Tips for working with APIs

GET

• Call (GET) the endpoint to list all the API
• Call (GET) the endpoint with $metadata to list all metadata for the API

• Calling a resource API (GET) will return a list of all instances of the resource type

• Each resource is uniquely identified through an ID, see the following example:

  {
      "@odata.context": "<endpoint>/$metadata#companies",
      "value": [
          {
              "id": "bb6d48b6-c7b2-4a38-9a93-ad5506407f12",
              "systemVersion": "18453",
              "name": "CRONUS USA, Inc.",
              "displayName": "CRONUS USA, Inc.",
              "businessProfileId": ""
          }
      ]
  }
  

• The resource ID must be provided in the URL when trying to read or modify a resource or any of its children. The ID is provided in () after the API endpoint. For example, to GET the "CRONUS USA, Inc." company details, you must call <endpoint>/companies(bb6d48b6-c7b2-4a38-9a93-ad5506407f12)/

• All resources live in the context of a parent company, which means that the company ID must be provided in the URL for all resource API calls. For example, to GET all customers in the "CRONUS USA, Inc." company, you must call <endpoint>/companies(bb6d48b6-c7b2-4a38-9a93-ad5506407f12)/customers

Accept-Language HTTP header

By specifying Accept-Language in the request header, you can set a specific language for your web service response. It's recommended to use this setting, if your app is dependent on a web service response to be in a specific language. If Accept-Language is set, it will override default settings. This setting also controls the regional formatting settings, affecting behavior such as how date and time will be formatted.

One of the most common examples is showing error messages to the users in their language. To see which possible error messages to display, see Error Codes. Another common example is displaying reports in a specific language, see the example below for how to specify Accept-Language. The following example sets the language to always be en-US.

Example

GET businesscentralPrefix/companies({id})/salesInvoices({salesInvoiceId})/pdfDocument({salesInvoiceId})/content

Request headers

Header	Value
Authorization	Bearer {token}. Required.
Accept-Language	en-US

Request body

Don't supply a request body for this method.

Response

If successful, this method returns a 200 OK response code and a report PDF file in the response body.

OData transactional $batch requests

APPLIES TO: Business Central 2020 release wave 2 (version 17.1) and later

It's possible to specify that all inner requests in a certain OData $batch request are processed in a transactional way. If one of the inner requests fails after another request (or requests) has committed changes, all changes within a batch will be reverted as if the batch request never happened. Transactional $batch requests are useful in scenarios where a single business operation spans multiple requests, because they prevent adverse effects if parts of the operation fail. Also, they can improve performance by reducing the number of requests the client needs to do when errors occur.

To enable transactional batch behavior, include the Isolation: snapshot header with the $batch request.

For more information, see Using OData Transactional $batch Requests

Specifying Data Access Intent for GET requests

By specifying HTTP request header Data-Access-Intent, it's possible to override data access intent of the API page or query that has been defined with DataAccessIntent property.

Note

Setting the DataAccessIntent property to ReadOnly doesn't guarantee that your data access will be running on the secondary replica. It's merely stating that the code only requires read ability, so a read-only connection can be used.

For example, the property doesn't apply to queries running at arbitrary times during normal AL execution (that is, the server doesn't change to ReadOnly mode in the middle of a transaction). So for queries, the property only fully applies when they're exposed as an API/OData feed directly.

Possible header values

Value	Description
ReadOnly	Intent to access records, but not to modify them. The page or query reads data from a replica of the database (if available), reducing the load on the primary database, but prevents modifications to the database records.
ReadWrite	Intent to access and modify records.

When request header is specified, the value of the DataAccessIntent property defined on the object, if any, is ignored. Overrides that are specified on the page 9880 Database Access Intent List take higher precedence than the value in the request header.

Modification requests (like POST, PUT, or DELETE) only support ReadWrite as a value for data access intent. Trying to specify Data-Access-Intent: ReadOnly for such requests will result in an error.

Example

GET businesscentralPrefix/companies({id})/salesInvoices({salesInvoiceId})/pdfDocument({salesInvoiceId})/content

Request headers

Header	Value
Authorization	Bearer {token}. Required.
Data-Access-Intent	ReadOnly

Request body

Don't supply a request body for this method.

Response

If successful, this method returns a 200 OK response code and a report PDF file in the response body.

See Also

Using Filtering With APIs
API performance
Performance Articles For Developers
DataAccessIntent property