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 agentmods add instructions/nimblebraininc/mcp-echo/claude-mdgit clone --depth 1 https://github.com/NimbleBrainInc/mcp-echoWrote 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/nimblebraininc/mcp-echo/claude-md)<a href="https://agentmods.dev/instructions/nimblebraininc/mcp-echo/claude-md"><img src="https://agentmods.dev/badge/instructions/nimblebraininc/mcp-echo/claude-md.svg" alt="Measured on agentmods" 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 | $0.00306 | $0.00306 |
| Opus 5 | $0.00153 | $0.00153 |
| Sonnet 5 | $0.00061 | $0.00061 |
| Haiku 4.5 | $0.00031 | $0.00031 |
Grade A, and why
mcp-echo 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- mcp-bash CLAUDE.md — 86% identical, 4 lines differ
What it actually says
Echo MCP Server
FastMCP echo server for testing MCP connections.
Commands
make test # Unit tests
make test-e2e # E2E tests (requires Docker + mcpb CLI)
make check # Format + lint + typecheck + unit tests
make bump VERSION=x.y.z # Bump version in all files
E2E Tests
e2e/ contains end-to-end tests that build and deploy the actual MCPB bundle in a Docker container, then verify health, tool listing, and tool invocation over HTTP.
Prerequisites: Docker running, mcpb CLI installed
The tests automatically vendor Linux-compatible deps (matching the Docker daemon's architecture) using uv pip install --python-platform, so they work on macOS and Linux hosts.
Config: e2e/conftest.py has BASE_IMAGE, PYTHON_VERSION, CONTAINER_PORT, and BUNDLE_NAME.
Release
See mcp-servers/CLAUDE.md for the full release workflow.
make bump VERSION=0.2.0
git add -A && git commit -m "Bump version to 0.2.0"
git tag v0.2.0 && git push origin main v0.2.0
gh release create v0.2.0 --title "v0.2.0" --notes "- changelog"
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.
- 4d ago First seen · 34 lines · 306 tokens per session scan A b42933e0b3da
mcp-echo CLAUDE.md is an instructions file published in the GitHub repository NimbleBrainInc/mcp-echo (1 stars, last pushed 1mo ago), licensed MIT. It adds 306 tokens to every session, about $0.0015 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.
Other instructions, from other repositories
mcp-ipinfo CLAUDE.md
Claude Code instructions for NimbleBrainInc/mcp-ipinfo, covering ipinfo mcp server, architecture, critical, skill resource and userconfig.
mcp-granola CLAUDE.md
Claude Code instructions for NimbleBrainInc/mcp-granola, covering granola mcp server, architecture, data source, structure and version differences.
maui uitests.instructions.md
Instructions for dotnet/maui, covering ui testing guidelines for .net maui, ui test structure, two-project requirement, base class and infrastructure and naming conventions.
Math-To-Manim tests.instructions.md
Guidelines for writing and maintaining tests in Math-To-Manim.
ios-simulator-skill CLAUDE.md
Instructions for conorluddy/ios-simulator-skill, covering claude.md - developer guide, project overview, project structure, architecture patterns and pattern 1: class-based script design.
antigravity-testing-kit GEMINI.md
Instructions for anhtester/antigravity-testing-kit, covering gemini ai - global automation agent rules, git pull restriction rule, browser rules (mandatory), 🖥️ viewport & mode and 🔄 thứ tự debug bắt buộc (playwright mcp).