What is the difference between a Claude skill and project instructions?

Project instructions in Claude.ai set the baseline for every conversation in a Project. A skill is a named instruction set you activate for a specific type of task. Project instructions apply always; skills apply when you choose them. In Claude Code, a slash command is equivalent to a skill.

Can multiple people share the same Claude skills?

In Claude.ai, everyone using the same Project shares its skills. In Claude Code, skills in a committed .claude/commands/ folder are available to everyone who clones the repository. In fenbs, any connected assistant can read skills from the Skills and prompts section regardless of which AI app it runs in.

What happens if I delete a skill file in Claude Code?

The slash command disappears from the list. Sessions that have already run with that command are not affected. If you might need the skill again, archive the file rather than deleting it.

Do skills count toward the context window?

Yes. When a skill is active, its instruction text is part of the session context. Keep skills concise to leave more of the context window for the content you are working on.

Claude Skills Cheat Sheet: Files, Setup and Reuse

A quick reference for understanding, organizing and using Claude skills, covering where they live, how they activate and how to keep a team's skill library useful.

September 30, 2026Updated October 21, 20266 min read

Claude skills are saved instruction sets that give a session a specific capability or focus without requiring you to retype the instructions each time. This cheat sheet covers where skills live, how to set them up in Claude.ai and Claude Code, how to activate them, and how to keep a shared library from becoming stale. Tools like fenbs keep the team's chosen skill instructions alongside project context, so any connected assistant can list the current skills and read the full text before starting work.

Where Claude skills live

The location depends on the Claude app you are using.

Where Claude skills are stored by app
App	Where skills live	How to access
Claude.ai	Project settings in a Claude.ai Project	Create or open a Project, go to Project instructions or Skills, and add the skill text
Claude Code	Slash command files in `.claude/commands/` in your project folder	Type `/` in the Claude Code input to list available commands and activate one
fenbs	Skills and prompts section, readable by any connected assistant	Connected AI apps list and read skills via MCP at the start of a session

A skill in Claude.ai is scoped to the Project it belongs to. A skill in Claude Code is scoped to the repository or folder where the command file lives. A skill in fenbs is accessible to every assistant connected to that fenbs project, regardless of which AI app it runs in.

Setting up a skill in Claude.ai

Create a new Project from the Claude.ai sidebar, or open an existing one.
Open the Project settings and find the Skills or Instructions section.
Write or paste your skill instruction text. Give it a clear name that describes the task it enables.
Save the skill. It will be available to all conversations within that Project.
To activate the skill in a conversation, start the conversation inside the Project. The skill is active for the duration of that session.

Setting up a skill in Claude Code

Create a .claude/commands/ folder in your project root if it does not exist.
Add a Markdown file for each skill, for example review-pr.md or check-types.md.
Write the skill instruction text in the file. The filename becomes the slash command name.
In a Claude Code session, type / to list available commands. Select the skill to activate it.
For project-level skills available to everyone on the team, commit the .claude/commands/ folder to version control.

For a full walkthrough of the setup steps, read how to create a Claude skill. For patterns and ready-to-use examples, see claude skills examples. The claude code commands cheat sheet covers the full command reference for Claude Code.

Activating and using skills

In Claude.ai, a skill is active whenever you use the Project it belongs to. You do not need to invoke it explicitly. In Claude Code, you type / followed by the skill name to activate a command. After activation, the skill instruction is added to the session context.

A skill sets up how Claude approaches the work. Your prompt then provides the content to work on. Say you have a "pre-delivery review" skill that checks for clarity and completeness. You activate the skill, then paste the document you want reviewed. The skill handles the checklist; your prompt handles the content.

How fenbs helps

Keep the team's skills in fenbs

fenbs Skills and prompts keeps the approved text for each active skill alongside the project context. When a connected assistant reads the AI context at the start of a session, it can list the available skills and use the current version without checking a project settings panel or file. Update the fenbs entry when the skill changes, and record the reason in Decisions and rules.

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Keeping a shared library useful

A skill library becomes a burden when it grows without maintenance. Each added skill is a choice someone has to make at the start of every relevant session. Keep the library small enough that a team member can scan the list and find the right skill in ten seconds.

One skill per distinct task type. Do not create separate skills for "review" and "check" if they cover the same ground.
Retire skills that no longer match how the team works. Archive the text rather than deleting it, in case the approach is revived.
Update a skill when a review misses something, not when someone has a new idea. Test the updated version before replacing the previous one.
Name skills after their function, not their author. "Pre-launch copy review" is findable. "Anna's checklist" is not.

Common questions at a glance

Quick answers to common Claude skills questions
Question	Answer
Can I use the same skill in Claude.ai and Claude Code?	The content can be the same; the storage differs. Keep the approved text in fenbs and copy it into each app's settings.
Do skills persist across conversations?	In Claude.ai, skills persist within a Project across all conversations in that Project. In Claude Code, a command file persists until it is changed or deleted.
Can a skill call another skill?	No. Skills are independent instruction sets. If you need both, activate each one separately or combine the instructions into a single skill.
How long should a skill be?	Short enough to read in under a minute and specific enough to produce consistent results. If you need more than a page, split it into two focused skills.

How to do this with fenbs

Use fenbs as the single source of truth for the team's approved skill text, separate from any one app's settings.

Create a free account and add a project for your team's work.
Add each active skill to fenbs Skills and prompts with its name, the approved instruction text, and a note on when to use it.
Connect Claude, Claude Code or another supported app via /integrations. Connected assistants can list and read skills from fenbs at the start of a session.
When a skill changes, update the fenbs entry and record the reason for the change in Decisions and rules.
Review the skills list each quarter. Retire skills that are no longer active and update ones that have drifted from the current process.

When fenbs is not needed

If you work alone and use Claude only in one app, storing skills in that app's project settings is sufficient. fenbs adds value when skills need to be available across multiple AI apps, shared with team members, or reviewed as part of a change decision. See claude projects vs skills vs artifacts for help choosing the format that fits your situation.