clears and the local note rows
(command list) append to the live pane.

frontend/packages/agent/src/Root.tsx

@@ -2,15 +2,16 @@
 // to the real `/api/state` snapshot via `useAgentState`. Still a slice,
 // not the whole page — see main.tsx's file comment for what's left
 // (the live SSE stream, login flow, inbox/todos, term input, overflow).
-import { useState } from 'preact/hooks';
+import { useRef, useState } from 'preact/hooks';
 import type { BadgeTone } from '@hive/shared/badge.js';
 import { Header } from './components/Header.js';
 import { StatusChips } from './components/StatusChips.js';
-import { LiveStream } from './components/LiveStream.js';
+import { LiveStream, type LiveStreamHandle } from './components/LiveStream.js';
 import { HeaderPill } from './components/HeaderPill.js';
 import { SidePanel } from './components/SidePanel.js';
 import { InboxPanel } from './components/InboxPanel.js';
 import { TodosPanel } from './components/TodosPanel.js';
+import { TermInput } from './components/TermInput.js';
 import { useAgentState } from './hooks/useAgentState.js';
 import { useTodos } from './hooks/useTodos.js';
 import { fmtAge, fmtTokens } from './lib/format.js';
@@ -51,6 +52,17 @@ export function Root() {
   const { state, refresh } = useAgentState();
   const { todos, refresh: refreshTodos } = useTodos();
   const [openPanel, setOpenPanel] = useState<OpenPanel>(null);
+  const liveStreamRef = useRef<LiveStreamHandle>(null);
+  const termInput = (
+    <footer class="agent-composer">
+      <TermInput
+        label={state?.label ?? '…'}
+        online={state?.status === 'online'}
+        onLocalNote={(text) => liveStreamRef.current?.pushNote(text)}
+        onClear={() => liveStreamRef.current?.clear()}
+      />
+    </footer>
+  );
 
   const pills = (
     <>
@@ -99,8 +111,9 @@ export function Root() {
           />
         </Header>
         <main className="agent-main">
-          <LiveStream />
+          <LiveStream ref={liveStreamRef} />
         </main>
+        {termInput}
         {panel}
       </>
     );
@@ -145,8 +158,9 @@ export function Root() {
         />
       </Header>
       <main className="agent-main">
-        <LiveStream onLiveTurnBoundary={refresh} />
+        <LiveStream ref={liveStreamRef} onLiveTurnBoundary={refresh} />
       </main>
+      {termInput}
       {panel}
     </>
   );

frontend/packages/agent/src/components/LiveStream.tsx

@@ -20,7 +20,8 @@
 //     unseen for an append. The old code inferred this from DOM
 //     mutation shape after the fact; here the caller already knows
 //     which one it did, so there's nothing to infer.
-import { useLayoutEffect, useRef, useState } from 'preact/hooks';
+import { useLayoutEffect, useRef, useState, useImperativeHandle } from 'preact/hooks';
+import { forwardRef } from 'preact/compat';
 import { useLiveStream } from '../hooks/useLiveStream.js';
 import { Row } from './Row.js';
 
@@ -33,8 +34,21 @@ export interface LiveStreamProps {
   onLiveTurnBoundary?: () => void;
 }
 
-export function LiveStream({ onLiveTurnBoundary }: LiveStreamProps) {
-  const { rows, hasMore, loadingMore, loadMore } = useLiveStream({ onLiveTurnBoundary });
+/** Imperative escape hatch for TermInput's local-only slash commands
+ * (`/help`, `/clear`) — same shape as app.js's old `termAPI` object,
+ * kept as a ref handle rather than lifting the whole row array up to
+ * Root so LiveStream/useLiveStream still own their state privately. */
+export interface LiveStreamHandle {
+  pushNote: (text: string) => void;
+  clear: () => void;
+}
+
+export const LiveStream = forwardRef<LiveStreamHandle, LiveStreamProps>(function LiveStream(
+  { onLiveTurnBoundary },
+  ref,
+) {
+  const { rows, hasMore, loadingMore, loadMore, pushLocalNote, clearLocal } = useLiveStream({ onLiveTurnBoundary });
+  useImperativeHandle(ref, () => ({ pushNote: pushLocalNote, clear: clearLocal }), [pushLocalNote, clearLocal]);
   const logRef = useRef<HTMLDivElement>(null);
   const [stickToBottom, setStickToBottom] = useState(true);
   const [unseen, setUnseen] = useState(0);
@@ -110,4 +124,4 @@ export function LiveStream({ onLiveTurnBoundary }: LiveStreamProps) {
       )}
     </div>
   );
-}
+});

