diff --git a/bin/mosaic b/bin/mosaic
index d4bea29..e98109a 100755
--- a/bin/mosaic
+++ b/bin/mosaic
@@ -34,6 +34,7 @@ Management:
   doctor [args...]       Audit runtime state and detect drift
   sync [args...]         Sync skills from canonical source
   bootstrap <path>       Bootstrap a repo with Mosaic standards
+  upgrade [path]         Clean up stale SOUL.md/CLAUDE.md in a project
 
 Options:
   -h, --help             Show this help
@@ -146,6 +147,11 @@ run_bootstrap() {
   exec "$MOSAIC_HOME/bin/mosaic-bootstrap-repo" "$@"
 }
 
+run_upgrade() {
+  check_mosaic_home
+  exec "$MOSAIC_HOME/bin/mosaic-upgrade" "$@"
+}
+
 # Main router
 if [[ $# -eq 0 ]]; then
   usage
@@ -163,6 +169,7 @@ case "$command" in
   doctor)     run_doctor "$@" ;;
   sync)       run_sync "$@" ;;
   bootstrap)  run_bootstrap "$@" ;;
+  upgrade)    run_upgrade "$@" ;;
   help|-h|--help)  usage ;;
   version|-v|--version) echo "mosaic $VERSION" ;;
   *)
diff --git a/bin/mosaic-upgrade b/bin/mosaic-upgrade
new file mode 100755
index 0000000..29492c9
--- /dev/null
+++ b/bin/mosaic-upgrade
@@ -0,0 +1,218 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# mosaic-upgrade — Clean up stale per-project files after Mosaic centralization
+#
+# SOUL.md    → Now global at ~/.config/mosaic/SOUL.md (remove from projects)
+# CLAUDE.md  → Now a thin pointer or removable (replace with pointer or remove)
+# AGENTS.md  → Keep project-specific content, strip stale load-order directives
+#
+# Usage:
+#   mosaic-upgrade [path]          Upgrade a specific project (default: current dir)
+#   mosaic-upgrade --all           Scan ~/src/* for projects to upgrade
+#   mosaic-upgrade --dry-run       Show what would change without touching anything
+
+MOSAIC_HOME="${MOSAIC_HOME:-$HOME/.config/mosaic}"
+
+# Colors (disabled if not a terminal)
+if [[ -t 1 ]]; then
+  GREEN='\033[0;32m' YELLOW='\033[0;33m' RED='\033[0;31m'
+  CYAN='\033[0;36m' BOLD='\033[1m' DIM='\033[2m' RESET='\033[0m'
+else
+  GREEN='' YELLOW='' RED='' CYAN='' BOLD='' DIM='' RESET=''
+fi
+
+ok()   { echo -e "  ${GREEN}✓${RESET} $1"; }
+skip() { echo -e "  ${DIM}–${RESET} $1"; }
+warn() { echo -e "  ${YELLOW}⚠${RESET} $1"; }
+act()  { echo -e "  ${CYAN}→${RESET} $1"; }
+
+DRY_RUN=false
+ALL=false
+TARGET=""
+SEARCH_ROOT="${HOME}/src"
+
+usage() {
+  cat <<USAGE
+mosaic-upgrade — Clean up stale per-project files
+
+Usage:
+  mosaic-upgrade [path]          Upgrade a specific project (default: cwd)
+  mosaic-upgrade --all           Scan ~/src/* for all git projects
+  mosaic-upgrade --dry-run       Preview changes without writing
+  mosaic-upgrade --all --dry-run Preview all projects
+
+After Mosaic centralization:
+  SOUL.md    → Removed (now global at ~/.config/mosaic/SOUL.md)
+  CLAUDE.md  → Replaced with thin pointer or removed
+  AGENTS.md  → Stale load-order sections stripped; project content preserved
+USAGE
+}
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)  DRY_RUN=true; shift ;;
+    --all)      ALL=true; shift ;;
+    --root)     SEARCH_ROOT="$2"; shift 2 ;;
+    -h|--help)  usage; exit 0 ;;
+    -*)         echo "Unknown flag: $1" >&2; usage >&2; exit 1 ;;
+    *)          TARGET="$1"; shift ;;
+  esac
+done
+
+# Generate the thin CLAUDE.md pointer
+CLAUDE_POINTER='# CLAUDE Compatibility Pointer
+
+This file exists so Claude Code sessions load Mosaic standards.
