copywriting

A set of writing rules for text that users read, such as interface labels, error messages, landing pages, emails, and changelogs. It uses the product's existing brand voice and terminology records.

In plain words
What is it for?
Use it to write or revise interface copy, messages, marketing pages, posts, release notes, advertisements, and emails while keeping wording consistent and accurate.
Why use it?
Product text can become inconsistent, unclear, or filled with invented facts when each piece is written separately. These rules require checking the approved voice, terms, facts, and action names first.

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/ssheleg/super-ux/copywriting
Clone the repo
git clone --depth 1 https://github.com/ssheleg/super-ux
Per session 59 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 774 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00059 $0.00774
Opus 5 $0.00030 $0.00387
Sonnet 5 $0.00012 $0.00155
Haiku 4.5 $0.00006 $0.00077

Measured 2d ago against content hash ce426497d0bc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

copywriting 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.

cursor/rules/copywriting.mdc · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

copywriting — write it in the product's own voice

brand-voice decides how the product speaks. This is the pass that writes in it. The two are not interchangeable: defining a voice mid-sentence to finish a button is how a product ends up with six voices.

First action, every time

Read the pack: docs/brand/voice.md, terminology.md, and the channels.md record for the surface being written. No pack? Stop and run /brand-init. Guessing the voice and being wrong costs more than the pause.

Never write to docs/brand/. A term missing from the dictionary, or a number with no row in facts.md, is reported — never invented to finish the sentence. Adding it is brand-voice's decision, not this pass's.

Rules that hold in every voice

  • Every figure comes from facts.md. No sourced fact, no number. Never fabricate a statistic, a quote, or an expert.
  • One action keeps one name across button, confirmation, toast, history, notification and accessible name. Search strings.md before naming one.
  • No humor, exclamation marks or emoji on error, destructive confirm, billing or paywall surfaces — including in a playful voice.
  • Errors say what happened and how to recover, in the user's words, and never blame the user.
  • A register is a delta on the voice axes, never a crossing of the invariants recorded in voice.md.
  • Every new interface string gets a strings.md row: key, file:line, and the scenario it serves. A string with no scenario is a candidate for deletion, not translation.
  • Claims reach a consequence. "AI-powered" is a mechanism; what the user stops doing is the copy.

The any-other-SaaS test

Could this sentence sit unchanged on a competitor's page? Then it says nothing. Rewrite it until it could not.

Machine-made tells to strip: tricolons that add nothing, "seamless / effortless / unlock / elevate / robust", em-dash cadence in every paragraph, "it's not just X, it's Y", hedges stacked two deep, and a closing sentence that summarizes what was just said.

Read the full file on GitHub · 66 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 · 66 lines · 59 tokens per session scan A ce426497d0bc

Subscribe to this mod's changes

copywriting is a cursor rule published in the GitHub repository ssheleg/super-ux (2 stars, last pushed 2d ago), licensed MIT. It adds 59 tokens to every session and 774 once invoked, about $0.0003 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.