Borrowing it
Nothing to install: this file belongs to ZenlixAI/echo-mcp. 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/ZenlixAI/echo-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/ZenlixAI/echo-mcpWrote 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/zenlixai/echo-mcp/agents-md)<a href="https://agentmods.dev/instructions/zenlixai/echo-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/zenlixai/echo-mcp/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/zenlixai/echo-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/zenlixai/echo-mcp/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 | $0.01979 | $0.01979 |
| Opus 5.5 | $0.00792 | $0.00792 |
| Sonnet 5.5 | $0.00396 | $0.00396 |
| Haiku 4.5 | $0.00198 | $0.00198 |
Grade A, and why
echo-mcp 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 — 136 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Echo MCP Agent Map
This file is a map for AI coding agents working in this repository. It is not the full product spec, and it is not a rigid workflow document. Use it to orient yourself quickly, identify the source of truth, and avoid making changes in the wrong layer.
Purpose
This repository implements Echo MCP: an MCP server for session-scoped schema registration, schema discovery, and payload echo with validation.
The server's job is narrow:
- register schemas for the current session
- list and inspect schemas
- validate payloads against a selected schema
- return valid payloads unchanged inside a stable envelope
It is not a business workflow engine, not a renderer, and not a state machine framework.
Source Of Truth
The primary source of truth for product and protocol behavior is docs/design-doc.md.
Treat that document as authoritative for:
- tool surface area
- protocol envelope shape
- error semantics
- session scoping rules
- schemaless behavior
- non-goals and design boundaries
Critical rule:
- If a requested change conflicts with
docs/design-doc.md, do not directly change code to satisfy it. - First confirm the change with the user.
- Only after explicit user confirmation should
docs/design-doc.mdbe updated. - After the design doc is updated, align implementation and tests with the new design.
If code and docs/design-doc.md diverge, assume the design doc is correct unless the user explicitly approves changing it.
Project Map
Core implementation files:
- index.ts: process entrypoint, creates the server and starts listening
- src/server.ts: MCP server assembly and tool registration
- src/echo-service.ts: session-scoped registry and protocol-level behavior
- src/json-schema-zod.ts: JSON Schema subset to Zod conversion and validation error mapping
- tests/echo-service.test.ts: protocol and behavior regression tests
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 · 136 lines · 1,979 tokens per session scan A bce31d229308
echo-mcp AGENTS.md is an instructions file published in the GitHub repository ZenlixAI/echo-mcp (8 stars, last pushed 6mo ago), licensed MIT. It adds 1,979 tokens to every session, about $0.0079 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 2026-08-31.
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.