Translator v3.0

What's new?

Version 3 of the Translator provides a modern JSON-based Web API. It improves usability and performance by consolidating existing features into fewer operations and it provides new features.

  • Transliteration to convert text in one language from one script to another script.
  • Translation to multiple languages in one request.
  • Language detection, translation, and transliteration in one request.
  • Dictionary to look up alternative translations of a term, to find back-translations and examples showing terms used in context.
  • More informative language detection results.

Base URLs

Requests to Translator are, in most cases, handled by the datacenter that is closest to where the request originated. If there's a datacenter failure when using the global endpoint, the request may be routed outside of the geography.

To force the request to be handled within a specific geography, use the desired geographical endpoint. All requests are processed among the datacenters within the geography.

Geography Base URL (geographical endpoint) Datacenters
Global (non-regional) api.cognitive.microsofttranslator.com Closest available datacenter
Asia Pacific api-apc.cognitive.microsofttranslator.com Korea South, Japan East, Southeast Asia, and Australia East
Europe api-eur.cognitive.microsofttranslator.com North Europe, West Europe
United States api-nam.cognitive.microsofttranslator.com East US, South Central US, West Central US, and West US 2

1 Customers with a resource located in Switzerland North or Switzerland West can ensure that their Text API requests are served within Switzerland. To ensure that requests are handled in Switzerland, create the Translator resource in the 'Resource region' 'Switzerland North' or 'Switzerland West', then use the resource's custom endpoint in your API requests. For example: If you create a Translator resource in Azure portal with 'Resource region' as 'Switzerland North' and your resource name is 'my-ch-n', then your custom endpoint is "https://my-ch-n.cognitiveservices.azure.com". And a sample request to translate is:

// Pass secret key and region using headers to a custom endpoint
curl -X POST " my-ch-n.cognitiveservices.azure.com/translator/text/v3.0/translate?to=fr" \
-H "Ocp-Apim-Subscription-Key: xxx" \
-H "Ocp-Apim-Subscription-Region: switzerlandnorth" \
-H "Content-Type: application/json" \
-d "[{'Text':'Hello'}]" -v

2 Custom Translator isn't currently available in Switzerland.

Authentication

Subscribe to Translator or Cognitive Services multi-service in Azure Cognitive Services, and use your key (available in the Azure portal) to authenticate.

There are three headers that you can use to authenticate your subscription. This table describes how each is used:

Headers Description
Ocp-Apim-Subscription-Key Use with Cognitive Services subscription if you're passing your secret key.
The value is the Azure secret key for your subscription to Translator.
Authorization Use with Cognitive Services subscription if you're passing an authentication token.
The value is the Bearer token: Bearer <token>.
Ocp-Apim-Subscription-Region Use with Cognitive Services multi-service and regional translator resource.
The value is the region of the multi-service or regional translator resource. This value is optional when using a global translator resource.

Secret key

The first option is to authenticate using the Ocp-Apim-Subscription-Key header. Add the Ocp-Apim-Subscription-Key: <YOUR_SECRET_KEY> header to your request.

Authenticating with a global resource

When you use a global translator resource, you need to include one header to call the Translator.

Headers Description
Ocp-Apim-Subscription-Key The value is the Azure secret key for your subscription to Translator.

Here's an example request to call the Translator using the global translator resource

// Pass secret key using headers
curl -X POST "https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=es" \
     -H "Ocp-Apim-Subscription-Key:<your-key>" \
     -H "Content-Type: application/json" \
     -d "[{'Text':'Hello, what is your name?'}]"

Authenticating with a regional resource

When you use a regional translator resource, there are two headers that you need to call the Translator.

Headers Description
Ocp-Apim-Subscription-Key The value is the Azure secret key for your subscription to Translator.
Ocp-Apim-Subscription-Region The value is the region of the translator resource.

Here's an example request to call the Translator using the regional translator resource

// Pass secret key and region using headers
curl -X POST "https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=es" \
     -H "Ocp-Apim-Subscription-Key:<your-key>" \
     -H "Ocp-Apim-Subscription-Region:<your-region>" \
     -H "Content-Type: application/json" \
     -d "[{'Text':'Hello, what is your name?'}]"

Authenticating with a Multi-service resource

A Cognitive Service multi-service resource allows you to use a single API key to authenticate requests for multiple services.

