mcp-builder

mcp-builder is a skill for Claude Code, Codex from danielw-sudo/skill-quiver. It costs 71 tokens per session (542 once invoked), scanned A, original, no licence file.

A guide for building MCP servers, which are small services that give AI agents access to extra tools or outside systems. It covers tool design, required input types, testing, and keeping secrets in environment settings.

In plain words
What is it for?
Use it to create an MCP server, add tools for an AI agent, or connect an agent to an API such as Claude.
Why use it?
It helps avoid unclear tool names, missing input rules, and accidentally putting passwords or API keys in code. It also focuses the build on requests to connect an agent to an API or add new agent tools.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/danielw-sudo/skill-quiver/mcp-builder
Any agent
npx skills add danielw-sudo/skill-quiver --skill mcp-builder
Clone the repo
git clone --depth 1 https://github.com/danielw-sudo/skill-quiver

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for mcp-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/danielw-sudo/skill-quiver/mcp-builder.svg)](https://agentmods.dev/skills/danielw-sudo/skill-quiver/mcp-builder)
Your own site
<a href="https://agentmods.dev/skills/danielw-sudo/skill-quiver/mcp-builder"><img src="https://agentmods.dev/badge/skills/danielw-sudo/skill-quiver/mcp-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 542 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00071 $0.00542
Opus 5 $0.00036 $0.00271
Sonnet 5 $0.00014 $0.00108
Haiku 4.5 $0.00007 $0.00054

Measured 4d ago against content hash 502662ae9d63, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-builder 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 4d 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.

code/tools/mcp-builder/SKILL.md · 48 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Changes

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.

  1. 4d ago First seen · 48 lines · 71 tokens per session scan A 502662ae9d63

Subscribe to this mod's changes

mcp-builder is a skill published in the GitHub repository danielw-sudo/skill-quiver (2 stars, last pushed 2mo ago), with no licence file. It adds 71 tokens to every session and 542 once invoked, about $0.0004 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 2026-08-31.

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