What is prompt-writer?

A packaged version of the Prompt Writer method for creating instructions for large language models. It includes metadata describing the add-on and its focus on prompts for agents, assistants, and repeatable tasks.

Use it when you need the Prompt Writer add-on for system prompts, agent prompts, prompt templates, or other LLM instructions.

It gives the prompt-writing method a distributable add-on format, making it easier to use as part of Claude-related tooling. The supplied information does not describe additional behavior beyond that method.

prompt-writer — Plugin for Claude Code by Londeren/claude-plugins

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.

Clone the repo

git clone --depth 1 https://github.com/Londeren/claude-plugins

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/londeren/claude-plugins/prompt-writer/github.svg)](https://agentmods.dev/plugins/londeren/claude-plugins/prompt-writer)

Your own site

<a href="https://agentmods.dev/plugins/londeren/claude-plugins/prompt-writer"><img src="https://agentmods.dev/badge/plugins/londeren/claude-plugins/prompt-writer/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.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/londeren/claude-plugins/prompt-writer"><img src="https://agentmods.dev/badge/plugins/londeren/claude-plugins/prompt-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 1 skill cost 208 tokens a session between them.

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.

Security

Grade A, and why

prompt-writer 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 2mo 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.

plugins/prompt-writer/.claude-plugin/plugin.json · 22 lines

What it actually says

{
  "name": "prompt-writer",
  "displayName": "Prompt Writer",
  "version": "1.0.1",
  "description": "Methodology for writing LLM prompts, derived from analysis of Claude system prompts (Opus 4.7, Fable 5, Opus 5) and attention mechanics. Routes a request into one of five prompt types and applies the matching template, then audits the draft against a self-check list.",
  "author": {
    "name": "Sergey Lebedev",
    "url": "https://github.com/Londeren"
  },
  "homepage": "https://github.com/Londeren/claude-plugins",
  "repository": "https://github.com/Londeren/claude-plugins",
  "license": "MIT",
  "keywords": [
    "prompt-engineering",
    "system-prompt",
    "prompt-writing",
    "llm",
    "agent-prompt",
    "multilingual"
  ]
}

Contents

What it installs

The manifest is a name and a version. 1 skill travel with it, and installing the plugin installs all of them — 208 tokens a session between them. Each is measured on its own page, and each can be installed alone.

Skill prompt-writer A 208 tokens

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.

2mo ago First seen · 22 lines scan A f8402cfedc17

Subscribe to this mod's changes

prompt-writer is a plugin published in the GitHub repository Londeren/claude-plugins (5 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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.

Building agents Data and AI Prompting

prompt-writer next to 6 plugins from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
prompt-writerLonderen/claude-plugins	Plugin	5	1mo ago	MIT	A	—	Claude Code
context-engineeringmuratcankoylan/Agent-Skills-for-Context-Engineering	Plugin	18k	26d ago	MIT	A	—	Claude Code
magic-wordsmichellemayes/magic-words	Plugin	6	16d ago	MIT	A	—	Claude Code
promptkittybaldaworks/promptkitty	Plugin	5	11d ago	MIT	A	—	Claude Code
prompt-engineering-skillstreylom/prompt-engineering-skills	Plugin	193	1mo ago	none	A	—	Claude Code
prompeteerprompeteer/prompeteer-mcp	Plugin	1	1mo ago	MIT	A	—	Gemini CLI
prompt-engineering-expertMiaoge-Ge/coding-agent-skills	Plugin	7	5mo ago	MIT	A	—	Claude Code