_base-rat

A planning rule based on the Riskiest Assumption Test: list assumptions, rank their risks, and check the most dangerous one before coding. Understanding the request always comes first.

In plain words
What is it for?
Use it when planning tasks of standard or high complexity, especially before starting implementation.
Why use it?
It reduces the chance of spending time building on a wrong interpretation or an untested key assumption.

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/dmitryprg-ai/cursor-develop-autorules/_base-rat
Clone the repo
git clone --depth 1 https://github.com/dmitryprg-ai/cursor-develop-autorules

Made for: Cursor.

Per session 68 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 806 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin unknown 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 $0.00068 $0.00806
Opus 5 $0.00034 $0.00403
Sonnet 5 $0.00014 $0.00161
Haiku 4.5 $0.00007 $0.00081

Measured 2d ago against content hash 98a9872d5ae3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

_base-rat scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

| 1 | API возвращает нужные поля | 🔴 HIGH | ✅ curl проверил |
.cursor/rules/_base-rat.mdc · 97 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 2d ago First seen · 97 lines · 68 tokens per session scan A 98a9872d5ae3

Subscribe to this mod's changes

_base-rat is a cursor rule published in the GitHub repository dmitryprg-ai/cursor-develop-autorules (9 stars, last pushed 5mo ago), with no licence file. It adds 68 tokens to every session and 806 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.