Talk to Your Car Data With AI — On Your Phone, Not in the Cloud

You’ve got months — maybe years — of your car’s life inside Magica: every refill, every trip, every service, every deadline. But to answer a plain question like “how much did I spend on fuel this month?” you still open the app and dig through screens.

What if you could just ask? And what if the answer came back without a single byte of your data leaving your phone?

That’s what Magica’s local API and MCP support let you do. It’s early access right now, and it’s the feature I’m most excited about — because it does something no other mileage tracker I know of does: it lets your own AI assistant read (and, if you allow it, update) your car data, while that data stays exactly where it already lives — on your device.

What this actually is, in plain terms

There’s a growing standard called MCP (Model Context Protocol). It’s the way an AI assistant — Claude, and a handful of others — plugs into external “tools” it can call while you’re talking to it. Think of it as giving the assistant a set of buttons it can press on your behalf.

Magica is one of those tools. When you turn on API Mode, the app starts a tiny server inside itself, on your phone. Your AI assistant connects to that server over your home Wi‑Fi and can then do things like:

• “How much did I spend on fuel this month?”
• “What deadlines do I have in the next 60 days?”
• “Log a refill of 35 litres for €60.50.”
• “Compare this January’s mileage with December’s.”

You ask in normal language. The assistant figures out which Magica tool to call, calls it, and answers you — with your real numbers, not a guess.

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The part that makes it different: the data stays on your phone

Most “AI features” in apps work by shipping your data off to a company’s cloud, running it through a model there, and sending a result back. Magica doesn’t have a cloud. It never has. The whole product is privacy-first, on-device — and the AI feature is built the same way, on purpose.

Here’s the honest, precise version of how it works:

• There is no Magica cloud. The server that answers your assistant runs on your phone. It’s reachable only on your local network. Magica doesn’t upload your trips, refills or expenses anywhere.
• Your assistant talks straight to your phone. When you connect Claude (or Cursor, or another client), it opens a direct connection to that on-device server. No middleman service of mine sits in between.
• You control the scope. Access is granted through a token you generate in the app, and you choose whether it’s read-only or read-and-write. You can see every connected client and revoke any of them with one tap.

One caveat I’ll be straight about, because it matters: the AI assistant you choose still processes the answer through its own model to talk back to you. So when you ask Claude “how’s my fuel this month?”, the numbers it fetched from your phone pass through Claude to form the reply. What’s different from every cloud tracker is that there’s no permanent copy of your history sitting on someone’s server — it lives on your device, and only what you actually ask about is ever fetched. It’s a conversation between you, your phone, and the assistant you picked.

What you can actually ask

The reason this feels different from a normal app is that you stop navigating and start asking. A few real examples:

A quick check-up.

You: How’s my Juke? Claude: Your Nissan Juke is at 10,950 km. This month you’ve driven 1,031 km across 76 trips, spending €141.71 on fuel (€307.71 total including services). No overdue services right now.

A consumption reality check.

You: Am I burning more fuel than usual? Claude: This month you’re averaging 6.4 L/100km versus 5.2 declared by the manufacturer — +23%. Last month you were at 5.9, so you’re up on yourself too. More city driving lately?

Logging without touching a form.

You: I just filled up, 35 litres at €1.728 per litre. Claude: That’s €60.48. Logged — it’s your third fill-up of the month, average €1.71/L so far.

Staying ahead of deadlines.

You: What do I need to pay in the next three months? Claude: Two things: insurance due 1 September, road tax due 13 September. Nothing critical yet. Want a reminder at the end of July?

You can also ask it to break down where your money went, find a specific trip (“when did I drive to Florence?”), or compare any two periods. It’s the same data you already track — you’re just getting to it by talking.

Read-only, or read and write — your call

By default you can keep the assistant read-only: it can look at everything but change nothing. That’s the safe starting point.

If you want, you can grant a read-and-write token, and then the assistant can also log a refill, record a service, or add a note to a trip — the “I just filled up…” example above only works with write access. It’s opt-in, per client, and revocable. If an assistant only needs to answer questions, give it a read token and reduce what could ever go wrong.

Which AI assistants work

Anything that speaks MCP over the modern Streamable HTTP transport. In practice that means Claude (Desktop), Cursor, Codex CLI, Continue, and other recent MCP clients. Connecting each one takes a couple of minutes — I wrote a separate, step-by-step guide for that.

👉 How to connect Magica to Claude and other AI assistants — the full setup walkthrough.

The honest limits (it’s early access)

I’d rather you go in with clear eyes than be disappointed:

• It’s local by design, which means local by default. The server runs on your phone and is reachable on your Wi‑Fi. If you want to reach it from outside your home network, that’s on you to set up (it’s possible, but not something the app does for you).
• Your phone has to be awake and running API Mode. The server auto-stops after a few minutes of inactivity to save battery — you can extend that up to an hour, or turn it off, but there’s no always-on 24/7 service here. Phones sleep; that’s a feature, not a bug.
• It’s early access. The set of things you can ask is already useful, but it’s still growing, and rough edges are possible. It’s built into the Magica app on both iOS and Android.

None of this is a limitation I’m apologising for — it’s the same trade I’ve made across the whole app. On-device means it depends on your device. That’s the deal, and for most people it’s the right one.

Why I built it this way

I could have taken the easy route: push your data to a server of mine, run the AI there, done. Plenty of apps do. But the entire point of Magica is that your car’s history is yours and stays with you. Bolting a cloud onto it just to say “we have AI” would have contradicted the one promise the app is built on.

So I did the harder version: a real MCP server, running inside the app, on your phone. Your AI assistant reaches your data on your device. It’s an architecture decision, not a marketing line.

How to get started

1. Open Magica → Account → API Mode and switch it on.
2. Generate a token (read-only to start).
3. Point your AI assistant at the app following the setup guide.
4. Ask it something about your car.

That’s it. No account, no signup, no cloud.

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FAQ

Do I need to be a developer to use this? No, not to use it — asking questions is just talking. Connecting an assistant the first time takes a couple of minutes of setup (pasting a token into a config), and I’ve written a guide that walks through it. After that, it’s plain conversation.

Does my car data get uploaded to the cloud? There’s no Magica cloud to upload it to. The server runs on your phone and your assistant connects to it directly over your local network. The one nuance: the AI assistant you choose processes the answers it fetches through its own model to reply to you — but your full history never leaves your device or lands on a server of mine.

Which AI assistants can I connect? Any modern MCP client using Streamable HTTP — Claude Desktop, Cursor, Codex CLI, Continue, and others. The setup guide covers the common ones.

Can the AI change my data, or only read it? Your choice. Read-only tokens let it look but not touch. Read-and-write tokens let it log refills, record services and edit trip notes. It’s opt-in per assistant, and you can revoke access anytime.

Is this available right now? Yes, as early access. It works today and is genuinely useful, but the feature set is still expanding and you may hit rough edges.

Does it work when my phone is asleep? No. The server runs while API Mode is on and stops after a period of inactivity to protect your battery. You can extend that timeout, but there’s no always-on background service — by design.

Magica is a privacy-first mileage and vehicle tracker I build as an independent developer. Your data stays on your device — including when you point your AI assistant at it.

Try Magica for Free

Download the app and start automatically tracking your business trips. No credit card required.

Download Now