Written in Rust • Open Source • Apache 2.0

Structured Reasoning at Rust Speed

A blazing-fast reasoning engine that forces AI to show its work. Every angle explored. Every assumption exposed. Every decision traceable. 10-100x faster than pure Python chains

curl -fsSL https://get.reasonkit.sh | bash
Get Started Free See Examples
reasonkit
$ rk analyze "We should rewrite this legacy codebase" GigaThink → Team wants new tech. Business wants stability. Users want features. LaserLogic → ✗ "Rewrite = faster" is a fallacy. You'll rebuild the same debt. BedRock → Core assumption: old code is the problem. Evidence? ProofGuard → Netscape, Borland, Basecamp Mobile: rewrites killed them. BrutalHonesty → You'll mass-produce the same bugs in trendier syntax. ─────────────────────────────────────────────────────────────── VERDICT: Refactor incrementally. Rewrites are where companies go to die. ⏱ 94ms
GigaThink
LaserLogic
BedRock
ProofGuard
BrutalHonesty
The Problem

AI Gives You Answers. But Are They Good?

Most AI responses sound helpful but miss the hard questions.

You ask:
"Should I take this job offer?"
"Consider salary, benefits, and culture fit."
What's missing:
Manager quality, team turnover, company trajectory, your leverage, opportunity cost, where people go after 2-3 years...
You ask:
"Should I buy a house?"
"Building equity is generally better long-term."
What's missing:
Mortgage interest isn't equity. Transaction costs. Maintenance. Flexibility. The actual math shows breakeven at 5-7 years.
You ask:
"I want to start a YouTube channel"
"Focus on a niche and be consistent!"
What's missing:
Median income is $0. 10-40 hours per video. 95% quit in year one. MrBeast has 100 people working for him.
ThinkTools

Five Tools. Five Blind Spots. Zero BS.

Each ThinkTool catches a specific type of oversight.

GigaThink

See All The Angles
The blind spot: You're only thinking about a decision from one angle.
Without GigaThink
TYPICAL AI RESPONSE: "When evaluating a job offer, consider these factors: 1. Compensation: Is the salary competitive? 2. Benefits: Health insurance, 401k, PTO 3. Culture fit: Does the company align with your values? 4. Growth potential: Room for advancement? 5. Work-life balance: Reasonable hours? Make a pros/cons list and trust your gut." Sounds helpful. Misses the questions that actually matter.
With GigaThink
10 PERSPECTIVES YOU MIGHT MISS: 1. FINANCIAL: Total comp? 401k match? Equity? 2. CAREER: Where do people go after 2-3 years? 3. MANAGER: Your manager = 80% of job satisfaction 4. TEAM: Why is this role open? Growth or exit? 5. COMPANY: Growing, stable, or declining? 6. WORK-LIFE: Glassdoor hours vs stated hours 7. LEARNING: Will you grow faster here? 8. LEVERAGE: Do they NEED you or just WANT you? 9. OPPORTUNITY: Best option or first option? 10. GUT CHECK: Relief or dread when accepting?
What GigaThink catches: The angles you forget when you're excited about an opportunity.

LaserLogic

Spot Bad Reasoning
The blind spot: Arguments that sound wise but hide flawed logic.
Without LaserLogic
TYPICAL AI RESPONSE: "The conventional wisdom is that buying is better than renting long-term because: • You build equity instead of 'throwing money away' • Real estate historically appreciates 3-5% annually • Mortgage payments are fixed while rent increases • Tax benefits from mortgage interest deduction • Pride of ownership and stability If you can afford a down payment and plan to stay 5+ years, buying is usually the smarter financial choice." Sounds reasonable. Hides 4 major logical flaws.
With LaserLogic
HIDDEN ASSUMPTIONS EXPOSED: 1. FALSE EQUIVALENCE Rent = 100% goes to housing Mortgage = 60-80% goes to INTEREST (not equity) 2. MISSING VARIABLES - Down payment could earn 10%/yr in S&P 500 - Transaction costs: 6% realtor fees - Maintenance: 1-2% of home value annually 3. ASSUMES APPRECIATION "Houses always go up" — ask 2007 buyers 4. IGNORES FLEXIBILITY Rent: 30 days to leave Own: 6+ months to sell VERDICT: "Renting is throwing money away" is OVERSIMPLIFIED. Breakeven = 5-7 years minimum.
What LaserLogic catches: Cliches that sound wise but hide bad math.

