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Agent skill

Craft Spec

by amplitude in amplitude/builder-skills

Turn messy ideas into a clear, structured PRD. An agent skill from amplitude/builder-skills.

No licenceAuto-check passedProduct & Project Management

Install Craft Spec

skills CLI
$ npx skills add amplitude/builder-skills --skill craft-spec -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install amplitude/builder-skills craft-spec --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/amplitude/builder-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/product-skills/skills/craft-spec .claude/skills/craft-spec && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
craft-spec
GitHub stars
160
Token cost
~486 tokens
SKILL.md length
99 words
Files
1
Skills in repo
61
Repo updated
First seen
Licence
None found

At a glance

Turn messy ideas into a clear, structured PRD. An agent skill from amplitude/builder-skills.

  • You have rough notes
  • SKILL.md covers Prompt Template and Tips
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
  • Half-formed ideas that need to become a product requirements document

What it does

Craft Spec is an agent skill from amplitude/builder-skills. Turn messy ideas into a clear, structured PRD. Use when you have rough notes, Slack threads, or half-formed ideas that need to become a product requirements document.

Its SKILL.md is about 490 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Product & Project Management, covering PRD writing. It works with Slack. The repository describes itself as: Open-source AI skills for product managers — battle-tested by PMs at Amplitude.

When your agent uses it

  • You have rough notes
  • Half-formed ideas that need to become a product requirements document

Example prompts

  • “/craft-spec”

What it can do on your machine

Read from SKILL.md and the folder at commit 51838c2. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Craft Spec loads about 486 tokens when it runs. Until then it costs about 44 tokens; SKILL.md has 99 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~44
When it runs · the whole SKILL.md, loaded when a task matches
~486

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

Without a licence we can't republish the file, so here is its outline and opening line. It has 99 words (~486 tokens).

“Turn messy ideas into a clear, structured PRD.”

— opening of SKILL.md by amplitude
name
craft-spec
suggest_when
User has rough notes and needs a spec, says "write a PRD", "spec this out", "turn this into a doc", or shares unstructured ideas that need to become a…

Read the full SKILL.md on GitHub

Files

Just SKILL.md in product-skills/skills/craft-spec of amplitude/builder-skills.

Open the folder on GitHubat commit 51838c2

Compare with similar skills

Craft Spec next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Craft Spec compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Craft Spec this skillamplitude/builder-skills160—~486Automated safety check: PassNone
Action Runnermohitagw15856/pm-claude-skills1.4k—~1.5kAutomated safety check: PassMIT
Ghostwritermblode/agent-skills144—~2.2kAutomated safety check: PassMIT
CCPM Project Managementautomazeio/ccpm8.4k—~1.1kAutomated safety check: PassMIT
Ralph Tui Create Beadssubsy/ralph-tui2.5k1 repos~2.6kAutomated safety check: PassMIT
Trellis Brainstormanjiemo/SunnyBeach1787 repos~4kAutomated safety check: PassApache-2.0

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  • Ghostwriter

    mblode/agent-skills

    Writes, rewrites, and critiques messages, posts, review comments, tickets, PRDs, design docs, talk scripts, docs, READMEs, and copy as the user or their company, in a private profile's voice with…

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Works with

Categories

Questions about Craft Spec

What does Craft Spec do?

Turn messy ideas into a clear, structured PRD. An agent skill from amplitude/builder-skills. Craft Spec is an agent skill from amplitude/builder-skills. Turn messy ideas into a clear, structured PRD.

When should I use Craft Spec?

Craft Spec fits situations like: you have rough notes; half-formed ideas that need to become a product requirements document.

How do I install Craft Spec in Claude Code?

Run `npx skills add amplitude/builder-skills --skill craft-spec -a claude-code`. Or copy the skill folder (product-skills/skills/craft-spec in amplitude/builder-skills) into .claude/skills/craft-spec in your project. Claude Code loads it when a task matches its description.

How do I install Craft Spec in Codex?

Run `npx skills add amplitude/builder-skills --skill craft-spec -a codex`. Or copy the skill folder (product-skills/skills/craft-spec in amplitude/builder-skills) into .agents/skills/craft-spec in your project. Codex loads it when a task matches its description.

Can I use Craft Spec in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add amplitude/builder-skills --skill craft-spec -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/craft-spec, .gemini/skills/craft-spec, .github/skills/craft-spec and .opencode/skills/craft-spec in your project.

What does Craft Spec need to run?

SKILL.md names no scripts, command-line tools or credentials: Craft Spec is instructions for the agent only.

Does Craft Spec access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Craft Spec safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Craft Spec use?

No licence was found for Craft Spec or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.

How many tokens does Craft Spec use?

About 486 tokens (SKILL.md is roughly 1.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Craft Spec?

Skills that share tags, products or a category with Craft Spec: Action Runner (mohitagw15856/pm-claude-skills, 1.4k stars), Ghostwriter (mblode/agent-skills, 144 stars), CCPM Project Management (automazeio/ccpm, 8.4k stars) and Ralph Tui Create Beads (subsy/ralph-tui, 2.5k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Craft Spec?

amplitude (a GitHub organization) maintains it in amplitude/builder-skills, which has 160 GitHub stars. The repository holds 61 skills in this directory. The repository was last updated on July 24, 2026.

Source: amplitude/builder-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.