diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..3696040
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,16 @@
+name: 🧪 Test
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    name: 🧪 Lock + scripts
+    runs-on: ubuntu-latest
+    steps:
+      - name: ⬇️ Checkout
+        uses: actions/checkout@v7
+
+      - name: 🧪 Run tests
+        run: make test
diff --git a/.github/workflows/update.yml b/.github/workflows/update.yml
new file mode 100644
index 0000000..841d70f
--- /dev/null
+++ b/.github/workflows/update.yml
@@ -0,0 +1,38 @@
+name: 🔄 Update
+
+on:
+  schedule:
+    - cron: "17 4 * * *"
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  update-skills:
+    name: 🧠 Update skills-lock.json
+    runs-on: ubuntu-latest
+    steps:
+      - name: ⬇️ Checkout
+        uses: actions/checkout@v7
+
+      - name: 🔧 Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: lts/*
+
+      - name: 🔄 Update skills
+        run: make update
+
+      - name: 🧪 Run tests
+        run: make test
+
+      - name: 📂 Open PR if skills-lock.json changed
+        uses: peter-evans/create-pull-request@v7
+        with:
+          branch: update/skills
+          commit-message: "update(skills): update skills-lock.json to latest versions"
+          title: "update(skills): update agent skills to latest versions"
+          body: "Automated daily update of `skills-lock.json` via `make update`."
+          add-paths: skills-lock.json
diff --git a/.gitignore b/.gitignore
index cb54ccd..2390cbf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,6 @@ dist/
 build/
 __pycache__/
 *.pyc
+.agents/
+.claude/
+node_modules/
diff --git a/MIRRORS b/MIRRORS
new file mode 100644
index 0000000..f49bb7c
--- /dev/null
+++ b/MIRRORS
@@ -0,0 +1,3 @@
+git@github.com:kevinveenbirkenbach/skills.git
+ssh://git@code.infinito.nexus:2201/kevinveenbirkenbach/skills.git
+ssh://git@git.veen.world:2201/kevinveenbirkenbach/skills.git
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2ddbc6a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,19 @@
+.PHONY: install project test update
+
+# Install the skills globally into $HOME (.agents/skills + .claude/skills).
+install:
+	@TARGET="$(HOME)" bash scripts/install.sh
+
+# Copy the skills into a project: make project TARGET=/path/to/repo
+project:
+	@test -n "$(TARGET)" || { echo "usage: make project TARGET=/path/to/repo"; exit 2; }
+	@TARGET="$(TARGET)" bash scripts/install.sh
+
+# Validate skills-lock.json and shellcheck the scripts.
+test:
+	@python3 -m unittest discover -s tests -v
+	@if command -v shellcheck >/dev/null; then shellcheck scripts/*.sh; else echo "shellcheck not installed - skipped"; fi
+
+# Update all skills to their latest versions and refresh skills-lock.json.
+update:
+	@bash scripts/update.sh
diff --git a/README.md b/README.md
index 4ef3510..586dc94 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,20 @@
-# skills
+# skills 🧠
 
-Homepage: https://github.com/kevinveenbirkenbach/skills
+Reproducible agent skill collection, pinned in `skills-lock.json`.
+Works for Claude Code, Codex, Gemini CLI, Cursor, Copilot, Windsurf, Cline, and more.
 
-## Author
-Kevin Veen-Birkenbach <kevin@veen.world>
+Homepage: [github.com/kevinveenbirkenbach/skills](https://github.com/kevinveenbirkenbach/skills)
+
+## Usage 🚀
+
+- `make install` installs the skills globally into your home (`~/.agents/skills` and `~/.claude/skills`).
+- `make project TARGET=/path/to/repo` copies the skills into a project (`<repo>/.agents/skills` and `<repo>/.claude/skills`).
+- `make update` refreshes every skill to its latest version and rewrites `skills-lock.json`.
+- `make test` validates `skills-lock.json` and shellchecks the scripts; CI runs it on every push and after every update.
+
+Node.js is REQUIRED (`npx skills`); `make update` additionally needs `jq`.
+Restart your agent after installing so it loads the new skills.
