can i somehow magically use the typescript types from npm libraries? ie I use the

stripe

package. do i need to create my own external interfaces(or use with dynamic) every time?

Hi all, i am trying to find a way to export suspend function for js target, i have gone through multiple resources online but i am not able to find a way to do that the way i want. I want that

suspend fun foo(): String

should get converted to

foo(): Promise<string>;

in Js. From what i know there is no native support for this. I was able to reach a Js signature

fooAsync(): Promise<String>;

using kotlin-suspend-transform-compiler-plugin , but i would want to have the same signature(without async) as it would be easier for all 3 targets(android, ios and js) to follow the generated docs and use it. Is there a way to achieve this ? other obv option is to have duplicate exported api interfaces for only js, but i really don't wish to go that route. I was also thinking if this plugin or some other plugin could help me generate a synthetic function

@JsExport
@JsName("foo")
fun fooSynthetic(): Promise<String> // generated synthetic function

@JsName("_foo")
suspend fun foo(): String // original function defined in api

If somehow above could be achieved, i was thinking it could work ? (Please correct me if my thought process is wrong here, i am new to KMP) Thanks.

How does one actually enable this? https://kotlinlang.org/docs/whatsnew20.html#suspend-functions-as-es2015-generators Couldn’t find any docs. Is it enabled by default when we set compilation target to es2015?

is there a kotlin js wrapper for framer motion or something else to get easy list animations (delete / insert of items) without writing much code myself

Hi, I’m Genis, a 3D developer specializing in immersive web and interactive experiences. I leverage cutting-edge tools like: Three.js, Babylon.js → High-performance WebGL & 3D web apps Cesium, Mapbox → Geospatial & real-time 3D mapping Unity 3D → Games, simulations, AR/VR With 7+ years of experience, I build visually stunning, scalable solutions for clients worldwide. Check out my work: 👉 Portfolio: https://kakao-3d.vercel.app/ Let’s collaborate! Open to freelance projects, contract roles, or innovative partnerships. #3DDevelopment #Three.js #WebGL #Unity3D #GameDev #TechArt

@broadway_lamb regarding the Clojure Compiler discussion, and the fact the JS code has to be parsed and potentially lowered to older targets, what about using the TS compiler API? It's just a random idea, but it gives you a visitable AST + the ability to downlevel by compiling it. Yes, you'll have to implement a separate program (and exchange data with it, e.g. via a pipe?) to translate TS AST to something you can read in Kotlin, spawn a separate process, but it doesn't seem totally crazy. With

tsgo

this might become even easier as it won't require a Node instance to be running.

How to check if code is running in test mode (unit test)?

How can I dynamically link resources to my index.html via webpack? https://kotlinlang.org/docs/running-kotlin-js.html#run-the-browser-target Only shows hardcoded strings for the generated js file. When i want to use the webpack content hash for example, what is the best way to implement this?

outputFileName = “main.bundle-[contenthash].js”

What’s the current status of Automatic generation of Kotlin wrappers from TypeScript typings mentioned in https://blog.jetbrains.com/kotlin/2025/05/present-and-future-kotlin-for-web/ ? Is there a ticket to track the progress at YouTrack or GitHub?

Hey, I have a small Problem with TanStackQuery. The options that expect functions don't work.

useQuery<Array<DocumentationElementDto>?, Error, Array<DocumentationElementDto>, QueryKey>(
    options = UseQueryOptions(
        queryKey = DOCUMENTATION_QUERY_KEY.plus(subCategory),
        queryFn = QueryFunction { 
            secureApi(DocumentationEndpoints
                .getDocumentationElement
                .copy(optionalQueryParams = pairListOf("category" to subCategory))
        )},
        refetchOnMount = { _ -> false },
        refetchOnWindowFocus = { _ -> false },
        refetchOnReconnect = { _ -> false },
        refetchInterval = 0,
        refetchIntervalInBackground = false,
    )
)

In this case

refetchOnMount = { _ -> false },
refetchOnWindowFocus = { _ -> false },
refetchOnReconnect = { _ -> false },

doesn't work, but these two:

refetchInterval = 0,
refetchIntervalInBackground = false,

behave as expected. I also tried

useCallback { _ -> false }

, but it isn't accepted by the compiler.

