swain-update

name	swain-update
description	Update swain skills to the latest version. Use when the user says 'update swain', 'upgrade swain', 'pull latest swain', 'reinstall swain', 'refresh skills', or wants to update their swain skills installation. Uses npx to pull the latest swain release from GitHub, with a git-clone fallback, then invokes swain-doctor to reconcile governance and validate project health.
user-invocable	true
allowed-tools	Bash, Read, Glob
metadata	{"short-description":"Update swain skills to latest","version":"1.4.0","author":"cristos","license":"MIT","source":"swain"}

Update Swain

Update the local installation of swain skills to the latest version, then reconcile governance configuration.

Step 1 — Detect current installation

Check whether .claude/skills/ contains any swain-* directories:

ls -d .claude/skills/swain-* 2>/dev/null

If no swain skill directories are found, inform the user this appears to be a fresh install rather than an update, then continue anyway — the steps below work for both cases.

Step 2 — Backup local modifications

Before overwriting skill directories, check for user modifications that should be preserved.

Detect modified files

Compare local skill files against the installed version's git origin:

# Create a temporary reference copy
tmp=$(mktemp -d)
git clone --depth 1 https://github.com/cristoslc/swain.git "$tmp/swain" 2>/dev/null

# Find locally modified files
modified_files=()
for skill_dir in .claude/skills/swain-*/; do
  skill_name=$(basename "$skill_dir")
  ref_dir="$tmp/swain/skills/$skill_name"
  [ -d "$ref_dir" ] || continue

  while IFS= read -r file; do
    rel="${file#$skill_dir}"
    ref_file="$ref_dir/$rel"
    if [ -f "$ref_file" ]; then
      if ! diff -q "$file" "$ref_file" >/dev/null 2>&1; then
        modified_files+=("$file")
      fi
    else
      # File exists locally but not in upstream — user-added file
      modified_files+=("$file")
    fi
  done < <(find "$skill_dir" -type f)
done

Backup modified files

If modified files are found:

1. Create a backup directory: .agents/update-backup/<ISO-date>/
2. Copy each modified file preserving directory structure
3. Inform the user: "Found N locally modified files — backed up to .agents/update-backup/<date>/"
4. List the modified files

If no modified files are found, skip and continue.

The reference clone from this step can be reused as the fallback source in Step 3.

Step 3 — Detect installed agent platforms

Before installing, detect which agent platforms are present on the system. This avoids creating dotfolder stubs for every supported platform (see GitHub issue #21).

Read the agent platform data from references/agent-platforms.json. Each entry in the agents array has a name (skills CLI identifier), an optional command (CLI binary), and a detection path (HOME config directory). A platform is detected if either check succeeds. Entries in always_include are added unconditionally.

SKILL_DIR="$(find . .claude skills -path '*/swain-update/references' -print -quit 2>/dev/null | sed 's|/references$||')"
detected_agents=()

# Always-include platforms (we're running inside claude-code)
for name in $(jq -r '.always_include[]' "$SKILL_DIR/references/agent-platforms.json"); do
  detected_agents+=("$name")
done

# Detect remaining platforms via command -v or HOME dotfolder
while IFS= read -r entry; do
  name=$(echo "$entry" | jq -r '.name')
  cmd=$(echo "$entry" | jq -r '.command // empty')
  det=$(echo "$entry" | jq -r '.detection // empty')

  # Skip always-include (already added)
  for ai in "${detected_agents[@]}"; do [[ "$ai" == "$name" ]] && continue 2; done

  found=false
  if [[ -n "$cmd" ]] && command -v "$cmd" &>/dev/null; then
    found=true
  fi
  if [[ -n "$det" ]] && ! $found; then
    det_expanded=$(echo "$det" | sed "s|~|$HOME|g")
    det_expanded=$(eval echo "$det_expanded" 2>/dev/null)
    [[ -d "$det_expanded" ]] && found=true
  fi

  $found && detected_agents+=("$name")
done < <(jq -c '.agents[]' "$SKILL_DIR/references/agent-platforms.json")

Build the -a flags from detected agents:

agent_flags=""
for agent in "${detected_agents[@]}"; do
  agent_flags="$agent_flags -a $agent"
done

Tell the user which platforms were detected:

Detected N agent platform(s): claude-code, codex, gemini-cli, ...

Step 4 — Update via npx

Run the skills package manager with only the detected agents:

npx skills add cristoslc/swain $agent_flags -s '*' -y

This installs all skills (-s '*') for only the detected platforms, skipping confirmation (-y). No dotfolder stubs are created for platforms that aren't installed.

If npx fails (command not found, network error, or non-zero exit), fall back to a direct git clone:

tmp=$(mktemp -d)
git clone --depth 1 https://github.com/cristoslc/swain.git "$tmp/swain"
# Detect skill install location
INSTALL_DIR=$(find . -maxdepth 2 -name "swain-doctor" -type d -print -quit 2>/dev/null | sed 's|/swain-doctor$||')
INSTALL_DIR="${INSTALL_DIR:-.claude/skills}"
cp -r "$tmp/swain/skills/"* "$INSTALL_DIR/"
rm -rf "$tmp"

Step 5 — Reconcile governance

Invoke the swain-doctor skill. This validates governance rules, cleans up legacy skill directories (including any renamed in this release), validates .tickets/, and untracks any runtime files that leaked into git. The skill is idempotent, so running it after every update is always safe.

Step 6 — Restore guidance

If files were backed up in Step 2:

1. List the backed-up files with their paths
2. For each, explain the situation:
   • User-added config files (e.g., config/yazi/yazi.toml): Suggest moving to .agents/config/<skill-name>/ or swain.settings.json where they'll survive future updates
   • Patched scripts: Show the diff between the backup and the new version. If the upstream version includes the fix, confirm the patch is no longer needed. If not, offer to re-apply the patch.
3. Remind the user: "To avoid this in future, store customizations in .agents/config/ or swain.settings.json — these survive updates."

Step 7 — Report

List the installed swain skill directories and extract each skill's version from its SKILL.md frontmatter:

for skill in .claude/skills/swain-*/SKILL.md; do
  name=$(grep '^name:' "$skill" | head -1 | sed 's/name: *//')
  version=$(grep 'version:' "$skill" | head -1 | sed 's/.*version: *//')
  echo "  $name  v$version"
done

Show the user the list and confirm the update is complete.

If backups were created in Step 2, also show: "Backed up N modified files to .agents/update-backup/<date>/. See Step 5 for restore guidance."