Trailhead

Trailhead

Meta skill that installs session tracking into any target skill. Every session that works on a tracked skill leaves a trail marker -- so the next session can find its way back.

What It Does

1. Creates {skill-name}-sessions.json in the target skill's directory with an empty array
2. Adds an ## On Activation section to the target SKILL.md (after frontmatter, before first content section)
3. Adds a ## Session History section to the target SKILL.md (before the last section, or at the end)
4. Reports what was added and commits the changes

Usage

/trailhead {skill-name}

Or naturally: "Add session tracking to the google-drive skill"

Installation Steps

When invoked with a target skill name:

Step 1: Validate the target skill

ls .claude/skills/{skill-name}/SKILL.md

If the skill doesn't exist, tell the user and stop.

Step 2: Check if already installed

grep -l "trailhead" .claude/skills/{skill-name}/SKILL.md

If found, tell the user Trailhead is already installed and stop.

Step 2.5: Skill type gate

Read the target skill's SKILL.md and assess whether it's a project-oriented skill or a utility skill. Session tracking is designed for project skills where work compounds across sessions.

Install without warning for: Skills that manage projects, external artifacts, or evolving domains.

Warn before installing on: Utility/reference skills, one-shot operation skills, or tool wrapper skills with no persistent state. Tell the user: "This looks like a utility skill -- Trailhead works best on project-oriented skills where work builds across sessions. Install anyway?"

If the user confirms, proceed. If not, stop.

Step 3: Create the session index file

Write .claude/skills/{skill-name}/{skill-name}-sessions.json:

[]

Step 4: Add On Activation section to SKILL.md

Insert after the frontmatter closing --- and before the first # heading:

## On Activation

Follow the Trailhead protocol in `/.claude/includes/trailhead.md`.
Session index: `/.claude/skills/{skill-name}/{skill-name}-sessions.json`

If the skill already has an ## On Activation section, append the two lines to it instead of creating a duplicate section.

Step 5: Add Session History section to SKILL.md

Insert before the last section of the file (or at the end if placement is unclear):

## Session History

Past sessions with summaries and IDs for easy context recovery:
**Session index:** `/.claude/skills/{skill-name}/{skill-name}-sessions.json`

Step 6: Commit

git add .claude/skills/{skill-name}/{skill-name}-sessions.json .claude/skills/{skill-name}/SKILL.md
git commit -m "Add Trailhead session tracking to {skill-name} skill"

Step 7: Confirm

Tell the user what was installed and that the skill will now track sessions automatically.

Protocol Reference

The shared protocol that defines how session tracking works at runtime: /.claude/includes/trailhead.md

Notes

• This installer does not modify the skill's triggers or description
• The On Activation section is intentionally minimal -- it just points to the shared protocol
• If the user wants to backfill past sessions, they can search past session transcripts and manually add entries to the index