hermes-agent/nix/hermes-agent.nix
Siddharth Balyan ef41d3bd45
feat(nix): declarative plugin installation for NixOS module (#15953)
* feat(nix): parameterize dependency-groups in python.nix

* refactor(nix): extract package to callPackage-able hermes-agent.nix

Makes the package overridable via .override{} and adds
extraPythonPackages parameter for PYTHONPATH injection.
Includes build-time collision check using PEP 503 name
canonicalization.

* feat(nix): add overlay for external NixOS consumption

External flakes can now add overlays = [ inputs.hermes-agent.overlays.default ]
to get pkgs.hermes-agent with full .override support.

* test(nix): add check for extraPythonPackages PYTHONPATH injection

Verifies wrapper has PYTHONPATH when extras provided, and
base package has no PYTHONPATH without extras.

* feat(nix): add extraPlugins option for directory-based plugins

Symlinks plugin packages into HERMES_HOME/plugins/ at activation time.
Validates plugin.yaml presence. Asserts unique plugin names at eval time.
Hermes discovers them automatically via its directory scan.

* feat(nix): add extraPythonPackages option for entry-point plugins

Overrides the hermes package with PYTHONPATH injection when
extraPythonPackages is non-empty. Plugin .dist-info directories
become visible to importlib.metadata for entry-point discovery.
Works in both native systemd and container modes.

* docs: add NixOS declarative plugin installation to nix-setup, plugins, and build-a-plugin guides

- nix-setup.md: new Plugins section with extraPlugins/extraPythonPackages
  examples, overlay usage, collision checking note, options reference rows
- plugins.md: Nix row in discovery table, NixOS declarative plugins section
- build-a-hermes-plugin.md: Distribute for NixOS section after pip section

* fix: address review feedback — remove unrelated umask, fix fetchFromGitHub naming, simplify checks

- Remove accidentally introduced umask/migration changes (unrelated to plugins)
- Add pluginName helper, fix fetchFromGitHub producing name='source'
- Show name= in extraPlugins example docs
- Simplify checks.nix: use hermes-agent.override instead of re-callPackage
- Fix fragile grep shell logic in checks

* refactor: address simplify feedback — lib.getName, drop unused inputs', Python list for extras

- Use lib.getName instead of custom pluginName helper
- Drop unused inputs' from checks.nix perSystem args
- Pass extraPythonPackages as Python list literal instead of colon-split string

* fix: walk propagatedBuildInputs for plugin PYTHONPATH and collision check

Uses python312.pkgs.requiredPythonModules to resolve the full transitive
closure of extraPythonPackages. Without this, a plugin with third-party
deps (e.g. requests) would fail at runtime if those deps weren't already
in the sealed uv2nix venv. The collision check now also scans the full
closure, catching transitive conflicts.

* cleanup: fold plugins into subdir loop, use find for symlink cleanup, inline lib.getName

- Add 'plugins' to the existing cron/sessions/logs/memories subdir loop
  instead of a separate mkdir/chown/chmod block
- Replace fragile for-glob with find -delete for stale symlink cleanup
- Inline lib.getName at both call sites, remove pluginName wrapper
2026-04-28 00:18:32 +05:30

