Reviewing Your AI Agents Offline

amux v0.9.200 caches every running session’s scrollback locally in your PWA, so you can review your full agent fleet without any internet connection — on a plane, subway, or anywhere signal drops out. Updated July 2026.

Why Offline Matters for AI Engineering Teams

Running an AI engineering team means your agents are always working, but you’re not always online. The morning commute, a trans-continental flight, a conference with spotty wifi, a walk between buildings — these are the moments when you most want to check what your overnight agents accomplished. Before amux v0.9.200, every one of these gaps meant opening your laptop, SSH-ing in, and running tmux attach — which required a working network connection.

The amux offline scrollback cache changes that. Every session’s terminal output is written to local IndexedDB the moment you view it while online. When you go offline, the full history is already on your device. No server needed to read what your agents did. The dashboard behaves identically, just with a last-synced timestamp instead of a live stream.

This pairs with the rest of the phone-first amux stack: you can read what your agents did (scrollback cache), review the task board (kanban cached locally), check what’s blocked or completed (stalled badge), and write your next instruction (offline outbox) — all without a connection, and all from your phone.

What Works Offline vs Online-Only

How the Scrollback Cache Works

The amux dashboard uses IndexedDB, the browser’s built-in structured storage, to persist session scrollback locally. Here’s the data flow:

1. Write on view: When you open a session’s Peek panel while online, the current scrollback buffer is written to IndexedDB under that session’s ID. This happens immediately, in the background, without any loading indicator.
2. Cache survives backgrounding: Unlike session storage (which clears when the tab is suspended), IndexedDB persists across background eviction, device lock, and app restarts on both iOS and Android.
3. Served from cache when offline: When the dashboard detects no server connection, it reads scrollback from IndexedDB and renders it exactly as it would render live output — same Peek panel, same formatting, same syntax highlighting for code blocks.
4. Auto-sync on reconnect: The moment the SSE connection re-establishes, the dashboard fetches fresh scrollback and writes it back to IndexedDB. The offline snapshot is replaced without any manual refresh.

The cache size is bounded by the session’s scrollback buffer (typically the last few thousand lines of output). It does not store the full JSONL conversation history — only the rendered terminal output you would see in the Peek panel.

Setup Guide

No configuration is needed — offline scrollback caching is on by default in amux v0.9.200 and later. The steps below ensure you have the best offline experience before you need it.

Step 1: Install amux

# Homebrew (recommended — macOS/Linux)
brew install mixpeek/amux/amux
amux serve   # → dashboard at https://localhost:8822

# PyPI
pipx install amux && amux serve

# Zero-install trial
uvx amux serve

Step 2: Install the PWA on your phone

The offline cache only works in the installed PWA or iOS app — it does not apply to a regular browser tab that gets closed. Install steps:

• iOS Safari: Open your amux dashboard URL → tap the Share button → Add to Home Screen. The PWA installs in standalone mode (full screen, no Safari chrome).
• Android Chrome: Open the dashboard → tap the three-dot menu → Add to Home Screen (or “Install App” if the banner appears).
• Native iOS app: Download from the App Store — includes the same offline cache behavior plus native push notifications for stalled sessions.

Step 3: Prime the cache before you go offline

Open each session’s Peek panel once while you have signal. The scrollback writes to IndexedDB in the background. A quick pass through the Sessions tab — tap each card to open Peek, let it load, move to the next — takes about 30 seconds for a fleet of 10 agents and leaves you with a full offline snapshot of every session.

For automated priming, schedule a daily amux scheduler job that opens and polls each session while your device is on wifi overnight.

Step 4: Use the dashboard offline

When signal drops, the dashboard shows a small offline indicator in the header. All previously-cached sessions remain fully readable. The last-synced timestamp appears in the Peek header so you know exactly how fresh your snapshot is.

Offline Outbox — Queue Messages for Later

Reading scrollback offline is useful. Writing instructions offline is what makes it operational. The amux offline outbox lets you compose a message to any session and hit Send while completely offline. The message is stored in IndexedDB with a pending status and automatically sent to the server the moment connectivity returns.

The outbox uses the same deduplication mechanism as the dictation offline queue: each message has a msg_id UUID generated at composition time. If the PWA reconnects and retries, the server rejects duplicate msg_ids, so you never accidentally send the same instruction twice.

Voice dictation offline

If you use voice dictation, recordings captured while offline are also queued. Your phone records and saves the audio locally; when signal returns, the audio uploads to Gemini for transcription, and the resulting text lands in the session composer for your final review before sending. The offline queue for dictation and for typed messages share the same auto-flush mechanism.

Real-World Scenarios

iOS-Specific Notes

iOS WebKit (Safari engine) has a few behaviors worth knowing when using the amux offline cache:

• IndexedDB persists through background eviction: iOS aggressively evicts PWA memory when you switch apps. The amux v0.9.200 cache is in IndexedDB, not in-memory, so the scrollback survives this eviction. When you tap the amux icon again, it reads from IndexedDB and shows the cached state instantly — no re-load from network needed.
• Stand-alone mode required for best behavior: The offline cache works in any browser, but the iOS-specific state restoration (re-selecting the last-open session, re-opening the Peek panel) only works in standalone PWA mode (Add to Home Screen). In a regular Safari tab, iOS may clear the tab’s session state on eviction.
• IndexedDB storage quota: iOS typically allows 1–2 GB of IndexedDB storage per origin. amux’s scrollback cache is kilobytes per session — even 100 active sessions with 10,000 lines of output each would use less than 50 MB.
• Native iOS app: The amux iOS app (App Store) uses the same IndexedDB-backed offline cache as the PWA and additionally supports push notifications for stalled session alerts, so you can be paged when an agent needs attention even while the app is in the background.

Quick Setup (5 Steps)

1. Install amux: brew install mixpeek/amux/amux && amux serve
2. Install the PWA: Open dashboard → Share → Add to Home Screen (iOS) or Install App (Android)
3. Start your sessions and run your normal agent workflow
4. Prime the offline cache: Open each session’s Peek panel once while on wifi to write the scrollback to IndexedDB
5. Go offline confidently: Open amux anywhere, read all your agents’ cached output, queue instructions, reconnect to deliver them

FAQ

Related Guides

• PWA Offline Sync Outbox Pattern — Queue Agent Messages When Offline
• Managing AI Agents from Your Phone — amux PWA Guide
• Voice Dictation for AI Coding Agents — Steer Your Fleet by Speaking
• Scheduling AI Agents — Automated Cron Jobs for Claude Code
• Running AI Coding Agents Overnight Unattended
• Self-Healing Configuration for AI Coding Agents
• AI Agent Daily Standup — Morning Review Workflow