Myco

Hand a useful app to the people around you. Phone to phone, and it keeps opening when the internet is gone.

Someone in the room has an app that helps: a schedule, a checklist, a game, a way to ring each other. With Myco they bump phones with you, and the app is on your phone too. It opens full-screen like any other app, and it still opens with no signal. Once you have it, you can hand it on to the next person.

Bump phones to pair	Hand over an app	Use it together, offline

Bump phones to pair	Your Circle	Share an app	Your apps	Apps run full-screen

What you can do with it today

• Pair by bumping phones (NFC), tapping someone Myco found nearby over Bluetooth, or scanning a QR code.
• Hand over an app. The other phone pulls it straight from yours.
• Open it with no internet, full-screen, from the Apps grid or a home-screen icon.
• Pass it on. The phone that received it can share it with someone else, even when you have left.
• Link over a USB cable, phone to phone or phone to a desktop running fips, for the fastest transfer (how).
• Run it on an Android TV. Myco shows up on the TV's home row and works with the remote; the TV joins the mesh over Wi-Fi or Ethernet.

All of this is tested with every phone in airplane mode and Bluetooth on (the runbook).

What Myco does not do yet:

• It is Android only (Android 10 or newer, 64-bit ARM phones).
• Myco itself comes from a download, not from another phone. See Get Myco. Sharing Myco from inside Myco is on the roadmap.
• Phones find each other only while Myco is open on screen. A phone in a pocket finds nobody.
• Mesh over the internet is opt-in (Settings › Mesh › Internet) and not yet tested on two phones on different networks. It links to public FIPS nodes, which see your phone's IP address but not what you send (how it works).

Pick your way in

• Someone is handing me an app — what to do, and why.
• I want to get an app to my group — setup, and what keeps working offline.
• I build apps — what to build, and how it travels.

---

Join a group

Someone near you uses an app that helps with what you are doing together. Myco lets them hand it to you in person.

1. Get Myco on your phone. This step needs a download. Android asks whether your browser may install apps. Allow it for this install.

2. Open it and tap "Yes, enable". Android then asks twice, each time after a card that explains it — tap Allow nearby devices, then Allow VPN:

   • Nearby devices, to find nearby mesh devices. On Android 12 and older this includes location: Android requires it to scan for Bluetooth. Myco does not record where you are.
   • A VPN prompt. The VPN connects your phone to the FIPS mesh, so any app can reach devices on it. Your regular internet traffic doesn't go through it.

   Then check your name — the phone's own name is filled in; edit it right there if you like, and tap Use this name. It is what the people you pair with see. The camera is asked for only when you scan a code. Notifications are optional: turn them on in Settings › Permissions.

3. Pair, in the Circle tab. Any one of these:

   • Bump: hold your phone back to back with theirs.
   • Nearby: tap them in the list of phones Myco found over Bluetooth, and they accept.
   • QR: they tap Show my code and you tap Scan.

4. Receive the app. They long-press the app and tap Share. You bump phones again, or scan the code on their screen from Apps › +. Scanning that code also pairs you, so you can skip step 3.

5. Open it. It lands in your Apps grid. Some apps first list what they want to use, such as nearby phones or your pictures. You choose.

After that the app is yours. It opens without internet, though what it can show offline depends on the app. You can share it with the next person the same way.

What pairing lets the other person do

Pairing works both ways. The person you pair with can:

• get the apps on your phone,
• read what your apps shared with nearby phones,
• offer you files.

Nothing else on your phone is open to them, and people you have not paired with get nothing. To undo it, tap them in Circle and choose Remove from circle.

Organize a group

Can you get a useful tool to the people here, and keep using it without the internet? Yes. Here is one full run you can repeat.

Example: a workshop app

You run a half-day workshop in a hall with poor signal. The group uses a napplet (a small app), say a checklist everyone ticks off together. It is passed between the phones in the room, and each phone picks up the latest ticks from the phones near it, even after joining late.

Before the day, with internet:

1. Install Myco on your own phone.
2. Add the app. Find it in the preinstalled AppStore app. Or, if its maker sent you a link (it starts with naddr), go to Apps › + and paste it. Review what it asks for and tap Add to my apps. Every file is now on your phone.
3. Ask people to install Myco before they come. Send them Join a group: it explains the permission prompts, including the VPN one.

On the day, no internet needed:

1. Keep Myco open on your screen.
2. Share the app with the first few people. Open the app's Share screen and let them scan the code or bump phones. That pairs you and hands it over in one go.
3. Let it spread. Everyone who has the app can share it the same way. You don't need to reach every person yourself, and people who arrive late can get it from whoever is next to them.
4. Each person reviews what the app asks for, and opens it.

