Borrowing it
Nothing to install: this file belongs to chevyphillip/system-designer-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/chevyphillip/system-designer-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/chevyphillip/system-designer-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/chevyphillip/system-designer-mcp/agents-md)<a href="https://agentmods.dev/instructions/chevyphillip/system-designer-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/chevyphillip/system-designer-mcp/agents-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 5.1 | $0.00648 | $0.00648 |
| Opus 5 | $0.00324 | $0.00324 |
| Sonnet 5 | $0.00130 | $0.00130 |
| Haiku 4.5 | $0.00065 | $0.00065 |
Grade A, and why
system-designer-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 6d 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 — 26 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository Guidelines
Project Structure & Module Organization
Source lives in src/ organised into types.ts (model contracts), schemas.ts, tools.ts, integration/, transformers/, validators/. CLI at src/cli.ts, worker entry src/worker.ts, local server src/index.ts. Tests under test/ mirroring source directories with *.test.ts. Docs in docs/, runnable examples in examples/, automation in scripts/, compiled assets emitted to dist/.
Build, Test, and Development Commands
Use Bun for everything. bun install seeds dependencies. bun run dev launches the stdio MCP server with watch reload. bun run dev:worker spins up Wrangler for the Cloudflare Worker. bun run build emits Node targets to dist/; bun run build:worker creates the browser bundle consumed by Workers. bun test runs the Bun test suite (bun test --watch for rapid feedback). Quality gates: bun run lint, bun run lint:fix, bun run format, and bun run format:check. Deploy the worker with bun run deploy.
Coding Style & Naming Conventions
TypeScript strictness is enforced via ESLint + @typescript-eslint (see eslint.config.js). Follow Prettier defaults: 2-space indentation, semicolons, single quotes, 100-char line width, trailing commas where valid. Prefer named exports and keep files cohesive to their domain (transformers, validators, integration). Branch prefixes mirror change intent (feature/*, fix/*, docs/*). Use descriptive entity IDs and tool names aligned with the MCP schema.
Testing Guidelines
Place tests in test/ mirroring the source path (e.g., src/validators/system-runtime.ts → test/validators/system-runtime.test.ts). Write Bun tests with describe/test from bun:test, favouring behaviour-focused descriptions. Target ≥95% coverage for new logic and include regression assertions for model/system runtime conversions. Run bun test before PRs and bun run dev:worker when touching Worker paths to confirm SSE behaviour.
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.
- 6d ago First seen · 26 lines · 648 tokens per session scan A 42a3e4dfed10
system-designer-mcp AGENTS.md is an instructions file published in the GitHub repository chevyphillip/system-designer-mcp (2 stars, last pushed 11mo ago), licensed MIT. It adds 648 tokens to every session, about $0.0032 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.
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