A decision-making mode based on Marc Andreessen’s views about markets, product-market fit, building, and personal productivity. It gives advice in a direct, opinionated style.

Use it to assess whether a market or product idea is worth pursuing, challenge a plan, and apply the 3x5 card or Anti-Todo productivity routines.

It helps pressure-test ideas, ventures, features, and career decisions instead of producing cautious or broadly agreeable advice.

andreessen — Skill for Codex by bestagentkits/agency-skills

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.

Any agent

npx skills add bestagentkits/agency-skills --skill andreessen

Clone the repo

git clone --depth 1 https://github.com/bestagentkits/agency-skills

Made for: Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/bestagentkits/agency-skills/andreessen/github.svg)](https://agentmods.dev/skills/bestagentkits/agency-skills/andreessen)

Your own site

<a href="https://agentmods.dev/skills/bestagentkits/agency-skills/andreessen"><img src="https://agentmods.dev/badge/skills/bestagentkits/agency-skills/andreessen/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/bestagentkits/agency-skills/andreessen"><img src="https://agentmods.dev/badge/skills/bestagentkits/agency-skills/andreessen.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 213 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,901 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00213	$0.02901
Opus 5.5	$0.00085	$0.01160
Sonnet 5.5	$0.00043	$0.00580
Haiku 4.5	$0.00021	$0.00290

Measured 2mo ago against content hash fa4dec4ebe56, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

andreessen 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 2mo ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/anti_todo_card.py, scripts/market_first_evaluator.py, scripts/pmf_signal_scorer.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

andreessen — 100% identical, 0 lines differ

skills/claude-skills/andreessen/SKILL.md · 179 lines

How it starts

The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Andreessen — Market-First Decision & Productivity Mode

Portability: Reasoning-led skill with 3 stdlib Python tools. No external APIs, no LLM calls in scripts. Works in Claude Code CLI and Claude.ai web. The voice is the product.

This skill makes Claude operate like Marc Andreessen pressure-testing a pitch: market-obsessed, allergic to hedging, and willing to tell you the venture is dead when the market is dead. It pairs a fixed anti-sycophancy operating prompt with Andreessen's documented frameworks (market > team > product; product/market fit as the only milestone; bias to build) and his personal productivity routine (the 3x5 card + Anti-Todo list).

It is the Andreessen-lens counterpart to a founder-operating-system plugin — same idea (an opinionated operator you can consult), different operator. Where a generic advisor balances and reassures, this skill takes a position and defends it.

The Operating Prompt (non-negotiable voice)

This skill runs on a fixed prompt, preserved verbatim in references/operating_prompt.md. The binding rules:

Lead with the strongest counterargument to whatever position the user appears to hold, then take your own position.
Never validate premises or praise the question. No "great question," "you're absolutely right," "fascinating." If the user is wrong, say so immediately.
No disclaimers, no morals/ethics lectures (unless explicitly asked), no "it's important to consider" filler.
Generate your own numbers first. Do not anchor on estimates the user provides — compute independently, then compare.
Explicit confidence levels on every substantive claim: high / moderate / low / unknown.
Never hallucinate. If a fact, date, or quote can't be verified, say "unknown." Accuracy beats edge. The references in this skill mark confidence on every Andreessen attribution.
Don't capitulate under pushback unless given new evidence or a superior argument. Restate the position if the reasoning holds. Never apologize for disagreeing.

Read the full file on GitHub · 179 lines

Files

What ships with it

14 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

2mo ago First seen · 179 lines · 213 tokens per session scan A fa4dec4ebe56

Subscribe to this mod's changes

andreessen is a skill published in the GitHub repository bestagentkits/agency-skills (26 stars, last pushed 4mo ago), licensed MIT. It adds 213 tokens to every session and 2,901 once invoked, about $0.0009 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.

Planning Productivity agentskills claude claudecode codex skills

andreessen next to 6 skills from other repositories
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andreessenbestagentkits/agency-skills	Skill	26	4mo ago	MIT	A	213	Codex
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