fix(tui): save live transcript from slash command

ui-tui/src/__tests__/createSlashHandler.test.ts

@@ -1,3 +1,5 @@
+import { existsSync, readFileSync, unlinkSync } from 'node:fs'
+
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import { createSlashHandler } from '../app/createSlashHandler.js'
@@ -287,6 +289,58 @@ describe('createSlashHandler', () => {
     expect(ctx.transcript.page).not.toHaveBeenCalled()
     expect(ctx.transcript.sys).toHaveBeenCalledWith('no conversation yet')
   })
+
+  it('/save writes the current TUI transcript without using the slash worker', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date(2026, 3, 25, 15, 4, 5))
+    const filename = 'hermes_conversation_20260425_150405.json'
+
+    try {
+      if (existsSync(filename)) {
+        unlinkSync(filename)
+      }
+
+      const ctx = buildCtx({
+        local: {
+          ...buildLocal(),
+          getHistoryItems: vi.fn(() => [
+            { role: 'system', text: 'intro' },
+            { role: 'user', text: 'hello' },
+            { role: 'assistant', text: 'hi there', tools: ['read_file'] },
+            { role: 'tool', text: 'tool output' }
+          ])
+        }
+      })
+
+      createSlashHandler(ctx)('/save')
+
+      expect(ctx.gateway.gw.request).not.toHaveBeenCalled()
+      expect(ctx.transcript.sys).toHaveBeenCalledWith(`conversation saved to: ${filename}`)
+
+      const saved = JSON.parse(readFileSync(filename, 'utf8'))
+
+      expect(saved.messages).toEqual([
+        { role: 'user', text: 'hello' },
+        { role: 'assistant', text: 'hi there', tools: ['read_file'] },
+        { role: 'tool', text: 'tool output' }
+      ])
+    } finally {
+      if (existsSync(filename)) {
+        unlinkSync(filename)
+      }
+
+      vi.useRealTimers()
+    }
+  })
+
+  it('/save reports empty state without touching the slash worker', () => {
+    const ctx = buildCtx()
+
+    createSlashHandler(ctx)('/save')
+
+    expect(ctx.gateway.gw.request).not.toHaveBeenCalled()
+    expect(ctx.transcript.sys).toHaveBeenCalledWith('no conversation yet')
+  })
 })
 
 const buildCtx = (overrides: Partial<Ctx> = {}): Ctx => ({

ui-tui/src/app/slash/commands/core.ts

@@ -1,3 +1,5 @@
+import { writeFileSync } from 'node:fs'
+
 import { NO_CONFIRM_DESTRUCTIVE } from '../../../config/env.js'
 import { dailyFortune, randomFortune } from '../../../content/fortunes.js'
 import { HOTKEYS } from '../../../content/hotkeys.js'
@@ -46,6 +48,24 @@ const DETAILS_USAGE =
 
 const DETAILS_SECTION_USAGE = 'usage: /details <section> [hidden|collapsed|expanded|reset]'
 
+const pad2 = (n: number): string => String(n).padStart(2, '0')
+
+const saveTimestamp = (d = new Date()): string =>
+  `${d.getFullYear()}${pad2(d.getMonth() + 1)}${pad2(d.getDate())}_${pad2(d.getHours())}${pad2(
+    d.getMinutes()
+  )}${pad2(d.getSeconds())}`
+
+const serializableTranscript = (items: Msg[]) =>
+  items
+    .filter(m => m.role === 'user' || m.role === 'assistant' || m.role === 'tool')
+    .filter(m => m.text.trim() || m.thinking?.trim() || m.tools?.length)
+    .map(m => ({
+      role: m.role,
+      text: m.text,
+      ...(m.thinking ? { thinking: m.thinking } : {}),
+      ...(m.tools?.length ? { tools: m.tools } : {})
+    }))
+
 export const coreCommands: SlashCommand[] = [
   {
     help: 'list commands + hotkeys',
@@ -351,6 +371,40 @@ export const coreCommands: SlashCommand[] = [
     }
   },
 
+  {
+    help: 'save the current transcript to JSON',
+    name: 'save',
+    run: (_arg, ctx) => {
+      const messages = serializableTranscript(ctx.local.getHistoryItems())
+
+      if (!messages.length) {
+        return ctx.transcript.sys('no conversation yet')
+      }
+
+      const filename = `hermes_conversation_${saveTimestamp()}.json`
+
+      try {
+        writeFileSync(
+          filename,
+          `${JSON.stringify(
+            {
+              model: ctx.ui.info?.model ?? null,
+              saved_at: new Date().toISOString(),
+              session_id: ctx.sid,
+              messages
+            },
+            null,
+            2
+          )}\n`,
+          'utf8'
+        )
+        ctx.transcript.sys(`conversation saved to: ${filename}`)
+      } catch (error) {
+        ctx.transcript.sys(`failed to save: ${String(error)}`)
+      }
+    }
+  },
+
   {
     aliases: ['sb'],
     help: 'status bar position (on|off|top|bottom)',