Cursor AI is an AI-powered code editor that uses your project's TypeScript language server, open type definitions, and compiler diagnostics as live context to generate code, which is why its output gets sharper as your types get stricter. Cursor is fast for everyone. For TypeScript developers, it's a different class of tool.
Language Server Protocol (LSP) is the mechanism that gives Cursor real-time visibility into type errors, hover types, and diagnostics as you type, rather than just the static text of the file. Discriminated union is a TypeScript pattern where a shared literal field, like status, lets the compiler narrow which branch of a type applies, which is also what lets Cursor generate exhaustive switch handling automatically.
When your type system is strict and complete, Cursor generates code that actually fits your codebase, not just code that compiles. It reads your tsconfig, your open type files, and your LSP diagnostics as live context. The more precise your types, the more accurate the generation. I've been using this combination for eight months across three production projects, and these are the patterns that genuinely changed my workflow.
These 20 tips skip the basics. No "press Tab to accept." Just TypeScript-specific patterns where the type system changes what Cursor can do, the same principle covered in TypeScript as AI contracts, applied to a Cursor-specific workflow.
Quick take: Cursor with TypeScript is a completely different tool than Cursor with JavaScript. It reads your tsconfig, your open type files, and live LSP diagnostics as context, so the stricter your types, the sharper its generations get, that's not marketing, I've measured it across eight months and three production projects. Write the interface first. Let Cursor fill in the body. Turn on
strict: true, keep a.cursorrulesfile banningany, and always reference specific interfaces by name in prompts. Runtsc --noEmitafter chaining more than one generation, it's caught combinations that looked fine alone but didn't compile.
How Do You Set Up Cursor for TypeScript Projects?
Cursor uses your project's TypeScript language server as a context source, this is documented in the Cursor official docs. With strict: true enabled and LSP running, Cursor sees every type error in real time and uses that signal when generating code. Four setup steps make this work properly.
Tip 1: Enable strict: true in tsconfig
Cursor reads your tsconfig to understand the constraints it must satisfy. Without strict: true, it'll generate any types, skip null checks, and produce implicit any parameters, all technically valid, all wrong. With strict mode on, Cursor knows those patterns will cause errors and avoids them. This single flag changes the quality of every generation in the project. For the full breakdown of what each strict flag catches and how to migrate an existing codebase without breaking everything at once, see the TypeScript strict mode guide.
Tip 2: Create a .cursorrules file with your TypeScript preferences
This file is read as context on every generation. I use it to set three rules: no any, explicit return types on all exported functions, and Zod for any external data validation. Write them the way you'd explain them to a new engineer: "Don't use any. If you need an unknown type, use unknown and narrow it. Always annotate the return type on exported functions." Plain rules work better than TypeScript-specific notation here.
Tip 3: Keep the TypeScript language server running
Cursor uses LSP diagnostics as live context, it can see which lines have errors and what those errors say before it generates anything. If your language server is off or slow, Cursor is flying blind. Check that tsserver is running in VS Code (bottom status bar should show TypeScript version). A cold language server is the most common reason Cursor suggestions feel less accurate right after opening a project.
Tip 4: Point Cursor at your types directory with @ references
When prompting in Cursor chat, use @ to add your types/ or @types/ folder to the context window explicitly. "Implement the payment handler using @types/payment.ts" gives Cursor the exact interface definitions rather than having it infer them from usage. This matters most for complex domain types with many interdependencies.
In practice, the stricter your tsconfig, the better Cursor gets: plain strict mode sharpens inference, adding noUncheckedIndexedAccess catches more edge cases, and a project .cursorrules file pushes accuracy higher still. The model is only ever as precise as the types you hand it.
Here's the setup checklist I run through on every new project before I trust Cursor with real work:
- Enable
strict: truein tsconfig.json and confirm zero existing errors, or budget time to fix them first. - Add a
.cursorrulesfile with no more than five core rules, longer lists get ignored more often. - Confirm the TypeScript language server is running by checking the version number in the editor status bar.
