Installing and configuring the JavaScript SDK

The SDK is distributed as the taxmaxi npm package and ships full TypeScript type definitions — no separate @types package is needed. Choose the installation command that matches your package manager, then follow the configuration steps for your runtime.

Install the package

npm install taxmaxi

yarn add taxmaxi

pnpm add taxmaxi

Configure your client

The TaxMaxi class is the single entry point for all SDK operations. How you construct it depends on how your application authenticates with the TaxMaxi API.

API key
Browser session
Server-side (SSR)

Use new TaxMaxi({ apiKey }) when your code runs on a server or in a script and you hold a session token directly. The apiKey is the session token returned by POST /auth/login — pass it as a bearer token.

import { TaxMaxi } from "taxmaxi"

const client = new TaxMaxi({ apiKey: "your-session-token" })

The apiKey option accepts the session token returned by POST /auth/login, not a long-lived API key. Treat it like a password and keep it out of source control.

Use TaxMaxi.fromBrowserSession() in browser applications that authenticate through your own login UI. The SDK sends requests with credentials: "include" so session cookies are forwarded automatically — no token management required.

import { TaxMaxi } from "taxmaxi"

const client = TaxMaxi.fromBrowserSession()

You can also supply a custom baseUrl or additional headers if needed:

const client = TaxMaxi.fromBrowserSession({
  baseUrl: "https://api.taxmaxi.com",
})

Use TaxMaxi.fromRequest() in server-side rendering contexts such as Next.js route handlers or SvelteKit load functions. Pass the raw Cookie header from the incoming request so the SDK can forward it to the TaxMaxi API on behalf of the user.

import { TaxMaxi } from "taxmaxi"

// Example: Next.js App Router route handler
export async function GET(request: Request) {
  const client = TaxMaxi.fromRequest({
    cookieHeader: request.headers.get("cookie") ?? "",
  })

  const sources = await client.sources.list()
  return Response.json(sources)
}

Constructor options

When using new TaxMaxi(options), the constructor accepts a TaxMaxiOptions object:

Option	Type	Required	Description
`apiKey`	`string`	Yes	Session token used as a bearer token on every request
`baseUrl`	`string \| URL`	No	Override the API base URL. Defaults to `https://api.taxmaxi.com`
`fetch`	`typeof globalThis.fetch`	No	Custom `fetch` implementation — useful for testing or edge runtimes
`headers`	`TaxMaxiHeadersProvider`	No	Additional headers to attach to every request

TypeScript support

The SDK is written in TypeScript and all types are included in the package. No additional configuration is required. Import types directly alongside values:

import { TaxMaxi } from "taxmaxi"
import type { TaxCalculation, SourceSyncJob } from "taxmaxi"

Your editor will surface parameter types, return types, and inline documentation for every SDK method as you type.

Get Started

CLI

JavaScript SDK

Core Concepts

Installing and configuring the JavaScript SDK

Install the package

Configure your client

Constructor options

TypeScript support

​Install the package

​Configure your client

​Constructor options

​TypeScript support

Install the package

Configure your client

Constructor options

TypeScript support