frontend/packages/agent/src/components/TermInput.tsx

@@ -0,0 +1,171 @@
+// <TermInput> — the fixed composer at the bottom of the page. Sends a
+// plain message to this agent's own turn loop (`POST send`), or
+// intercepts a `/slash` command locally (never sent to the agent).
+// Ported from app.js's `renderTermInput`/`handleSlashCommand`/
+// `completeSlash`, with one deliberate UX change: `/new-session` and
+// `/logout` used to pop the old shadow-DOM `themedConfirm` modal
+// (@hive/shared/modal.js) before firing — this rewrite's destructive
+// actions all avoid that widget family (see SidePanel.tsx's/
+// useConfirmClick.ts's file comments for why), and a modal doesn't fit
+// a text-input flow anyway. Instead: typing the command once arms it
+// (a local note explains what confirming does), typing it again within
+// the same "armed" state fires it — a keyboard-native two-step confirm.
+import { useRef, useState } from 'preact/hooks';
+import { postModel, postEffort } from '../lib/modelEffort.js';
+import { postCancelTurn, postCompact, postNewSession, postLogout, postSend } from '../lib/termActions.js';
+
+export interface TermInputProps {
+  label: string;
+  online: boolean;
+  onLocalNote: (text: string) => void;
+  onClear: () => void;
+}
+
+const SLASH_COMMANDS: { name: string; desc: string }[] = [
+  { name: '/help', desc: 'list slash commands' },
+  { name: '/clear', desc: 'wipe the terminal panel (local-only)' },
+  { name: '/cancel', desc: 'SIGINT the in-flight claude turn' },
+  { name: '/compact', desc: 'compact the persistent claude session' },
+  { name: '/model', desc: '/model <name>  — switch claude model for future turns' },
+  { name: '/effort', desc: '/effort <level>  — set claude effort (medium/high/xhigh) for future turns' },
+  { name: '/new-session', desc: 'fresh claude session next turn (type twice to confirm)' },
+  { name: '/logout', desc: 'rotate OAuth creds + park in needs-login (type twice to confirm)' },
+];
+
+const MAX_PX = 12 * 16; // ~8 lines @ 1.5 line-height, 1em base
+
+function completeSlash(prefix: string): string | null {
+  const matches = SLASH_COMMANDS.filter((c) => c.name.startsWith(prefix));
+  if (!matches.length) return null;
+  const idx = matches.findIndex((c) => c.name === prefix);
+  return matches[(idx + 1) % matches.length].name;
+}
+
+export function TermInput({ label, online, onLocalNote, onClear }: TermInputProps) {
+  const [value, setValue] = useState('');
+  const taRef = useRef<HTMLTextAreaElement>(null);
+  // Which destructive command is currently "armed" (typed once, waiting
+  // for the confirming repeat) — any other command clears it.
+  const armedRef = useRef<string | null>(null);
+
+  function grow() {
+    const ta = taRef.current;
+    if (!ta) return;
+    ta.style.height = 'auto';
+    ta.style.height = Math.min(ta.scrollHeight, MAX_PX) + 'px';
+  }
+
+  function reportFailure(label_: string, detail?: string) {
+    onLocalNote(`✗ ${label_} failed${detail ? ': ' + detail : ''}`);
+  }
+
+  function handleSlash(line: string): boolean {
+    const trimmed = line.trim();
+    const [cmd, ...rest] = trimmed.split(/\s+/);
+    const arg = rest.join(' ');
+    const wasArmed = armedRef.current === cmd;
+    armedRef.current = null;
+
+    switch (cmd) {
+      case '/help':
+        onLocalNote('/help');
+        for (const c of SLASH_COMMANDS) onLocalNote(`    ${c.name.padEnd(13)} — ${c.desc}`);
+        return true;
+      case '/clear':
+        onClear();
+        onLocalNote('· terminal cleared (local view only — server history kept)');
+        return true;
+      case '/cancel':
+        postCancelTurn().then((r) => !r.ok && reportFailure('/cancel', r.detail));
+        return true;
+      case '/compact':
+        postCompact().then((r) => !r.ok && reportFailure('/compact', r.detail));
+        return true;
+      case '/new-session':
+        if (wasArmed) {
+          postNewSession().then((r) => !r.ok && reportFailure('/new-session', r.detail));
+        } else {
+          armedRef.current = '/new-session';
+          onLocalNote('⚠ drops all prior --continue context. type /new-session again to confirm.');
+        }
+        return true;
+      case '/logout':
+        if (wasArmed) {
+          postLogout().then((r) => !r.ok && reportFailure('/logout', r.detail));
+        } else {
+          armedRef.current = '/logout';
+          onLocalNote('⚠ SIGINTs the current turn + rotates OAuth credentials. type /logout again to confirm.');
+        }
+        return true;
+      case '/model':
+        if (!arg) onLocalNote('✗ /model needs a name (e.g. /model haiku, /model sonnet, /model opus)');
+        else postModel(arg).then((r) => !r.ok && reportFailure('/model', r.detail));
+        return true;
+      case '/effort':
+        if (!arg) onLocalNote('✗ /effort needs a level (e.g. /effort medium, /effort high, /effort xhigh)');
+        else postEffort(arg).then((r) => !r.ok && reportFailure('/effort', r.detail));
+        return true;
+      default:
+        onLocalNote(`✗ unknown slash command: ${cmd} — try /help`);
+        return true;
+    }
+  }
+
+  function submit() {
+    const line = value;
+    if (!line.trim()) return;
+    setValue('');
+    requestAnimationFrame(grow);
+    if (line.trim().startsWith('/')) {
+      handleSlash(line);
+      return;
+    }
+    armedRef.current = null;
+    postSend(line).then((r) => !r.ok && reportFailure('send', r.detail));
+  }
+
+  function onInput(e: Event) {
+    setValue((e.currentTarget as HTMLTextAreaElement).value);
+    grow();
+  }
+
+  function onKeyDown(e: KeyboardEvent) {
+    if (e.key === 'Tab' && value.startsWith('/') && !value.includes(' ')) {
+      const next = completeSlash(value);
+      if (next) {
+        e.preventDefault();
+        setValue(next);
+      }
+      return;
+    }
+    if (e.key === 'Enter' && !e.shiftKey && !e.isComposing) {
+      e.preventDefault();
+      submit();
+    }
+  }
+
+  return (
+    <div class={`term-input${online ? '' : ' disabled'}`}>
+      <form
+        class="sendform-term"
+        onSubmit={(e) => {
+          e.preventDefault();
+          submit();
+        }}
+      >
+        <span class="prompt">operator@{label} ▸</span>
+        <textarea
+          ref={taRef}
+          value={value}
+          placeholder={`message ${label}…`}
+          rows={1}
+          disabled={!online}
+          autocomplete="off"
+          onInput={onInput}
+          onKeyDown={onKeyDown}
+        />
+        <span class="submit-hint">↵ send · ⇧↵ newline · /help</span>
+      </form>
+    </div>
+  );
+}