BedRock

Find the Simple Answer
The blind spot: Overwhelmed with options, missing what actually matters.
Without BedRock
TYPICAL AI RESPONSE: "For optimal health, consider a holistic approach: • Nutrition: Balanced diet with whole foods, consider Mediterranean or keto • Exercise: 150 min moderate or 75 min vigorous weekly • Sleep: 7-9 hours in a dark, cool room • Stress: Meditation, journaling, breathing exercises • Supplements: Vitamin D, omega-3s, magnesium • Biohacking: Cold showers, red light therapy • Fasting: Try 16:8 intermittent fasting • Hydration: 8 glasses of water daily Start with small changes and build habits gradually." 12 things to optimize. But what actually moves the needle?
With BedRock
FIRST PRINCIPLES (Research Consensus): What actually moves the needle? 1. Sleep: 7-9 hours (most ignored, highest impact) 2. Movement: 150 min/week moderate OR 75 min vigorous 3. Nutrition: Mostly plants, enough protein, not too much THE 80/20 ANSWER: If you do ONLY these three things: 1. Sleep 7+ hours (non-negotiable) 2. Walk 30 min daily 3. Eat one vegetable with every meal → You'll be healthier than 80% of people. THE UNCOMFORTABLE TRUTH: You probably already know what to do. The problem isn't information, it's execution.
What BedRock catches: The simple answer hiding under complicated advice.

ProofGuard

Verify Before You Believe
The blind spot: Acting on "facts" you never verified.
Without ProofGuard
TYPICAL AI RESPONSE: "Yes, staying properly hydrated is crucial for health: • Aim for 8 glasses (64 oz) of water daily • Hydration improves energy, skin, and cognition • Dehydration causes headaches and fatigue • Drink more if exercising or in hot weather • Watch for signs: dark urine means drink more The '8x8 rule' is a good baseline for most adults. Keep a water bottle with you as a reminder to stay hydrated throughout the day." Confident advice. But where does "8 glasses" actually come from?
With ProofGuard
CLAIM: "Drink 8 glasses of water a day" SOURCE 1: British Medical Journal (2007) "No scientific evidence for 8x8 recommendation" → Origin traced to 1945 misinterpretation SOURCE 2: Mayo Clinic (2022) → Adequate intake varies by individual → TOTAL fluids (includes food), not just water SOURCE 3: National Academy of Sciences "Most people meet hydration needs through thirst" → No evidence of widespread dehydration VERDICT: MOSTLY MYTH • "8 glasses" has no scientific basis • Food provides 20-30% of water intake • Coffee/tea count toward hydration • Your body's hydration sensor: thirst PRACTICAL TRUTH: Drink when thirsty. Check urine color.
What ProofGuard catches: Widely-believed "facts" that aren't actually true.

BrutalHonesty

See Your Blind Spots
The blind spot: You love your plan and can't see its flaws.
Without BrutalHonesty
TYPICAL AI RESPONSE: "Starting a YouTube channel can be rewarding! Here's how to succeed: • Find your niche: What are you passionate about? • Be consistent: Post 2-3x per week minimum • Invest in quality: Good audio > good video • Engage with your audience: Reply to comments • Use SEO: Optimize titles, tags, descriptions • Be patient: Most channels take 1-2 years to grow • Collaborate: Partner with similar creators Many successful YouTubers started as a hobby and grew it into a full-time income. The key is persistence and genuine passion for your content." Encouraging! But what are the actual odds of success?
With BrutalHonesty
UNCOMFORTABLE TRUTHS: 1. THE MATH DOESN'T WORK FOR 99% • Median YouTuber income: $0 • Top 3% of channels get 90% of views 2. TIME INVESTMENT IS MASSIVE • 1 quality video = 10-40 hours • That's a part-time job for months with no pay 3. YOU'RE COMPETING WITH PROFESSIONALS • MrBeast has a 100-person team • Your "side hustle" vs their full-time career 4. BURNOUT IS THE ACTUAL OUTCOME • 95% of channels quit within first year HONEST QUESTIONS: • Can you do 20+ hrs/week for 2 years with zero return? • Why YouTube? (Newsletter/podcast may be easier) • Is this for money or creative expression? IF YOU STILL WANT TO DO IT: • Make 10 videos before "launching" • Treat it as hobby, not business, until proven
What BrutalHonesty catches: The gap between your optimistic plan and reality.
How It Works

