composer-core

composer-core is a cursor rule for Cursor from madebyaris/cursor-composer-rules. It costs 1,777 tokens per session, scanned A, original, MIT.

A set of always-on rules for continuing and building software work in small, demonstrable steps.

In plain words
What is it for?
It is for starting features, fixing problems, choosing between designs, and handing off runnable work.
Why use it?
It helps the agent keep track of the intended outcome, avoid unnecessary questions, and show when a change works.

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/madebyaris/cursor-composer-rules/composer-core
Clone the repo
git clone --depth 1 https://github.com/madebyaris/cursor-composer-rules

Made for: Cursor.

Wrote this? Show the measurements

A badge for your README with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them.

agentmods badge for composer-core

README.md
[![agentmods](https://agentmods.dev/badge/rules/madebyaris/cursor-composer-rules/composer-core.svg)](https://agentmods.dev/rules/madebyaris/cursor-composer-rules/composer-core)
Per session 1,777 This file is loaded in full into every session.
When invoked 1,777 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.01777 $0.01777
Opus 5 $0.00889 $0.00889
Sonnet 5 $0.00355 $0.00355
Haiku 4.5 $0.00178 $0.00178

Measured 3d ago against content hash 753b8b917a01, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

composer-core 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 3d 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.

.cursor/rules/composer-core.mdc · 137 lines

How it starts

The opening of the file, as written. The whole thing — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Composer core

How to build and continue an app, in priority order. These principles override habits and shortcuts. Tuned for Cursor Grok 4.6 and Grok 4.5; same contract on Composer.

1. Intent + mode

Read for the outcome, not the literal words. Name what would prove this works, then pick a mode:

Mode When
Continue Follow-up refining open work — default when the thread has unfinished work
Build New feature or vertical slice
Fix Broken or unexpected behavior
Decide Architectural fork; plan or one decisive question
  • Follow the thread. Turn N usually steers work in progress, not a greenfield. Default to continuing unless the user clearly changes direction ("new task", "forget that", "start over").
  • Watch for the X-Y problem. They ask for Y because they think it solves X — reconcile when Y is awkward.
  • Don't re-ask answered constraints. Proceed and state assumptions inline.
  • Build / Continue: before the first edit, one sentence of acceptance — "The user can X and see Y." That is the slice until it is true.

2. Confusion weight

Default: infer, state the assumption in one line, act. Ask only when weight is high. Details and phrasing: clarify-first.

Weight Examples Action
Low Naming, local style, which nearby util Decide silently
Medium Plausible default exists in the repo State assumption, act
High Irreversible/destructive; contract-changing (schema, auth, public API, persisted formats); contradictory cues; no repo signal and a wrong guess wastes real work Ask one decision-linked question

3. Evidence over assumption

Before claiming, doing, or recommending: read the code, run the command, check the output. Never guess what a function does, what a test asserts, or that an API exists. If you cannot get evidence, say so. Intent inference is not a license to invent.

4. Read before you write

Read the full file on GitHub · 137 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. 3d ago First seen · 137 lines · 1,777 tokens per session scan A 753b8b917a01

Subscribe to this mod's changes

composer-core is a cursor rule published in the GitHub repository madebyaris/cursor-composer-rules (3 stars, last pushed 15d ago), licensed MIT. It adds 1,777 tokens to every session, about $0.0089 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.