A set of project rules for Cursor, an AI coding editor. It tells the agent which project-status files to read and whether the work uses one or several workstreams, meaning separate areas of work.

Use it at the beginning of a coding session to inspect the project map and status, identify the active workstream, and report the current progress and blocker.

It prevents the agent from starting with the wrong project context or silently choosing the wrong workstream.

cursorrules — Cursor rule for Cursor by Ethan-YS/project-brain

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.

Clone the repo

git clone --depth 1 https://github.com/Ethan-YS/project-brain

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/ethan-ys/project-brain/cursorrules/github.svg)](https://agentmods.dev/rules/ethan-ys/project-brain/cursorrules)

Your own site

<a href="https://agentmods.dev/rules/ethan-ys/project-brain/cursorrules"><img src="https://agentmods.dev/badge/rules/ethan-ys/project-brain/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/ethan-ys/project-brain/cursorrules"><img src="https://agentmods.dev/badge/rules/ethan-ys/project-brain/cursorrules.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 827 This file is loaded in full into every session.

When invoked 827 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	$0.00827	$0.00827
Opus 5.5	$0.00331	$0.00331
Sonnet 5.5	$0.00165	$0.00165
Haiku 4.5	$0.00083	$0.00083

Measured 10d ago against content hash 2604a624e025, 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 10d 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.

templates/.cursorrules · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

[Project Name] — Cursor Rules

This is the project-level instruction file for Cursor.

Layered above your global Cursor rules.

Write only what's specific to THIS project here.

First 30 seconds of a new session

Decide single- or multi-workstream (look at file naming under brain/):

Only STATUS.md / HANDOFF.md → single-workstream branch
Multiple STATUS_<workstream>.md → multi-workstream branch (v2.1)

Single-workstream (default)

Must read (under brain/):

brain/MAP.md — project map
brain/STATUS.md — current state
brain/HANDOFF.md if it exists — previous session's still-warm thoughts

Then briefly report: project recognized + current progress + last blocker. Don't silently start working — confirm understanding first.

Multi-workstream (v2.1)

First read shared files: brain/MAP.md + brain/PROJECT.md. Don't guess this window's workstream — use explicit signals only (the window is named for a workstream, e.g. web-6, or the user said so); otherwise ask: "I see this is a multi-workstream project with [list workstreams]. Which one does this window work on?" Then read brain/STATUS_<workstream>.md + brain/HANDOFF_<workstream>.md. Concurrent windows (v2.8 — MAP §6 has a "Who's on it now" roster): also check other workstreams' STATUS for requests to yours still marked sent. Once the user confirms and work begins, write this window's name + date into your workstream's roster row (that cell only, committed alone) and say so.

If the user switches workstreams mid-session, re-read the new one's files and don't carry over memory.

Update responsibility

The AI never silently modifies a file in brain/ (tiered trust, METHODOLOGY §4.1): STATUS / HANDOFF / mechanical MAP registrations — write after the work lands, then announce what was written; DECISIONS / PROJECT / structural MAP changes — propose, then user approves.

Judgment division:

The user decides "should we record now" (high-level pacing)
The AI decides "specifically what to record / how to write each entry"
The user has approval/rejection authority

Read the full file on GitHub · 61 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.

10d ago Changed · +3 lines · +221 tokens per session 2604a624e025
1mo ago First seen · 58 lines · 606 tokens per session scan A 68bc96891e40

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository Ethan-YS/project-brain (173 stars, last pushed 11d ago), licensed MIT. It adds 827 tokens to every session, about $0.0033 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 2026-08-30.

Claude Code ai-assistant ai-coding ai-pair-programming context-management cursor

cursorrules