What keeps working offline

Works with no internet	Needs the internet
Pairing, while both phones have Myco open	Installing Myco itself
Handing an app to someone you paired with	Adding an app nobody here has yet
Opening any app already on your phone	Public Nostr content, like profiles and the AppStore feed
Apps built to talk over nearby phones, while those phones are in reach	Anything an app loads from the web

Know before you rely on it

• Phones must be close, and Myco must be on screen, to find each other.
• Bluetooth is slow for big apps. Keep what you hand out small, or add it before the day. Phones on the same Wi-Fi network use it, and that is faster.
• Myco is not an emergency radio. It does not promise that a message gets through, and it cannot confirm that a message came from an organizer.

Try it on two phones first: the runbook.

Build apps for Myco

What can you build, what can it use, and how does it reach people?

Napplets

A napplet is a small program in a sandbox (napplet.run, NIP-5D). It is what Myco is built to run. It asks Myco for what it needs, and gets only what the person grants:

• an identity to sign as,
• Nostr relays: this phone's own relay, and public ones when online,
• the mesh: publish to and read from nearby paired phones, up to a hop limit the person sets,
• pictures and files by content hash, from this phone, a paired phone, or public servers,
• other apps, by role: "open this profile" opens the person's profile app, the one they chose as the default, or the one they pick when asked.

nsites, as a bonus

An nsite is a static website published on Nostr. Myco stores its signed files and shows them, so any nsite works offline once it is on the phone. It asks for no permissions and gets no mesh.

Sharing an app is not syncing its data

Myco copies an app's files from phone to phone. It does not make an app collaborative on its own. For people to work together offline, a napplet uses the mesh capability:

• Publish stores a note on this phone and floods it to paired phones, up to the hop limit.
• Subscribe returns matching notes this phone already holds, then asks phones within the hop limit for theirs. So a phone that joins late catches up from the phones near it.
• Ephemeral notes (with a NIP-40 expiration, such as chat) disappear once they expire, so catch-up is only possible until then.

A napplet can also keep a note or picture it was shown on this phone, and pass on a note it was shown to nearby phones or public relays again — only ever what it was shown, never signed as you.

With your OK on the install sheet, a napplet can also upload a file, such as a picture to post, to your Blossom servers, signed as you. It can also open or save a file you pick in Android's file picker, and only that file.

From a small example to two phones

1. Build a single-file napplet, following napplet.run. (Or a static site, for an nsite.)
2. Publish it to Nostr. (An nsite: nsite-cli upload dist.)
3. Add it on one phone while online: Apps › +, then paste its naddr (or the nsite's link).
4. Hand it over to a second phone in airplane mode, and open it there. Follow the two-phone runbook.
5. Test the offline part on real phones. Bluetooth, NFC and the mesh need real hardware. Emulators are not supported.

How it works underneath

Every phone runs its own Nostr relay and Blossom file store, and keeps the signed files of every app it holds. That is why a phone that got an app can hand it on. Phones connect over a FIPS mesh: Bluetooth (L2CAP), Wi-Fi Aware, a USB cable, the local network, or the internet when there is one. Links are encrypted. The Circle — the people you paired with — decides who may pull from your phone.

The reusable content layer (relay, Blossom, gateway, sync) is the nsite-deck crate. myco-core wires it to FIPS and the Android app.

Read on:

• Concepts & glossary — start here
• Architecture
• Napplet runtime · NAP-MESH · NAP-INTENT · NAP-UPLOAD · NAP-FS
• The nsite layer · Propagation
• Identity & pairing · Security
• Build from source · All docs · Roadmap

---

Get Myco

• Download: the APK from the latest release, or through Zapstore.
• Installing the APK: Android asks whether your browser (or file app) may install apps. Allow it, install Myco, and you can turn it off again.
• Needs: Android 10 or newer, on a 64-bit ARM phone. NFC is optional; QR works everywhere.

Myco cannot pass itself on from phone to phone yet (on the roadmap). Each person needs the APK before they can receive apps.

Status

Myco is released and under active development: see the releases, CHANGELOG.md and the roadmap. Every install also has a Nostr account from the first launch: a guest you can keep, or replace with your own nsec or a signer app such as Amber.

Built on the FIPS mesh, with an embedded Nostr relay and Blossom store in Rust and a Compose shell in Kotlin.