I am using multiple kotlinjs in one project. Problem is, yarn is in root project and it is shared. thats makes conflicts, because of overwriting. Is there smart way to handle this?

Hey, I have a problem with the google maps api and the predefined marker symbols. I looked at this this and I use

<http://vis.gl/react-google-maps|vis.gl/react-google-maps>

, but I also loaded

googlemaps/js-api-loader

. If you look at the Marker example there is:

new google.maps.Marker({
    position: map.getCenter(),
    icon: {
      path: google.maps.SymbolPath.CIRCLE,
      scale: 10,
    },
    draggable: true,
    map: map,
  });

But I can't figure out how to aquire the predefined

google.maps.SymbolPath.CIRCLE

constant? object? Just providing the path as a string doesn't work it says unexpected g at position 0 (the g from google I guess). I tried

@file:JsModule("@googlemaps/js-api-loader")
@file:JsNonModule

package shared.utils.maps

@JsName("CIRCLE")
external val CIRCLE: dynamic

But that also doesn't work. I know I can provide my own SVG and PNG and such, but it kinda irks me, someone got an idea? Edit: Okay I added the npm https://www.npmjs.com/package/google-maps and added:

@file:JsModule("google-maps")
@file:JsNonModule

package shared.utils.maps

@JsName("CIRCLE")
external val CIRCLE: dynamic

But it seems that

CIRCLE

is

null

when I access it.

Are singletons not allowed anymore? I updated to

2025.6.11

and now I get

org.jetbrains.kotlin.util.FileAnalysisException: While analysing Authentication.kt:47:1: org.jetbrains.kotlin.utils.exceptions.KotlinIllegalArgumentExceptionWithAttachments: Exception in declaration checker

Caused by: java.lang.IllegalStateException: Symbol for Any not found

For every top level

object

declaration like

object Foo {
  val bar: Bar
}

where there is no

Any

? EDIT Okay I cleaned and invalidated everything and it doesn't come up for now. I'll check back once the migration is fixed. Edit2 I get the error with Kotlin 2.1.0, but not with 2.2.0, but migrating to 2.2.0 is much work now. sigh.

Vite for Kotlin 0.5.2 is released, and it finally supports Kotlin 2.1.0+! https://opensavvy.gitlab.io/automation/kotlin-vite/api-docs/

I have a KMP library with a JS library export. My Kotlin declarations are namespaced in JS so for example the user has to do:

const { PokeApi } = require('pokekotlin').co.pokeapi.pokekotlin

Is there any way to override that namespacing so JS users can use my library like:

const { PokeApi } = require('pokekotlin')

Or alternatively, is there a way to include some custom js and .d.ts in my Kotlin/JS library export? So I can define an index.js myself that re-exports my declarations from the root My goal is to have a single KMP library with an idiomatic API for Kotlin, Java, JS/TS, and Swift/ObjC, but the package name being exposed to JS is awkward there. It’s more than just the import syntax; LSP tooling like automatic imports and stuff don’t work well when the importable declarations are buried under a package hierarchy.

How do sourcemaps work? If I create a simple project and run

jsBrowserDevelopmentRun

, I get: •

build/js/packages/example-simple/kotlin/example-simple.js

•

build/js/packages/example-simple/kotlin/example-simple.js.map

The second one contains:

{
	"version": 3,
	"sources": [
		"../../../../../src/jsMain/kotlin/Main.kt",
		"../../../../compileSync/js/main/developmentExecutable/kotlin/src/kotlin/util/Standard.kt"
	],
    // …

The

Main.kt

file refers to my own source code, fine. However, I don't understand that

Standard.kt

file. The

build/compileSync/js/main/developmentExecutable/kotlin

folder does NOT contain a

src/

folder, and there is no

Standard.kt

file anywhere in the

build/

directory. What's going on here?

