first-principles-mode

first-principles-mode is a skill for Claude Code, Codex from mohitmishra786/anti-vibe-skills. It costs 85 tokens per session (1,227 once invoked), scanned A, original, MIT.

A questioning mode that examines the assumptions beneath a proposed approach before work continues. It focuses on the actual constraints rather than accepted conventions.

In plain words
What is it for?
Reviewing statements such as “this is the standard way,” testing why each component or abstraction is needed, and documenting the assumptions before exploring solutions.
Why use it?
It exposes reasons that may have been inherited or left untested, especially when a solution includes complexity without a clearly stated need.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Reviewing statements such as “this is the standard way,” testing why each component or abstraction is needed, and documenting the assumptions before exploring solutions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mohitmishra786/anti-vibe-skills/first-principles-mode
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 mohitmishra786/anti-vibe-skills --skill first-principles-mode
Clone the repo
git clone --depth 1 https://github.com/mohitmishra786/anti-vibe-skills

Made for: Claude Code, 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.

agentmods badge for first-principles-mode

README.md
[![agentmods](https://agentmods.dev/badge/skills/mohitmishra786/anti-vibe-skills/first-principles-mode/github.svg)](https://agentmods.dev/skills/mohitmishra786/anti-vibe-skills/first-principles-mode)
Your own site
<a href="https://agentmods.dev/skills/mohitmishra786/anti-vibe-skills/first-principles-mode"><img src="https://agentmods.dev/badge/skills/mohitmishra786/anti-vibe-skills/first-principles-mode/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.

agentmods 80×15 button for first-principles-mode

Your own site · 80×15
<a href="https://agentmods.dev/skills/mohitmishra786/anti-vibe-skills/first-principles-mode"><img src="https://agentmods.dev/badge/skills/mohitmishra786/anti-vibe-skills/first-principles-mode.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 85 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,227 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00085 $0.01227
Opus 5 $0.00043 $0.00613
Sonnet 5 $0.00017 $0.00245
Haiku 4.5 $0.00009 $0.00123

Measured 12d ago against content hash ee68e7f3f284, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

first-principles-mode 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 12d 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.

skills/cognitive-forcing/first-principles-mode/SKILL.md · 110 lines

How it starts

The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.

first-principles-mode

Purpose

Deconstruct every assumption beneath a proposed approach before allowing any forward progress — guide the human to reason from the actual constraints of the problem rather than inherited conventions, never propose an alternative approach or solution.

Hard Refusals

  • Never propose an alternative approach — the goal is to clear the ground, not to build on it. Building is the human's job.
  • Never confirm that an assumption is valid — even if you believe it is. Confirmation short-circuits the reasoning.
  • Never let "everyone does it this way" stand as a justification. Convention is not a first principle.
  • Never accept complexity as a given — always ask what the complexity is solving.
  • Never move to solution exploration until all assumptions have been named and tested.

Triggers

  • "The standard way to do this is..."
  • "I assumed we'd need [pattern/technology/layer]"
  • "Everyone uses [X] for this kind of problem"
  • "We need [complex solution] because [vague reason]"
  • Any proposed solution whose complexity seems disproportionate to the problem description

Workflow

1. State the actual problem

Before examining the proposed solution, get the raw problem.

AI Asks Purpose
"Forget the solution for a moment — what is the actual problem you are trying to solve?" Strips away the solution frame
"Who has this problem? How often? What happens if it's not solved?" Establishes problem severity and frequency
"How do you know this is the problem? What evidence do you have?" Tests whether the problem itself is well-defined

Gate 1: Human has stated the problem independently of the solution, with evidence that it is real.

Memory note: Record the stripped problem statement in SKILL_MEMORY.md.

2. List every assumption in the proposed approach

Ask the human to enumerate — not defend — every assumption their approach rests on.

AI Asks Purpose
"List the things that have to be true for your approach to be the right one." Surfaces implicit assumptions
"What would have to change about the world for your approach to be obviously wrong?" Forces falsifiability
"Which parts of this approach could you remove if you had to, without breaking the core?" Identifies necessary vs. assumed components

Read the full file on GitHub · 110 lines

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.

  1. 12d ago First seen · 110 lines · 85 tokens per session scan A ee68e7f3f284

Subscribe to this mod's changes

first-principles-mode is a skill published in the GitHub repository mohitmishra786/anti-vibe-skills (5 stars, last pushed 6mo ago), licensed MIT. It adds 85 tokens to every session and 1,227 once invoked, about $0.0004 per session on Opus 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.

Related

Other skills, from other repositories

refactoring-workflow

Improve the structure of existing code without changing its behaviour, in small verified steps under a green test suite. Use when the user asks to refactor, clean up, restructure or simplify code, wants to reduce duplication or coupling, is preparing a codebase for a feature it cannot currently accommodate, or when…

personamanagmentlayer/pcl · 83 tokens

code-quality-review

A code-review guide for judging whether software stays easy to understand, change, test, and extend.

bahayonghang/my-ai-cli-toolkit · 149 tokens

decision-backfill

Use when auditing an existing codebase, documentation set, plans, RFCs, or git history for architecture decisions that were made but never recorded as ADRs, and when triaging potential records before drafting them.

mbeacom/adrkit · 46 tokens

decision-memory

Use when planning, designing, reviewing, or changing code in a repository that keeps ADRs (usually docs/adr) — to load the decisions that already govern the work, check a plan or diff against them, or record a new decision. Also use when a choice feels already-settled and you cannot find where it was settled.

mbeacom/adrkit · 71 tokens

refactor

Refactors specified code to improve clarity, reduce duplication, or align with the project's architectural patterns — without changing external behavior. Invoked when the user asks to refactor, clean up, simplify, or restructure code.

soulcodex/agentic · 46 tokens

codebase-organizer

Universal codebase operations: analyze, organize, and architecturally deepen any repo. Two commands: /organize for read-only analysis and /deepen for multi-agent refactoring. Use when the user wants a codebase scan, deep module scoring, dependency mapping, architectural improvement, or code-to-skill conversion.…

AnkitClassicVision/ankit_shared_skills · 116 tokens