openusage: Cursor rule for Claude Code

.cursor/skills/implement-feature.mdc

implement-feature is a cursor rule for Claude Code, Cursor from janekbaraniewski/openusage. It costs 29 tokens per session (203 once invoked), scanned A, original, MIT.

A guided workflow for building a software feature from an existing design document. It requires the design and an approved work plan before coding begins.

In plain words
What is it for?
Use it when a feature has already been designed and needs to be analyzed, coded, tested, and summarized.
Why use it?
It reduces the risk of implementing the wrong requirements or skipping tests, reviews, and integration checks.

Cursor rule for Claude CodeCursor

Written for Claude Code and Cursor: $ARGUMENTS substitution, but also installed under .cursor/.

This is janekbaraniewski/openusage's own configuration. It tells Claude Code and Cursor how to work on openusage itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything openusage configures →

Reuse

Borrowing it

Nothing to install: this file belongs to janekbaraniewski/openusage. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/janekbaraniewski/openusage/main/.cursor/skills/implement-feature.mdc
Clone the repo
git clone --depth 1 https://github.com/janekbaraniewski/openusage

Made for: Claude Code, Cursor.

Wrote 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.

agentmods badge for implement-feature

README.md
[![agentmods](https://agentmods.dev/badge/rules/janekbaraniewski/openusage/implement-feature/github.svg)](https://agentmods.dev/rules/janekbaraniewski/openusage/implement-feature)
Your own site
<a href="https://agentmods.dev/rules/janekbaraniewski/openusage/implement-feature"><img src="https://agentmods.dev/badge/rules/janekbaraniewski/openusage/implement-feature/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for implement-feature

Your own site · 80×15
<a href="https://agentmods.dev/rules/janekbaraniewski/openusage/implement-feature"><img src="https://agentmods.dev/badge/rules/janekbaraniewski/openusage/implement-feature.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 29 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 203 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00029 $0.00203
Opus 5.5 $0.00012 $0.00081
Sonnet 5.5 $0.00006 $0.00041
Haiku 4.5 $0.00003 $0.00020

Measured 1mo ago against content hash b17e1b1f0319, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

implement-feature 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 1mo 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/skills/implement-feature.mdc · 21 lines

What it actually says

@docs/skills/implement-feature/SKILL.md contains the full skill specification. Read and follow it completely.

The user's request is to implement the feature "$ARGUMENTS" from its design doc.

Follow all phases in order:

  1. Phase 0: Load the design doc, extract tasks
  2. Phase 1: Analyze the codebase for affected files
  3. Phase 1.5: Pre-implementation quiz for ambiguities
  4. Phase 2: Present execution plan, wait for approval
  5. Phase 3: Execute tasks with tests, parallel where possible
  6. Phase 4: Integration check (build, test, lint)
  7. Phase 5: Summary of all changes

Do NOT skip loading the design doc. Do NOT code without an approved plan.

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. 1mo ago First seen · 21 lines · 29 tokens per session scan A b17e1b1f0319

Subscribe to this mod's changes

implement-feature is a cursor rule published in the GitHub repository janekbaraniewski/openusage (235 stars, last pushed yesterday), licensed MIT. It adds 29 tokens to every session and 203 once invoked, about $0.0001 per session on Opus 5.5. 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.