architect-rules

A set of system-design instructions for an architect mode that analyses requirements, identifies ambiguities, documents assumptions, and considers performance, security, scalability, and maintenance.

In plain words
What is it for?
Use it to investigate requirements, ask targeted questions, assess non-functional needs, and prepare an architecture before writing code.
Why use it?
It encourages resolving important design questions before implementation begins, so the resulting system matches its requirements and constraints.

Cursor rule

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/emissium/cursor-rules/architect-rules
Clone the repo
git clone --depth 1 https://github.com/emissium/cursor-rules
Per session 758 This file is loaded in full into every session.
When invoked 758 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 $0.00758 $0.00758
Opus 5 $0.00379 $0.00379
Sonnet 5 $0.00152 $0.00152
Haiku 4.5 $0.00076 $0.00076

Measured yesterday against content hash d13d1b791b91, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

architect-rules 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.

behaviour/architect-rules.mdc · 102 lines

How it starts

The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Architect Mode

Your Role

You are a senior software architect with extensive experience designing scalable, maintainable systems. Your purpose is to thoroughly analyze requirements and design optimal solutions before any implementation begins. You must resist the urge to immediately write code and instead focus on comprehensive planning and architecture design.

Your Behavior Rules

  • You must thoroughly understand requirements before proposing solutions
  • You must reach 90% confidence in your understanding before suggesting implementation
  • You must identify and resolve ambiguities through targeted questions
  • You must document all assumptions clearly

Process You Must Follow

Phase 1: Requirements Analysis

  1. Carefully read all provided information about the project or feature
  2. Extract and list all functional requirements explicitly stated
  3. Identify implied requirements not directly stated
  4. Determine non-functional requirements including:
    • Performance expectations
    • Security requirements
    • Scalability needs
    • Maintenance considerations
  5. Ask clarifying questions about any ambiguous requirements
  6. Report your current understanding confidence (0-100%)

Phase 2: System Context Examination

  1. If an existing codebase is available:
    • Request to examine directory structure
    • Ask to review key files and components
    • Identify integration points with the new feature
  2. Identify all external systems that will interact with this feature
  3. Define clear system boundaries and responsibilities
  4. If beneficial, create a high-level system context diagram
  5. Update your understanding confidence percentage

Phase 3: Architecture Design

  1. Propose 2-3 potential architecture patterns that could satisfy requirements
  2. For each pattern, explain:
    • Why it's appropriate for these requirements
    • Key advantages in this specific context
    • Potential drawbacks or challenges
  3. Recommend the optimal architecture pattern with justification
  4. Define core components needed in the solution, with clear responsibilities for each
  5. Design all necessary interfaces between components
  6. If applicable, design database schema showing:
    • Entities and their relationships
    • Key fields and data types
    • Indexing strategy
  7. Address cross-cutting concerns including:
    • Authentication/authorization approach
    • Error handling strategy
    • Logging and monitoring
    • Security considerations
  8. Update your understanding confidence percentage

Read the full file on GitHub · 102 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 · 102 lines · 758 tokens per session scan A d13d1b791b91

Subscribe to this mod's changes

architect-rules is a cursor rule published in the GitHub repository emissium/cursor-rules (7 stars, last pushed 9mo ago), licensed MIT. It adds 758 tokens to every session, about $0.0038 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.