When you use a multi-service secret key, you must include two authentication headers with your request. There are two headers that you need to call the Translator.

Headers Description
Ocp-Apim-Subscription-Key The value is the Azure secret key for your multi-service resource.
Ocp-Apim-Subscription-Region The value is the region of the multi-service resource.

Region is required for the multi-service Text API subscription. The region you select is the only region that you can use for text translation when using the multi-service key. It must be the same region you selected when you signed up for your multi-service subscription through the Azure portal.

If you pass the secret key in the query string with the parameter Subscription-Key, then you must specify the region with query parameter Subscription-Region.

Authenticating with an access token

Alternatively, you can exchange your secret key for an access token. This token is included with each request as the Authorization header. To obtain an authorization token, make a POST request to the following URL:

Resource type Authentication service URL
Global https://api.cognitive.microsoft.com/sts/v1.0/issueToken
Regional or Multi-Service https://<your-region>.api.cognitive.microsoft.com/sts/v1.0/issueToken

Here are example requests to obtain a token given a secret key for a global resource:

// Pass secret key using header
curl --header 'Ocp-Apim-Subscription-Key: <your-key>' --data "" 'https://api.cognitive.microsoft.com/sts/v1.0/issueToken'

// Pass secret key using query string parameter
curl --data "" 'https://api.cognitive.microsoft.com/sts/v1.0/issueToken?Subscription-Key=<your-key>'

And here are example requests to obtain a token given a secret key for a regional resource located in Central US:

// Pass secret key using header
curl --header "Ocp-Apim-Subscription-Key: <your-key>" --data "" "https://centralus.api.cognitive.microsoft.com/sts/v1.0/issueToken"

// Pass secret key using query string parameter
curl --data "" "https://centralus.api.cognitive.microsoft.com/sts/v1.0/issueToken?Subscription-Key=<your-key>"

A successful request returns the encoded access token as plain text in the response body. The valid token is passed to the Translator service as a bearer token in the Authorization.

Authorization: Bearer <Base64-access_token>

An authentication token is valid for 10 minutes. The token should be reused when making multiple calls to the Translator. However, if your program makes requests to the Translator over an extended period of time, then your program must request a new access token at regular intervals (for example, every 8 minutes).

Authentication with Azure Active Directory (Azure AD)

Translator v3.0 supports Azure AD authentication, Microsoft's cloud-based identity and access management solution. Authorization headers enable the Translator service to validate that the requesting client is authorized to use the resource and to complete the request.

Prerequisites

Headers

Header Value
Authorization The value is an access bearer token generated by Azure AD.
  • The bearer token provides proof of authentication and validates the client's authorization to use the resource.
  • An authentication token is valid for 10 minutes and should be reused when making multiple calls to Translator.
  • See Sample request: 2. Get a token
Ocp-Apim-Subscription-Region The value is the region of the translator resource.
  • This value is optional if the resource is global.
Ocp-Apim-ResourceId The value is the Resource ID for your Translator resource instance.
  • You'll find the Resource ID in the Azure portal at Translator Resource → Properties.
  • Resource ID format:
    /subscriptions/<subscriptionId>/resourceGroups/<resourceGroupName>/providers/Microsoft.CognitiveServices/accounts/<resourceName>/
Translator property page—Azure portal

Screenshot:Translator properties page in the Azure portal.

Examples

Using the global endpoint

 // Using headers, pass a bearer token generated by Azure AD, resource ID, and the region.

curl -X POST "https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=es" \
     -H "Authorization: Bearer <Base64-access_token>"\
     -H "Ocp-Apim-ResourceId: <Resource ID>" \
     -H "Ocp-Apim-Subscription-Region: <your-region>" \
     -H "Content-Type: application/json" \
     -data-raw "[{'Text':'Hello, friend.'}]"

Using your custom endpoint

// Using headers, pass a bearer token generated by Azure AD.

curl -X POST https://<your-custom-domain>.cognitiveservices.azure.com/translator/text/v3.0/translate?api-version=3.0&to=es \
     -H "Authorization: Bearer <Base64-access_token>"\
     -H "Content-Type: application/json" \
     -data-raw "[{'Text':'Hello, friend.'}]"

Examples using managed identities

Translator v3.0 also supports authorizing access to managed identities. If a managed identity is enabled for a translator resource, you can pass the bearer token generated by managed identity in the request header.

