Use nfr-spec

Sweep a feature or system through the full non-functional requirements catalog

Sweep a feature or system through the full non-functional requirements catalog — performance, throughput, availability, durability, privacy/retention, accessibility, i18n, observability, operability, compatibility, cost — forcing every category to a measurable target, an explicit n/a, or a tagged default.

Reach for it when the user needs NFRs, quality attributes, "how fast/reliable does it need to be", SLO targets for a feature, or the requirements everyone forgets until they're incidents.

Install it

npx skilldrop-cli install nfr-spec                 # Claude Code, your user folder
npx skilldrop-cli install nfr-spec --project       # Claude Code, this repo
npx skilldrop-cli install nfr-spec --ide cursor    # or kiro, codex, antigravity, copilot

It is part of the Solution architect pack: --pack solution-architect installs it with its neighbours.

Ask for it

Say it the way you would to a colleague. Requests like these route to it:

• "What are the non-functional requirements for this service?"
• "Sweep the NFRs — latency, availability, privacy, accessibility, operability"
• "Set performance and availability targets for this feature"
• "We keep forgetting the -ilities; give me the full NFR ledger"

Requests like these belong to a different skill, so it shouldn't answer them:

• "Write the functional requirements and user stories"
• "Draft the OpenAPI contract for this service"
• "Design the dashboards, SLOs, and alerts we should build"

If another skill answers instead, ask for this one by name: "use nfr-spec".

Check what you get

A good result:

• Every category lands in one of three states — target, n/a-with-reason, or tagged default. The ledger shows all of them; silence fails the doc.
• Every target has a percentile, a load condition, and a verification. A latency number without load is a screenshot of a quiet day.
• Availability matches the down-for-an-hour answer, not the marketing instinct. The cost of each extra nine is named when the target exceeds the archetype default.
• Every data class has a retention period and a deletion mechanism. "Indefinite" is written as the decision it is.
• Accessibility names level and scope — "WCAG 2.2 AA on all agent-facing screens, axe + manual screen-reader pass" — not "accessible".
• Cost has a number at target volume, or a tagged [assumption] placeholder that explicitly hands the sizing to capacity-cost-model. Either way the line is present — an NFR spec that's silent on cost has delegated it to the first invoice.

Use something else when

• Functional requirements — that's prd-draft
• Security threat depth — one posture line here, the analysis is threat-model
• Designing the architecture that meets the targets — design-doc
• Writing the verification tests themselves — hand the methods to test-plan-generator

Where a loop runs it

• Stage constrain of the design loop

Next

• SKILL.md, the instructions the agent reads
• Its page on the site
• Related: capacity-cost-model, design-doc, prd-draft, test-plan-generator, threat-model

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