mcaf-nfr

A guide for defining non-functional requirements: qualities such as accessibility, reliability, scalability, maintainability, performance, and compliance. These describe how a feature should work, beyond what it does.

In plain words
What is it for?
Capturing quality requirements for a feature or architecture change, documenting trade-offs, and linking those expectations to tests and operational plans.
Why use it?
It turns vague goals such as “fast” or “secure” into clear expectations. It helps keep requirements, architecture decisions, documentation, and tests aligned.

Skill for Claude CodeCodex

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 skills/managedcode/mcpgateway/mcaf-nfr
Any agent
npx skills add managedcode/MCPGateway --skill mcaf-nfr
Clone the repo
git clone --depth 1 https://github.com/managedcode/MCPGateway

Made for: Claude Code, Codex.

Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 795 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod 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 $0.00042 $0.00795
Opus 5 $0.00021 $0.00398
Sonnet 5 $0.00008 $0.00159
Haiku 4.5 $0.00004 $0.00080

Measured 2d ago against content hash 241bca30ea97, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcaf-nfr 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 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.

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.

Origin

This is a copy

86% identical to dotnet-mcaf-nfr — 25 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.codex/skills/mcaf-nfr/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCAF: Non-Functional Requirements

Trigger On

  • a feature or architecture change needs explicit quality attributes
  • a team is using vague words like "fast", "reliable", or "secure" without measurable meaning
  • docs, ADRs, and tests are out of sync on quality expectations

Value

  • produce a concrete project delta: code, docs, config, tests, CI, or review artifact
  • reduce ambiguity through explicit planning, verification, and final validation skills
  • leave reusable project context so future tasks are faster and safer

Do Not Use For

  • generic architecture or feature writing with no quality-attribute decision
  • loading all NFR references at once

Inputs

  • the changed feature, boundary, or rollout path
  • the quality attributes that materially affect it
  • current docs, ADRs, tests, and ops expectations

Quick Start

  1. Read the nearest AGENTS.md and confirm scope and constraints.
  2. Run this skill's Workflow through the Ralph Loop until outcomes are acceptable.
  3. Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

  1. Decide which quality attributes materially affect the change.
  2. Turn vague goals into explicit requirements, constraints, or testable expectations.
  3. Link NFRs to feature docs, ADRs, and verification when they affect design or rollout.
  4. Use only the specific reference files that match the active quality attribute.

Deliver

  • explicit NFRs for the changed area
  • docs or ADRs that describe measurable quality attributes
  • better alignment between architecture, testing, and operations

Validate

  • each chosen NFR is measurable or at least falsifiable
  • the selected attributes are the ones that actually drive design trade-offs
  • verification and operational expectations are linked where needed

Ralph Loop

Use the Ralph Loop for every task, including docs, architecture, testing, and tooling work.

  1. Plan first (mandatory):
    • analyze current state
    • define target outcome, constraints, and risks
    • write a detailed execution plan
    • list final validation skills to run at the end, with order and reason
  2. Execute one planned step and produce a concrete delta.
  3. Review the result and capture findings with actionable next fixes.
  4. Apply fixes in small batches and rerun the relevant checks or review steps.
  5. Update the plan after each iteration.
  6. Repeat until outcomes are acceptable or only explicit exceptions remain.
  7. If a dependency is missing, bootstrap it or return status: not_applicable with explicit reason and fallback path.

Read the full file on GitHub · 93 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. 2d ago First seen · 93 lines · 42 tokens per session scan A 241bca30ea97

Subscribe to this mod's changes

mcaf-nfr is a skill published in the GitHub repository managedcode/MCPGateway (5 stars, last pushed 2d ago), licensed MIT. It adds 42 tokens to every session and 795 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to dotnet-mcaf-nfr, differing in 25 lines, and is treated as a copy.