Modal SDKs for JavaScript and Go

Modal also provides SDKs (currently in beta) that enable using Modal Functions and Sandboxes from JavaScript/TypeScript and Go projects.

While Python is the primary language for building Modal applications and implementing Modal Functions, these SDKs enable use cases like:

Using Sandboxes in JS/Go projects, to safely execute arbitrary commands, run untrusted user code, or as a safe environment for AI agents.
Directly calling Modal Functions without having to go through a web endpoint.
Interacting with Modal resources like Volumes, Secrets, Queues, etc. directly from JS/Go.

We’re working towards feature parity with the main Modal Python SDK, although defining Modal Functions will likely remain exclusive to Python.

Installation

For installation instructions, see the READMEs for JavaScript and Go on GitHub.

JavaScript/TypeScript

The modal package is distributed via npm. See the JS API reference documentation for details.

Simple JavaScript Example

import { ModalClient } from "modal";

const modal = new ModalClient();

const app = await modal.apps.fromName("libmodal-example", {
  createIfMissing: true,
});

// Create a Sandbox with the specified Image, and mount a Volume
const volume = await modal.volumes.fromName("libmodal-example-volume", {
  createIfMissing: true,
});
const image = modal.images.fromRegistry("alpine:3.21");
const sb = await modal.sandboxes.create(app, image, {
  volumes: { "/mnt/volume": volume },
});
const p = await sb.exec(["cat", "/mnt/volume/message.txt"]);
console.log(`Message: ${await p.stdout.readText()}`);
await sb.terminate();

// Call a previously deployed Modal Function
const echo = await modal.functions.fromName("libmodal-example", "echo");
console.log(await echo.remote(["Hello world!"]));

There are many more examples available on GitHub.

Go

The modal-go package is installed via go get. See the Go API reference documentation for details.

Simple Go Example

package main

import (
	"context"
	"fmt"
	"io"

	"github.com/modal-labs/libmodal/modal-go"
)

func main() {
	// Skipping err handling throughout for brevity
	ctx := context.Background()

	mc, _ := modal.NewClient()

	app, _err := mc.Apps.FromName(ctx, "libmodal-example", &modal.AppFromNameParams{CreateIfMissing: true})

	// Create a Sandbox with the specified Image, and mount a Volume
	volume, _ := mc.Volumes.FromName(ctx, "libmodal-example-volume", &modal.VolumeFromNameParams{CreateIfMissing: true})
	image := mc.Images.FromRegistry("alpine:3.21", nil)
	sb, _ := mc.Sandboxes.Create(ctx, app, image, &modal.SandboxCreateParams{
		Volumes: map[string]*modal.Volume{"/mnt/volume": volume},
	})
	defer sb.Terminate(context.Background())
	p, _ := sb.Exec(ctx, []string{"cat", "/mnt/volume/message.txt"}, nil)
	stdout, _ := io.ReadAll(p.Stdout)
	fmt.Printf("Message: %s\n", stdout)

	// Call a previously deployed Modal Function
	echo, _ := mc.Functions.FromName(ctx, "libmodal-example", "echo", nil)
	result, _ := echo.Remote(ctx, []any{"Hello world!"}, nil)
	fmt.Println(result)
}

There are many more examples available on GitHub.

Support

The JS and Go Modal SDKs are in active development, and we love to hear your feedback. If you have questions or suggestions, please reach out on the Modal Community Slack.