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3-Minute Quick Start: Build Your Private P2P Network

This guide shows the shortest beginner-friendly path to connect two of your own devices with Fungi.

ping.gif

You will:

  • start the Fungi daemon on both devices
  • add each device to the other device's address book
  • allow inbound access only for your own device
  • verify the connection with fungi ping

In this example, assume your two devices are named my-laptop and home-pc.

Before You Start​

  1. Install Fungi CLI on both devices from Install Fungi.
  2. Open two terminals on each device if possible:
    • one terminal for fungi daemon
    • one terminal for the commands in this guide
  3. Make sure both devices can reach the internet, or at least the same local network.

Step 1: Start The Daemon On Both Devices​

Run this command on both devices:

fungi daemon

If you want to disable the built-in community relay or use your own relay addresses before the daemon makes network connections, configure relay settings first. See Self-hosted Relay.

You will see startup logs similar to this:

Configuration file already exists at $HOME/.fungi/config.toml
INFO [fungi::commands::fungi_daemon] Starting Fungi daemon...
Fungi directory: "$HOME/.fungi"
Loading Fungi config from: "$HOME/.fungi/config.toml"
...
INFO [libp2p_swarm] local_peer_id=...
...

Keep fungi daemon running on both devices.

In another terminal, you can print the current device's PeerID:

fungi info id

Step 2: Add my-laptop To home-pc's Address Book​

On home-pc, try local discovery first:

fungi device mdns

If both devices are on the same LAN, you may see output like this:

16Uiu2H........Co7Cw9 -  (macbook-pro)

If mDNS does not find the other device, copy the PeerID manually from fungi info id on my-laptop.

The name in parentheses [(macbook-pro)] is the discovered device hostname, not your local Fungi alias.

Now save that PeerID in the address book on home-pc:

fungi device add --alias my-laptop 16Uiu2H........Co7Cw9

alias and hostname are different:

  • the hostname comes from the remote device and usually looks like a system name such as macbook-pro
  • the alias is the name you choose locally for that peer, such as my-laptop
  • different devices can show similar or changing hostnames, but your alias is the stable name you use in Fungi commands
  • in this guide, you will mainly use the alias

To verify the saved entry:

fungi device list

Step 3: Allow my-laptop To Access home-pc​

On home-pc, allow inbound access from my-laptop:

fungi security allowed-peers add my-laptop

Fungi will show a confirmation screen before it updates the allowlist.

================ SECURITY CONFIRMATION ================
You are about to trust this peer for incoming access:
  Peer: my-laptop
  Peer ID: 16Uiu2H........Co7Cw9

This peer will be able to:
  1. Access these allowed host paths:
    - $HOME/.fungi/services
  2. Manage services on this device
  3. Use these explicitly allowed host ports:
    - none configured
  4. Use these allowed host port ranges:
    - 18080-18199
=======================================================
Proceed? [Y/n]:

Important:

  • only allow your own devices
  • never add an unknown PeerID

The alias can be used here, but a raw PeerID also works. For example, both of these are valid:

fungi security allowed-peers add my-laptop
fungi security allowed-peers add 16Uiu2H........Co7Cw9

Step 4: Add home-pc To my-laptop's Address Book​

Go back to my-laptop.

Find home-pc with mDNS:

fungi device mdns

Example output:

16Uiu2H........ZC3bdZ -  (workstation-b)

Then save it locally:

fungi device add --alias home-pc 16Uiu2H........ZC3bdZ

Step 5: Ping home-pc From my-laptop​

On my-laptop, run:

fungi ping home-pc

Expected output looks like this:

Target peer: home-pc(16Uiu2H........ZC3bdZ)
Ping stream peer=16Uiu2H........ZC3bdZ interval=2000ms (Ctrl+C to stop)
TICK   CONN   DIR      RLY   RTT        ADDR/MSG
0      -      -        -     -          connecting
1      6      outbound no    5ms        /ip4/192.168.x.x/tcp/45189/p2p/16Uiu2H........ZC3bdZ
2      6      outbound no    6ms        /ip4/192.168.x.x/tcp/45189/p2p/16Uiu2H........ZC3bdZ

If you see round-trip time values such as 5ms or 6ms, the secure P2P link is working.

What Just Happened?​

You created a one-way trust relationship:

  • home-pc allows inbound access from my-laptop
  • my-laptop can now open a connection to home-pc
  • home-pc still cannot control my-laptop unless you explicitly allow it too

That is why the reverse direction will fail:

on home-pc:

fungi ping my-laptop
TICK   CONN   DIR      RLY   RTT        ADDR/MSG
0      -      -        -     -          connecting
1      -      -        -     -          no active connections
2      -      -        -     -          no active connections

This is expected. Fungi does not automatically create mutual trust.

Next Step​

Continue with 2-Minute Quick Start: Run a Remote Sandbox App Locally.

If you want more detail, see: