Migrate Core Code to Submodules
tinyhumansai/openhuman
Plans and carries out moving non-host-specific code and its tests from the OpenHuman core into vendored tiny submodule libraries, then releases the submodule and re-pins the host.
Manage Git worktrees for parallel Claude Code development. An agent skill from jamesrochabrun/skills.
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install jamesrochabrun/skills git-worktrees --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/git-worktrees .claude/skills/git-worktrees && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .claude/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktreesType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install jamesrochabrun/skills git-worktrees --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/git-worktrees .agents/skills/git-worktrees && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .agents/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install jamesrochabrun/skills git-worktrees --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/git-worktrees .cursor/skills/git-worktrees && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .cursor/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/jamesrochabrun/skills.git --path skills/git-worktrees--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install jamesrochabrun/skills git-worktrees --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/git-worktrees .gemini/skills/git-worktrees && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .gemini/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install jamesrochabrun/skills git-worktreesInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/git-worktrees .github/skills/git-worktrees && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .github/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add jamesrochabrun/skills --skill git-worktrees -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install jamesrochabrun/skills git-worktrees --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jamesrochabrun/skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/git-worktrees .opencode/skills/git-worktrees && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "git-worktrees" agent skill from https://github.com/jamesrochabrun/skills/tree/main/skills/git-worktrees into .opencode/skills/git-worktrees/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "git-worktrees", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
git-worktreesManage Git worktrees for parallel Claude Code development. An agent skill from jamesrochabrun/skills.
Git Worktrees is an agent skill from jamesrochabrun/skills. Manage Git worktrees for parallel Claude Code development. Use this skill when engineers ask to "create a worktree", "run parallel Claude sessions", "work on multiple features simultaneously", or need help with worktree management.
Its SKILL.md is about 4.2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 9 other files, including scripts and reference files (for example `references/best_practices.md`, `references/slash_command_template.md` and `references/worktree_commands.md`).
It sits in Development, covering Git worktrees. The licence is MIT.
10 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 2482c17. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Ships 4 files in scripts/ (Shell), which the agent can run.
Shell commands in SKILL.md call:
gitFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md. Its commands use git, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Git Worktrees loads about 4.2k tokens when it runs, and up to ~12k if it reads all its reference files. Until then it costs about 61 tokens; SKILL.md has 1,358 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
The full file from jamesrochabrun/skills at commit 2482c17, republished under its MIT licence (© jamesrochabrun). 1,358 words, ~4,183 tokens.
.claude/skills/git-worktrees/SKILL.md (or your agent's skills folder). This skill also uses 7 other files; get the full folder from GitHub.Run multiple Claude Code sessions in parallel on different branches using Git worktrees. This skill provides simple scripts and workflows to set up, manage, and clean up worktrees, enabling true parallel development without conflicts.
Why Worktrees?
Just run the interactive script:
scripts/create_worktree.shThis will:
That's it! The script handles all complexity.
scripts/list_worktrees.shShows a clean, formatted list of all your worktrees with their branches and status.
scripts/cleanup_worktrees.shInteractive removal of merged or abandoned worktrees.
Scenario: You want Claude to build feature A while you work on feature B.
Steps:
Create worktree for feature A:
scripts/create_worktree.sh
# Enter: feature-a
# Script creates: ../repo-feature-a/Open Claude Code in the new worktree:
/init to orient ClaudeGive Claude the task:
"Build the user authentication feature with OAuth support"Continue your work in main:
When both are done, merge:
# Review Claude's work
cd ../repo-feature-a
git log
# If good, merge back
git checkout main
git merge feature-a
# Clean up
scripts/cleanup_worktrees.shScenario: You want Claude to refactor a large module while you continue development.
Steps:
Create refactor worktree:
scripts/create_worktree.sh
# Enter: refactor-auth-moduleStart Claude in refactor worktree:
"Refactor the authentication module to use dependency injection"Continue your daily work in main:
Review and integrate when ready:
cd ../repo-refactor-auth-module
git log --oneline
# Review changes
# Merge when satisfied
git checkout main
git merge refactor-auth-moduleScenario: You want 3 Claude instances working on different features simultaneously.
