0WM Server

The 0WM Server is the central backend for 0WM. It receives Wi-Fi scans from the 0WM Client and floorplan data from the 0WM OpMode, and stores and serves them, along with generated coverage heatmaps.

The 0WM project is in alpha stage. Interfaces and configuration may still change.

Getting Started

Debian packages

The easiest way to install the server is through your package manager. We provide nightly Debian packages for the following distributions and architectures:

Distribution	Suites	Architectures
Debian	bookworm, trixie, forky	amd64, arm64
Ubuntu	jammy, noble	amd64, arm64

Nix development environment

A development environment can be entered with:

nix develop github:lab0-cc/0WM-Server -L

The project can be build with:

nix build github:lab0-cc/0WM-Server -L

Building from sources

The server is written in OCaml. OPAM is the OCaml package manager, on which we rely in this project. Some of our dependencies are pinned from Git because required versions are not yet published on OPAM.

In the rest of this README, we refer to 0wm and 0wmd binaries; when building from sources using dune, those binaries are named zwm and zwmd. The latter names are used in this section only but apply to the whole document if your are building from sources.

Prerequisites

• OCaml (5+)
• Opam
• Git

Installation

# 1. Initialize OPAM if you haven’t already
opam init --compiler=ocaml-option-flambda --shell-setup
eval $(opam env)

# 2. Pin development dependencies (Irmin and Dream)
opam pin add --no-action --yes git+https://github.com/mirage/irmin
opam pin add --no-action --yes git+https://github.com/camlworks/dream

# 3. Clone and install dependencies
git clone https://github.com/lab0-cc/0WM-Server.git
cd 0WM-Server
opam install --confirm-level=unsafe-yes --deps-only .

Running the Server

To start the server daemon (which listens for API requests):

dune exec src/zwmd.exe

By default, it listens on port 8000.

In the rest of this document we use the 0wm command. When using dune, it should be invoked with dune exec src/zwm.exe -- <subcommand> instead of 0wm <command>.

Configuration

The project ships with a CLI (0wm) to inspect/edit the daemon configuration:

0wm config show

To edit the settings:

0wm config edit

The most important keys are interface (bind address), port, aps (AP endpoints for clients to contact), and ssids (list of SSIDs to include in heatmaps).

Typical development environment configuration

Use values similar to:

interface: 127.0.0.1
port: 8000
aps:
  - http://127.0.0.1:8003
  - http://ap.local
ssids:
  - MySurveySSID

API Documentation

An OpenAPI file is available in static/api.yml, and when the server is running, it is also available at http://localhost:8000/api.yml, with a Swagger interface at http://localhost:8000/.

Troubleshooting

Client connects but scanning/heatmap does not work

Confirm aps includes at least one reachable AP endpoint and ssids includes the SSIDs you want to visualize.

Heatmaps look empty

Heatmap generation uses the ssids configuration key to filter SSIDs to use. If this list is empty, scans are still recorded but heatmaps will look empty/uniform.

Funding

This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.