Pack Switch

You are the PACK-SWITCH skill — switches which pack the operator's cycles read from.

What this skill does

Writes ~/.lintel/packs/active-pack to the new pack name. The next session picks up the new pack; the current session keeps its cached pack (per pack-resolver semantics in pack-resolver.md).

When to use

• Operator moves from one customer/team domain to another
• Operator wants to test a newly created pack
• After running /li:v4-migrate (which recommends pack-switch as the final step)

When NOT to use

• Mid-cycle — switch takes effect at NEXT session; the current cycle ignores
• One-off override for a single workflow — use --mode or --pack <name> flags

Workflow

Step 1 — Resolve target pack

target="${1:?usage: /li:pack-switch <pack-name>}"
source "$REPO_ROOT/lib/pack-resolver.sh"

if ! validate_pack "$target" 2>&1; then
  echo "ERROR: pack '$target' does not validate; switch refused"
  echo "Hint: /li:pack-list to see valid packs"
  exit 1
fi

Step 2 — Read current active

LINTEL_HOME="${LINTEL_HOME:-$HOME/.lintel}"
ACTIVE_FILE="$LINTEL_HOME/packs/active-pack"
mkdir -p "$LINTEL_HOME/packs" 2>/dev/null

current="_default"
[ -f "$ACTIVE_FILE" ] && current=$(head -1 "$ACTIVE_FILE" | tr -d '[:space:]')

Step 3 — Confirm switch (when target differs)

If current == target: no-op, surface "already active" and exit DONE.

Otherwise surface diff:

Pack switch:
  Current: <current>
  Target:  <target>

  Effective at: next session (current session keeps cached pack)
  Operator's workflows after switch: <target>'s defaults
  
  Proceed? [Y/n]

Step 4 — Write active-pack file + audit

echo "$target" > "$ACTIVE_FILE"

ts=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
printf '{"ts":"%s","kind":"pack_switched","from":"%s","to":"%s","operator":"%s"}\n' \
  "$ts" "$current" "$target" "$(whoami)" \
  >> "$LINTEL_HOME/audit/pack-lifecycle.jsonl"

echo "✓ Active pack: $target (next session)"

Step 5 — Surface effective changes

Read both packs and surface fields that differ:

Effective field changes (next session):
  voice.default_tier: <old> → <new>
  compliance.mode:    <old> → <new>
  navigation.default_workflow: <old> → <new>
  (etc.)

Operator sees what changes before living with the new pack.

Step 5b — Surface extension-pack surface (ADR-0018)

If the target is an extension pack it brings its OWN skills/agents/hooks + a workflow — not just identity. Read the TARGET manifest with the shared _pack_ext_field parser (block-scoped + comment-stripped + truthy-alias aware — one parser, not three; resolve_pack_field/pack_is_extension read the active cached pack, which is not the target until next session):

tgt_dir=$(_pack_dir "$target") && tgt="$tgt_dir/pack.yaml"
case "$(_pack_ext_field "$tgt" is_extension)" in true|yes|on)
  ns=$(_pack_ext_field "$tgt" namespace)
  wf=$(_pack_ext_field "$tgt" workflow)
  echo "Extension pack '$target' — brings its own surface (active next session):"
  echo "  namespace: /$ns:    workflow: /$ns:$wf  (run the full pack cycle)"
  echo "  ships: skills + agents + hooks"
;; esac

An extension pack must ALSO be installed as a plugin (/plugin install <name>) for its skills/agents/hooks to load. pack-switch activates its identity and makes Lintel aware of it; the plugin install provides the executable surface.

Pause-points

• Step 3: confirm switch when current ≠ target (skipped with --auto)

Integration

Reads:

• lib/pack-resolver.sh (validation)
• ~/.lintel/packs/<target>/pack.yaml (field-diff)
• ~/.lintel/packs/<current>/pack.yaml (field-diff)

Writes:

• ~/.lintel/packs/active-pack
• ~/.lintel/audit/pack-lifecycle.jsonl

Anti-patterns

• Skipping field-diff surface — operator deserves to see what changes
• Switching mid-cycle and expecting current session to update — per resolver semantics, cache survives until next session
• Auto-switching after /li:pack-create — operator decides

Mid-session override

If the operator REALLY wants the current session to pick up the new pack:

# Run clear_pack_cache from a shell that sources lib/pack-resolver.sh
source $REPO_ROOT/lib/pack-resolver.sh && clear_pack_cache

This is documented but not automated — explicit override per L-004.