mcp CLAUDE.md

mcp CLAUDE.md is an instructions file for coding agents from sirrlock/mcp. It costs 833 tokens per session, scanned A, original, MIT.

A project instruction guide for building the Sirr MCP server, which lets AI assistants access a secret vault through the Model Context Protocol. It documents the TypeScript project, its structure, and five available tools.

In plain words
What is it for?
Use it when developing, testing, formatting, or reviewing the Sirr MCP server and its secret-storage tools.
Why use it?
It gives developers a shared reference for how the server works, what it exposes, and which parts are handled outside the server.

Instructions file

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 instructions/sirrlock/mcp/claude-md
Clone the repo
git clone --depth 1 https://github.com/sirrlock/mcp

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 CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/sirrlock/mcp/claude-md.svg)](https://agentmods.dev/instructions/sirrlock/mcp/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/sirrlock/mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/sirrlock/mcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 833 This file is loaded in full into every session.
When invoked 833 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00833 $0.00833
Opus 5 $0.00417 $0.00417
Sonnet 5 $0.00167 $0.00167
Haiku 4.5 $0.00083 $0.00083

Measured 4d ago against content hash 4d5721c2b964, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp CLAUDE.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 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.

CLAUDE.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

@sirrlock/mcp — Claude Development Guide

Purpose

MCP (Model Context Protocol) server for Sirr — gives AI assistants direct access to the Sirr secret vault. Published to npm as @sirrlock/mcp.

Stack

  • TypeScript, Node 18+
  • @modelcontextprotocol/sdk for MCP protocol
  • Native fetch — no axios, no node-fetch
  • @biomejs/biome for lint + format
  • Jest + ts-jest for tests

Structure

src/
├── index.ts       # MCP server entry: 5 tools, env vars (SIRR_SERVER, SIRR_TOKEN, SIRR_ORG)
└── helpers.ts     # Pure helpers: parseKeyRef, path builders, formatTtl

Tools exposed (5 total)

Tool Description
store_secret With name: org-scoped named secret (requires SIRR_ORG). Without: anonymous dead drop.
read_secret By id: public dead drop. By name: org-scoped (requires SIRR_ORG).
check_secret Metadata check without consuming a read.
share_secret Burn-after-read link via sirrlock.com. No auth needed.
audit Query the audit log.

Everything else (webhooks, keys, orgs, roles, principals) is CLI/web-only — not exposed via MCP.

Routing semantics

  • store_secret without namePOST /secrets (public dead drop). Returns {id}.
  • store_secret with namePOST /orgs/{SIRR_ORG}/secrets (org-scoped). Returns {key, id}. 409 if name exists.
  • read_secret with idGET /secrets/{id} (public).
  • read_secret with nameGET /orgs/{SIRR_ORG}/secrets/{name} (org-scoped).
  • share_secretPOST {SIRRLOCK_URL}/api/public/secret (sirrlock.com hosted).

Key Rules

  • Never log or echo secret values in tool output
  • SIRR_ORG env var is required for named secrets (store/read by name) and audit
  • SIRR_TOKEN = master key for full access, or a principal key for org-scoped access
  • check_secret does NOT consume a read — safe to call freely
  • Tool descriptions tell Claude not to memorize or repeat retrieved secret values
  • store_secret with a name returns 409 Conflict if the name already exists

Read the full file on GitHub · 84 lines

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 · 84 lines · 833 tokens per session scan A 4d5721c2b964

Subscribe to this mod's changes

mcp CLAUDE.md is an instructions file published in the GitHub repository sirrlock/mcp (0 stars, last pushed 14d ago), licensed MIT. It adds 833 tokens to every session, about $0.0042 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 2026-09-01.

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