diff --git a/AGENTS.md b/AGENTS.md
index a16c8e3..e9ddb07 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -251,6 +251,33 @@ When modifying overlay behavior:
 - [Nix Flake Patterns](https://github.com/NixOS/flake-patterns)
 - [Rust in Nixpkgs](https://nixos.org/manual/nixpkgs/stable/#rust)
 
+## Updating Packages
+
+Use [nix-update](https://github.com/Mic92/nix-update) to bump versions and update hashes:
+
+```bash
+# Update a package to the latest version
+nix-update <package-name>
+
+# Update to a specific version
+nix-update <package-name> --version <version>
+
+# Update a package pinned to a commit hash (e.g. skillsmcp)
+nix-update <package-name> --version=branch=main
+```
+
+After updating, always test the build:
+
+```bash
+nix build .#<package-name>
+```
+
+### Package-Specific Notes
+
+- **goose-cli**: Also updates `librusty_v8` hashes automatically via the custom fetcher
+- **mcp-gateway**: Standard Rust package, `nix-update` handles version + cargoHash
+- **skillsmcp**: Pinned to a commit hash; use `--version=branch=main` or specify the target commit with `--commit`
+
 ## Git Workflow
 
 ### Committing Completed Work
diff --git a/README.md b/README.md
index 447ca4e..70c650b 100644
--- a/README.md
+++ b/README.md
@@ -95,13 +95,16 @@ nix develop
 ```
 nix-overlay/
 ├── flake.nix                    # Flake definition
+├── treefmt.toml                 # Code formatting configuration (nixfmt)
 ├── overlays/                    # Overlay implementations
 │   ├── default.nix             # Binary-cache-friendly overlay
 │   └── shared-nixpkgs.nix      # Dependency-sharing overlay
 ├── packages/                    # Package definitions
 │   ├── default/                # Meta-package listing all packages
-│   ├── goose-cli/              # Goose CLI package
-│   └── flake-inputs/           # Utility for caching flake inputs
+│   ├── flake-inputs/           # Utility for caching flake inputs
+│   ├── goose-cli/              # Goose AI agent CLI
+│   ├── mcp-gateway/            # MCP protocol gateway
+│   └── skillsmcp/              # MCP server for Agent Skills
 └── README.md
 ```
 
diff --git a/flake.nix b/flake.nix
index 6ed398c..dc6fe2f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,6 +1,10 @@
 {
   description = "Various packages for Nix";
 
+  nixConfig = {
+    extra-substituters = [ "https://cache.nixos.org" ];
+  };
+
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     systems.url = "github:nix-systems/default";
diff --git a/packages/goose-cli/package.nix b/packages/goose-cli/package.nix
index 5b40757..339411e 100644
--- a/packages/goose-cli/package.nix
+++ b/packages/goose-cli/package.nix
@@ -8,6 +8,7 @@
   dbus,
   versionCheckHook,
   librusty_v8,
+  llvmPackages,
 }:
 
 rustPlatform.buildRustPackage rec {
@@ -23,7 +24,10 @@ rustPlatform.buildRustPackage rec {
 
   cargoHash = "sha256-fN0FKDYFkZrQQPWdUlemOaGzIAZhqFyskz9TEmG+X4o=";
 
-  nativeBuildInputs = [ pkg-config ];
+  nativeBuildInputs = [
+    pkg-config
+    llvmPackages.libclang
+  ];
 
   buildInputs = [
     openssl
@@ -35,6 +39,9 @@ rustPlatform.buildRustPackage rec {
   # To avoid this we pre-download the file and export it via RUSTY_V8_ARCHIVE
   env.RUSTY_V8_ARCHIVE = librusty_v8;
 
