medusa-store/www/apps/docs/content/references/medusa/classes/medusa.AbstractTaxService.mdx

---
displayed_sidebar: homepage
---

import ParameterTypes from "@site/src/components/ParameterTypes"

# AbstractTaxService

## Overview

A tax provider is used to retrieve the tax lines in a cart. The Medusa backend provides a default `system` provider. You can create your own tax provider,
either in a plugin or directly in your Medusa backend, then use it in any region.

A tax provider class is defined in a TypeScript or JavaScript file under the `src/services` directory and the class must extend the
`AbstractTaxService` class imported from `@medusajs/medusa`. The file's name is the tax provider's class name as a slug and without the word `Service`.

For example, you can create the file `src/services/my-tax.ts` with the following content:

```ts title="src/services/my-tax.ts"
import {
  AbstractTaxService,
  ItemTaxCalculationLine,
  ShippingTaxCalculationLine,
  TaxCalculationContext,
} from "@medusajs/medusa"
import {
  ProviderTaxLine,
} from "@medusajs/medusa/dist/types/tax-service"

class MyTaxService extends AbstractTaxService {
  async getTaxLines(
    itemLines: ItemTaxCalculationLine[],
    shippingLines: ShippingTaxCalculationLine[],
    context: TaxCalculationContext):
    Promise<ProviderTaxLine[]> {
    throw new Error("Method not implemented.")
  }
}

export default MyTaxService
```

---

## Identifier Property

The `TaxProvider` entity has 2 properties: `identifier` and `is_installed`. The `identifier` property in the tax provider service is used when the tax provider is added to the database.

The value of this property is also used to reference the tax provider throughout Medusa. For example, it is used to [change the tax provider](https://docs.medusajs.com/modules/taxes/admin/manage-tax-settings#change-tax-provider-of-a-region) to a region.

```ts title="src/services/my-tax.ts"
class MyTaxService extends AbstractTaxService {
  static identifier = "my-tax"
  // ...
}
```

---

## constructor

You can use the `constructor` of your tax provider to access the different services in Medusa through dependency injection.

You can also use the constructor to initialize your integration with the third-party provider. For example, if you use a client to connect to the third-party provider’s APIs, you can initialize it in the constructor and use it in other methods in the service.
Additionally, if you’re creating your tax provider as an external plugin to be installed on any Medusa backend and you want to access the options added for the plugin, you can access it in the constructor.

### Example

```ts
// ...
import { LineItemService } from "@medusajs/medusa"

type InjectedDependencies = {
  lineItemService: LineItemService
}

class MyTaxService extends AbstractTaxService {
  protected readonly lineItemService_: LineItemService

  constructor({ lineItemService }: InjectedDependencies) {
    super(arguments[0])
    this.lineItemService_ = lineItemService

    // you can also initialize a client that
    // communicates with a third-party service.
    this.client = new Client(options)
  }

  // ...
}

export default MyTaxService
```

### Parameters

<ParameterTypes parameters={[{"name":"container","type":"`Record<string, unknown>`","description":"An instance of `MedusaContainer` that allows you to access other resources, such as services, in your Medusa backend.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"config","type":"`Record<string, unknown>`","description":"If this tax provider is created in a plugin, the plugin's options are passed in this parameter.","optional":true,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="new AbstractTaxService"/>

___

## Properties

<ParameterTypes parameters={[{"name":"identifier","type":"`string`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"container","type":"`Record<string, unknown>`","description":"An instance of `MedusaContainer` that allows you to access other resources, such as services, in your Medusa backend.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"manager_","type":"`EntityManager`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"transactionManager_","type":"`undefined` \\| `EntityManager`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"__container__","type":"`any`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"config","type":"`Record<string, unknown>`","description":"If this tax provider is created in a plugin, the plugin's options are passed in this parameter.","optional":true,"defaultValue":"","expandable":false,"children":[]},{"name":"__configModule__","type":"`Record<string, unknown>`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]},{"name":"__moduleDeclaration__","type":"`Record<string, unknown>`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="AbstractTaxService"/>

___

## Accessors

### activeManager\_

#### Returns

<ParameterTypes parameters={[{"name":"EntityManager","type":"`EntityManager`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="activeManager_"/>

___

## Methods

### getTaxLines

This method is used when retrieving the tax lines for line items and shipping methods.
This occurs during checkout or when calculating totals for orders, swaps, or returns.

