02-pattern-discovery

A required set of rules for finding existing patterns before writing code. A pattern library is a collection of example approaches for areas such as APIs, interfaces, databases, testing, security, and continuous integration.

In plain words
What is it for?
Use it before implementation to search related specifications, review user stories, find a matching pattern, and inspect the code for similar solutions.
Why use it?
It reduces duplicated work and helps new changes match existing specifications, conventions, and implementations. It requires checking specifications, the pattern library, and the codebase first.

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/bybren-llc/safe-agentic-workflow/02-pattern-discovery
Clone the repo
git clone --depth 1 https://github.com/bybren-llc/safe-agentic-workflow

Made for: Cursor.

Per session 685 This file is loaded in full into every session.
When invoked 685 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 $0.00685 $0.00685
Opus 5 $0.00342 $0.00342
Sonnet 5 $0.00137 $0.00137
Haiku 4.5 $0.00068 $0.00068

Measured 3d ago against content hash 67d6af6d457a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

02-pattern-discovery 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/02-pattern-discovery.mdc · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Pattern Discovery Protocol (MANDATORY)

Before writing ANY code, you MUST complete pattern discovery. This is not optional.

Step 0: Search Specs Directory (FIRST)

# Find similar implementations in specs
ls specs/*-spec.md

# Review SAFe user stories for related work
grep -r "As a.*I want to" specs/

# Check patterns referenced by past specs
cat specs/{{TICKET_PREFIX}}-XXX-similar-spec.md

Step 1: Search Pattern Library

Check patterns_library/ for an existing pattern that fits your use case.

Available categories:

Category Path Contents
API patterns_library/api/ User context, admin, webhooks, Zod
UI patterns_library/ui/ Authenticated pages, forms, tables
Database patterns_library/database/ RLS migration, Prisma transactions
Testing patterns_library/testing/ API integration, E2E user flows
Security patterns_library/security/ Input sanitization, rate limiting
CI patterns_library/ci/ GitHub Actions, deployment pipeline
Config patterns_library/config/ Environment config, logging

See patterns_library/README.md for the full index of 18+ patterns.

Step 2: Search Codebase

# Search for similar functionality
grep -r "feature_name" app/ lib/ components/

# Find existing helpers
ls lib/
grep -r "helper_pattern" lib/

# Check for existing components
grep -r "ComponentName" components/

Step 3: Consult Documentation

Required reading before implementation:

  • CONTRIBUTING.md -- Workflow and git process
  • docs/database/DATA_DICTIONARY.md -- Database schema (SINGLE SOURCE OF TRUTH)
  • docs/database/RLS_IMPLEMENTATION_GUIDE.md -- Row Level Security (MANDATORY for DB ops)
  • docs/security/SECURITY_FIRST_ARCHITECTURE.md -- Security patterns

Step 4: Architectural Validation

Read the full file on GitHub · 85 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 · 85 lines · 685 tokens per session scan A 67d6af6d457a

Subscribe to this mod's changes

02-pattern-discovery is a cursor rule published in the GitHub repository bybren-llc/safe-agentic-workflow (404 stars, last pushed 1mo ago), licensed MIT. It adds 685 tokens to every session, about $0.0034 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 2026-08-30.