186 lines
5.6 KiB
Nix

# nix/hermes-agent.nix — Overridable Hermes Agent package
#
# callPackage auto-wires nixpkgs args; flake inputs are passed explicitly.
# Users override via: pkgs.hermes-agent.override { extraPythonPackages = [...]; }
{
lib,
stdenv,
makeWrapper,
callPackage,
python312,
nodejs_22,
ripgrep,
git,
openssh,
ffmpeg,
tirith,
# Flake inputs — passed explicitly by packages.nix and overlays.nix
uv2nix,
pyproject-nix,
pyproject-build-systems,
npm-lockfile-fix,
# Overridable parameters
extraPythonPackages ? [ ],
}:
let
hermesVenv = callPackage ./python.nix {
inherit uv2nix pyproject-nix pyproject-build-systems;
};
hermesNpmLib = callPackage ./lib.nix {
inherit npm-lockfile-fix;
};
hermesTui = callPackage ./tui.nix {
inherit hermesNpmLib;
};
hermesWeb = callPackage ./web.nix {
inherit hermesNpmLib;
};
bundledSkills = lib.cleanSourceWith {
src = ../skills;
filter = path: _type: !(lib.hasInfix "/index-cache/" path);
};
runtimeDeps = [
nodejs_22
ripgrep
git
openssh
ffmpeg
tirith
];
runtimePath = lib.makeBinPath runtimeDeps;
sitePackagesPath = python312.sitePackages;
# Walk propagatedBuildInputs to include transitive Python deps in PYTHONPATH.
# Without this, a plugin listing e.g. requests as a dep would fail at runtime
# if requests isn't already in the sealed uv2nix venv.
allExtraPythonPackages = python312.pkgs.requiredPythonModules extraPythonPackages;
pythonPath = lib.makeSearchPath sitePackagesPath allExtraPythonPackages;
pyprojectHash = builtins.hashString "sha256" (builtins.readFile ../pyproject.toml);
uvLockHash =
if builtins.pathExists ../uv.lock then
builtins.hashString "sha256" (builtins.readFile ../uv.lock)
else
"none";
in
stdenv.mkDerivation {
pname = "hermes-agent";
version = (builtins.fromTOML (builtins.readFile ../pyproject.toml)).project.version;
dontUnpack = true;
dontBuild = true;
nativeBuildInputs = [ makeWrapper ];
installPhase = ''
runHook preInstall
mkdir -p $out/share/hermes-agent $out/bin
cp -r ${bundledSkills} $out/share/hermes-agent/skills
cp -r ${hermesWeb} $out/share/hermes-agent/web_dist
mkdir -p $out/ui-tui
cp -r ${hermesTui}/lib/hermes-tui/* $out/ui-tui/
${lib.concatMapStringsSep "\n"
(name: ''
makeWrapper ${hermesVenv}/bin/${name} $out/bin/${name} \
--suffix PATH : "${runtimePath}" \
--set HERMES_BUNDLED_SKILLS $out/share/hermes-agent/skills \
--set HERMES_WEB_DIST $out/share/hermes-agent/web_dist \
--set HERMES_TUI_DIR $out/ui-tui \
--set HERMES_PYTHON ${hermesVenv}/bin/python3 \
--set HERMES_NODE ${nodejs_22}/bin/node \
${lib.optionalString (extraPythonPackages != [ ]) ''--suffix PYTHONPATH : "${pythonPath}"''}
'')
[
"hermes"
"hermes-agent"
"hermes-acp"
]
}
${lib.optionalString (extraPythonPackages != [ ]) ''
echo "=== Checking for plugin/core package collisions ==="
${hermesVenv}/bin/python3 -c "
import pathlib, sys, re
def canonical(name):
return re.sub(r'[-_.]+', '-', name).lower()
# Collect core venv package names
core = set()
venv_sp = pathlib.Path('${hermesVenv}/${sitePackagesPath}')
for di in venv_sp.glob('*.dist-info'):
meta = di / 'METADATA'
if meta.exists():
for line in meta.read_text().splitlines():
if line.startswith('Name:'):
core.add(canonical(line.split(':', 1)[1].strip()))
break
# Check each extra package for collisions
extras_dirs = [${lib.concatMapStringsSep ", " (p: "'${toString p}'") allExtraPythonPackages}]
for edir in extras_dirs:
sp = pathlib.Path(edir) / '${sitePackagesPath}'
if not sp.exists():
continue
for di in sp.glob('*.dist-info'):
meta = di / 'METADATA'
if not meta.exists():
continue
for line in meta.read_text().splitlines():
if line.startswith('Name:'):
pkg = canonical(line.split(':', 1)[1].strip())
if pkg in core:
print(f'ERROR: plugin package \"{pkg}\" collides with a package in hermes sealed venv', file=sys.stderr)
print(f' from: {di}', file=sys.stderr)
print(f' Remove this dependency from extraPythonPackages.', file=sys.stderr)
sys.exit(1)
break
print('No collisions found.')
"
echo "=== No collisions ==="
''}
runHook postInstall
'';
passthru = {
inherit hermesTui hermesWeb hermesNpmLib hermesVenv;
devShellHook = ''
STAMP=".nix-stamps/hermes-agent"
STAMP_VALUE="${pyprojectHash}:${uvLockHash}"
if [ ! -f "$STAMP" ] || [ "$(cat "$STAMP")" != "$STAMP_VALUE" ]; then
echo "hermes-agent: installing Python dependencies..."
uv venv .venv --python ${python312}/bin/python3 2>/dev/null || true
source .venv/bin/activate
uv pip install -e ".[all]"
[ -d mini-swe-agent ] && uv pip install -e ./mini-swe-agent 2>/dev/null || true
[ -d tinker-atropos ] && uv pip install -e ./tinker-atropos 2>/dev/null || true
mkdir -p .nix-stamps
echo "$STAMP_VALUE" > "$STAMP"
else
source .venv/bin/activate
export HERMES_PYTHON=${hermesVenv}/bin/python3
fi
'';
};
meta = with lib; {
description = "AI agent with advanced tool-calling capabilities";
homepage = "https://github.com/NousResearch/hermes-agent";
mainProgram = "hermes";
license = licenses.mit;
platforms = platforms.unix;
};
}