happs/

.happ bundles are not committed to this repository (ADR-012). Nothing in the flake reads from this directory any more; it exists to document where bundles come from and how to point the module at one.

Referencing a hApp

Fetch it by hash, so the configuration is reproducible and the bundle stays out of git:

services.holochain-edgenode.happs = {
  dino-adventure = {
    src = pkgs.fetchurl {
      url = "https://github.com/holochain/dino-adventure/releases/download/v0.3.0/dino-adventure-v0.3.0.happ";
      sha256 = "4dd11f7c5f5ee73f9472827e48ab3538f53f37f819af610bf8de95c10ee74f72";
    };
    networkSeed = "workshop-2026";
  };
};

The attribute name is the installed app id: it is what install-app --app-id is given and what list-apps reports back.

To get the hash of a bundle you have not used before:

nix-prefetch-url --type sha256 <url>   # base32
# or, from a local file
sha256sum <file>

Bundles the VM tests use

Both are published releases, fetched by hash in flake.nix:

Neither test is conditional. An earlier version of vmTestWithHapp was gated on builtins.pathExists ./happs/windtunnel.happ, which meant it silently did not exist: a flake only sees git-tracked files, and *.happ is gitignored.

Workshop bundles

The Sensorica workshop fleet runs hREA, Kando and Requests & Offers on the 0.6 line (ADR-015), fetched by hash in modules/sensorica-happs.nix and installed by the sensorica-event-node profile. Versions and bundles are listed once, in the Sensorica fleet README (examples/sensorica-fleet/README.md, “Holochain line and hApps”). Participants join the Sensorica Moss group from their own laptop with Moss, and the group’s always-online node runs on the monitor Holoport (holochain-moss-node). Wind Tunnel is not a workshop bundle: the holochain-windtunnel module lends a machine to the Foundation’s test cluster and feeds nothing to Grafana.

Check each project’s releases for a bundle built against the Holochain line the fleet runs. As of this writing Wind Tunnel, hREA, Requests & Offers and Nondominium all still publish 0.6.x bundles; only Moss 0.16-dev targets 0.7.