Customize an upstream skill

This guide takes Anthropic’s skill-creator skill, adapts it to your team’s conventions, and keeps it up to date as Anthropic improves it. It assumes you have a source repo at ~/code/my-skills (see Quick start) and a project ~/code/my-app to test in.

1. Find it

tricks search skill creator --limit 4

skill-creator  anthropics/skills//skills/skill-creator
    Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an e
    [official · licence:unknown · 390.9k installs · ★178.2k]  in 2 catalog(s) · 16 variant(s) · scripts
pr-creator  google-gemini/gemini-cli//.gemini/skills/pr-creator
    …
skill-creator  openai/skills//skills/.system/skill-creator
    Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Codex's capabili
    [official · licence:unknown · 4.3k installs · ★27.6k · Tessl quality 76%]  in 2 catalog(s) · 16 variant(s) · scripts

Two popular skills share the name, and 16 variants exist. The identifier after the name tells them apart. See Discovery for filters such as --license allow and --no-scripts.

2. Check it

tricks info anthropics/skills//skill-creator

skill-creator  github.com/anthropics/skills//skills/skill-creator@main
  …
  trust    official
  licence  Apache-2.0 [allow] via skill-file
  risk     10 script(s); 7 URL reference(s)
  installs 390.9k
  listed   clawhub, skills.sh
  files:
    LICENSE.txt                                          11345
    SKILL.md                                             33168
    …

The full licence check finds Apache-2.0 in the skill’s LICENSE.txt (search showed unknown because it only looks at frontmatter). The skill ships ten scripts; read the ones that matter before you let an agent run them:

tricks view anthropics/skills//skill-creator | glow -
tricks view anthropics/skills//skill-creator scripts/run_eval.py

3. Try it

Try the skill as-is in a project, with a real agent, before you decide to own a copy:

cd ~/code/my-app
tricks try anthropics/skills//skill-creator

trying skill-creator into ~/code/my-app
  claude   ~/code/my-app/.claude/skills/skill-creator (link)
see trials with `tricks list --trials`; remove with `tricks untry skill-creator`

Start your agent in ~/code/my-app and use it. git status in the project stays clean. When you’re done:

tricks untry skill-creator

Remove the trial before you link your own copy: both would be called skill-creator in the same directory, and New Tricks refuses to overwrite one with the other. More in Links and trials.

4. Vendor it

cd ~/code/my-skills
tricks vendor anthropics/skills//skill-creator
git add -A && git commit -m "Vendor skill-creator"

added skill-creator at skills/skill-creator
  upstream github.com/anthropics/skills//skills/skill-creator @ 079fa83de
  licence  Apache-2.0 [allow]
  risk     10 script(s); 7 URL reference(s)
  not committed yet: review and `git commit` when ready; `tricks link skill-creator` to try it

The skill is now in skills/skill-creator/, and tricks.lock records the upstream commit you started from. Commit the vendored copy unchanged first, so your customization is a separate commit you can read later.

5. Customize it

Edit the files like any other code. Here the opening line of SKILL.md points at a new house-style reference:

$EDITOR skills/skill-creator/SKILL.md
$EDITOR skills/skill-creator/references/house-style.md
tricks lint skill-creator
tricks link skill-creator --to ~/code/my-app          # test your version with an agent
git add -A && git commit -m "Point skill-creator at our house style"

For larger changes, start an experiment with tricks experiment start skill-creator@<name> and link it into one project; see Experiments.

Check what you changed relative to upstream at any time:

tricks diff skill-creator base..

--- base/skill-creator/SKILL.md
+++ working/skill-creator/SKILL.md
@@ -27,7 +27,7 @@

 Then after the skill is done (but again, the order is flexible), you can also run the skill description improver, which we have a whole separate script for, to optimize the triggering of the skill.

-Cool? Cool.
+Before you start, read [our house style](references/house-style.md): it covers naming, tone and the review checklist our team uses.

 ## Communicating with the user

6. Later: see what upstream changed

Weeks later, tricks list shows upstream has main next to the skill (from cached state). Fetch and review:

tricks outdated --diff

skill-creator            079fa83de → main
    M SKILL.md
    A scripts/check_links.py
    risk + script scripts/check_links.py
    risk +1 URL(s): https://agentskills.io/specification
--- base/skill-creator/SKILL.md
+++ upstream/skill-creator/SKILL.md
@@ -5,7 +5,7 @@
…
+++ upstream/skill-creator/scripts/check_links.py
@@ -0,0 +1,7 @@
+import sys, pathlib, re
…

Upstream added a script. Read it before you take it: once merged and linked, your agents can run it.

7. Preview and merge

tricks update skill-creator --dry-run     # what will change in your version
tricks update skill-creator

merged       skill-creator → main
    incoming M SKILL.md
    incoming A scripts/check_links.py
    merged   SKILL.md
    updated  scripts/check_links.py
    risk     + script scripts/check_links.py
    risk     +1 URL(s): https://agentskills.io/specification
    merged into the working tree (uncommitted); review with `git diff` and commit (links to the main checkout already load it)

Your house-style line and upstream’s changes are both in the file. Review with git diff, then commit:

git diff
git add -A && git commit -m "Update skill-creator from upstream"

The link in ~/code/my-app follows your main checkout, so the agent there loaded the merged version as soon as update wrote it. You can try it with the agent before you commit.

8. Resolve a conflict

Next time, upstream rewrites the very line you changed. update stops with conflict markers:

tricks update skill-creator

conflicts    skill-creator → main
    incoming M SKILL.md
    CONFLICT SKILL.md (text)
    resolve the conflicts, then run `tricks update --continue` (or `--abort`)

<<<<<<< skill-creator (yours)
Before you start, read [our house style](references/house-style.md): it covers naming, tone and the review checklist our team uses.
=======
Ready? Start by asking the user what the skill should do.
>>>>>>> upstream main

Edit SKILL.md to what you want. Here, keep both lines:

Ready? Start by asking the user what the skill should do.

Before you start, read [our house style](references/house-style.md): it covers naming, tone and the review checklist our team uses.

Then finish and commit:

tricks update --continue
git add -A && git commit -m "Merge upstream opening into skill-creator"

continued    skill-creator → 98225f475
    update completed (uncommitted); review and commit

--continue refuses while conflict markers remain. To back out instead, tricks update --abort restores your version exactly as it was.

9. Confirm your customization survived

tricks diff skill-creator base..

--- base/skill-creator/SKILL.md
+++ working/skill-creator/SKILL.md
@@ -29,6 +29,8 @@

 Ready? Start by asking the user what the skill should do.

+Before you start, read [our house style](references/house-style.md): it covers naming, tone and the review checklist our team uses.
+
 ## Communicating with the user

Your change is now expressed against the new base, and tricks outdated reports all vendored skills are up to date.

10. Optional: contribute it back

If the change would help everyone, offer it upstream. Preview first:

tricks contribute skill-creator --dry-run

skill-creator → github.com/anthropics/skills (branch tricks/skill-creator-1790368223)
 skills/skill-creator/SKILL.md                  | 2 ++
 skills/skill-creator/references/house-style.md | 5 +++++
 2 files changed, 7 insertions(+)

Without --dry-run, New Tricks shows the files that will become public, asks you to confirm, forks the upstream repository with gh, and opens a pull request containing only this skill’s change.

Keep a vendored skill on its current version with update = "pinned", or stop checking it with paused: see update policies.
Ship it: Publishing carries the upstream licence and records provenance for vendored skills.