+
+## MANDATORY — Read Before Any Response
+
+BEFORE responding to any user message, READ `~/.config/mosaic/AGENTS.md`.
+
+That file is the universal agent configuration. Do NOT respond until you have loaded it.
+Then read the project-local `AGENTS.md` in this repository for project-specific guidance.'
+
+upgrade_project() {
+  local project_dir="$1"
+  local project_name
+  project_name="$(basename "$project_dir")"
+  local changed=false
+
+  echo -e "\n${BOLD}$project_name${RESET} ${DIM}($project_dir)${RESET}"
+
+  # ── SOUL.md ──────────────────────────────────────────────
+  local soul="$project_dir/SOUL.md"
+  if [[ -f "$soul" ]]; then
+    if [[ "$DRY_RUN" == "true" ]]; then
+      act "Would remove SOUL.md (now global at ~/.config/mosaic/SOUL.md)"
+    else
+      rm "$soul"
+      ok "Removed SOUL.md (now global)"
+    fi
+    changed=true
+  else
+    skip "No SOUL.md (already clean)"
+  fi
+
+  # ── CLAUDE.md ────────────────────────────────────────────
+  local claude_md="$project_dir/CLAUDE.md"
+  if [[ -f "$claude_md" ]]; then
+    local claude_content
+    claude_content="$(cat "$claude_md")"
+
+    # Check if it's already a thin pointer to AGENTS.md
+    if echo "$claude_content" | grep -q "READ.*~/.config/mosaic/AGENTS.md"; then
+      skip "CLAUDE.md already points to global AGENTS.md"
+    else
+      if [[ "$DRY_RUN" == "true" ]]; then
+        act "Would replace CLAUDE.md with thin pointer to global AGENTS.md"
+      else
+        # Back up the original
+        cp "$claude_md" "${claude_md}.mosaic-bak"
+        echo "$CLAUDE_POINTER" > "$claude_md"
+        ok "Replaced CLAUDE.md with pointer (backup: CLAUDE.md.mosaic-bak)"
+      fi
+      changed=true
+    fi
+  else
+    skip "No CLAUDE.md"
+  fi
+
+  # ── AGENTS.md (strip stale load-order, preserve project content) ─
+  local agents="$project_dir/AGENTS.md"
+  if [[ -f "$agents" ]]; then
+    # Detect stale load-order patterns
+    local has_stale=false
+
+    # Pattern 1: References to SOUL.md in load order
+    if grep -qE "(Read|READ|Load).*SOUL\.md" "$agents" 2>/dev/null; then
+      has_stale=true
+    fi
+
+    # Pattern 2: Old "## Load Order" section that references centralized files
+    if grep -q "## Load Order" "$agents" 2>/dev/null && \
+       grep -qE "STANDARDS\.md|SOUL\.md" "$agents" 2>/dev/null; then
+      has_stale=true
+    fi
+
+    # Pattern 3: Old ~/.mosaic/ path (pre-centralization)
+    if grep -q '~/.mosaic/' "$agents" 2>/dev/null; then
+      has_stale=true
+    fi
+
+    if [[ "$has_stale" == "true" ]]; then
+      if [[ "$DRY_RUN" == "true" ]]; then
+        act "Would strip stale load-order section from AGENTS.md"
+        # Show what we detect
+        if grep -qn "## Load Order" "$agents" 2>/dev/null; then
+          local line
+          line=$(grep -n "## Load Order" "$agents" | head -1 | cut -d: -f1)
+          echo -e "    ${DIM}Line $line: Found '## Load Order' section referencing SOUL.md/STANDARDS.md${RESET}"
+        fi
+        if grep -qn '~/.mosaic/' "$agents" 2>/dev/null; then
