Slant reads a decision you're stuck on through one mental model at a time. It won't tell you which option to take. It reframes the decision and gives you one small thing to test. It came out of Farnam Street's The Great Mental Models. The books explain the lenses well, but they can't put one in front of you on the day you're going in circles, pointed at the decision you have.
How It Works
When you're stuck, it's usually because you can only see the problem one way. So you describe it the way you'd say it out loud: one paragraph, no fields to fill in and no questions to answer first. Slant deals you another way of seeing it, then another, until one makes better sense.
Every reframe comes with the lens it was read through, its name and a one-line definition, alongside it. The definitions are fixed text, written once against the source and shipped with the app, so the model reasons from the book's idea of the term instead of its own. The reframe itself is five parts, always in this order.
① Question Something this lens would ask that no other lens would, and the first thing you read.
② Tell Your own words the whole reframe hangs on, quoted back to you. It's how you can tell it read you and not your topic.
③ Claim What this lens says the decision actually is.
④ Prediction What it says happens if nothing changes.
⑤ Move One concrete thing to do or test this week.
All Thirty-Six Lenses
Activation Energy
Bottlenecks
Churn
Circle of Competence
Commitment and Consistency Bias
Confirmation Bias
Debt
Diminishing Returns
Equilibrium
Feedback Loops
First Principles Thinking
Framing
Hanlon's Razor
Incentives
Inertia
Interdependence
Inversion
Leverage
Local vs Global Maxima
Map Is Not Territory
Margin of Safety
Narrative Instinct
Niches
Opportunity Cost
Reciprocity
Red Queen Effect
Scarcity
Second-Order Thinking
Sensitivity to Fairness
Setting
Social Proof
Specialization
Survivorship Bias
Tendency to Want to Do Something
Trade-Offs
Two-Front War
Another thirty-eight are written and waiting.
How It Was Built
Plain HTML, CSS and JavaScript. No framework, no build step, no server, no account. It runs on Google Gemini with your own key, and the key is the only thing it keeps. It installs as a PWA, built desktop-first, and runs on a phone.
Building it was the easy part: Claude Code wrote both versions from my designs in Figma. The hard part was finding the form. The first version was built fast and used for real, to find out whether the idea held up. It did. The second was a rewrite and a full redesign, and it came out simpler: less to navigate and no editing on the result screen.
