Patch Skill

Patch Skill

When you have improved a skill you installed from another repo, this skill guides you through contributing that improvement back to the source via a pull request.

When to use

• You modified a skill (global ~/.agents/skills/<name>/ or repo-internal .agents/skills/<name>/) and want to send the improvement upstream
• The skill was installed from a public repo tracked in skills-lock.json

Do NOT use for repo-native skills under this repo's skills/<name>/ — if you're the author here, this repo IS the source.

Source repository scope (required)

Only update files under the source repo's canonical skills tree:

<repo-root>/skills/<skill-name>/
  SKILL.md
  scripts/          ← include when changed
  …                 ← any other files in that skill folder

Rules:

• Always map upstream paths to skills/<skill-name>/…, even when skills-lock.json skillPath points at .agents/skills/… or another layout in the consumer repo.
• Never update .agents/skills/, duplicate trees, or paths outside skills/<skill-name>/ in the source repository.
• Include every changed file under that skill folder (e.g. scripts/*.mjs), not only SKILL.md.
• Never include SKILL.local.md — local augmentations stay local.

Derive paths:

Steps

1. Identify the skill(s) to patch

From context or ask the user. Look up origin using the cyber-skills CLI, which checks the repo-local lock, the global lock, and npx skills find in order:

npx cyber-skills@<version> skill source <skill-name>

Output is JSON: { name, source, sourceUrl, skillPath, foundIn }. Extract source (owner/repo).

If the CLI exits non-zero (foundIn: null), fall back to reading the lockfiles directly:

# Repo-local (committed, version 1 schema):
jq '.skills["<skill-name>"]' skills-lock.json

# Global (version 3 schema, has sourceUrl):
jq '.skills["<skill-name>"]' ~/.agents/.skill-lock.json

If there is still no lock entry, ask for owner/repo and the skill folder name.

For multiple related skills (user confirms one PR), repeat file discovery for each skills/<name>/ directory.

2. Find the local skill directory

Collect files to contribute (exclude SKILL.local.md):

find "<local-dir>" -type f ! -name 'SKILL.local.md' | sort

3. Diff against source

For each local file, map to skills/<skill-name>/<relative-path> and compare to upstream on the default branch.

List upstream skill folder (optional sanity check):

gh api "repos/<owner>/<repo>/contents/skills/<skill-name>?ref=<default-branch>" \
  --jq '.[] | .path'
# If scripts/ exists, list nested files too:
gh api "repos/<owner>/<repo>/contents/skills/<skill-name>/scripts?ref=<default-branch>" \
  --jq '.[]? | .path' 2>/dev/null

Per-file diff:

UPSTREAM="skills/<skill-name>/SKILL.md"
gh api "repos/<owner>/<repo>/contents/${UPSTREAM}" --jq '.content' | base64 -d > /tmp/upstream.md
diff /tmp/upstream.md "<local-dir>/SKILL.md"

• No diffs across all mapped files → nothing to contribute; stop
• Any diff → show unified diffs and get user confirmation before proceeding

4. Check write access

gh api repos/<owner>/<repo> --jq '{push: .permissions.push, default: .default_branch}'

• push: true → branch on owner/repo
• push: false → gh repo fork <owner>/<repo> --clone=false, then use <your-username>/<repo>

5. Create branch and push (single commit — Git Data API)

Use the Git Data API so all files land in one commit. Do not use PUT /contents/{path} per file (that creates one commit per file).

Set variables:

OWNER=<owner>
REPO=<repo>
REPO_FULL="${OWNER}/${REPO}"
DEFAULT_BRANCH=main   # from step 4
BRANCH="patch/<skill-name>-<short-slug>"   # or shared slug for multi-skill PR
MSG="fix(<skill-name>): <description>"
SKILL_NAME=<skill-name>
LOCAL_DIR="<absolute-local-skill-dir>"

5a. Create branch ref from default branch tip

BASE_SHA=$(gh api "repos/${REPO_FULL}/git/refs/heads/${DEFAULT_BRANCH}" --jq '.object.sha')
BASE_TREE=$(gh api "repos/${REPO_FULL}/git/commits/${BASE_SHA}" --jq '.tree.sha')

gh api "repos/${REPO_FULL}/git/refs" \
  --method POST \
  --field ref="refs/heads/${BRANCH}" \
  --field sha="${BASE_SHA}"

If the branch already exists, skip creation and set BASE_SHA to the branch tip instead (for amending, prefer a fresh branch).

