Building Plugins

Last verified: 13 February 2026 | Applies to: Pro, Max, Team, Enterprise

In 30 seconds

You have three paths to custom plugins: Plugin Create (Anthropic’s dedicated meta-plugin for building new plugins from scratch), Plugin Customiser (adapt existing plugins to your organisation), or manual construction (for developers who want full control). Plugin Create is the recommended starting point — describe what you want and Claude builds the entire plugin.

Plugin Create

Plugin Create is one of Anthropic’s 11 knowledge-work plugins. Install it from claude.com/plugins or the Cowork interface.

What it does: You describe a plugin in natural language. Claude generates the full structure — manifest, skills, optional scripts — and delivers it as a ZIP ready to install.

How to use it:

1. Install Plugin Create
2. In a Cowork session, describe the plugin you want:

Build me a plugin for client onboarding. It should have a checklist of accounts to set up, our standard welcome email template, and SLA terms as reference data. Include a /onboard slash command.

3. Claude asks clarifying questions
4. Claude generates and delivers the plugin as a ZIP
5. Install: unzip → Cowork tab → Plugins → Upload plugin

Tips for better results

• Be specific about what the plugin should do, who it’s for, and any rules
• Include example outputs if you have them
• Mention if you want slash commands and what they should trigger
• Tell Claude about terminology your team uses

Plugin Customiser

Already using an Anthropic plugin but want it to match your organisation? Plugin Customiser adapts existing plugins.

How to use it:

Customise the Finance plugin: we use AASB standards instead of GAAP. Our fiscal year ends in March. We call reconciliation 'balance review' internally. Our controller is Sarah and she prefers workpapers in a specific format [describe or upload example].

Claude modifies the plugin’s skills and configuration. The customised version replaces the original.

Common customisations:

• Terminology changes (your internal names for processes)
• Standard/framework swaps (GAAP → AASB, US → UK conventions)
• Template modifications (your report formats, your document structures)
• Workflow additions (extra steps specific to your process)

Plugin structure

For operators who want to understand what’s inside:

my-plugin/
  manifest.json          ← Required: plugin metadata and configuration
  skills/
    SKILL.md             ← Required: instructions with YAML frontmatter
    additional-skill.md  ← Optional: additional skills
  scripts/               ← Optional: executable Python/JavaScript
  data/                  ← Optional: reference files, templates

manifest.json — tells Claude the plugin’s name, version, which skills to load, and what slash commands are available.

SKILL.md — the knowledge layer. Markdown instructions with YAML frontmatter (name and description fields required). This is what makes Claude behave like a specialist.

scripts/ — for plugins that need to run code (data processing, API calls, file manipulation).

data/ — reference materials the plugin can access (templates, regulatory documents, lookup tables).

Manual plugin building

For developers who want full control:

1. Create the folder structure above
2. Write your manifest.json with plugin metadata
3. Write SKILL.md files with YAML frontmatter and detailed instructions
4. Add optional scripts and data files
5. ZIP the folder and install via Cowork

The open-source repository contains all 11 Anthropic plugins — study them for structure and patterns.

What to watch out for

• YAML frontmatter is required. SKILL.md files without name and description in the frontmatter won’t be discovered by Claude.
• First attempts may need iteration. Budget time for 1-2 rounds of feedback when using Plugin Create.
• Custom plugins are account-specific. They don’t sync across devices unless provisioned by a Team/Enterprise admin.
• Test with real data. A plugin that looks right structurally may produce poor output. Test against actual tasks.

Related

• Building a Plugin — step-by-step workflow guide
• Skills — how the knowledge layer works independently
• All Plugins

---

Something wrong or outdated? Let us know →

Get weekly workflows — subscribe to the newsletter.