xmcp is a TypeScript framework for building applications with the Model Context Protocol, a standard for connecting AI models with tools and external context. Developers use it to create MCP-based integrations.
Borrowing it
Nothing to install: this file belongs to basementstudio/xmcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/basementstudio/xmcp/main/AGENTS.mdgit clone --depth 1 https://github.com/basementstudio/xmcpWrote 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/instructions/basementstudio/xmcp/agents-md)<a href="https://agentmods.dev/instructions/basementstudio/xmcp/agents-md"><img src="https://agentmods.dev/badge/instructions/basementstudio/xmcp/agents-md/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/instructions/basementstudio/xmcp/agents-md"><img src="https://agentmods.dev/badge/instructions/basementstudio/xmcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00487 | $0.00487 |
| Opus 5.5 | $0.00195 | $0.00195 |
| Sonnet 5.5 | $0.00097 | $0.00097 |
| Haiku 4.5 | $0.00049 | $0.00049 |
Grade A, and why
xmcp AGENTS.md 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 47 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent guidance - xmcp
This file is the root instruction set for coding agents and contributors. Read
the scoped AGENTS.md file for any area you touch:
packages/AGENTS.mdfor framework, CLI, scaffolder, and plugin packages.examples/AGENTS.mdfor examples.apps/website/AGENTS.mdfor the docs site and website.
Repo basics
- Use Node 22 and pnpm.
- All changes target
main. There is nocanarybranch; canary npm releases are cut frommainas Changesets snapshot releases. - Keep PRs focused. If related work appears while editing, leave it for a follow-up unless it is required for the current fix.
- User-facing feature or behavior changes need docs and a runnable example. If an example is not appropriate, explain why in the PR.
- Prefer existing patterns and helper APIs over new abstractions.
- Do not add dependencies unless the repo already has no reasonable primitive for the job.
Review standards
Apply these before handing work back:
- Use repo formatting and linting, not editor defaults.
- Keep logs minimal. Do not add process narration or debug logs.
- Do not add fixed
setTimeoutorsetIntervalnumbers unless the delay is a named constant with a clear reason. Prefer signal-based flow. - Avoid broad rewrites, especially in compiler, loader, runtime, and scaffold paths.
- Preserve transport semantics. Do not turn stateless HTTP flows into stateful session-based flows, or stateful flows into stateless ones, unless the task explicitly requires that transport contract change.
- Stateless HTTP must not depend on server-side memory from previous requests.
Any client metadata needed by tools after
initializemust be repeated in the current request, not recovered from a hidden session/cache. - Do not force users to wrap every tool, resource, or prompt for a framework feature.
- Keep config fields optional when values can be inferred safely.
- Delete stale examples instead of patching deprecated patterns.
- Explain non-obvious choices in code or PR notes: new hooks, wrappers, required fields, timers, plugin registration, and foundational rewrites.
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.
- 1mo ago First seen · 47 lines · 487 tokens per session scan A 6831a23e6044
xmcp AGENTS.md is an instructions file published in the GitHub repository basementstudio/xmcp (1,342 stars, last pushed today), licensed MIT. It adds 487 tokens to every session, about $0.0019 per session on Opus 5.5. 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 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deno copilot-instructions.md
Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.