+          echo -e "    ${DIM}Found references to old ~/.mosaic/ path${RESET}"
+        fi
+      else
+        cp "$agents" "${agents}.mosaic-bak"
+
+        # Strip the Load Order section (from "## Load Order" to next "##" or "---")
+        if grep -q "## Load Order" "$agents"; then
+          awk '
+            /^## Load Order/ { skip=1; next }
+            skip && /^(## |---)/ { skip=0 }
+            skip { next }
+            { print }
+          ' "${agents}.mosaic-bak" > "$agents"
+        fi
+
+        # Fix old ~/.mosaic/ → ~/.config/mosaic/
+        if grep -q '~/.mosaic/' "$agents"; then
+          sed -i 's|~/.mosaic/|~/.config/mosaic/|g' "$agents"
+        fi
+
+        ok "Stripped stale load-order from AGENTS.md (backup: AGENTS.md.mosaic-bak)"
+      fi
+      changed=true
+    else
+      skip "AGENTS.md has no stale directives"
+    fi
+  else
+    skip "No AGENTS.md"
+  fi
+
+  # ── .claude/settings.json (leave alone) ──────────────────
+  # Project-specific settings are fine — don't touch them.
+
+  if [[ "$changed" == "false" ]]; then
+    echo -e "  ${GREEN}Already up to date.${RESET}"
+  fi
+}
+
+# ── Main ───────────────────────────────────────────────────
+
+if [[ "$DRY_RUN" == "true" ]]; then
+  echo -e "${BOLD}Mode: DRY RUN (no files will be changed)${RESET}"
+fi
+
+if [[ "$ALL" == "true" ]]; then
+  echo -e "${BOLD}Scanning $SEARCH_ROOT for projects...${RESET}"
+  count=0
+  for dir in "$SEARCH_ROOT"/*/; do
+    [[ -d "$dir/.git" ]] || continue
+    upgrade_project "$dir"
+    count=$((count + 1))
+  done
+  echo -e "\n${BOLD}Scanned $count projects.${RESET}"
+elif [[ -n "$TARGET" ]]; then
+  if [[ ! -d "$TARGET" ]]; then
+    echo "[mosaic-upgrade] ERROR: $TARGET is not a directory." >&2
+    exit 1
+  fi
+  upgrade_project "$TARGET"
+else
+  upgrade_project "$(pwd)"
+fi
+
+if [[ "$DRY_RUN" == "true" ]]; then
+  echo -e "\n${YELLOW}This was a dry run. Run without --dry-run to apply changes.${RESET}"
+fi
diff --git a/bin/mosaic.ps1 b/bin/mosaic.ps1
index 5a4d14f..47175c7 100644
--- a/bin/mosaic.ps1
+++ b/bin/mosaic.ps1
@@ -31,6 +31,7 @@ Management:
   doctor [args...]       Audit runtime state and detect drift
   sync [args...]         Sync skills from canonical source
   bootstrap <path>       Bootstrap a repo with Mosaic standards
+  upgrade [path]         Clean up stale SOUL.md/CLAUDE.md in a project
 
 Options:
   -h, --help             Show this help
@@ -140,6 +141,11 @@ switch ($command) {
         Write-Host "[mosaic] NOTE: mosaic-bootstrap-repo requires bash. Use Git Bash or WSL." -ForegroundColor Yellow
         & (Join-Path $MosaicHome "bin\mosaic-bootstrap-repo") @remaining
     }
+    "upgrade" {
+        Assert-MosaicHome
+        Write-Host "[mosaic] NOTE: mosaic-upgrade requires bash. Use Git Bash or WSL." -ForegroundColor Yellow
+        & (Join-Path $MosaicHome "bin\mosaic-upgrade") @remaining
+    }
     { $_ -in "help", "-h", "--help" } { Show-Usage }
     { $_ -in "version", "-v", "--version" } { Write-Host "mosaic $Version" }
     default {