Steps:
Create 3 worktrees:
scripts/create_worktree.sh # feature-api-endpoints
scripts/create_worktree.sh # feature-ui-dashboard
scripts/create_worktree.sh # feature-email-notificationsOpen 3 Claude Code sessions:
../repo-feature-api-endpoints/../repo-feature-ui-dashboard/../repo-feature-email-notifications/Assign tasks to each Claude:
Monitor progress:
scripts/list_worktrees.shMerge features as they complete:
# Feature by feature
git checkout main
git merge feature-api-endpoints
git merge feature-ui-dashboard
git merge feature-email-notifications
# Clean up
scripts/cleanup_worktrees.shScenario: Production bug needs immediate fix while Claude is working on a feature.
Steps:
Claude is already working in a feature worktree
Create hotfix worktree from main:
scripts/create_worktree.sh
# Enter: hotfix-login-bug
# Choose base branch: mainFix the bug yourself or with another Claude session:
cd ../repo-hotfix-login-bug
# Make fixes
git add .
git commit -m "Fix login redirect bug"Merge hotfix to main:
git checkout main
git merge hotfix-login-bug
git push origin mainSync feature worktree with latest main:
cd ../repo-feature-xyz
scripts/sync_worktree.sh
# Merges latest main into feature branchInteractive worktree creation with all the right defaults.
What it does:
Usage:
scripts/create_worktree.sh
# Prompts:
# Feature name: my-feature
# Base branch (default: main):
#
# Creates: ../repo-my-feature/
# Branch: my-featureAdvanced usage:
# Create from specific branch
scripts/create_worktree.sh --base develop
# Specify location
scripts/create_worktree.sh --dir ~/worktrees/my-featureShows all active worktrees with status.
Output:
╔════════════════════════════════════════════════╗
║ Active Git Worktrees ║
╚════════════════════════════════════════════════╝
📁 Main Worktree
Path: /home/user/project
Branch: main
Status: clean
📁 Feature Worktrees
Path: /home/user/project-feature-api
Branch: feature-api
Status: 2 uncommitted changes
Path: /home/user/project-refactor
Branch: refactor-auth
Status: cleanInteractive cleanup of old worktrees.
Features:
Usage:
scripts/cleanup_worktrees.sh
# Output:
# Found 3 worktrees
#
# 1. feature-api (merged to main) - Safe to remove
# 2. feature-dashboard (not merged) - Keep
# 3. old-experiment (not merged, 30 days old) - Consider removing
#
# Which worktrees to remove? (1,3): 1Keep worktree up-to-date with main branch.
What it does:
Usage:
# From within a worktree
cd ../repo-feature-api
scripts/sync_worktree.sh
# Or specify worktree
scripts/sync_worktree.sh ../repo-feature-apiWhen you open a new Claude Code session in a worktree, always run /init first:
/initThis ensures Claude:
/init to orient Claudegit log or file watchingGood names:
feature-user-auth ✅refactor-api-layer ✅hotfix-login-bug ✅experiment-new-db ✅Bad names:
test ❌ (too vague)wt1 ❌ (meaningless)fixes ❌ (unclear)Recommended format:
<type>-<short-description>
Types:
- feature-*
- refactor-*
- hotfix-*
- experiment-*
- review-*Recommended layout:
~/projects/
└── myapp/ # Main worktree (main branch)
├── myapp-feature-api/ # Feature worktree
├── myapp-refactor-auth/ # Refactor worktree
└── myapp-hotfix-bug/ # Hotfix worktreeThe scripts default to creating worktrees as siblings to your main directory with a naming pattern: <repo>-<branch-name>.
✅ Use worktrees when:
❌ Don't use worktrees for:
git checkout)Problem: Feature branches can get out of date with main.
Solution: Regularly sync worktrees:
# Option 1: Use the sync script
cd ../repo-feature-api
scripts/sync_worktree.sh
# Option 2: Manual sync
cd ../repo-feature-api
git fetch origin
git merge origin/mainRecommended frequency:
Quick status of all worktrees:
scripts/list_worktrees.shRegular cleanup (weekly):
scripts/cleanup_worktrees.shFind stale worktrees:
# Worktrees with old commits
git worktree list | while read path branch commit; do
cd "$path"
last_commit=$(git log -1 --format=%cr)
echo "$branch: Last commit $last_commit"
doneCause: Branch name has invalid characters
Solution: Use alphanumeric + hyphens only:
# Bad
feature/my_feature ❌
# Good
feature-my-feature ✅Cause: Worktree directory was manually deleted
Solution: Prune worktree references:
git worktree pruneCause: Didn't run /init after opening worktree
Solution: Always run /init when starting Claude in a new worktree:
/initCause: Changes in worktree conflict with main
Solution 1: Resolve conflicts manually:
cd ../repo-feature-api
git fetch origin
git merge origin/main
# Fix conflicts in editor
git add .
