AI Prompts for Claude for TypeScript

I need to model [DESCRIBE DOMAIN CONCEPT] in TypeScript. The data has [DESCRIBE FIELDS AND RELATIONSHIPS]. Write a set of interfaces and types, using union types, optional fields, and generics where they add real value.

Design a discriminated union for [STATE MACHINE OR EVENT TYPE]. It should have these variants: [LIST]. Show the type definition and a type guard for each variant.

I have this plain JavaScript object: [PASTE OBJECT]. Convert it to a strict TypeScript interface. Infer the best type for each field and flag anything that should be an enum or literal type.

Create a utility type that [DESCRIBE TRANSFORMATION, E.G. "MAKES ALL NESTED PROPERTIES OPTIONAL" OR "EXTRACTS KEYS WHOSE VALUES ARE STRINGS"]. Show how to apply it to an existing type.

I need a type for a function that behaves differently based on its arguments: [DESCRIBE THE OVERLOADS]. Write the overload signatures and explain when TypeScript requires this vs when a union return type works.

Write a generic function that [DESCRIBE BEHAVIOR, E.G. "GROUPS AN ARRAY BY A KEY"]. The return type should infer correctly so callers get full autocomplete. Show two usage examples.

Build a type-safe event emitter where events are defined in this map: [PASTE EVENT MAP]. The on(), off(), and emit() methods should be fully typed.

Explain conditional types with a practical example: [DESCRIBE USE CASE, E.G. "UNWRAP A PROMISE TYPE" OR "FLATTEN A NESTED ARRAY"]. Show the implementation and three real-world applications.

Write a builder pattern for [DESCRIBE OBJECT] where each method call narrows the type — so TypeScript enforces that required fields are set before .build() is callable.

I want to use the satisfies operator for this config object: [PASTE CONFIG]. Explain what satisfies adds compared to a plain type annotation and when to prefer it over as const.

I fetch data from this API: [DESCRIBE RESPONSE SHAPE]. Write the TypeScript types, a typed fetch wrapper with error handling, and a typed hook or service function to consume it.

Add strict TypeScript to this Redux or Zustand store: [PASTE STORE]. Type the state, actions, and selectors. Handle async actions with proper loading and error state types.

Write a typed React form for [DESCRIBE FIELDS AND VALIDATION RULES]. Use React Hook Form with Zod schema validation so the form is end-to-end type safe.

I want to add TypeScript to this Node.js Express route: [PASTE ROUTE]. Type the request params, query, body, and response. Show how to create a typed middleware wrapper.

Convert this untyped configuration to strict TypeScript: [PASTE CONFIG]. Add proper types, use const assertions or satisfies where appropriate, and explain why each change matters.

I have this TypeScript error: [PASTE FULL ERROR AND CODE]. Explain exactly what TypeScript is detecting, what it protects against, and show two correct ways to fix it.

Convert this JavaScript file to TypeScript: [PASTE FILE]. Add types progressively from function signatures outward, flag anything that needs runtime validation, and avoid using any.

I want to enable strict mode in this project. My current tsconfig: [PASTE]. Walk me through what each strict flag enables, the order to turn them on, and the most common errors each will surface.

This file is full of any types: [PASTE EXCERPT]. Replace every any with a proper type. Use unknown where the type is truly unknown and add type guards where narrowing is needed.

Explain the practical difference between these TypeScript patterns I keep mixing up: [LIST PAIRS, E.G. "INTERFACE VS TYPE ALIAS", "AS CONST VS SATISFIES", "UNKNOWN VS ANY"].