The 5-Step Process

Every deep analysis follows this pattern.

1. DIVERGE (GigaThink)

Explore all angles before narrowing down

→

2. CONVERGE (LaserLogic)

Check logic, detect fallacies, find flaws

→

3. GROUND (BedRock)

First principles, simplify to what matters

→

4. VERIFY (ProofGuard)

Check facts against sources, triangulate claims

→

5. CUT (BrutalHonesty)

Be honest about weaknesses and risks

✓
Divergent → Convergent

Explore widely first, then focus ruthlessly

Abstract → Concrete

From ideas to first principles to evidence

Constructive → Destructive

Build up possibilities, then attack your own work

Profiles

How Thorough Do You Need?

Choose your depth based on the decision's importance.

--quick
~30 sec
Daily decisions
"Should I buy this?"
--balanced
~2 min
Important choices
"Should I take this job?"
--deep
~5 min
Major decisions
"Should I move cities?"
--paranoid
~10 min
High-stakes
"Should I invest $100K?"
Quick Start

Get Started in 30 Seconds

reasonkit — zsh 
# Install ReasonKit
cargo install reasonkit-core

# Career decisions
rk-core think "Should I ask for a raise or find a new job?" --profile balanced

# Life decisions
rk-core think "Should I move to a new city?" --profile deep

# Fact checking
rk-core think "Is intermittent fasting actually effective?" --profile balanced

# See the before/after difference
rk-compare "Your question here" --profile balanced
Try It Now

See ReasonKit in Action

Enter a question and watch all five ThinkTools analyze it

Try these:
Performance

Rust-Powered Speed

ReasonKit's Rust core delivers enterprise-grade performance

10-100x
Faster than Python
Reasoning chain execution benchmarked against pure Python implementations
<200ms
5-Tool Analysis
Complete reasoning chain with all 5 ThinkTools running in parallel
Zero
Runtime Dependencies
Single binary, no Python environment or heavy frameworks required
ReasonKit (Rust) 208ms
Pure Python Chain 2,340ms
LangChain Equivalent 4,180ms

Benchmarks run on Apple M2 Pro, 16GB RAM. View methodology →

What Developers Say

Built for Skeptics

Engineers who've integrated ReasonKit into their workflows

"I was skeptical another reasoning framework would add value. Then I ran my first benchmark—literally 50x faster than my LangChain setup. The Rust core isn't marketing fluff."

MK
Marcus K.
ML Engineer, Series B Startup

"The BrutalHonesty tool caught an edge case in our recommendation engine that 3 senior engineers missed in code review. Now it's part of our CI pipeline."

SR
Sarah R.
Tech Lead, E-commerce Platform

"We replaced 2,000 lines of custom prompt engineering with 50 lines of ReasonKit config. Same accuracy, 10x less maintenance. Should've switched months ago."

JC
James C.
Principal Engineer, FinTech
Pricing

Start Free. Pay When It's Worth It.

Free
Open source forever
$0 forever
  • 5 core ThinkTools
  • PowerCombo (all 5 in sequence)
  • Local execution
  • Self-host forever
  • Apache 2.0 licensed
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From the Blog

Latest Insights

Featured

Why AI Needs Structured Reasoning: The Case for Protocols Over Prompts

AI gives you answers fast. But how do you know they're good? Most LLM responses sound confident but skip the hard questions. We built ReasonKit to fix that: five tools that force AI to think systematically, explore all angles, and expose its assumptions.

December 23, 2025 8 min read Read Article

Think Deeper. Reason Better.

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