diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 7627062..63e844f 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -12,7 +12,8 @@
 
 ## Checklist
 
-- [ ] `skillshare-hub.json` is valid JSON
+- [ ] Added entry to the correct `skills/*.json` category file (see [CONTRIBUTING.md](../CONTRIBUTING.md#categories))
+- [ ] Ran `make build` and committed the updated `skillshare-hub.json`
 - [ ] `name` is lowercase with hyphens only
 - [ ] `description` is a clear one-liner
 - [ ] `source` repo is publicly accessible and contains a valid `SKILL.md`
diff --git a/.github/workflows/validate-pr.yml b/.github/workflows/validate-pr.yml
index 596efe0..67480b0 100644
--- a/.github/workflows/validate-pr.yml
+++ b/.github/workflows/validate-pr.yml
@@ -2,6 +2,7 @@ name: Validate PR
 on:
   pull_request:
     paths:
+      - 'skills/**'
       - 'skillshare-hub.json'
       - 'scripts/**'
       - '.github/workflows/validate-pr.yml'
@@ -16,6 +17,17 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Build hub.json from skills/
+        run: ./scripts/build.sh
+
+      - name: Check hub.json is up to date
+        run: |
+          if ! git diff --quiet skillshare-hub.json; then
+            echo "::error::skillshare-hub.json is out of date. Run 'make build' and commit the result."
+            git diff skillshare-hub.json
+            exit 1
+          fi
+
       - name: Validate hub.json
         run: ./scripts/validate.sh
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8d1b628..e396ae8 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -5,10 +5,29 @@ Thanks for sharing your skill with the community!
 ## How to Add a Skill
 
 1. Fork this repo
-2. Edit `skillshare-hub.json` — add your skill entry to the `skills` array
-3. Open a Pull Request
-4. CI will validate your entry automatically
-5. A maintainer will review and merge
+2. Find the right category file in `skills/` (see [Categories](#categories) below)
+3. Add your skill entry to the JSON array in that file
+4. Run `make build` to regenerate `skillshare-hub.json`
+5. Commit **both** the `skills/*.json` change and `skillshare-hub.json`
+6. Open a Pull Request
+7. CI will validate and audit your entry automatically
+8. A maintainer will review and merge
+
+> **Important**: Do not edit `skillshare-hub.json` directly — it is generated from `skills/*.json` by `make build`. CI will reject PRs where the hub file is out of sync.
+
+## Categories
+
+| File | Description |
+|------|-------------|
+| `skills/skill.json` | Hub meta-skills (skillshare, skill-creator, find-skills, template-skill) |
+| `skills/anthropic.json` | Skills from `anthropics/skills` |
+| `skills/marketing.json` | Skills from `coreyhaines31/marketingskills` |
+| `skills/workflow.json` | Skills from `obra/superpowers` and `obra/episodic-memory` |
+| `skills/expo.json` | Skills from `expo/skills` |
+| `skills/vercel.json` | Skills from `vercel-labs/*` and `vercel/*` |
+| `skills/community.json` | Everything else — independent authors and orgs |
+
+> **Not sure where to put your skill?** Just add it to `skills/community.json`. Maintainers will move it if needed.
 
 ## Skill Entry Format
 
@@ -23,7 +42,18 @@ Single-skill repo:
 }
 ```
 
-Multi-skill repo (use `skill` to specify which one):
+Multi-skill repo (use subpath in `source`):
+
+```json
+{
+  "name": "my-skill",
+  "description": "One-line description of what the skill does",
+  "source": "your-username/your-repo/my-skill",
+  "tags": ["relevant", "tags"]
+}
+```
+
+Multi-skill repo (use `skill` field to specify which one):
 
 ```json
 {
@@ -52,7 +82,7 @@ Non-GitHub platforms (GitLab, Bitbucket, self-hosted, etc.):
 |-------|----------|-------------|
 | `name` | Yes | Unique skill name — lowercase, hyphens only (e.g. `commit-helper`) |
 | `description` | Yes | One-line description of what the skill does |
-| `source` | Yes | GitHub `owner/repo`, full git URL, or any platform URL |
+| `source` | Yes | GitHub `owner/repo[/subpath]`, full git URL, or any platform URL |
 | `skill` | No | Specific skill name within a multi-skill repo (installs via `-s`) |
 | `tags` | No | 1-3 classification tags |
 
@@ -71,6 +101,15 @@ Feel free to introduce new tags if none fit — maintainers may suggest changes
 - **Clear description** — explain what the skill does, not how it works
 - **No duplicates** — search existing entries before adding
 
