ECC is a toolkit that organizes and improves how coding agents work through skills, memory, security checks, research practices, and related extensions. It is for developers using agents such as Claude Code, Codex, OpenCode, and Cursor.
Borrowing it
Nothing to install: this file belongs to affaan-m/ECC. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/affaan-m/ECC/main/.kiro/steering/patterns.mdgit clone --depth 1 https://github.com/affaan-m/ECCWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/affaan-m/ecc/patterns)<a href="https://agentmods.dev/instructions/affaan-m/ecc/patterns"><img src="https://agentmods.dev/badge/instructions/affaan-m/ecc/patterns.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00232 | $0.00232 |
| Opus 5 | $0.00116 | $0.00116 |
| Sonnet 5 | $0.00046 | $0.00046 |
| Haiku 4.5 | $0.00023 | $0.00023 |
Grade A, and why
patterns 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 today.
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.
What it actually says
Common Patterns
Skeleton Projects
When implementing new functionality:
- Search for battle-tested skeleton projects
- Use parallel agents to evaluate options:
- Security assessment
- Extensibility analysis
- Relevance scoring
- Implementation planning
- Clone best match as foundation
- Iterate within proven structure
Design Patterns
Repository Pattern
Encapsulate data access behind a consistent interface:
- Define standard operations: findAll, findById, create, update, delete
- Concrete implementations handle storage details (database, API, file, etc.)
- Business logic depends on the abstract interface, not the storage mechanism
- Enables easy swapping of data sources and simplifies testing with mocks
API Response Format
Use a consistent envelope for all API responses:
- Include a success/status indicator
- Include the data payload (nullable on error)
- Include an error message field (nullable on success)
- Include metadata for paginated responses (total, page, limit)
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.
- today First seen · 38 lines · 232 tokens per session scan A 1c55f367658d
patterns is an instructions file published in the GitHub repository affaan-m/ECC (251,781 stars, last pushed today), licensed MIT. It adds 232 tokens to every session, about $0.0012 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 2026-09-07.
Other instructions, from other repositories
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AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.