---
title: "Dynamic Import (experimental)"
description: "Learn about how the SolidStart SDK leverages dynamic input() in the build output."
url: https://docs.sentry.io/platforms/javascript/guides/solidstart/install/dynamic-import/
---

# Dynamic Import (experimental) | Sentry for SolidStart

## [Understanding the `import()` expression](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/dynamic-import.md#understanding-the-import-expression)

This setting is experimental as it is not guaranteed to work with every setup and the underlying functionality could change.

We recommend reading the guide for installing the SDK with the [CLI flag `--import`](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/cli-import.md) or [limited server tracing](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/limited-server-tracing.md)

The `import()` expression, or dynamic import, enables flexible, conditional module loading in ESM. Node.js will generate a separate module graph for any code wrapped in a dynamic `import()`. This separate graph is evaluated **after** all modules, which are statically `import`ed.

By using the Sentry SolidStart SDK, the server-side application will be wrapped in a dynamic `import()`, while the Sentry instrumentation file will be imported with a static `import`. This makes it possible to initialize the Sentry SolidStart SDK at startup, while the Nitro server runtime loads later because it is `import()`ed. This early initialization of Sentry is required to correctly set up the SDK's instrumentation of various libraries.

## [Scenarios where `import()` doesn't work](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/dynamic-import.md#scenarios-where-import-doesnt-work)

Depending on your setup and which version of Vinxi is used (and respectively Nitro, as this runs under the hood), the server-side is sometimes not correctly initialized. The build output **must not** include a regular `import` of the Nitro runtime (e.g. `import './chunks/nitro/nitro.mjs'`).

You can also check out the guide for installing the SDK with the [CLI flag `--import`](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/cli-import.md) or [limited-server-tracing](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/limited-server-tracing.md).

## [Initializing Sentry with Dynamic `import()`](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/dynamic-import.md#initializing-sentry-with-dynamic-import)

Enable the dynamic `import()` by setting `autoInjectServerSentry`:

`app.config.ts`

```typescript
import { defineConfig } from "@solidjs/start/config";
import { withSentry } from "@sentry/solidstart";

export default defineConfig(
  withSentry(
    {},
    {

      autoInjectServerSentry: "experimental_dynamic-import",

    },
  ),
);
```

After setting this, the Sentry SolidStart SDK will add build-time configuration so that your app will be wrapped with `import()`, ensuring that Sentry can be initialized before any other modules.

The SolidStart server entry file will look something like this:

`.output/server/index.mjs`

```javascript
// Note: The file may have some imports and code, related to debug IDs
Sentry.init({
  dsn: "...",
});

import("./chunks/nitro/nitro.mjs").then(function (n) {
  return n.r;
});
```

## [Re-exporting serverless handler functions](https://docs.sentry.io/platforms/javascript/guides/solidstart/install/dynamic-import.md#re-exporting-serverless-handler-functions)

Sentry automatically detects serverless handler functions in the build output and re-exports them from the server entry file.

By default, Sentry re-exports functions named `handler`, `server`, and `default` exports. This will work in most cases and no other action is required. If your serverless function has a custom name, you can override it with `experimental_entrypointWrappedFunctions`:

`app.config.ts`

```javascript
import { defineConfig } from "@solidjs/start/config";
import { withSentry } from "@sentry/solidstart";

export default defineConfig(
  withSentry(
    {},
    {
      autoInjectServerSentry: "experimental_dynamic-import",
      // Customize detected function names
      // Default value: ['default', 'handler', 'server']

      experimental_entrypointWrappedFunctions: ["customFunctionName"],

    },
  ),
);
```