+## Local Development
+
+```bash
+make build      # Build skillshare-hub.json from skills/*.json
+make validate   # Validate format and rules
+make audit      # Audit new/changed skills against main
+make ci         # Run all three (build → validate → audit)
+```
+
 ## Using Skills from the Hub
 
 ```bash
diff --git a/Makefile b/Makefile
index cad5348..c1923b0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,9 @@
-.PHONY: format validate audit ci
+.PHONY: build format validate audit ci
 
-format: ## Format skillshare-hub.json (sort by name, 2-space indent)
-	@./scripts/format.sh
+build: ## Build skillshare-hub.json from skills/*.json
+	@./scripts/build.sh
+
+format: build ## Alias for build (build already sorts and formats)
 
 validate: ## Validate skillshare-hub.json format and rules
 	@./scripts/validate.sh
@@ -9,4 +11,4 @@ validate: ## Validate skillshare-hub.json format and rules
 audit: ## Audit new/changed skills against main
 	@./scripts/audit.sh main
 
-ci: validate audit ## Run full CI locally
+ci: build validate audit ## Run full CI locally
diff --git a/scripts/audit.sh b/scripts/audit.sh
index f3f53cc..acffb7c 100755
--- a/scripts/audit.sh
+++ b/scripts/audit.sh
@@ -11,110 +11,60 @@ log_group() { is_ci && echo "::group::$1" || echo "=== $1 ==="; }
 log_endgroup() { is_ci && echo "::endgroup::" || true; }
 log_error() { is_ci && echo "::error::$1" || echo "ERROR: $1"; }
 
-# --- Find new/changed sources ---
-base_sources=$(git show "${BASE_REF}:${HUB_FILE}" 2>/dev/null \
-  | jq -r '.skills[] | "\(.name)|\(.source)"' | sort) || base_sources=""
-
-pr_sources=$(jq -r '.skills[] | "\(.name)|\(.source)"' "$HUB_FILE" | sort)
-
-new_entries=$(comm -13 <(echo "$base_sources") <(echo "$pr_sources"))
-new_sources=$(echo "$new_entries" | cut -d'|' -f2 | sort -u)
-
-if [ -z "$new_entries" ]; then
-  echo "No new or changed skill sources to audit"
-  [ -n "$REPORT_FILE" ] && echo "No new or changed skill sources to audit." > "$REPORT_FILE"
-  exit 0
-fi
-
-echo "New/changed sources to audit:"
-echo "$new_sources"
-echo ""
-
-# --- Check skillshare is available ---
-if ! command -v skillshare &>/dev/null; then
-  echo "ERROR: skillshare CLI not found. Install from https://github.com/runkids/skillshare"
-  exit 1
-fi
+# --- Parse source into clone_url and subpath ---
+# Output: clone_url<TAB>subpath
+parse_source() {
+  local source="$1"
+  local clone_url="" subpath=""
 
-# --- Audit each source ---
-failed=0
-results=()
-details=()
-
-while IFS= read -r source; do
-  [ -z "$source" ] && continue
-
-  # Parse source into clone_url + optional subpath
-  subpath=""
   if [[ "$source" =~ ^https?://github\.com/([^/]+/[^/]+)/tree/[^/]+/(.+)$ ]]; then
-    # GitHub browser URL: https://github.com/owner/repo/tree/branch/path
     clone_url="https://github.com/${BASH_REMATCH[1]}.git"
     subpath="${BASH_REMATCH[2]}"
   elif [[ "$source" =~ ^https?://github\.com/([^/]+/[^/]+)/?$ ]]; then
-    # GitHub repo URL (no subpath): https://github.com/owner/repo
     clone_url="https://github.com/${BASH_REMATCH[1]}.git"
   elif [[ "$source" =~ ^github\.com/([^/]+/[^/]+)(/(.+))?$ ]]; then
-    # github.com shorthand: github.com/owner/repo[/path]
     clone_url="https://github.com/${BASH_REMATCH[1]}.git"
     subpath="${BASH_REMATCH[3]}"
   elif [[ "$source" =~ ^(https?://[^/]+)/([^/]+/[^/]+)/src/branch/[^/]+/(.+)$ ]]; then
-    # Gitea/Forgejo browser URL: https://host/owner/repo/src/branch/main/path
     clone_url="${BASH_REMATCH[1]}/${BASH_REMATCH[2]}.git"
     subpath="${BASH_REMATCH[3]}"
   elif [[ "$source" =~ ^(https?://[^/]+)/([^/]+/[^/]+)/src/branch/ ]]; then
-    # Gitea/Forgejo repo URL (branch root, no subpath)
     clone_url="${BASH_REMATCH[1]}/${BASH_REMATCH[2]}.git"