git commit -m "Merge main and resolve conflicts"Solution 2: If you want to discard worktree changes and restart:
cd ../repo-feature-api
git fetch origin
git reset --hard origin/main
# Start feature overCause: Branch exists in multiple worktrees
Solution: You can't have the same branch checked out in multiple worktrees. Create a new branch:
scripts/create_worktree.sh
# Use a different branch nameCause: Git worktrees share the .git directory, but files are duplicated
Solution 1: Clean up old worktrees:
scripts/cleanup_worktrees.shSolution 2: For large repos, use sparse-checkout:
git -C ../repo-feature-api sparse-checkout set src/ tests/Create a /worktree command for Claude Code. See references/slash_command_template.md for the complete setup.
Usage after setup:
/worktree feature-new-apiClaude will:
Worktrees are local only, but you can share the workflow:
Share branch, not worktree:
cd ../repo-feature-api
git push origin feature-api
# Teammate creates their own worktree
git worktree add ../repo-feature-api feature-apiDocument your worktree structure in team docs
Use consistent naming across team
For large repos:
Use sparse-checkout (only checkout files you need):
git -C ../repo-feature-api sparse-checkout init
git -C ../repo-feature-api sparse-checkout set src/ tests/Use worktree prune regularly:
git worktree pruneLimit concurrent worktrees to 3-5 for best performance
| Task | Command |
|---|---|
| Create new worktree | scripts/create_worktree.sh |
| List all worktrees | scripts/list_worktrees.sh |
| Clean up worktrees | scripts/cleanup_worktrees.sh |
| Sync with main | scripts/sync_worktree.sh |
| Manual create | git worktree add ../path branch-name |
| Manual list | git worktree list |
| Manual remove | git worktree remove ../path |
| Prune references | git worktree prune |
Setup:
# Create API worktree
scripts/create_worktree.sh
# Name: feature-api
# Create UI worktree
scripts/create_worktree.sh
# Name: feature-uiExecution:
../repo-feature-api: "Build REST API for user management"../repo-feature-ui: "Create React UI for user management"Merge:
git checkout main
git merge feature-api
git merge feature-ui
scripts/cleanup_worktrees.shScenario: Need to review PR while Claude works on feature
Setup:
# Claude is working in feature worktree
# You need to review PR #123
scripts/create_worktree.sh
# Name: review-pr-123
# Base: pr-branch-nameExecution:
../repo-review-pr-123../repo-feature-xyzCleanup:
# After review
scripts/cleanup_worktrees.sh
# Select review-pr-123Scenario: Want to try a radical refactor without breaking current work
Setup:
scripts/create_worktree.sh
# Name: experiment-new-architectureExecution:
../repo-experiment-new-architectureDecision:
# If experiment succeeded
git checkout main
git merge experiment-new-architecture
# If experiment failed
scripts/cleanup_worktrees.sh
# Delete experiment worktree (no harm done)scripts/cleanup_worktrees.sh every Fridayscripts/list_worktrees.sh to see what's active/worktree commandGit worktrees enable true parallel development with Claude Code:
✅ Run multiple Claude sessions without conflicts ✅ Switch contexts instantly without stashing ✅ Experiment safely without breaking main ✅ Simple scripts handle all complexity ✅ Clean workflows for common scenarios
Get started:
scripts/create_worktree.shThat's it! The scripts make worktrees simple and practical.
© jamesrochabrun, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
SKILL.md and 7 other files (scripts, references) in skills/git-worktrees of jamesrochabrun/skills.
