A small set of project rules for a FastAPI server that is being used to learn the Model Context Protocol, a standard for connecting AI models to tools. The rules also say not to edit the README file.

Use it to guide changes to this FastAPI and MCP learning project, especially when refactoring for readability or adding simple features.

It keeps development focused on a simple, readable learning project rather than production-level completeness. It records the project's current scope and constraints for the coding agent.

How jverre/chrome-mcp-server configures Cursor

Reuse

Borrowing it

Nothing to install: this file belongs to jverre/chrome-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/jverre/chrome-mcp-server/main/.cursorrules

Clone the repo

git clone --depth 1 https://github.com/jverre/chrome-mcp-server

Made for: Cursor.

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.

README.md

[![agentmods](https://agentmods.dev/badge/rules/jverre/chrome-mcp-server/cursorrules/github.svg)](https://agentmods.dev/rules/jverre/chrome-mcp-server/cursorrules)

Your own site

<a href="https://agentmods.dev/rules/jverre/chrome-mcp-server/cursorrules"><img src="https://agentmods.dev/badge/rules/jverre/chrome-mcp-server/cursorrules/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.

Your own site · 80×15

<a href="https://agentmods.dev/rules/jverre/chrome-mcp-server/cursorrules"><img src="https://agentmods.dev/badge/rules/jverre/chrome-mcp-server/cursorrules.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 138 This file is loaded in full into every session.

When invoked 138 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00138	$0.00138
Opus 5.5	$0.00055	$0.00055
Sonnet 5.5	$0.00028	$0.00028
Haiku 4.5	$0.00014	$0.00014

Measured 2mo ago against content hash 1827910e9456, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cursorrules 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 2mo 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.

.cursorrules · 12 lines

What it actually says

Don't edit the README.md file.

We are using FastAPI to build the server.

Development rules

The goal of this project is to learn about the MCP protocol and how it works, it is not to write a production ready server. As such, always focus on simplicity and readability over performance and completeness. This also means we do not need to follow all best-practices and instead focus on having just a small number of files that are easy to understand.

Let's refactor the code to make it more readable and easier to understand. For now, we are implementing just a simple tool that retruns the input to the user. We will focus on adding more features later.

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.

2mo ago First seen · 12 lines · 138 tokens per session scan A 1827910e9456

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository jverre/chrome-mcp-server (4 stars, last pushed 1y ago), licensed MIT. It adds 138 tokens to every session, about $0.0006 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.

cursorrules next to 6 cursor rules from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
cursorrulesjverre/chrome-mcp-server	Cursor rule	4	1y ago	MIT	A	138	Cursor
ponytailDietrichGebert/ponytail	Cursor rule	185k	8d ago	MIT	A	604	Cursor
angular-20angular/angular	Cursor rule	101k	yesterday	MIT	A	0	Cursor
dev-standardapache/superset	Cursor rule	75k	yesterday	Apache-2.0	A	1,147	Cursor
prefer-assertions-over-defensive-checksprisma/orm	Cursor rule	48k	yesterday	Apache-2.0	A	0	Cursor
prefer-direct-imports-over-module-mocksprisma/orm	Cursor rule	48k	yesterday	Apache-2.0	A	0	Cursor
shared-plane-packagesprisma/orm	Cursor rule	48k	yesterday	Apache-2.0	A	0	Cursor

chrome-mcp-server: Cursor rule for Cursor