+
+## Author 👤
+
+Kevin Veen-Birkenbach [kevin@veen.world](mailto:kevin@veen.world)
diff --git a/flake.nix b/flake.nix
deleted file mode 100644
index 479ff3e..0000000
--- a/flake.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-  description = "skills";
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-  outputs = { self, nixpkgs }:
-  let system = "x86_64-linux"; pkgs = import nixpkgs { inherit system; };
-  in {
-    devShells.${system}.default = pkgs.mkShell {
-      packages = with pkgs; [ python312 python312Packages.pytest python312Packages.ruff ];
-    };
-  };
-}
diff --git a/pyproject.toml b/pyproject.toml
deleted file mode 100644
index f5f6130..0000000
--- a/pyproject.toml
+++ /dev/null
@@ -1,21 +0,0 @@
-[build-system]
-requires = ["setuptools>=68", "wheel"]
-build-backend = "setuptools.build_meta"
-
-[project]
-name = "skills"
-version = "0.1.0"
-description = ""
-readme = "README.md"
-requires-python = ">=3.10"
-authors = [{ name = "Kevin Veen-Birkenbach", email = "kevin@veen.world" }]
-license = { text = "All rights reserved by Kevin Veen-Birkenbach" }
-urls = { Homepage = "https://github.com/kevinveenbirkenbach/skills" }
-
-dependencies = []
-
-[tool.setuptools]
-package-dir = {"" = "src"}
-
-[tool.setuptools.packages.find]
-where = ["src"]
diff --git a/scripts/install.sh b/scripts/install.sh
new file mode 100644
index 0000000..0cf926f
--- /dev/null
+++ b/scripts/install.sh
@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# Render the skills from skills-lock.json and copy them into TARGET.
+# TARGET defaults to $HOME (global install); pass a project root to
+# equip that project. Skills land in <TARGET>/.agents/skills and are
+# mirrored to <TARGET>/.claude/skills.
+set -euo pipefail
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
+TARGET="${TARGET:-${HOME}}"
+
+log() { printf '%s\n' "$*"; }
+warn() { printf '%s\n' "$*" >&2; }
+
+if ! command -v npx &>/dev/null; then
+	warn "skills: npx not found — install Node.js first: https://nodejs.org"
+	exit 1
+fi
+
+if [[ ! -d "${TARGET}" ]]; then
+	warn "skills: TARGET does not exist: ${TARGET}"
+	exit 2
+fi
+
+cd "${REPO_ROOT}"
+log "skills: restoring from skills-lock.json..."
+npx --yes skills experimental_install
+
+src="${REPO_ROOT}/.agents/skills"
+if [[ ! -d "${src}" ]]; then
+	warn "skills: ${src} not found after install."
+	exit 1
+fi
+
+for dst in "${TARGET}/.agents/skills" "${TARGET}/.claude/skills"; do
+	log "skills: copying -> ${dst}"
+	rm -rf "${dst}"
+	mkdir -p "${dst}"
+	cp -a "${src}/." "${dst}/"
+done
+
+log "skills: done. Restart your agent to load the skills."
diff --git a/scripts/update.sh b/scripts/update.sh
new file mode 100644
index 0000000..fd58c99
--- /dev/null
+++ b/scripts/update.sh
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Update all skills to their latest versions and refresh skills-lock.json.
+# Reads unique sources from skills-lock.json and re-runs skills add for each.
+set -euo pipefail
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
+
+log() { printf '%s\n' "$*"; }
+warn() { printf '%s\n' "$*" >&2; }
+
+if ! command -v npx &>/dev/null; then
+	warn "skills: npx not found — install Node.js first: https://nodejs.org"
+	exit 1
+fi
+
+if ! command -v jq &>/dev/null; then
+	warn "skills: jq not found — cannot parse skills-lock.json."
+	exit 1
+fi
+
+cd "${REPO_ROOT}"
+
+lockfile="skills-lock.json"
+if [[ ! -f "${lockfile}" ]]; then
+	warn "skills: ${lockfile} not found in ${REPO_ROOT}."
