From af9786a87eb020f16fd4ae6d76d1ce44d3e1dd50 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <3998+srid@users.noreply.github.com>
Date: Mon, 10 Nov 2025 14:58:52 -0500
Subject: [PATCH] nix + skill

---
 modules/home/claude-code/default.nix          | 26 ++++++++++----
 .../skills/article-extractor/SKILL.md         | 22 +-----------
 .../skills/article-extractor/default.nix      | 34 +++++++++++++++++++
 3 files changed, 54 insertions(+), 28 deletions(-)
 create mode 100644 modules/home/claude-code/skills/article-extractor/default.nix

diff --git a/modules/home/claude-code/default.nix b/modules/home/claude-code/default.nix
index 3b5e592..a64cfcb 100644
--- a/modules/home/claude-code/default.nix
+++ b/modules/home/claude-code/default.nix
@@ -20,6 +20,24 @@ let
 
   skillsDir = ./skills;
   skillDirs = lib.filterAttrs (_: type: type == "directory") (builtins.readDir skillsDir);
+
+  # Process skill: if it has default.nix, build and substitute; otherwise use as-is
+  processSkill = skillName:
+    let
+      skillPath = skillsDir + "/${skillName}";
+      hasDefaultNix = builtins.pathExists (skillPath + "/default.nix");
+    in
+    if hasDefaultNix then
+      let
+        skillPkg = pkgs.callPackage skillPath { };
+      in
+      pkgs.runCommand "${skillName}-skill" { } ''
+        mkdir -p $out
+        substitute ${skillPath}/SKILL.md $out/SKILL.md \
+          --replace-fail '@${skillName}@' '${skillPkg}/bin/${skillName}'
+      ''
+    else
+      skillPath;
 in
 {
   # Packages often used by Claude Code CLI.
@@ -32,17 +50,11 @@ in
   home.file = lib.mapAttrs'
     (skillName: _:
       lib.nameValuePair ".claude/skills/${skillName}" {
-        source = skillsDir + "/${skillName}";
+        source = processSkill skillName;
         recursive = true;
       }
     )
     skillDirs;
-
-  home.packages = [
-    # Used in skills
-    # TODO: Encapsulate
-    pkgs.reader
-  ];
   programs.claude-code = {
     enable = true;
 
diff --git a/modules/home/claude-code/skills/article-extractor/SKILL.md b/modules/home/claude-code/skills/article-extractor/SKILL.md
index a72c0a2..183c90d 100644
--- a/modules/home/claude-code/skills/article-extractor/SKILL.md
+++ b/modules/home/claude-code/skills/article-extractor/SKILL.md
@@ -20,26 +20,6 @@ User wants to:
 ## Workflow
 
 ```bash
-# Download HTML
-curl -L "$URL" > /tmp/temp.html
-
-# Extract article
-reader /tmp/temp.html > /tmp/temp.txt
-
-# Get title from first line
-TITLE=$(head -n 1 /tmp/temp.txt | sed 's/^# //')
-
-# Clean filename
-FILENAME=$(echo "$TITLE" | tr '/:?"<>| ' '-' | cut -c 1-80 | sed 's/-*$//')".txt"
-
-# Save
-mv /tmp/temp.txt "/tmp/$FILENAME"
-
-# Clean up
-rm /tmp/temp.html
-
-# Show preview
-echo "✓ Saved: /tmp/$FILENAME"
-head -n 10 "/tmp/$FILENAME"
+@article-extractor@ "$URL"
 ```
 
diff --git a/modules/home/claude-code/skills/article-extractor/default.nix b/modules/home/claude-code/skills/article-extractor/default.nix
new file mode 100644
index 0000000..aa4c9ed
--- /dev/null
+++ b/modules/home/claude-code/skills/article-extractor/default.nix
@@ -0,0 +1,34 @@
+{ writeShellApplication, curl, reader }:
+
+# Inspired by https://github.com/michalparkola/tapestry-skills-for-claude-code/blob/main/article-extractor/SKILL.md
+writeShellApplication {
+  name = "article-extractor";
+
+  runtimeInputs = [ curl reader ];
+
+  text = ''
+    URL="$1"
+
+    # Download HTML
+    curl -L "$URL" > /tmp/temp.html
+
+    # Extract article
+    reader /tmp/temp.html > /tmp/temp.txt
+
+    # Get title from first line
+    TITLE=$(head -n 1 /tmp/temp.txt | sed 's/^# //')
+
+    # Clean filename
+    FILENAME=$(echo "$TITLE" | tr '/:?"<>| ' '-' | cut -c 1-80 | sed 's/-*$//')".txt"
+
+    # Save
+    mv /tmp/temp.txt "/tmp/$FILENAME"
+
+    # Clean up
+    rm /tmp/temp.html
+
+    # Show preview
+    echo "✓ Saved: /tmp/$FILENAME"
+    head -n 10 "/tmp/$FILENAME"
+  '';
+}