- Open your
types/folder in a split pane so its interfaces stay in Cursor's active context automatically.
According to the Cursor documentation, the editor treats the language server as one of its primary context sources for in-editor suggestions, alongside open files and recently edited code. That means a cold or crashed tsserver process silently degrades suggestion quality without throwing any visible error, which is why checking the status bar is step three above and not an afterthought.
Should You Write Types First and Let Cursor Fill in Logic?
Writing the interface before the implementation is the single biggest multiplier for Cursor quality. With a complete type definition in context, Cursor's job becomes implementing logic that satisfies a known contract, not guessing the shape of data. Here's how to do it across five patterns. In my own measurements across three production repos over eight months, generations that started from a hand-written interface needed roughly one-third the review edits compared to generations where I described the shape in plain English and let Cursor infer types from scratch. That gap held whether the target was a REST handler, a form validator, or a data transform.
Tip 5: Write the interface first, then ask Cursor to implement it
This is the base pattern. Define your input types and return type, write the function signature with explicit return annotation, leave the body empty with a // TODO: implement comment, then accept Cursor's completion. The comment triggers Cursor to fill in the body, and because the signature constrains the output, the generation is almost always type-correct.
Tip 6: Use discriminated unions as prompts, Cursor handles each branch
Define a discriminated union and Cursor generates exhaustive handling automatically. TypeScript will error at the switch statement if a case is missing, so Cursor is incentivized to handle every branch (the TypeScript generics guide covers when to reach for unions vs. generics). This produces better code than asking "write an error handler" in plain English ever will.
type FetchResult<T> =
| { status: 'success'; data: T }
| { status: 'error'; code: string; message: string }
| { status: 'loading' };
// Cursor completes: write a renderOrder function that handles FetchResult<Order>Tip 7: Ask for Zod schemas that match your existing TypeScript types
Paste your interface and ask "write a Zod schema for this type." Cursor produces a schema that matches your types, and you get z.infer<typeof Schema> back for free, keeping your Zod schema and TypeScript type in sync without manual maintenance. Pair this with the vibe-coding TypeScript quality framework for the broader review checklist around AI-generated code.
Tip 8: Generate test scaffolding from TypeScript function signatures
Cursor reads function signatures and infers what tests make sense. "Write Vitest unit tests for this function" with the typed signature in context produces tests with correct argument types and return value assertions. Tests generated without types tend to use any throughout, worthless as a quality gate.
Tip 9: Let Cursor write generic utilities when you define the type constraints first
Generics are dense specifications. T extends { id: string; createdAt: Date } tells Cursor exactly what it can assume about T. It knows item.id is valid, item.name is not. The constraint removes guessing entirely. Write the generic signature, add a // TODO: implement in the body, and Cursor fills it in correctly.
What Prompting Patterns Work Best with TypeScript?
How you phrase prompts matters as much as what context you provide. These five patterns consistently produce type-correct output with less review time.
Tip 10: Reference specific interfaces by name in every prompt
"Implement using the UserService interface" is dramatically better than "write a user service." The interface name is a pointer to a concrete contract Cursor can read. In my workflow, I keep the relevant type files open in split view so they're in Cursor's active context window automatically.
Tip 11: Paste tsc errors directly into Cursor chat
Don't describe what's wrong, paste the full compiler error. The error message contains the exact types involved, the expected shape, and the actual shape. Cursor can parse that structured information more reliably than natural language descriptions. "Fix this error: [paste full tsc output]" works better than "the function returns the wrong type."
Tip 12: Ask for refactors bounded by the interface contract
"Refactor this function without changing the public interface" keeps Cursor from changing function signatures in ways that break callers. The explicit constraint matters, Cursor will otherwise optimize for what looks clean, not for what's compatible with the rest of the codebase.
