What Are Claude Skills? How to Install Them From GitHub (PowerPoint Skill Tested)

Claude skills are folders of instructions that Claude opens on its own when your request matches them: each one has a name, a description, the steps to follow and, optionally, scripts. You install Claude skills in Claude Code with two terminal commands that pull Anthropic's skills from GitHub, then Claude loads the right skill only when a task needs it. Below we explain how skills work, install one from GitHub, and run the PowerPoint (pptx) skill for real on a sales spreadsheet.

Tested on October 8, 2026 with Claude Code 2.1.293 on Linux. The figures in the file are sample data, not any company's real revenue. The test was run with non-English content: the request and the generated deck are in Vietnamese, so the screenshots show Vietnamese text.

Watch the real test run (3 min 45 s, Vietnamese narration): https://youtu.be/wDorAILWYxo

Key results

• Install: two commands added Anthropic's document-skills plugin to Claude Code, enabled only for the project folder.
• Speed: from sending the request to a finished bao-cao-q3.pptx took about 2 minutes 10 seconds.
• Output: a 6-slide deck with a native PowerPoint column chart (editable data, not a pasted image).
• Self-check: the skill's validation passed ("All validations PASSED"); Claude then rendered the slides, found 3 line-wrapping problems on slides 2, 4 and 6, and fixed them on its own.
• Accuracy: every figure in the deck matched the source CSV when we re-added them by hand.

What are Claude skills?

A Claude skill is a folder that must contain a SKILL.md file:

• The top of the file holds name and description: what the skill does and when to use it.
• The rest is the detailed instructions: steps, caveats, how to check the result.
• It can also include a scripts/ folder, reference documents and templates.

Claude does not read every skill up front. It loads them in three layers:

1. Discovery: at startup it only reads each skill's name and description.
2. Activation: when your request matches a description, Claude reads the full SKILL.md.
3. Execution: bundled scripts and resources are used only when needed.

You can also call a skill directly with /skill-name in Claude Code. Unlike a prompt you paste every time, a skill stays on your machine and is reused on every later task. If you want to write your own instead of installing one, see how to create a Claude skill with skill-creator.

Where to find Claude skills on GitHub

Anthropic publishes a public skill repository on GitHub: github.com/anthropics/skills. These Anthropic skills come in two main groups:

• document-skills: four skills for Word (docx), PDF (pdf), PowerPoint (pptx) and Excel (xlsx) files. These four are source-available, not open source.
• example-skills: sample skills for design, development, internal communication, creating new skills and more, under the Apache 2.0 license.

According to the repository README, the document skills are already available in the Claude apps on paid plans. The skill format is also an open standard (agentskills.io): OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI and other tools can read the same skill folder, although support differs from tool to tool.

How to install Claude skills from GitHub in Claude Code

In a terminal, run two commands:

claude plugin marketplace add anthropics/skills
claude plugin install document-skills@anthropic-agent-skills --scope project

• The first command adds the anthropics/skills repository to Claude Code's marketplaces, under the name anthropic-agent-skills.
• The second installs the document-skills plugin. --scope project enables it only in the current folder: Claude Code writes enabledPlugins to that folder's .claude/settings.json.

You can do the same from inside Claude Code: type /plugin marketplace add anthropics/skills, then /plugin install document-skills@anthropic-agent-skills. To remove it later, run claude plugin uninstall document-skills@anthropic-agent-skills.

Where Claude Code skills you write yourself go

Skills you write yourself need no marketplace. Put the folder at ~/.claude/skills/<skill-name>/SKILL.md to use it in every project, or at .claude/skills/<skill-name>/ for a single project.

Claude pptx skill test: six slides from a CSV file

The test folder held doanh-thu-q3.csv with 9 rows: revenue and order counts for 3 branches (District 1, District 3, Thu Duc) in July, August and September. The request sent to Claude Code (in Vietnamese) asked it to use the pptx skill to build a 6-slide Vietnamese deck summarizing third-quarter revenue for the three branches, with one column chart of monthly revenue, saved as bao-cao-q3.pptx.