5b. Create blobs and tree entries for each local file

Build a JSON array of tree items. Each local file maps to skills/${SKILL_NAME}/<relative-path>.

Use temp files for --input, not inline $(jq …). Embedding file content in the shell argument hits ARG_MAX and fails with errors like file name too long on typical SKILL.md sizes.

TREE_ITEMS='[]'
while IFS= read -r -d '' file; do
  rel="${file#${LOCAL_DIR}/}"
  upstream_path="skills/${SKILL_NAME}/${rel}"

  jq -n --rawfile content "$file" '{content: $content, encoding: "utf-8"}' > /tmp/patch-blob-input.json
  blob_sha=$(gh api "repos/${REPO_FULL}/git/blobs" \
    --method POST \
    --input /tmp/patch-blob-input.json \
    --jq '.sha')

  TREE_ITEMS=$(jq -n \
    --argjson items "$TREE_ITEMS" \
    --arg path "$upstream_path" \
    --arg sha "$blob_sha" \
    '$items + [{path: $path, mode: "100644", type: "blob", sha: $sha}]')
done < <(find "$LOCAL_DIR" -type f ! -name 'SKILL.local.md' -print0)

Repeat the loop for additional skills in the same PR (append to TREE_ITEMS with each skill's SKILL_NAME and LOCAL_DIR).

5c. Create tree, commit, update branch ref

Write tree and commit payloads to temp files as well (large multi-skill TREE_ITEMS can also exceed shell limits):

jq -n \
  --arg base "$BASE_TREE" \
  --argjson tree "$TREE_ITEMS" \
  '{base_tree: $base, tree: $tree}' > /tmp/patch-tree-input.json
NEW_TREE=$(gh api "repos/${REPO_FULL}/git/trees" \
  --method POST \
  --input /tmp/patch-tree-input.json \
  --jq '.sha')

jq -n \
  --arg msg "$MSG" \
  --arg tree "$NEW_TREE" \
  --arg parent "$BASE_SHA" \
  '{message: $msg, tree: $tree, parents: [$parent]}' > /tmp/patch-commit-input.json
COMMIT_SHA=$(gh api "repos/${REPO_FULL}/git/commits" \
  --method POST \
  --input /tmp/patch-commit-input.json \
  --jq '.sha')

gh api "repos/${REPO_FULL}/git/refs/heads/${BRANCH}" \
  --method PATCH \
  --field sha="${COMMIT_SHA}"

Result: exactly one commit on the patch branch containing all updated paths under skills/<skill-name>/.

6. Open PR

gh pr create \
  --repo "${REPO_FULL}" \
  --base "${DEFAULT_BRANCH}" \
  --head "${BRANCH}" \
  --title "fix(<skill-name>): <description>" \
  --body "$(cat <<'EOF'
## Summary

<what changed and why — only under `skills/<skill-name>/`>

## Test plan

- [ ] Run audit-skill / `audit validate` against the updated skill(s)
- [ ] Confirm no files outside `skills/` were modified

🤖 Generated with [Claude Code](https://claude.com/claude-code)
EOF
)"

7. Report

Output the PR URL. After merge, run npx skills update in the consumer repo to refresh skills-lock.json hashes.

What NOT to do

• Do not include SKILL.local.md content in the PR
• Do not push without showing diffs and getting user confirmation
• Do not create a PR if every mapped file is identical to upstream
• Do not update .agents/skills/ or any path outside skills/<skill-name>/ in the source repo
• Do not use Contents API PUT per file (multi-commit noise); use Git Data API (section 5)