fstack — the simple stack

Agent skills that ask: can this be less?

The problem

Skill collections keep growing. 30 skills, personas, pipelines, voice triggers. You can't hold that in your head, so you stop using it.

And the complexity doesn't stay in the workflow. A process built to sound smart — phases, personas, ceremony — produces code that sounds smart too: layers, abstractions, and options nobody asked for.

The idea

fstack is 13 skills. Plain names, one job each.

The agent works in small steps and checks in with you. You approve; it executes. No long autonomous runs.

One skill — /fstack-simplify — exists only to remove things. No other stack has that.

Install

npx skills@latest add flaviocopes/fstack

That's it. No dependencies, no build step, no config.

The core loop

flowchart TD
    Start{"Human: task clear?"}
    Start -->|No| N["fstack-nail"]
    N --> Task["Human approves the task"]
    Task --> P["fstack-plan"]
    Start -->|Yes| P
    P --> Plan["Human approves the plan"]
    Plan --> B["fstack-build"]
    B --> C["fstack-check"]
    C -->|Ready to push| Push["fstack-push"]
    C -->|Not ready| Earlier["Human picks the right earlier step"]
    Earlier -.-> N
    Earlier -.-> P
    Earlier -.-> B

Loading

Invoke a skill directly, or ask /fstack to choose one. Nothing continues automatically.

Before the loop:

• /fstack-roast — when you have a product idea and want honest pushback before writing code
• /fstack-interview — when the agent should know the business behind the project; it asks, you answer, the answers land in AGENTS.md

Sprinkle in anywhere:

• /fstack-simplify — when something feels bloated, from one file to the whole codebase
• /fstack-design — when UI looks off or inconsistent with the rest
• /fstack-document — when the project needs docs, or the docs have gone stale
• /fstack-learn — when something is worth remembering
• /fstack-counselors — when a decision is big enough to want three independent model opinions

Don't know where to start? /fstack is the front door.

flowchart LR
    Map["Where each skill fits"]
    Map --> Front["Front door<br/>fstack"]
    Map --> Before["Before building<br/>fstack-roast<br/>fstack-interview"]
    Map --> Core["Core loop<br/>fstack-nail<br/>(when unclear)<br/>fstack-plan<br/>fstack-build<br/>fstack-check<br/>fstack-push"]
    Map --> Needed["Use when needed<br/>fstack-simplify<br/>fstack-design<br/>fstack-document<br/>fstack-counselors"]
    Map --> After["After useful work<br/>fstack-learn"]

Loading

The 13 skills

Skill	What it does
/fstack	The front door. Picks the right skill for your request.
/fstack-roast	Stress-tests a product idea. Ends with a verdict and the smallest version worth building.
/fstack-interview	Interviews you about the product — demand, customer, pricing, risks — and records the answers in AGENTS.md.
/fstack-counselors	Asks the 3 most capable models the same question, independently, and synthesizes one verdict plus each opinion.
/fstack-nail	Clarifies a vague task, nails down a 3-line summary, and gets your yes before planning.
/fstack-plan	Writes a one-page plan with a mandatory "what we're NOT doing" section.
/fstack-build	Implements the plan one small step at a time, asking at real choices.
/fstack-simplify	Audits for unnecessary complexity and proposes deletions — one file or the whole codebase. Only deletions.
/fstack-design	Makes UI adhere to the project's existing styles and cleans up design slop.
/fstack-document	Writes docs/ for the project, ELI5 to deep. Run again to update them with changes.
/fstack-check	Three questions: does it work, does it match the plan, is it simple.
/fstack-learn	Captures one lesson in three lines, so future sessions start smarter.
/fstack-push	Commits the current task's changes and pushes to the remote. Nothing else — no tests, no deploy.

Philosophy

1. Short sentences. One idea per sentence.
2. Short paragraphs, then a blank line.
3. No jargon. If a plumber wouldn't understand the word, find a simpler one.
4. No personas. Skills describe steps, not characters.
5. One job per skill.
6. Prefer deletion. When something can be shorter, make it shorter.
7. Every skill fits in ~150 lines. If it doesn't, it's doing too much.
8. The human drives. Skills pause at decision points and ask.
9. Agent-agnostic. Plain markdown, no hardcoded tool names.
10. Plain-English tone. Like explaining to a friend.

Credits

fstack exists because of the stacks it distills. gstack by Garry Tan gave it the full lifecycle idea and, through office hours, the idea-roasting step. pstack by Lauren Tan gave it design-before-code and blast-radius thinking. Compound Engineering by Every gave it the plan artifact and the lesson-capture step. Matt Pocock's skills gave it grilling, the two-axis review, and the small-skills shape. counselors by Aaron Francis gave it the council-of-advisors pattern behind /fstack-counselors. Go look at all of them — they're generous, thoughtful work.

License

MIT