Open the folder on GitHubat commit 2482c17
Git Worktrees next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Git Worktrees this skilljamesrochabrun/skills | 215 | — | ~4.2k | Automated safety check: Pass | MIT | |
| Migrate Core Code to Submodulestinyhumansai/openhuman | 41k | — | ~2.6k | Automated safety check: Pass | GPL-3.0 | |
| Nagentdavidondrej/skills | 4.1k | — | ~1.7k | Automated safety check: Notes | MIT | |
| Git Worktree IsolationjnMetaCode/superpowers-zh | 8.3k | 1 repos | ~982 | Automated safety check: Pass | MIT | |
| WorktreeAgentsMesh/AgentsMesh | 2.4k | — | ~553 | Automated safety check: Notes | Custom licence | |
| Cursor Composer Task DelegateChachamaru127/claude-code-harness | 3.2k | — | ~4.4k | Automated safety check: Notes | MIT |
tinyhumansai/openhuman
Plans and carries out moving non-host-specific code and its tests from the OpenHuman core into vendored tiny submodule libraries, then releases the submodule and re-pins the host.
davidondrej/skills
Launch a new bb worker thread with the right project, model, worktree, and task brief.
jnMetaCode/superpowers-zh
Sets up an isolated workspace before feature work or plan execution, preferring native worktree tools and falling back to git worktree, with instructions in Chinese.
AgentsMesh/AgentsMesh
Creates or reuses an isolated AgentsMesh Git worktree from a verified base branch, preserves existing changes, and optionally starts the worktree-scoped development environment.
Chachamaru127/claude-code-harness
Hands one implementation task to Cursor Composer in an isolated git worktree, then reviews its diff and cherry-picks the result into the main branch.
k8zdev/k8z
Automate git worktree creation and copy private files (not tracked in git) to new workdirs.
jamesrochabrun/skills
Generate comprehensive Product Requirements Documents (PRDs) for product managers.
jamesrochabrun/skills
This skill should be used when users want to route LLM requests to different AI providers (OpenAI, Grok/xAI, Groq, DeepSeek, OpenRouter) using SwiftOpenAI-CLI.
jamesrochabrun/skills
Plan and execute technical product launches for developer tools, APIs, and technical products.
jamesrochabrun/skills
Generate comprehensive design briefs for design projects. An agent skill from jamesrochabrun/skills.
jamesrochabrun/skills
Generate comprehensive content briefs for writers, ensuring clarity, alignment, and strategic content creation across all formats.
jamesrochabrun/skills
This skill provides comprehensive guidance for implementing advanced SwiftUI animations, transitions, matched geometry effects, and Metal shader integration.
Categories
Manage Git worktrees for parallel Claude Code development. An agent skill from jamesrochabrun/skills. Git Worktrees is an agent skill from jamesrochabrun/skills. Manage Git worktrees for parallel Claude Code development.
Git Worktrees fits situations like: engineers ask to create a worktree; run parallel Claude sessions; work on multiple features simultaneously; need help with worktree management.
Run `npx skills add jamesrochabrun/skills --skill git-worktrees -a claude-code`. Or copy the skill folder (skills/git-worktrees in jamesrochabrun/skills) into .claude/skills/git-worktrees in your project. Claude Code loads it when a task matches its description.
Run `npx skills add jamesrochabrun/skills --skill git-worktrees -a codex`. Or copy the skill folder (skills/git-worktrees in jamesrochabrun/skills) into .agents/skills/git-worktrees in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add jamesrochabrun/skills --skill git-worktrees -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/git-worktrees, .gemini/skills/git-worktrees, .github/skills/git-worktrees and .opencode/skills/git-worktrees in your project.
Going by SKILL.md and its folder, Git Worktrees needs a shell for the scripts in its folder and the command-line tools its instructions call (git). Our summary lists: A Bash shell.
SKILL.md contains no URLs. Its commands use git, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
Git Worktrees is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
About 4.2k tokens (SKILL.md is roughly 17k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 7.8k tokens, read only when the agent opens those files.
Skills that share tags, products or a category with Git Worktrees: Migrate Core Code to Submodules (tinyhumansai/openhuman, 41k stars), Nagent (davidondrej/skills, 4.1k stars), Git Worktree Isolation (jnMetaCode/superpowers-zh, 8.3k stars) and Worktree (AgentsMesh/AgentsMesh, 2.4k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
jamesrochabrun (a GitHub user) maintains it in jamesrochabrun/skills, which has 215 GitHub stars. The repository holds 23 skills in this directory. The repository was last updated on January 14, 2026.
Source: jamesrochabrun/skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.