mikko-install

The slash-command face of the claude-skills installers. Reads mikko-* skills from a cloned source repo on disk and writes them into ~/.claude/skills/ via the repo's existing bash scripts. Lets you install / update / remove from inside any Claude Code session.

When to invoke

• "install the mikko skills" / "install everything" — bulk install all mikko-* skills, mikko-prefixed.
• "install <name>" (e.g. "install readme-drift-sync", "install ai-codegen-smell-audit") — install one specific skill.
• "update my mikko skills" / "re-run the install" — after a git pull in the source repo, re-copy everything so installed copies match source.
• "what mikko skills are new since last install" / "anything new to install" — list source skills that aren't installed yet.
• "uninstall mikko-foo" / "remove mikko-foo" — delete the user-wide install of one skill.

When NOT to invoke

• Not for cloning the source repo. The user clones claude-skills once, by hand. This skill assumes the clone already exists on disk.
• Not for non-mikko-* skills. Anthropic-shipped skills and skills under other namespaces are out of scope.
• Not for editing skill content. Edit the source repo and re-run install; never hand-edit the installed copy.
• Not for installing into a project (only user-wide is in scope here). For per-project install, use the underlying ./install.sh <name> --target project --repo <path> directly — that's a different use case.

Procedure

1. Locate the source repo

The source repo is the cloned claude-skills directory. The skill looks for it, in order:

1. Current working directory — if cwd contains install-mikko.sh AND a skills/ directory, use cwd.
2. Parent directory of cwd — walk up two levels checking for the same markers (handles "I'm in <repo>/some/sub/dir/").
3. Ask the user once — if neither hits, ask: "Where's your claude-skills clone? (full path)". Bail with a clear message if no answer. Do NOT probe hardcoded author-specific paths — every fork lives somewhere different.

Once located, verify by checking that <source>/install-mikko.sh and <source>/skills/*/SKILL.md both exist. Cache the resolved path in the conversation context for the rest of the turn.

2. Map intent to action

The skill dispatches based on what the user asked for. Default to install all when intent is unclear.

Diff-logic note (for the "what's new" intent): the user's namespace may be mixed — most skills are mikko-prefixed (from install-mikko.sh) but some may be unprefixed (from install.sh <name>). To avoid reporting mikko-foo as "new" when an unprefixed foo already exists, the diff compares source skill names against installed directory names, treating foo and mikko-foo as equivalent. A source skill counts as installed if ~/.claude/skills/<source-name>/ OR ~/.claude/skills/mikko-<source-name>/ exists. When the source name is already mikko-prefixed (e.g. mikko-help), this naturally collapses to checking ~/.claude/skills/mikko-help/ once via the first form.

3. Execute the action

Run the bash command via the Bash tool. Capture stdout / stderr / exit code. On non-zero exit, print the error block to the user and bail — don't try to "fix" install failures from inside this skill.

4. Confirm + summarise

After a successful install, print a one-line summary:

installed N skill(s) into ~/.claude/skills/  (M new, K updated)

If the user requested "what's new" without installing, just print the list and stop — don't install on a list query.

5. Restart hint

End the run with: Claude Code picks up new skills on the next conversation turn — no restart needed. (Empirically true; the harness re-globs the skills dir each turn.)

Output format

Default (install all):

mikko-install — source: <resolved-path-to-claude-skills>

[install-mikko.sh output here]

installed 9 skill(s) into ~/.claude/skills/ (1 new, 8 updated)

"What's new":

mikko-install — source: <resolved-path-to-claude-skills>

new skills available (not installed):
  mikko-readme-drift-sync
  mikko-foo  (if applicable)

run /mikko-install to add them.

Uninstall:

mikko-install — about to remove:
  ~/.claude/skills/mikko-foo

confirm? [y/N]

What this skill does NOT do

• Does not clone, fetch, or pull from a remote. The user runs git pull in the source repo by hand. This skill reads from whatever's already on disk.
• Does not edit installed skill content. Source is the source of truth; the installed copy is downstream.
• Does not touch skills outside the mikko-* prefix. Anthropic-shipped skills (init, review, etc.) and other namespaces are invisible to this skill.
• Does not double-prefix. Source skills already starting with mikko- (like mikko-help, mikko-audit-suite, this skill itself) install as-is, not as mikko-mikko-foo. install-mikko.sh already handles that — the skill just delegates.
• Does not auto-uninstall. Removing a skill always asks for confirmation, even with explicit --force from the user.

Failure modes

• Source repo not found. Probes the known locations; if nothing matches, asks the user once. If still nothing, exits with error: can't find your claude-skills clone — pass the path explicitly.
• install-mikko.sh or install.sh missing from source. Should never happen on a clean clone; if it does, the skill exits with error: <source>/install-mikko.sh is missing — your clone might be partial. Re-clone or git pull.
• Permission denied writing to ~/.claude/skills/. Surface the underlying bash error; don't try to escalate privileges.
• Symlink fails on Windows without Developer Mode (for install.sh per-skill). install.sh symlinks; on Windows Git Bash with default settings, that may fall back to copy. install-mikko.sh copies by design — recommend install-mikko.sh on Windows when symlink-vs-copy doesn't matter.
• Skill installed but not appearing as a slash command. Tell the user: Claude Code reads ~/.claude/skills/ each turn. If /<skill-name> still doesn't trigger, check that ~/.claude/skills/<name>/SKILL.md exists and the frontmatter has a name: field matching the directory.

Why this skill exists

The claude-skills repo ships with two bash installers (install.sh, install-mikko.sh) that work fine on the command line. They're not discoverable from inside a Claude Code conversation — to use them you have to (a) know they exist, (b) find the cloned repo, (c) cd there, (d) remember the flags, (e) run the script. Five steps no /mikko-help ever tells you about.

This skill closes that loop. Once installed (via install-mikko.sh one time on a fresh machine), /mikko-install lets you add the next skill, update everything after a git pull, or remove a skill — all without leaving the chat.

The chicken-and-egg of "you need install to install" is solved by install-mikko.sh being the bootstrap (one-time bash invocation), after which this skill is the steady-state installer (slash command from any session).

Token expectations

~3–5K tokens per typical invocation:

• Source probe + verification: ~1K (Glob + existence checks)
• Action dispatch: ~1K (bash invocation + capture)
• Summary print: ~1K

Run /mikko-skill-usage for measured numbers after a few invocations.

Cadence: once at machine setup, then a handful of times per year when new skills land or you want to update.

Freshness check

Staleness checks run by /mikko-skills-freshness on any change to this skill — they assert the skill's load-bearing pieces still ship / stay documented. See that skill for the check vocabulary.

[[check]]
kind = "file_contains"
path = "SKILL.md"
pattern = "install-mikko\\.sh"

[[check]]
kind = "file_contains"
path = "SKILL.md"
pattern = "--dry-run"