   elif [[ "$source" == http* ]]; then
-    # Other HTTP URLs — use as-is
     clone_url="$source"
   else
-    # GitHub shorthand: owner/repo[/path]
+    local owner_repo
     owner_repo=$(echo "$source" | cut -d'/' -f1-2)
     subpath=$(echo "$source" | cut -d'/' -f3-)
     clone_url="https://github.com/${owner_repo}.git"
   fi
 
-  safe_name=$(echo "$source" | tr '/' '-')
-  clone_dir="/tmp/audit-${safe_name}"
-
-  log_group "Auditing ${source}"
+  printf '%s\t%s' "$clone_url" "$subpath"
+}
 
-  if ! clone_output=$(git clone --depth 1 "$clone_url" "$clone_dir" 2>&1); then
-    log_error "Failed to clone ${source}"
-    results+=("| \`${source}\` | :x: Clone failed | - |")
-    details+=("DETAIL_SEP### \`${source}\`"$'\n'"Clone failed:"$'\n'"\`\`\`"$'\n'"${clone_output}"$'\n'"\`\`\`")
-    failed=1
-    log_endgroup
-    continue
-  fi
-
-  # Audit subpath if specified, otherwise audit entire clone
-  audit_target="$clone_dir"
-  if [ -n "$subpath" ] && [ -d "$clone_dir/$subpath" ]; then
-    audit_target="$clone_dir/$subpath"
-  fi
+# --- Audit a single target and record results ---
+# Sets: results[], details[], failed
+audit_target() {
+  local source="$1" audit_target="$2"
 
+  local audit_json
   audit_json=$(skillshare audit "$audit_target" --threshold high --json 2>/dev/null) || true
 
-  # Check if output is valid audit JSON
   if ! echo "$audit_json" | jq -e '.summary' >/dev/null 2>&1; then
-    # Not valid JSON — command errored (e.g. path not found)
+    local audit_err
     audit_err=$(skillshare audit "$audit_target" --threshold high 2>&1) || true
     echo "$audit_err"
     results+=("| \`${source}\` | :x: Error | - |")
     details+=("DETAIL_SEP### \`${source}\`"$'\n'"\`\`\`"$'\n'"${audit_err}"$'\n'"\`\`\`")
     failed=1
-    rm -rf "$clone_dir"
-    log_endgroup
-    continue
+    return
   fi
 
-  # Extract risk info with jq
+  local risk_score risk_label risk findings_text audit_display
   risk_score=$(echo "$audit_json" | jq -r '.summary.riskScore')
   risk_label=$(echo "$audit_json" | jq -r '.summary.riskLabel' | tr '[:lower:]' '[:upper:]')
   risk="${risk_label} (${risk_score}/100)"
 
-  # Format findings for display
   findings_text=$(echo "$audit_json" | jq -r '
     [.results[] | (.findings // [])[] | "  \(.severity): \(.message) (\(.file):\(.line))\n  \"\(.snippet)\""]
     | join("\n\n")')
@@ -131,16 +81,108 @@ while IFS= read -r source; do
     results+=("| \`${source}\` | :white_check_mark: Passed | ${risk} |")
     details+=("DETAIL_SEP### \`${source}\`"$'\n'"\`\`\`"$'\n'"${audit_display}"$'\n'"\`\`\`")
   fi
+}
+
+# --- Find new/changed sources ---
+base_sources=$(git show "${BASE_REF}:${HUB_FILE}" 2>/dev/null \
+  | jq -r '.skills[] | "\(.name)|\(.source)"' | sort) || base_sources=""
+
+pr_sources=$(jq -r '.skills[] | "\(.name)|\(.source)"' "$HUB_FILE" | sort)
+
+new_entries=$(comm -13 <(echo "$base_sources") <(echo "$pr_sources"))
+new_sources=$(echo "$new_entries" | cut -d'|' -f2 | sort -u)
+
+if [ -z "$new_entries" ]; then
+  echo "No new or changed skill sources to audit"
+  [ -n "$REPORT_FILE" ] && echo "No new or changed skill sources to audit." > "$REPORT_FILE"
+  exit 0
+fi
+
+# --- Check skillshare is available ---
+if ! command -v skillshare &>/dev/null; then
+  echo "ERROR: skillshare CLI not found. Install from https://github.com/runkids/skillshare"
+  exit 1
+fi
+
+# --- Group sources by clone_url (clone once per repo) ---
+# Use temp dir instead of associative arrays (Bash 3.x compat)
+group_dir=$(mktemp -d)
+trap 'rm -rf "$group_dir"' EXIT
+clone_order_file="$group_dir/_order"
+touch "$clone_order_file"
+
+while IFS= read -r source; do
+  [ -z "$source" ] && continue
+
+  parsed=$(parse_source "$source")
+  clone_url=$(echo "$parsed" | cut -f1)