Tip 13: Chain prompts in sequence: schema, then validator, then tests
This builds on each step's output. Define the interface, ask for the Zod schema, ask for a validator using that schema, ask for tests using the validator. Each generation has the previous output as context. Run tsc --noEmit between each step. The chain produces coherent, type-consistent code in a way that single large prompts rarely do.
Tip 14: Use // TODO: implement inside typed function bodies
Don't ask Cursor to write a function from scratch, write the signature, add the comment, and let inline completion fill in the body. This pattern gets you better output than chat because Cursor sees the full file context, not just what you pasted. The TypeScript signature is a constraint the completion has to satisfy right there in the editor.
How Do You Review and Catch AI Mistakes in TypeScript?
Cursor makes mistakes. TypeScript catches most of them, but not all. These six habits cover the cases TypeScript misses and the patterns AI tools get wrong most often.
Tip 15, search for any in every generated file.
noImplicitAny prevents some any usage, but not explicit as any casts or : any annotations. After a generation, run a quick search for any in the changed files. AI tools reach for any when they can't infer a type, which is exactly when you need the type to be explicit.
Tip 16, Verify Zod schemas match TypeScript types.
Cursor sometimes generates a Zod schema that compiles but has subtle differences from the source type, an optional() where the field is required, a string() where the type expects a union. The TypeScript type and the Zod schema can diverge in ways that TypeScript won't catch unless you're using z.infer and assigning the result to the typed variable. Check field-by-field on any Zod generation.
Tip 17, Run tsc --noEmit after every major generation.
Single-function completions inside a well-typed file rarely need this. But after generating a Zod schema, a validator, and a set of tests in sequence, the compiler catches combinations that look right individually but don't compose. I run it with a keyboard shortcut bound to tsc --noEmit. Three seconds, zero surprises. On TypeScript 7 the check drops under a second on most repos, which makes the habit free; the TypeScript 7 migration guide covers the upgrade if you're still on 5.x.
Tip 18, verify async error handling. Check that generated async functions handle errors with typed catch blocks.
Cursor often generates async functions with catch (e) and then uses e.message, which is wrong because e is typed as unknown in strict mode. The pattern should be catch (e: unknown) with a type guard. It's a small thing but it's a type error that only surfaces at compile time, not runtime, and Cursor gets it wrong regularly.
Tip 19, Validate union type narrowing in generated switch statements.
Cursor sometimes generates exhaustive switches that miss a discriminant case, usually a newer variant that was added after the base pattern was generated. Add an exhaustiveness check:
function assertNever(x: never): never {
throw new Error('Unhandled case: ' + JSON.stringify(x));
}
// Add to switch default: default: return assertNever(result);TypeScript will error at the assertNever(result) call if result can still be any of the union variants. Cursor doesn't always add this. Add it yourself.
Tip 20, Use Cursor's diff view before accepting any multi-line change.
One as unknown as SomeType cast can hide a type error for weeks. The diff view makes these casts visible, they is notable as a red flag in the diff even when they blend into surrounding code. I never accept a generation larger than five lines without reviewing the diff. This is the single habit that has caught the most subtle AI mistakes in my actual projects.
The TypeScript type system isn't just a safety net. It's a specification that Cursor can read. The more precise your types, the more accurate the generation, and the less time you spend reviewing output for type correctness rather than for logic. Strict types make Cursor faster, not slower. That's the whole argument.
All Tips at a Glance
| Category | Tips | Focus |
|---|---|---|
| Setup (1-4) | strict tsconfig, .cursorrules, language server, @ type references | Give Cursor the right context before generating |
| Types-first workflow (5-9) | Interface first, discriminated unions, Zod schemas, test scaffolding, generic utilities | Let types drive what Cursor generates |
| Prompting patterns (10-14) | Name interfaces, paste tsc errors, bound refactors, chain prompts, TODO markers | Shape prompts around the type contract |
| Review and catch mistakes (15-20) | Search for any, verify Zod/type match, exhaustiveness checks, diff view before accepting | Catch what TypeScript alone won't |