While running jsBrowserProductionWebpack, some of the modules generate with warnings. How can I see what those warning are?

> Task :web:jsBrowserProductionWebpack
asset web.js 221 KiB [emitted] [minimized] (name: main) 2 related assets
modules by path ../../node_modules/ 539 KiB
  modules by path ../../node_modules/react-dom/ 512 KiB 4 modules
  modules by path ../../node_modules/react/ 16.9 KiB
    ../../node_modules/react/index.js 186 bytes [built] [code generated]
    ../../node_modules/react/cjs/react.production.js 16.7 KiB [built] [code generated]
  modules by path ../../node_modules/scheduler/ 10.1 KiB
    ../../node_modules/scheduler/index.js 194 bytes [built] [code generated]
    ../../node_modules/scheduler/cjs/scheduler.production.js 9.94 KiB [built] [code generated]
modules by path ./kotlin/*.js 158 KiB
  ./kotlin/prison-web.js 16.2 KiB [built] [code generated] [3 warnings]
  ./kotlin/kotlin-kotlin-stdlib.js 124 KiB [built] [code generated] [64 warnings]
  ./kotlin/kotlin-react.js 2.92 KiB [built] [code generated] [5 warnings]
  ./kotlin/kotlin-react-core.js 6.69 KiB [built] [code generated] [6 warnings]
  ./kotlin/prison-core.js 3.82 KiB [built] [code generated]
  ./kotlin/kotlin-react-dom.js 4.5 KiB [built] [code generated] [6 warnings]
webpack 5.94.0 compiled successfully in 4535 ms

If I have a Kotlin/JS library with a dependency on an NPM module, is that NPM module passed on as a transient dependency to my consumers, or do those library consumers also have to include the

npm(..)

entry in their gradle file?

I have a problem where I am writing a multiplatform library, but marking classes with

@JsExport

only works on classes that exclusively use non-suspending functions. Is there a way to transform the suspending functions into functions returning promises automatically? In case I need to do it manually I am also not quite sure how to do that, since I want to mostly keep the existing class but only transform a couple of suspending functions to promises.

Could anyone provide feedback or articles on how to profile Kotlin code running in a browser environment?

Hey, I was wondering if it is possible to publish have Kotlin/Js project for node so it's accessible through Typescript, the usage is simple, I have serializable classes in the backend and being able to re-use it in the frontend (react) without needing to re-make them in Typescript would be awesome.

Hey everyone! I'm encountering an error (

No matching export in "<kmp-library>.mjs" for import "KtList"

) when I switch to ES2015 target. The issue is also described in this ticket. Is there any workaround for it?

Any idea why kotlinx-browser is available for wasm js but not for js ir?

With Kotlin 2.2.0 I'm seeing a ton of

> Task :kotlinNpmInstall FAILED
error <https://registry.yarnpkg.com/webpack-merge/-/webpack-merge-4.2.2.tgz>: Extracting tar content of undefined failed, the file appears to be corrupt: "ENOENT: no such file or directory, open '/usr/local/share/.cache/yarn/v6/npm-webpack-merge-4.2.2-a27c52ea783d1398afd2087f547d7b9d2f43634d-integrity/node_modules/webpack-merge/lib/join-arrays.js.map'"

across all my projects, across all CI runners, with different packages. Do we know what could cause this? At the moment, it's hard to upgrade because all JS pipelines fail more than ~50% of the time

Hi everyone waving from afar right I'm looking for more information on the JetBrains Kotlin-wrapper library. Does anyone have experience working with this library, especially the wrappers for kotlin-react or kotlin-react-dom? It seems that the latest versions require Kotlin 2.2.0, but I cannot find this info in the changelogs. I would like to use this library, but since I cannot find version compatibility info or any official communication channels, I am worried about maintainability.

