Borrowing it
Nothing to install: this file belongs to impactbrussels/FounderOS. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/impactbrussels/FounderOS/main/AGENTS.mdgit clone --depth 1 https://github.com/impactbrussels/FounderOSWrote 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.
[](https://agentmods.dev/instructions/impactbrussels/founderos/agents-md)<a href="https://agentmods.dev/instructions/impactbrussels/founderos/agents-md"><img src="https://agentmods.dev/badge/instructions/impactbrussels/founderos/agents-md/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.
<a href="https://agentmods.dev/instructions/impactbrussels/founderos/agents-md"><img src="https://agentmods.dev/badge/instructions/impactbrussels/founderos/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00506 | $0.00506 |
| Opus 5.5 | $0.00202 | $0.00202 |
| Sonnet 5.5 | $0.00101 | $0.00101 |
| Haiku 4.5 | $0.00051 | $0.00051 |
Grade A, and why
FounderOS AGENTS.md 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 1mo 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.
What it actually says
Founder OS - Agent Instructions (Codex / Cursor mirror)
This mirrors
CLAUDE.mdfor harnesses that readAGENTS.md(Codex) or.cursor/rules(Cursor). Gemini CLI readsGEMINI.md. Keep it in sync withCLAUDE.md, the canonical master file.
What this is
Founder OS - the open operating system for first-time founders. A theme-agnostic library of skills, flows, loops, and advisor agents covering the founder journey:
Idea & Validation → Build / MVP → Launch & GTM → Fundraise → Operate & Scale
Unsure where a founder is? Run the start-here skill first. Full map: docs/STAGES.md.
Skills live in skills/; flows in flows/; loops in loops/; advisor agents in agents/.
Operating principles (enforce every time)
- Research before asserting - verify checkable claims or label them assumptions; never invent market numbers or legal/tax thresholds.
- A draft is not a decision - name what needs the founder's human judgement.
- Batch, then decide - generate, gather all feedback, revise once.
- Ask before assuming - one tight question beats the wrong artifact.
- Route to the earliest unvalidated assumption - highest-value work is upstream.
- Stay theme-agnostic - use the placeholder glossary; bake in no sector.
- Protect the founder - no secrets/PII in prompts; flag irreversible decisions; add the not-legal/financial-advice caveat on legal/finance/equity topics.
Learning loop
After any real outcome, run capture-learning to append a dated, sourced lesson to
knowledge-base/ (PRINCIPLES.md, DOS-AND-DONTS.md, PLAYBOOK-LESSONS.md). Append, never
overwrite. Read the KB before substantive work.
Tooling
Skills speak in actions, not tool names. Per-platform mapping: docs/cross-platform-guide.md.
Licensing & attribution (preserve)
Content CC-BY-4.0, code Apache-2.0. Attribution required: Founder OS by Adam M. Adamek
(Impact Brussels ASBL). See ATTRIBUTION.md.
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.
- 1mo ago First seen · 44 lines · 506 tokens per session scan A 0b7351204467
FounderOS AGENTS.md is an instructions file published in the GitHub repository impactbrussels/FounderOS (3 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 506 tokens to every session, about $0.0020 per session on Opus 5.5. 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.
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