For Mac, Windows and iPhone
Your computer, handled.
HandleBy is an AI agent that runs your desktop: your inbox, your texts, your Word documents and the apps themselves. It picks the right model for each step and writes itself new skills from the work you give it.
Draft a reply to Sarah confirming Tuesday's call.
Here's a draft. I kept your usual sign-off and moved the call to 2:30 PM so it clears your 2:00 meeting.
Models
The right model for every turn
Automatic routing
Each turn is sorted by difficulty and sent to a fast, balanced or top model with matching effort. A badge on the reply shows which model ran and why, and you can override it from the composer.
Claude and ChatGPT in one chat
Sign in to both and switch mid-conversation. Each model is caught up on the turns the other one handled, so nothing is lost in the handoff.
Fallback that can't double-send
If a model is overloaded or rate-limited, the turn reruns once on the other provider or a smaller model, but only when no tool has run yet. An email can't go out twice.
Learning
It gets better at your work
Skills it writes for itself
After a substantial task, a reviewer reads the transcript and either writes a new skill, improves one that fell short, or keeps nothing. Every change is versioned, with Undo on the notice and an editor in Settings.
Recall across every chat
A full-text index covers every message you've ever sent or received in HandleBy. The agent searches and reads past chats on its own, and History finds words inside messages, not just titles.
Memory that stays on your computer
Chats, memory and learned skills are stored locally. The agent reads and updates its memory as it works.
Your day
Works where you already work
Inbox triage
Mail is sorted as it arrives, with reply drafts ready for anything that needs an answer.
iMessage and Teams in your voice
Drafts read the full thread and sound like you. Edit, ask for another take, or send.
Word documents, footnotes intact
Open a .docx in HandleBy, see each footnote's sources, and edit text without disturbing formatting, footnotes or cross-references.
Your apps, operated for you
Computer use lets the agent open apps, click and type. A preview pane opens spreadsheets and PDFs beside the chat.
Automation
Runs while you're away
Scheduled tasks
Say “every weekday at 8:30, brief me on my calendar and inbox” and it becomes a schedule. Each run lands in a chat, and a notification takes you straight to it.
Programs instead of fifty tool calls
For bulk work, the agent writes a short program that reads files, spreadsheets, Word documents and PDFs in one pass and returns only the answer. “Total the balance column across these 12 loan tapes” is one step, not twelve.
Fork any reply
Branch a new chat from any point in a conversation to try a different direction without losing the original.
Beyond one window
Take it with you, share it, extend it
iPhone app
See your computer's screen live, tap and type to control it, approve the agent's actions, and work through chats, inbox, messages and documents from anywhere. A relay passes messages between phone and computer without storing them.
Shared chats
Invite someone by email to a chat. Their messages run on your HandleBy, with your tools and context.
Plugins
Drop a file in the plugins folder to add tools or hook into every turn: rewrite a message, block a tool call, or log what happened. Saved changes load instantly.
Tabs and windows
Run several chats at once in tabs or separate windows, with projects and folders as context. Old chats stay one search away.
Skins
Six looks, light and dark
Pick a skin in Settings on your computer or phone. Each one has its own light and dark palette, checked for readable contrast. Try them here; the preview follows this page's light or dark mode.
Hot magenta and cyan on violet-black.
Draft a reply to Sarah confirming Tuesday's call.
Here's a draft. I kept your usual sign-off and moved the call to 2:30 PM so it clears your 2:00 meeting.
Under the hood
How it's built
- Agent
- Claude Agent SDK and Codex, with MCP servers and skills shared across both
- Recall
- SQLite full-text index with stemming, updated seconds after each message
- Programs
- Model-written code runs in an isolated context with no shell access
- Phone link
- Cloudflare Worker relay, one private room per account
- Apps
- Electron for Mac and Windows, native SwiftUI for iPhone
Hand it the busywork.
HandleBy is in private early access. Book a short call and we'll set it up on your Mac or PC.
Request early accessOr email hi@handleby.ai