I'm intermittently receiving this issue in Intellij IDEA Community. It seemed to start happening after switching to Kotlin 2.2.0. It's not too intrusive yet, since rerunning the

jsBrowserDevelopmentRun

task usually works. I'm nowhere near max RAM on on my box though, this happens when usage is at < 30%. No noticeable increase in usage before or after.

java.lang.OutOfMemoryError: GC overhead limit exceeded
	at java.base/java.util.ArrayList.iterator(ArrayList.java:1029)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$DeclarationTransformer.rewriteTypesInFunction(PartiallyLinkedIrTreePatcher.kt:1397)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$DeclarationTransformer.visitSimpleFunction(PartiallyLinkedIrTreePatcher.kt:293)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:131)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:19)
	at org.jetbrains.kotlin.ir.declarations.IrSimpleFunction.accept(IrSimpleFunction.kt:39)
	at org.jetbrains.kotlin.ir.IrElementBase.transform(IrElementBase.kt:33)
	at org.jetbrains.kotlin.ir.declarations.IrProperty.transformChildren(IrProperty.kt:55)
...

Hey, I have a Problem with TanStackQuery and TanStackTables, When I receive an

Array

through

useQuery<Array<MyType>>()

and feed it into the TanStackTable directly everyting works, no problems. But when I filter the

Array

or convert it to a list for other reasons and then convert it back via

.toTypedArray()

the TanStackTable displays the data correctly, but it refreshes infinitely and very fast lagging the tab. I can see the constant

getXXXModel()

log messages in the console.

previewDataQuery
  .data
  ?.filter { it.active }
  ?.toTypedArray()

Someone got a suggestion how to fix this? Edit: So the behaviour is essentially like this:

useReactTable(data = previewData) // OK
useReactTable(data = previewData.toList().toTypedArray()) // Infinite Loop

Looks like the

BigInt

adoption in place of a custom

Long

implementation will be very useful for kotlinx-io, or for the UUID/hex stdlib utilities, as they make use of longs quite often.

for sure :), was stuck with this problem for providing common types in a library on all 3 targets (js, ios, android) And KMP messes it up for Long types in JS, as generated code and .d.ts mapped it to

any

type solved it like below:

// common

expect class NativeLong

expect fun toNativeLong(value: Long): NativeLong

actual fun toKtLong(value: NativeLong): Long

// js

actual typealias NativeLong = BigInt

actual fun toNativeLong(value: Long) = (js("BigInt") as (dynamic) -> BigInt)(value.toString())

actual fun toKtLong(value: NativeLong) = value.toString().toLong() // throws if out-of-range

// ios/android

actual typealias NativeLong = Long

actual fun toNativeLong(value: Long): NativeLong = value

actual fun toKtLong(value: NativeLong): Long = value

And if it’s used in a

@Serializable

class, we provide a custom serializer based on target platform Now I can use it as:

data class UserId(id: NativeLong)

fun takeInput(value: NativeLong)

And its easily usable for js devs

// generated .d.ts

export declare class UserId {

constructor(id: BigInt);

get id(): BigInt;

copy(id?: BigInt): UserId;

toString(): string;

hashCode(): number;

equals(other: Nullable<any>): boolean;

}

export declare function takeInput(num: BigInt): void;

The primary downside here is overhead of

toKtLong()

in js, which decodes->encodes the value on every call. Solvable using a “holder” type for native values, which has a lazy prop that holds the kotlin long value. For folks who have tackled this, please suggest your methods and any issues you see with above. (like if using typealiasing like this has any risks for exported types etc)

This is just me arbitrarily assuming things, so I might be completely wrong. With the incoming transition to using an external JS downleveling tool (e.g., SWC, Babel, etc.), the K/JS compiler backend could be simplified as it doesn't have to consider many options related to the ES targets anymore, or related to the module systems. That is, the compiler could simply emit ESM ES20xx code and delegate the translation to CJS/UMD/etc. and older ES versions to the external tool. This also means if Kotlin sets some baseline options (e.g., ESM + ES2020), and the developer doesn't need to change that baseline, the external tool could be skipped entirely. Theoretically it means compilation speed, especially during development, could get a lot better. Edit: tho I'm still ignorant about how the TS type declaration generation will be reshaped.