Watching my agent work from the phone and the desktop at the same time — I can't go back
You'd expect the phone to be a "downgraded" web page. After a side-by-side test, I found some experiences are actually better on mobile.
Before building DeepSeek Phone Harness, I set my own acceptance bar: the phone must reach 80% of the desktop web experience, or it's not done.
After finishing, I ran a controlled test: the same task, watched simultaneously on a desktop browser and a phone browser. The result surprised me — a few experiences are genuinely better on mobile.
The test: one task, both screens
Task: let the agent read the project config, summarize current progress, and run a test.
| Dimension | Desktop web | Phone |
|---|---|---|
| Streaming output | Fine | Fine (typewriter) |
| Tool-call visibility | Present | Stronger: each card shows the file path; tap for args + result |
| Approvals | Dialog/panel | Cards inline in the message stream — no page switch |
| Questions | Input takeover | Option cards, one tap |
| Model switching | Dropdown | Bottom sheet, thumb-reachable |
| Away from desk | Must be at the computer | Works from anywhere |
Why mobile is better at some things
1. Approvals/questions don't break context
On desktop, an approval is a separate dialog that interrupts what you're reading. On mobile, I made approvals and questions cards inserted directly into the message stream — the context of where the agent is and why it's asking stays continuous.
2. Tool cards are naturally built for portrait
"Read file → run command → edit code" — a vertical sequence of tool calls is made for a portrait screen. On desktop you juggle logs and lists; on mobile it's one clean timeline:
[📄 read] C:/.../config.json ● done
[⚙️ pwsh] npm test ● running…
3. Your thumb is the best mouse
Model switching, attachments, card expansion — everything lives within thumb reach.
An honest comparison
Mobile is not a replacement for the desktop — heavy work (editing lots of code, digging logs, multi-terminal) still belongs at a desk. But mobile closes the desktop's biggest gap: the moments you're not at the computer.
- Send a task on the commute, read the result when you arrive
- Tweak a config before bed, find it verified in the morning
- Approve an agent request mid-meeting with one tap
"Wherever you are, your agent is too" — that's mobile's real value, not "a smaller webpage."
The project
Open source (MIT):
Direct 4G/5G (free Tailscale), three-minute setup, zero npm dependencies.
Which of your agent tasks could be done while you're away from the desk? List them below — I'll see what belongs on the roadmap.
