mcp-builder

mcp-builder is a cursor rule for Cursor from Treevu-ai/cli-market-world. It costs 28 tokens per session (2,628 once invoked), scanned A, original, no licence file.

A guide for building MCP servers, which are small services that give AI agents extra tools, information sources, or instructions.

In plain words
What is it for?
Designing, building, and testing custom MCP servers with tools, resources, and prompts.
Why use it?
It helps when an AI agent needs capabilities that are not available by default, while also covering how to test the server.

Cursor rule for Cursor

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 rules/treevu-ai/cli-market-world/mcp-builder
Clone the repo
git clone --depth 1 https://github.com/Treevu-ai/cli-market-world

Made for: Cursor.

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/rules/treevu-ai/cli-market-world/mcp-builder.svg)](https://agentmods.dev/rules/treevu-ai/cli-market-world/mcp-builder)
Your own site
<a href="https://agentmods.dev/rules/treevu-ai/cli-market-world/mcp-builder"><img src="https://agentmods.dev/badge/rules/treevu-ai/cli-market-world/mcp-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,628 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 $0.00028 $0.02628
Opus 5 $0.00014 $0.01314
Sonnet 5 $0.00006 $0.00526
Haiku 4.5 $0.00003 $0.00263

Measured 3d ago against content hash acd2b53cd448, 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 3d 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.

.cursor/rules/mcp-builder.mdc · 246 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. 3d ago First seen · 246 lines · 28 tokens per session scan A acd2b53cd448

Subscribe to this mod's changes

mcp-builder is a cursor rule published in the GitHub repository Treevu-ai/cli-market-world (1 stars, last pushed 4d ago), with no licence file. It adds 28 tokens to every session and 2,628 once invoked, about $0.0001 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.