#### Example

An example of how this method is implemented in the `system` provider implemented in the Medusa backend:

```ts
// ...

class SystemTaxService extends AbstractTaxService {
  // ...

  async getTaxLines(
    itemLines: ItemTaxCalculationLine[],
    shippingLines: ShippingTaxCalculationLine[],
    context: TaxCalculationContext
  ): Promise<ProviderTaxLine[]> {
    let taxLines: ProviderTaxLine[] = itemLines.flatMap((l) => {
      return l.rates.map((r) => ({
        rate: r.rate || 0,
        name: r.name,
        code: r.code,
        item_id: l.item.id,
      }))
    })

    taxLines = taxLines.concat(
      shippingLines.flatMap((l) => {
        return l.rates.map((r) => ({
          rate: r.rate || 0,
          name: r.name,
          code: r.code,
          shipping_method_id: l.shipping_method.id,
        }))
      })
    )

    return taxLines
  }
}
```

#### Parameters

<ParameterTypes parameters={[{"name":"itemLines","type":"[ItemTaxCalculationLine](../types/medusa.ItemTaxCalculationLine.mdx)[]","description":"The line item lines to calculate taxes for.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"shippingLines","type":"[ShippingTaxCalculationLine](../types/medusa.ShippingTaxCalculationLine.mdx)[]","description":"The shipping method lines to calculate taxes for.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"context","type":"[TaxCalculationContext](../types/medusa.TaxCalculationContext.mdx)","description":"Context relevant and useful for the taxes calculation.","optional":false,"defaultValue":"","expandable":false,"children":[{"name":"shipping_address","type":"[Address](../../entities/classes/entities.Address.mdx) \\| `null`","description":"The shipping address used in the cart.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"customer","type":"[Customer](../../entities/classes/entities.Customer.mdx)","description":"The customer that the cart belongs to.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"region","type":"[Region](../../entities/classes/entities.Region.mdx)","description":"The cart's region.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"is_return","type":"`boolean`","description":"Whether the cart is used in a return flow.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"shipping_methods","type":"[ShippingMethod](../../entities/classes/entities.ShippingMethod.mdx)[]","description":"The shipping methods used in the cart.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"allocation_map","type":"[LineAllocationsMap](../types/medusa.LineAllocationsMap.mdx)","description":"The gift cards and discounts applied on line items.\nEach object key or property is an ID of a line item","optional":false,"defaultValue":"","expandable":false,"children":[]}]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="getTaxLines"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;[ProviderTaxLine](../types/medusa.ProviderTaxLine.mdx)[]&#62;","optional":false,"defaultValue":"","description":"The list of calculated line item and shipping method tax lines.\nIf an item in the array has the `shipping_method_id` property, then it's a shipping method tax line. Otherwise, if it has\nthe `item_id` property, then it's a line item tax line.","expandable":false,"children":[{"name":"ProviderTaxLine[]","type":"[ProviderTaxLine](../types/medusa.ProviderTaxLine.mdx)[]","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="getTaxLines"/>

### withTransaction

#### Parameters

<ParameterTypes parameters={[{"name":"transactionManager","type":"`EntityManager`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="withTransaction"/>

#### Returns

<ParameterTypes parameters={[{"name":"this","type":"`this`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="withTransaction"/>

### shouldRetryTransaction\_

#### Parameters

<ParameterTypes parameters={[{"name":"err","type":"`Record<string, unknown>` \\| `object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="shouldRetryTransaction_"/>

#### Returns

<ParameterTypes parameters={[{"name":"boolean","type":"`boolean`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="shouldRetryTransaction_"/>

### atomicPhase\_

Wraps some work within a transactional block. If the service already has
a transaction manager attached this will be reused, otherwise a new
transaction manager is created.

#### Type Parameters

<ParameterTypes parameters={[{"name":"TResult","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"TError","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="atomicPhase_"/>

#### Parameters

<ParameterTypes parameters={[{"name":"work","type":"(`transactionManager`: `EntityManager`) => Promise&#60;TResult&#62;","description":"the transactional work to be done","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"isolationOrErrorHandler","type":"`IsolationLevel` \\| (`error`: TError) => Promise&#60;void \\| TResult&#62;","description":"the isolation level to be used for the work.","optional":true,"defaultValue":"","expandable":false,"children":[]},{"name":"maybeErrorHandlerOrDontFail","type":"(`error`: TError) => Promise&#60;void \\| TResult&#62;","description":"Potential error handler","optional":true,"defaultValue":"","expandable":false,"children":[]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="atomicPhase_"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;TResult&#62;","optional":false,"defaultValue":"","description":"the result of the transactional work","expandable":false,"children":[{"name":"TResult","type":"TResult","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}]} expandUrl="https://docs.medusajs.com/development/entities/repositories#retrieving-a-list-of-records" sectionTitle="atomicPhase_"/>