Claude Code Plugins Directory is a marketplace containing plugins for Claude Code, including tools, commands, skills, agents, hooks, and model context servers. Claude Code users browse it to install Anthropic-maintained or approved third-party extensions.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add anthropics/claude-plugins-official --skill build-mcp-servergit clone --depth 1 https://github.com/anthropics/claude-plugins-officialWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/anthropics/claude-plugins-official/build-mcp-server)<a href="https://agentmods.dev/skills/anthropics/claude-plugins-official/build-mcp-server"><img src="https://agentmods.dev/badge/skills/anthropics/claude-plugins-official/build-mcp-server/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/anthropics/claude-plugins-official/build-mcp-server"><img src="https://agentmods.dev/badge/skills/anthropics/claude-plugins-official/build-mcp-server.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00111 | $0.02791 |
| Opus 5 | $0.00056 | $0.01396 |
| Sonnet 5 | $0.00022 | $0.00558 |
| Haiku 4.5 | $0.00011 | $0.00279 |
Grade A, and why
build-mcp-server scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
8 near-identical copies found in the catalogue:
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 100% identical, 0 lines differ
- build-mcp-server — 94% identical, 21 lines differ
- build-mcp-server — 94% identical, 13 lines differ
How it starts
The opening of the file, as written. The whole thing — 222 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Build an MCP Server
You are guiding a developer through designing and building an MCP server that works seamlessly with Claude. MCP servers come in many forms — picking the wrong shape early causes painful rewrites later. Your first job is discovery, not code.
Load Claude-specific context first. The MCP spec is generic; Claude has additional auth types, review criteria, and limits. Before answering questions or scaffolding, fetch https://claude.com/docs/llms-full.txt (the full export of the Claude connector docs) so your guidance reflects Claude's actual constraints.
Do not start scaffolding until you have answers to the questions in Phase 1. If the user's opening message already answers them, acknowledge that and skip straight to the recommendation.
Phase 1 — Interrogate the use case
Ask these questions conversationally (batch them into one message, don't interrogate one-at-a-time). Adapt wording to what the user has already told you.
1. What does it connect to?
| If it connects to… | Likely direction |
|---|---|
| A cloud API (SaaS, REST, GraphQL) | Remote HTTP server |
| A local process, filesystem, or desktop app | MCPB or local stdio |
| Hardware, OS-level APIs, or user-specific state | MCPB |
| Nothing external — pure logic / computation | Either — default to remote |
2. Who will use it?
- Just me / my team, on our machines → Local stdio is acceptable (easiest to prototype)
- Anyone who installs it → Remote HTTP (strongly preferred) or MCPB (if it must be local)
- Users of Claude desktop who want UI widgets → MCP app (remote or MCPB)
3. How many distinct actions does it expose?
This determines the tool-design pattern — see Phase 3.
- Under ~15 actions → one tool per action
- Dozens to hundreds of actions (e.g. wrapping a large API surface) → search + execute pattern
4. Does a tool need mid-call user input or rich display?
- Simple structured input (pick from list, enter a value, confirm) → Elicitation — spec-native, zero UI code. Host support is rolling out (Claude Code ≥2.1.76) — always pair with a capability check and fallback. See
references/elicitation.md. - Rich/visual UI (charts, custom pickers with search, live dashboards) → MCP app widgets — iframe-based, needs
@modelcontextprotocol/ext-apps. Seebuild-mcp-appskill. - Neither → plain tool returning text/JSON.
What ships with it
8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 222 lines · 111 tokens per session scan A 088cd04be7f0
build-mcp-server is a skill published in the GitHub repository anthropics/claude-plugins-official (36,026 stars, last pushed yesterday), licensed Apache-2.0. It adds 111 tokens to every session and 2,791 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
data-manager-api-setup
Guides developers through client library installation and authentication setup steps for the Data Manager API. Use this skill when a user is getting started with the Data Manager API and needs to setup their local environment, install the client library, or setup access to the API. Don't use for implementing audience…
workers-best-practices
Cloudflare Workers best practices for production applications. Use when writing, reviewing, or configuring Workers.
new
Create a new project to start development quickly.
skd-edit
A focused editor for 1C data composition schemas, the report definitions that describe queries, fields, filters, totals, and parameters. It changes an existing Template.xml file through specific operations.
skd-info
A structure reader for 1C data composition schemas, the report definitions that contain queries, fields, parameters, and display variants. It gives a compact summary instead of requiring you to read the raw XML.
xdto-validate
A validator for XDTO packages in 1C:Enterprise. It checks the package model, its metadata object, and its connection to the configuration.