prospero

prospero is a skill for Claude Code from bguthrie/prospero. It costs 43 tokens per session (1,163 once invoked), scanned A, original, MIT.

A routing guide for writing blog posts. It selects a suitable stage, such as questioning, outlining, criticism, drafting, or sentence-level revision, based on the request and project state.

In plain words
What is it for?
Use it when starting, outlining, reviewing, drafting, or revising a blog post.
Why use it?
It avoids applying the wrong writing process to the task. It also keeps different stages of blog writing from being repeated or mixed together.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the prospero plugin — 6 skills, 5 commands shipped together

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/bguthrie/prospero/prospero
Any agent
npx skills add bguthrie/prospero --skill prospero
Clone the repo
git clone --depth 1 https://github.com/bguthrie/prospero

Made for: Claude Code.

Or install prospero, the plugin that ships this one along with the rest of its 6 skills, 5 commands.

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 prospero

README.md
[![agentmods](https://agentmods.dev/badge/skills/bguthrie/prospero/prospero.svg)](https://agentmods.dev/skills/bguthrie/prospero/prospero)
Your own site
<a href="https://agentmods.dev/skills/bguthrie/prospero/prospero"><img src="https://agentmods.dev/badge/skills/bguthrie/prospero/prospero.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,163 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 5.1 $0.00043 $0.01163
Opus 5 $0.00022 $0.00581
Sonnet 5 $0.00009 $0.00233
Haiku 4.5 $0.00004 $0.00116

Measured 5d ago against content hash 236202dd4b39, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

prospero 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 5d 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.

skills/prospero/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prospero

Prospero is a dialectical pipeline for writing blog posts: interrogation into an outline, oppositional critique, voice-calibrated authoring, and line-level revision. This skill is the router — it reads the user's intent and the current project state, picks one phase skill to invoke, and hands off. It does not chain phases or duplicate their preflight logic.

When to use

Invoke this skill when the user's message expresses intent to produce or work on a blog post, without naming a specific phase. Typical phrasings:

  • "Help me write a post about X."
  • "I want to outline a piece on Y."
  • "Can you review this outline?"
  • "Draft the post from the outline."
  • "I've edited the draft — give me feedback."
  • "Let's work on a blog post."

If the user invoked a specific phase directly via /interrogate, /critique, /author, or /revise, do not invoke this skill — that phase skill is already running.

When NOT to use

  • The user asks an edit-level question about a single sentence or paragraph in an existing draft → invoke /revise directly.
  • The user asks how Prospero works, what a phase does, or wants to inspect configuration → answer the question; do not route.
  • The user is working on non-blog content (documentation, email, README, code comments) → do not route. Prospero is scoped to blog posts.

Routing logic

Pick exactly one phase skill based on what the user has and what they are asking for.

  1. Topic or raw idea, no outline yet → /interrogate. The first phase extracts the argumentative spine through Socratic questioning and writes the outline artifact. This is the entry point for any post that does not yet have an outline on disk.

  2. Outline exists at <drafts_dir>/<slug>/outline.md and the user wants adversarial review → /critique. Critique is an independent, oppositional reader; routing here before drafting is how the pipeline stress-tests the argument.

  3. Outline exists (usually reviewed) and the user says "draft it" or equivalent → /author. The author reads the outline, voice, audience, and sample posts, then writes the post at the resolved post_path_pattern.

Read the full file on GitHub · 68 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. 5d ago First seen · 68 lines · 43 tokens per session scan A 236202dd4b39

Subscribe to this mod's changes

prospero is a skill published in the GitHub repository bguthrie/prospero (6 stars, last pushed 4mo ago), licensed MIT. It adds 43 tokens to every session and 1,163 once invoked, about $0.0002 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.