+	exit 1
+fi
+
+log "skills: updating from ${lockfile}..."
+jq -r '.skills[].source' "${lockfile}" | sort -u | while read -r source; do
+	log "skills: updating ${source}..."
+	npx --yes skills add --yes "${source}"
+done
+log "skills: update complete."
diff --git a/skills-lock.json b/skills-lock.json
new file mode 100644
index 0000000..b103d18
--- /dev/null
+++ b/skills-lock.json
@@ -0,0 +1,53 @@
+{
+  "version": 1,
+  "skills": {
+    "cavecrew": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/cavecrew/SKILL.md",
+      "computedHash": "c5527c994fbd4c22b36714e3b124a0f167a533d114ab164fb1d35e2123533917"
+    },
+    "caveman": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman/SKILL.md",
+      "computedHash": "d18cdf73a5f5c496d681a43a6846336b110223bdffa6817b8992529c57f1a815"
+    },
+    "caveman-commit": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman-commit/SKILL.md",
+      "computedHash": "790a4eeace0be35c6691faf923518ba5bd50f1f1305d1101d09dd4971be94e00"
+    },
+    "caveman-compress": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman-compress/SKILL.md",
+      "computedHash": "84517cd4cf7a49d8d2bc1baf00f61bc359306c6ad9389756b6937eff958bd374"
+    },
+    "caveman-help": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman-help/SKILL.md",
+      "computedHash": "dd85267e76baad76995157e7b9f762dfa557cd58951ee92af0c283f48aa26537"
+    },
+    "caveman-review": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman-review/SKILL.md",
+      "computedHash": "fb7214a1c5793bae6ba8b1be4329e2e6f40dbec6dd911dfb335ad29f09c316a1"
+    },
+    "caveman-stats": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/caveman-stats/SKILL.md",
+      "computedHash": "47ce2de3d6cb39a75047b5c962e4eb3da15594e7397c94103e9a104d42626553"
+    },
+    "compress": {
+      "source": "JuliusBrussee/caveman",
+      "sourceType": "github",
+      "skillPath": "skills/compress/SKILL.md",
+      "computedHash": "c91bdf427a68b686ee9d6f63766c72d164b16915434736edfedf13e24dae0e8c"
+    }
+  }
+}
diff --git a/tests/test_lock.py b/tests/test_lock.py
new file mode 100644
index 0000000..b089bf3
--- /dev/null
+++ b/tests/test_lock.py
@@ -0,0 +1,55 @@
+"""Validate skills-lock.json: shape, required fields, and hash format."""
+
+from __future__ import annotations
+
+import json
+import re
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+LOCK_FILE = REPO_ROOT / "skills-lock.json"
+
+HASH_RE = re.compile(r"^[0-9a-f]{64}$")
+REQUIRED_FIELDS = ("source", "sourceType", "skillPath", "computedHash")
+
+
+class TestSkillsLock(unittest.TestCase):
+    def setUp(self):
+        self.lock = json.loads(LOCK_FILE.read_text(encoding="utf-8"))
+
+    def test_version_is_supported(self):
+        self.assertEqual(self.lock.get("version"), 1)
+
+    def test_skills_present(self):
+        self.assertTrue(self.lock.get("skills"), "lock holds no skills")
+
+    def test_every_skill_is_complete(self):
+        for name, entry in self.lock["skills"].items():
+            with self.subTest(skill=name):
+                for field in REQUIRED_FIELDS:
+                    self.assertTrue(
+                        str(entry.get(field, "")).strip(),
+                        f"{name}: missing or empty field '{field}'",
+                    )
+                self.assertRegex(
+                    entry["computedHash"],
+                    HASH_RE,
+                    f"{name}: computedHash is not a sha256 hex digest",
+                )
+                self.assertTrue(
+                    entry["skillPath"].endswith("SKILL.md"),
+                    f"{name}: skillPath must point to a SKILL.md",
+                )
+
+    def test_skills_sorted_ascending(self):
+        names = list(self.lock["skills"].keys())
+        self.assertEqual(
+            names,
+            sorted(names),
+            f"skills must be sorted ascending; expected {sorted(names)}",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()