frontend/packages/agent/src/hooks/useLiveStream.ts

@@ -35,6 +35,13 @@ export interface UseLiveStreamResult {
   hasMore: boolean;
   loadingMore: boolean;
   loadMore: () => void;
+  /** Append a local-only note row (TermInput's `/help` output, error
+   * feedback on a failed slash-command POST) — never sent anywhere,
+   * purely a client-side echo. */
+  pushLocalNote: (text: string) => void;
+  /** Wipe the local view only (server-side history is untouched) —
+   * TermInput's `/clear`. */
+  clearLocal: () => void;
 }
 
 function appendRow(rows: StreamRow[], row: StreamRow): StreamRow[] {
@@ -179,5 +186,14 @@ export function useLiveStream(opts: UseLiveStreamOptions = {}): UseLiveStreamRes
     }
   }
 
-  return { rows, hasMore, loadingMore, loadMore };
+  const localKeyRef = useRef(0);
+  function pushLocalNote(text: string) {
+    localKeyRef.current += 1;
+    setRows((prev) => appendRow(prev, { key: `local-${localKeyRef.current}`, cssClass: 'note', fromHistory: false, text }));
+  }
+  function clearLocal() {
+    setRows([]);
+  }
+
+  return { rows, hasMore, loadingMore, loadMore, pushLocalNote, clearLocal };
 }

frontend/packages/agent/src/lib/termActions.ts

@@ -0,0 +1,25 @@
+// Same-origin fetch POST helpers for the term-input slash commands —
+// same shape as modelEffort.ts's `post()` ({ ok, detail } rather than
+// throwing), reused by TermInput.tsx.
+async function post(path: string, body?: URLSearchParams): Promise<{ ok: boolean; detail?: string }> {
+  try {
+    const resp = await fetch(path, {
+      method: 'POST',
+      headers: body ? { 'Content-Type': 'application/x-www-form-urlencoded' } : undefined,
+      body,
+      redirect: 'manual',
+    });
+    const ok = resp.ok || resp.type === 'opaqueredirect' || (resp.status >= 200 && resp.status < 400);
+    if (ok) return { ok: true };
+    const detail = await resp.text().catch(() => '');
+    return { ok: false, detail: `http ${resp.status}${detail ? ' — ' + detail : ''}` };
+  } catch (err) {
+    return { ok: false, detail: err instanceof Error ? err.message : String(err) };
+  }
+}
+
+export const postCancelTurn = () => post('api/cancel');
+export const postCompact = () => post('api/compact');
+export const postNewSession = () => post('api/new-session');
+export const postLogout = () => post('api/logout');
+export const postSend = (body: string) => post('send', new URLSearchParams({ body }));