What appeared in the terminal, in order:

1. Loading the skill: Claude called document-skills:pptx and reported "Successfully loaded skill".
2. Checking available libraries: there was no icon library on the machine, so Claude used colored circles with branch codes (Q1, Q3, TĐ) instead of installing more packages.
3. Writing a script: it created tao-bao-cao.js, over 300 lines, using the pptxgenjs library to build each slide and the chart.
4. Checking itself: it ran the skill's validation step ("All validations PASSED"), then rendered every slide to an image to review it.
5. Fixing itself: on the first review Claude found 3 line-wrapping problems on slides 2, 4 and 6, fixed the script, and the second check passed.

From sending the request to finishing took about 2 minutes 10 seconds. This session had Claude Code's auto mode on, so the commands Claude ran were approved by that mode instead of asking each time.

Result: six slides with a native PowerPoint chart

bao-cao-q3.pptx contains a title slide, a Q3 overview (four key figures), a monthly revenue chart, a comparison of the three branches, growth from July to September, and conclusions with recommendations.

• The chart is a native PowerPoint chart, not a pasted image, so you can edit the data after opening the file.
• The figures match the source file (we re-added them by hand): total revenue of 3,065 million VND in the sample data, 23,950 orders, 23.1% growth from July to September; District 1 accounts for 44.2%, District 3 for 31.2%, Thu Duc for 24.6%.
• The recommendations on the last slide were written by the AI from sample data. With real figures, a person should still review them.

For the spreadsheet side of the same skill set, see our Claude Excel (xlsx) skill test.

What you need to run the pptx skill yourself

According to the pptx skill's SKILL.md, the machine needs:

• Claude Code with the document-skills plugin installed as above.
• Node.js and the pptxgenjs library to build the PowerPoint file.
• Python with the libraries the skill uses to read and check files (such as defusedxml and markitdown).
• LibreOffice and pdftoppm (Poppler) to convert slides to PDF and images during the self-check.

In this test, the libraries were installed in the working folder before sending the request, so Claude did not have to install unfamiliar packages on its own.

Is it safe to install Claude skills?

• Skills and plugins can run code on your machine with your account's permissions. Claude Code's security documentation advises installing only what you trust, since Anthropic does not control what third-party plugins contain.
• Read before you use it: SKILL.md, the scripts, and any hook commands the plugin ships.
• Plugins can update themselves, so what you reviewed may change later.

Looking for more to try? We are ranking the Claude skills we tested.

Frequently asked questions

What are Claude skills?

A Claude skill is a folder with a SKILL.md file that holds a name, a description and step-by-step instructions, and can also include scripts, reference documents and templates. Claude reads only the name and description at startup and loads the full skill when your request matches it.

How do I install Claude skills in Claude Code?

Run claude plugin marketplace add anthropics/skills, then claude plugin install document-skills@anthropic-agent-skills --scope project. Skills you write yourself go in ~/.claude/skills/<skill-name>/ or in a project's .claude/skills/<skill-name>/.

Are Claude skills free?

A skill itself is just a folder of text and scripts: writing one costs nothing, and the anthropics/skills repository is free to download. Using a skill requires Claude, though: according to the repository README, the document skills are available in the Claude apps on paid plans, and in Claude Code you install them as shown above.

How is a skill different from a prompt?

A prompt has to be pasted every time. A skill stays on your machine, Claude loads it automatically when your request matches its description, and it can include runnable scripts, such as the PowerPoint skill's file check.

Can Claude skills be used with Codex or Copilot?

The skill format is an open standard (agentskills.io). OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI and other tools can read skill folders, but support and installation differ by tool.

How do I remove an installed skill?

Run claude plugin uninstall document-skills@anthropic-agent-skills. To switch it off temporarily, use claude plugin disable.