+  subpath=$(echo "$parsed" | cut -f2)
+
+  safe_name=$(echo "$clone_url" | sed 's|https://||;s|\.git$||' | tr '/:' '-')
+  if ! grep -qxF "$safe_name" "$clone_order_file" 2>/dev/null; then
+    echo "$safe_name" >> "$clone_order_file"
+    echo "$clone_url" > "$group_dir/${safe_name}.url"
+  fi
+  printf '%s\t%s\n' "$source" "$subpath" >> "$group_dir/${safe_name}.sources"
+done <<< "$new_sources"
+
+unique_repos=$(wc -l < "$clone_order_file" | tr -d ' ')
+echo "New/changed sources to audit: $(echo "$new_sources" | wc -l | tr -d ' ') sources across ${unique_repos} repos"
+echo ""
+
+# --- Audit each repo ---
+failed=0
+results=()
+details=()
+
+while IFS= read -r safe_name; do
+  [ -z "$safe_name" ] && continue
+  clone_url=$(cat "$group_dir/${safe_name}.url")
+  clone_dir="/tmp/audit-${safe_name}"
+  rm -rf "$clone_dir"
+
+  log_group "Cloning ${clone_url}"
+
+  if ! clone_output=$(git clone --depth 1 "$clone_url" "$clone_dir" 2>&1); then
+    # Clone failed — mark all sources in this repo as failed
+    while IFS=$'\t' read -r source subpath; do
+      [ -z "$source" ] && continue
+      log_error "Failed to clone ${source}"
+      results+=("| \`${source}\` | :x: Clone failed | - |")
+      details+=("DETAIL_SEP### \`${source}\`"$'\n'"Clone failed:"$'\n'"\`\`\`"$'\n'"${clone_output}"$'\n'"\`\`\`")
+      failed=1
+    done < "$group_dir/${safe_name}.sources"
+    rm -rf "$clone_dir"
+    log_endgroup
+    continue
+  fi
+
+  echo "Cloned ${clone_url} — auditing subpaths..."
+
+  # Audit each source/subpath in this repo
+  while IFS=$'\t' read -r source subpath; do
+    [ -z "$source" ] && continue
+
+    local_target="$clone_dir"
+    if [ -n "$subpath" ] && [ -d "$clone_dir/$subpath" ]; then
+      local_target="$clone_dir/$subpath"
+    fi
+
+    echo "  Auditing: ${source}"
+    audit_target "$source" "$local_target"
+  done < "$group_dir/${safe_name}.sources"
 
   rm -rf "$clone_dir"
   log_endgroup
-done <<< "$new_sources"
+done < "$clone_order_file"
 
 # --- Generate report ---
 if [ -n "$REPORT_FILE" ]; then
   {
     echo "## Skill Audit Results"
     echo ""
+    echo "Audited $(echo "$new_sources" | wc -l | tr -d ' ') sources across ${unique_repos} repos."
+    echo ""
     echo "| Source | Status | Risk |"
     echo "|--------|--------|------|"
     for row in "${results[@]}"; do
diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..d2ba0c8
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SKILLS_DIR="${1:-skills}"
+HUB_FILE="skillshare-hub.json"
+
+if [ ! -d "$SKILLS_DIR" ]; then
+  echo "ERROR: $SKILLS_DIR directory not found"
+  exit 1
+fi
+
+# Count source files
+files=("$SKILLS_DIR"/*.json)
+if [ ${#files[@]} -eq 0 ]; then
+  echo "ERROR: No .json files found in $SKILLS_DIR"
+  exit 1
+fi
+
+# Merge all arrays, sort by name, wrap in hub schema
+jq -s '{
+  schemaVersion: 1,
+  skills: ([.[][]] | sort_by(.name))
+}' "${files[@]}" > "$HUB_FILE"
+
+count=$(jq '.skills | length' "$HUB_FILE")
+echo "Built: $HUB_FILE ($count skills from ${#files[@]} files)"
diff --git a/skills/skill.json b/skills/skill.json
new file mode 100644
index 0000000..560e3e0
--- /dev/null
+++ b/skills/skill.json
@@ -0,0 +1,21 @@
+[
+  {
+    "name": "skill-creator",
+    "description": "Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations.",
+    "source": "anthropics/skills",
+    "skill": "skill-creator",
+    "tags": [
+      "skill"
+    ]
+  },
+  {
+    "name": "skillshare",
+    "description": "Built-in AI skill for skillshare – helps install, search, and manage skills from the hub",
+    "source": "https://github.com/runkids/skillshare/tree/main/skills/skillshare",
+    "tags": [
+      "skillshare",
+      "agent",
+      "skill"
+    ]
+  }
+]