+  # bindgen (used by llama-cpp-sys-2) needs libclang
+  env.LIBCLANG_PATH = llvmPackages.libclang.lib;
+
   # Build only the CLI package
   cargoBuildFlags = [
     "--package"
@@ -67,5 +74,6 @@ rustPlatform.buildRustPackage rec {
     license = licenses.asl20;
     sourceProvenance = with sourceTypes; [ fromSource ];
     mainProgram = "goose";
+    platforms = platforms.all;
   };
 }
diff --git a/packages/goose-cli/update.py b/packages/goose-cli/update.py
deleted file mode 100755
index 687dc0e..0000000
--- a/packages/goose-cli/update.py
+++ /dev/null
@@ -1,107 +0,0 @@
-#!/usr/bin/env nix
-#! nix shell --inputs-from .# nixpkgs#python3 --command python3
-
-"""Update script for goose-cli package.
-
-This script updates both the goose-cli version and the librusty_v8 hashes.
-The v8 version is extracted from the Cargo.lock file of the goose repository.
-"""
-
-import sys
-from pathlib import Path
-
-sys.path.insert(0, str(Path(__file__).parent.parent.parent / "scripts"))
-
-from updater import (
-    calculate_platform_hashes,
-    fetch_text,
-    load_hashes,
-    save_hashes,
-)
-
-HASHES_FILE = Path(__file__).parent / "librusty_v8_hashes.json"
-
-PLATFORMS = {
-    "x86_64-linux": "x86_64-unknown-linux-gnu",
-    "aarch64-linux": "aarch64-unknown-linux-gnu",
-    "x86_64-darwin": "x86_64-apple-darwin",
-    "aarch64-darwin": "aarch64-apple-darwin",
-}
-
-
-def fetch_v8_version_from_cargo_lock(goose_version: str) -> str:
-    """Extract the v8 version from goose's Cargo.lock file."""
-    url = f"https://raw.githubusercontent.com/block/goose/v{goose_version}/Cargo.lock"
-    cargo_lock = fetch_text(url)
-
-    # Parse the Cargo.lock to find v8 version
-    lines = cargo_lock.split("\n")
-    for i, line in enumerate(lines):
-        if line.strip() == 'name = "v8"':
-            # Look for version in the next few lines
-            for j in range(i + 1, min(i + 10, len(lines))):
-                if "version = " in lines[j]:
-                    return lines[j].split('"')[1]
-
-    msg = "Could not find v8 version in Cargo.lock"
-    raise ValueError(msg)
-
-
-def main() -> None:
-    """Update the librusty_v8 hashes for goose-cli."""
-    # Read the current goose-cli version from package.nix
-    package_nix = (Path(__file__).parent / "package.nix").read_text()
-    for line in package_nix.split("\n"):
-        if "version = " in line and '"' in line:
-            goose_version = line.split('"')[1]
-            break
-    else:
-        msg = "Could not find version in package.nix"
-        raise ValueError(msg)
-
-    print(f"Goose version: {goose_version}")
-
-    # Get the v8 version from Cargo.lock
-    v8_version = fetch_v8_version_from_cargo_lock(goose_version)
-    print(f"V8 version: {v8_version}")
-
-    # Check if we need to update
-    try:
-        data = load_hashes(HASHES_FILE)
-        current_v8 = data.get("version", "")
-        if current_v8 == v8_version:
-            print(f"V8 hashes already up to date ({v8_version})")
-            return
-    except FileNotFoundError:
-        print("No existing hashes file, creating new one")
-
-    # Calculate hashes for all platforms
-    url_template = f"https://github.com/denoland/rusty_v8/releases/download/v{v8_version}/librusty_v8_release_{{platform}}.a.gz"
-    hashes = calculate_platform_hashes(url_template, PLATFORMS)
-
-    # Save the hashes
-    save_hashes(HASHES_FILE, {"version": v8_version, "hashes": hashes})
-
-    # Update librusty_v8.nix
-    librusty_v8_nix = Path(__file__).parent / "librusty_v8.nix"
-    content = f"""# Pre-built librusty_v8 library for goose-cli
-# This file specifies the rusty_v8 version and hashes for all supported platforms
-{{ fetchLibrustyV8 }}:
-
-fetchLibrustyV8 {{
-  version = "{v8_version}";
-  shas = {{
-    x86_64-linux = "{hashes["x86_64-linux"]}";
-    aarch64-linux = "{hashes["aarch64-linux"]}";
-    x86_64-darwin = "{hashes["x86_64-darwin"]}";
-    aarch64-darwin = "{hashes["aarch64-darwin"]}";
-  }};
-}}
-"""
-    librusty_v8_nix.write_text(content)
-
-    print(f"Updated librusty_v8 to {v8_version}")
-
-
-if __name__ == "__main__":
-    main()
diff --git a/packages/mcp-gateway/package.nix b/packages/mcp-gateway/package.nix
index 7e9c119..4e1618e 100644
--- a/packages/mcp-gateway/package.nix
+++ b/packages/mcp-gateway/package.nix
@@ -27,12 +27,15 @@ rustPlatform.buildRustPackage rec {
 
   doCheck = false;
 
+  passthru.category = "MCP Servers";
+
   meta = with lib; {
     description = "Universal Model Context Protocol gateway that sits between AI client and MCP tools/servers";
     homepage = "https://github.com/MikkoParkkola/mcp-gateway";
     changelog = "https://github.com/MikkoParkkola/mcp-gateway/releases/tag/v${version}";
-    license = lib.licenses.mit;
-    sourceProvenance = with lib.sourceTypes; [ fromSource ];
+    license = licenses.mit;
+    sourceProvenance = with sourceTypes; [ fromSource ];
     mainProgram = "mcp-gateway";
+    platforms = platforms.all;
   };
 }
diff --git a/packages/skillsmcp/package.nix b/packages/skillsmcp/package.nix
index a3f71ce..56f776b 100644
--- a/packages/skillsmcp/package.nix
+++ b/packages/skillsmcp/package.nix
@@ -28,7 +28,7 @@ python3Packages.buildPythonApplication rec {
 
   # Disable all checks to avoid version issues
   doCheck = false;
-  pythonImportsCheck = [ ];
+  pythonImportsCheck = [ "skillsmcp" ];
 
   # Patch to accept fastmcp 2.x from nixpkgs
   postPatch = ''
@@ -43,6 +43,6 @@ python3Packages.buildPythonApplication rec {
     homepage = "https://github.com/aviddiviner/skillsmcp";
     license = licenses.mit;
     mainProgram = "skillsmcp";
-    maintainers = with maintainers; [ ];
+    platforms = platforms.all;
   };
 }
diff --git a/treefmt.toml b/treefmt.toml
new file mode 100644
index 0000000..8c09172
--- /dev/null
+++ b/treefmt.toml
@@ -0,0 +1,6 @@
+[global]
+excluded = ["flake.lock"]
+
+[formatter.nix]
+command = "nixfmt"
+includes = ["*.nix"]