cursorrules

A set of project rules for storing decisions, plans, deferred work, and evaluations in documents. An ADR is a record of an important technical decision, while a monorepo is one repository containing multiple related projects or packages.

In plain words
What is it for?
Use it to decide where to record architecture decisions, multi-step work, postponed tasks, and retrospectives. It also defines rules for archiving plans, keeping accepted decisions unchanged, and maintaining documentation conventions.
Why use it?
It prevents important decisions and follow-up work from being lost in chat, and keeps project documents organized with consistent names, locations, and status rules.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/juliocbm/beacon-docs/cursorrules
Clone the repo
git clone --depth 1 https://github.com/Juliocbm/beacon-docs

Made for: Cursor.

Per session 1,029 This file is loaded in full into every session.
When invoked 1,029 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin 95% copy Near-identical to another mod 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.

ModelPer sessionOnce invoked
Fable 5 $0.01029 $0.01029
Opus 5 $0.00515 $0.00515
Sonnet 5 $0.00206 $0.00206
Haiku 4.5 $0.00103 $0.00103

Measured yesterday against content hash 4faf1f30b9a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 yesterday.

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.

Origin

This is a copy

95% identical to beacon — 6 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.cursorrules · 46 lines

How it starts

The opening of the file, as written. The whole thing — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Universal rules

  1. One doc = one category. Never duplicate across folders.
  2. Status via folder, never filename. Closed plan → _archive/, never *_DONE.md or *_v2.md.
  3. kebab-case for all filenames. No camelCase, no snake_case, no spaces.
  4. README required in every category folder.
  5. ADRs are append-only. Supersede with a new ADR; never edit an accepted one.
  6. Evaluations are immutable snapshots. To revise, create a new dated file.
  7. Plans archive to _archive/ when done. Move them, never rename.
  8. Generated AI files (this one) must match docs/_meta/convention.md. Run beacon sync after editing the convention.
  9. Don't create folders outside the convention. Run beacon enable <addon> or propose an ADR.

Persistence rule: Decisions live in ADRs, multi-step work lives in plans, deferred work lives in backlog, retrospection lives in evals. Chat memory is session-scoped and lost when the conversation ends. If you find yourself relying on chat memory to track a decision, plan, or follow-up — write the document instead.

Project-specific rules

  • operations/*.guide.md — deploy guides, admin runbooks, troubleshooting. Post-mortems go in evaluations/.

Workflow triggers — when to create documents

These are the conversational signals that should prompt you to create or update Beacon documents. Treat them as imperatives, not suggestions.

  • Design decision made → write an ADR before implementing. Decisions about architecture, dependencies, naming conventions, or future flexibility belong in adr/. Run beacon new adr <slug>. Draft the ADR inline; don't ask permission to write it.
  • Multi-step work agreed (3+ distinct actions) → write a plan with checkbox steps. Run beacon new plan <slug> and write bite-sized steps. Check off each step in the same commit that completes it. Don't keep multi-step work only in chat memory.
  • Scope deferred → capture it as a backlog item immediately. When the user says "let's do that later", "out of scope for now", "maybe v0.5", or similar, run beacon new todo <slug> and write the why plus acceptance criteria. Don't let deferred work live only in conversation.
  • Release shipped or milestone reached → write a dated retrospective eval. Run beacon new eval <slug>-retrospective and capture what worked, what didn't, what you'd do differently. Even a 10-line eval is better than zero.
  • Approach explained twice → write a pattern doc. If you find yourself explaining the same technical approach across multiple files or sessions, run beacon new pattern <slug> and capture it in reference/.
  • System structure changed → update or add an architecture doc. New module, new layer, new external dependency that affects how the system is shaped — that goes in architecture/.

Read the full file on GitHub · 46 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.

  1. yesterday First seen · 46 lines · 1,029 tokens per session scan A 4faf1f30b9a4

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository Juliocbm/beacon-docs (6 stars, last pushed 3mo ago), licensed MIT. It adds 1,029 tokens to every session, about $0.0051 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to beacon, differing in 6 lines, and is treated as a copy.