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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.

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:

  • Device A: laptop-A
  • Device B: pc-B

If you want the longer CLI walkthrough, see Fungi CLI Quick Start. If you want to run an app after the devices can talk to each other, continue with 3-Minute Quick Start: Run a Remote Sandbox App Locally.

Before You Start​

  1. Download Fungi CLI on both devices from GitHub Releases.
  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

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 Device A To Device B's Address Book​

On pc-B, try local discovery first:

./fungi device mdns

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

16Uiu2H........Co7Cw9 -  (laptop-A)

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

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

./fungi device add --alias laptop-A 16Uiu2H........Co7Cw9

You can use any alias you want. The alias is only a local nickname.

To verify the saved entry:

./fungi device list

Step 3: Allow Device A To Access Device B​

On pc-B, allow inbound access from laptop-A:

./fungi security allowed-peers add laptop-A

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

================ SECURITY CONFIRMATION ================
You are about to trust this peer for incoming access:
  Peer: laptop-A
  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 laptop-A
./fungi security allowed-peers add 16Uiu2H........Co7Cw9

Step 4: Add Device B To Device A's Address Book​

Go back to laptop-A.

Find pc-B with mDNS:

./fungi device mdns

Example output:

16Uiu2H........ZC3bdZ -  (pc-B)

Then save it locally:

./fungi device add --alias pc-B 16Uiu2H........ZC3bdZ

Step 5: Ping Device B From Device A​

On laptop-A, run:

./fungi ping pc-B

Expected output looks like this:

Target peer: pc-B(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:

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

That is why the reverse direction may still fail:

./fungi ping laptop-A

Possible output on pc-B:

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​

Now that the two devices can talk to each other, continue with 3-Minute Quick Start: Run a Remote Sandbox App Locally.

If you want more detail before that, see: