When the module is loaded by logoscore, it is constructed without arguments, so options are supplied through the LIBP2P_MODULE_CONFIG environment variable — set to either inline JSON or a path to a JSON file. The config is overlaid onto the defaults at load time; every key is optional, and an omitted key keeps its default. If the config is unset, unreadable, not valid JSON, or has a wrong-typed field, the module logs a warning and falls back to the full default options.

# inline
export LIBP2P_MODULE_CONFIG='{
  "addrs": ["/ip4/0.0.0.0/tcp/9000"],
  "bootstrapNodes": [
    { "peerId": "16Uiu2...", "addrs": ["/ip4/1.2.3.4/tcp/9000"] }
  ],
  "transport": "tcp",
  "privKey": "08021220..."
}'

# or a file
export LIBP2P_MODULE_CONFIG=/etc/logos/libp2p.json

See config.example.json for a ready-to-edit sample and the config section of metadata.json for the full schema. Code that constructs Libp2pModuleImpl directly (tutorials, tests) passes Libp2pModuleOptions to the constructor and bypasses this path.

Running a node via logoscore

The module can be driven directly from logoscore without any other module. A default node is created when the module is loaded; createNode then rebuilds it from a call-time config (same schema as LIBP2P_MODULE_CONFIG, so @config.json expands to the file's contents), and getNodeInfo reads back node details.

First build the module's .lgx bundle, install it into a modules directory, and start the daemon against that directory:

nix build '.#lgx'                       # result/ holds the .lgx bundle
lgpm --modules-dir ./modules --allow-unsigned install --file result/*.lgx
lgpm --modules-dir ./modules list       # confirm "libp2p_module" is listed

logoscore -D -m ./modules &             # start the daemon against ./modules

The daemon binds its socket asynchronously, so the first load-module can race it — retry once if it reports an RPC failure. Then drive the node:

logoscore load-module libp2p_module
logoscore call libp2p_module createNode @config.example.json   # or inline JSON
logoscore call libp2p_module start
logoscore call libp2p_module getNodeInfo Version        # module version
logoscore call libp2p_module getNodeInfo MyBoundPorts   # bound ports, e.g. [9000]
logoscore call libp2p_module getNodeInfo PeerId         # this node's peer id
logoscore call libp2p_module getNodeInfo Multiaddrs     # full bound multiaddrs
logoscore stop

createNode is optional: if you set LIBP2P_MODULE_CONFIG before loading, the node is already configured and you can start straight away. Calling createNode tears down the existing node and builds a fresh one from the supplied config, so issue it before start. It accepts inline JSON or @config.json (the file's contents); wrap inline JSON in single quotes so the shell doesn't mangle it.

logoscore only relays a generic "call failed" to the CLI; the specific reason (createNode: invalid config: …, libp2p_new failed: …) is written to the daemon's stderr, so check the daemon output (or its redirected log) when a call fails.

A scripted version of this flow runs in CI and locally via nix run .#standalone-e2e (see tests/README.md).

Building

Currently the recommended and supported building way is using Nix

Build everything (default)

nix build

Or explicitly

nix build '.#default'

The result will include:

/lib/libp2p_module_plugin.so (or .dylib on macOS) — The Logos libp2p module plugin
/include/libp2p_module_api.h — Generated module API header
/include/libp2p_module_api.cpp — Generated module API implementation

Build Individual Components

Build only the library (plugin)

nix build '.#lib'

Build only the generated headers

nix build '.#include'

Development Shell

Enter development environment

nix develop

This provides:

CMake
Ninja
Qt6
Logos SDK dependencies
Proper environment variables

If flakes are not enabled globally:

nix build --extra-experimental-features 'nix-command flakes'

To enable globally, add flake as a experimental-feature to ~/.config/nix/nix.conf:

echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf