Plugin Claude Code
The open operating system for first-time founders: AI skills, flows, loops, and advisor agents spanning the whole founder journey - idea, validation, MVP, launch, fundraising, and operations. Theme-agnostic.
Cursor rule Cursor
Founder OS - the open operating system for first-time founders. Skills, flows, loops, and advisor agents for the whole startup journey. Apply when the user is working on a startup: validating an idea, talking to customers, scoping an MVP, positioning, launching, finding first customers, fundraising, incorporating…
Instructions file CodexOpenCode
Instructions for impactbrussels/FounderOS, covering founder os - agent instructions (codex / cursor mirror), what this is, operating principles (enforce every time), learning loop and tooling.
Instructions file
Instructions for impactbrussels/FounderOS, covering founder os - master instructions, what founder os is, the journey (primary organising axis), how the pieces fit and operating principles (enforce these in every interaction).
Instructions file Gemini CLI
Instructions for impactbrussels/FounderOS, covering founder os - agent instructions (gemini cli mirror), what this is, operating principles (enforce every time), learning loop and tooling & attribution.
Agent
Dispatch to stress-test a product, pitch, landing page, or message against a specific target customer before spending money or talking to real ones - when the founder says "react as my customer", "would they buy this", "is this message clear", or wants Mom-Test-honest feedback. Simulates a specific [ICP] reacting…
Agent
Dispatch when a first-time founder is stuck, overwhelmed, unsure what to do next, or spinning on busywork - the default advisor for routing, unblocking, and keeping the founder honest about the riskiest assumption. Use when they ask "what should I do next", "I'm overwhelmed", "am I working on the right thing", or are…
Agent
Dispatch to red-team a pitch, deck, model, or market claim before a real investor sees it - when the founder says "poke holes in this", "is this fundable", "what will they ask", or is preparing to fundraise. A sharp seed/VC who demands evidence, attacks the numbers, and surfaces the questions a real investor will ask.…
Skill Claude CodeCodex
Use when a founder faces a hard, ambiguous, or high-stakes decision and wants to think it through with proven lenses rather than gut alone - "help me think about this", "what am I missing", "should I do X or Y", "stress-test my thinking", "I'm stuck on a decision". Applies the right mental models (inversion…
Skill Claude CodeCodex
Use when a founder needs to name the company or product and set a simple brand voice - when they say "what should I call it", "help me name my startup", "is this name any good", "the domain is taken", "what's my brand voice", or are stuck cycling through names. Produces a screened name shortlist (with availability…
Skill Claude CodeCodex
Use after a Founder OS skill, flow, or decision produced a real outcome worth remembering - when something worked, something failed, advice turned out wrong, or the founder says "remember this", "note this lesson", "that didn't work", or "update the playbook". Appends a dated, sourced lesson to the living knowledge…
Skill Claude CodeCodex
Use when a founder is choosing a co-founder or splitting equity - when they ask "do I need a co-founder", "how do I find a co-founder", "how do I split equity", "is 50/50 fair", "what's a fair founder split", "how do I evaluate a potential co-founder", "should we vest", "what if a co-founder leaves", or are about to…
Skill Claude CodeCodex
Use when a founder has a real or prototype consumer/physical product (food, beverage, cosmetic, personal-care, household, hardware, or a packaged good) and needs to test whether it actually works for real users - beyond problem interviews. Triggers: "how do I test my product", "prototype test", "home-use test", "does…
Skill Claude CodeCodex
Use when a founder needs to talk to potential customers and wants real signal, not flattery - when they say "I'm going to interview some users", "how do I do customer discovery", "I want to validate the problem", "no one will give me honest feedback", or are about to pitch their idea in a "research" call. Applies Mom…
Skill Claude CodeCodex
Use when a founder needs their first paying customers and there's no inbound, no audience, and no growth engine yet - when they say "how do I get my first customers", "nobody's signing up", "how do I do outbound", "I hate selling", "how do I get to 10 customers", or are waiting for customers to magically appear.…
Skill Claude CodeCodex
Use when a founder is making early hires - when they ask "should I hire someone", "what's my first hire", "who do I hire first", "how do I write a job description", "how do I interview", "employee or contractor", "how do I find good candidates", "how do I onboard", or are about to hire to feel less overwhelmed. Covers…
Skill Claude CodeCodex
Use when writing, refining, or porting any Founder OS prompt or skill, or when a founder asks "how do I write a good prompt for this" - provides the shared 3-tier (Low/Medium/High) scaffold, placeholder glossary, and quality rules every Founder OS skill is built on. Invoke before authoring a new skill or when an AI…
Skill Claude CodeCodex
Use when a founder is starting or running a fundraise and needs to manage it like a sales process - when they say "how do I find investors", "I'm raising and don't know where to start", "my raise is dragging", "should I raise now", "how do I run investor meetings", or are taking one-off investor coffees with no…
Skill Claude CodeCodex
Use when a founder needs words for a landing page that converts - when they say "write my landing page", "what should my headline be", "my page isn't converting", "people don't get what I do", "help me with the hero section", or are about to ship a page full of features and jargon. Produces conversion-first page copy…
Skill Claude CodeCodex
Use when a founder is approaching a launch and needs a sequenced plan instead of a single chaotic "go live" day - when they say "I'm launching next week", "how do I launch", "what do I need before I launch", "should I do a Product Hunt / waitlist / public launch", "build me a launch checklist", or are about to ship to…
Skill Claude CodeCodex
Use when a founder is forming the company or worried they've skipped legal basics - when they ask "should I incorporate", "when do I form a company", "LLC or C-corp or what", "do I need a founders' agreement", "how do I assign IP to the company", "what's founder vesting", "is my cap table clean", "what contracts do I…
Skill Claude CodeCodex
Use when a founder needs to decide what to measure - when they say "what metric should I track", "what's my north star", "I'm drowning in dashboards", "is this a vanity metric", "what should I focus on this quarter", or are tracking everything and steering by nothing. Picks the ONE north-star metric that captures…
Skill Claude CodeCodex
Use when a founder needs to build or fix an investor pitch deck - when they say "help me make a pitch deck", "my deck isn't landing", "what slides do I need", "investors keep ghosting after the deck", or are about to send a deck to a VC/angel. Builds the investor narrative first, then a tight 10-12 slide deck where…
Skill Claude CodeCodex
Use when a founder has run real experiments and must decide whether to keep going, change direction, or stop - the moment validation results, retention, pipeline, or runway are forcing a call. Reach for this when they say "should I pivot", "is this working", "do I keep going", "should I kill it", "the numbers are…