With the global endpoint

// Using headers, pass a bearer token generated either by Azure AD or Managed Identities, resource ID, and the region.

curl -X POST https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=es \
     -H "Authorization: Bearer <Base64-access_token>"\
     -H "Ocp-Apim-ResourceId: <Resource ID>" \
     -H "Ocp-Apim-Subscription-Region: <your-region>" \
     -H "Content-Type: application/json" \
     -data-raw "[{'Text':'Hello, friend.'}]"

With your custom endpoint

//Using headers, pass a bearer token generated by Managed Identities.

curl -X POST https://<your-custom-domain>.cognitiveservices.azure.com/translator/text/v3.0/translate?api-version=3.0&to=es \
     -H "Authorization: Bearer <Base64-access_token>"\
     -H "Content-Type: application/json" \
     -data-raw "[{'Text':'Hello, friend.'}]"

Virtual Network support

The Translator service is now available with Virtual Network (VNET) capabilities in all regions of the Azure public cloud. To enable Virtual Network, See Configuring Azure Cognitive Services Virtual Networks.

Once you turn on this capability, you must use the custom endpoint to call the Translator. You can't use the global translator endpoint ("api.cognitive.microsofttranslator.com") and you can't authenticate with an access token.

You can find the custom endpoint after you create a translator resource and allow access from selected networks and private endpoints.

Headers Description
Ocp-Apim-Subscription-Key The value is the Azure secret key for your subscription to Translator.
Ocp-Apim-Subscription-Region The value is the region of the translator resource. This value is optional if the resource is global

Here's an example request to call the Translator using the custom endpoint

// Pass secret key and region using headers
curl -X POST "https://<your-custom-domain>.cognitiveservices.azure.com/translator/text/v3.0/translate?api-version=3.0&to=es" \
     -H "Ocp-Apim-Subscription-Key:<your-key>" \
     -H "Ocp-Apim-Subscription-Region:<your-region>" \
     -H "Content-Type: application/json" \
     -d "[{'Text':'Hello, what is your name?'}]"

Errors

A standard error response is a JSON object with name/value pair named error. The value is also a JSON object with properties:

  • code: A server-defined error code.
  • message: A string giving a human-readable representation of the error.

For example, a customer with a free trial subscription would receive the following error once the free quota is exhausted:

{
  "error": {
    "code":403001,
    "message":"The operation isn't allowed because the subscription has exceeded its free quota."
    }
}

The error code is a 6-digit number combining the 3-digit HTTP status code followed by a 3-digit number to further categorize the error. Common error codes are:

Code Description
400000 One of the request inputs isn't valid.
400001 The "scope" parameter is invalid.
400002 The "category" parameter is invalid.
400003 A language specifier is missing or invalid.
400004 A target script specifier ("To script") is missing or invalid.
400005 An input text is missing or invalid.
400006 The combination of language and script isn't valid.
400018 A source script specifier ("From script") is missing or invalid.
400019 One of the specified languages isn't supported.
400020 One of the elements in the array of input text isn't valid.
400021 The API version parameter is missing or invalid.
400023 One of the specified language pair isn't valid.
400035 The source language ("From" field) isn't valid.
400036 The target language ("To" field) is missing or invalid.
400042 One of the options specified ("Options" field) isn't valid.
400043 The client trace ID (ClientTraceId field or X-ClientTranceId header) is missing or invalid.
400050 The input text is too long. View request limits.
400064 The "translation" parameter is missing or invalid.
400070 The number of target scripts (ToScript parameter) doesn't match the number of target languages (To parameter).
400071 The value isn't valid for TextType.
400072 The array of input text has too many elements.
400073 The script parameter isn't valid.
400074 The body of the request isn't valid JSON.
400075 The language pair and category combination isn't valid.
400077 The maximum request size has been exceeded. View request limits.
400079 The custom system requested for translation between from and to language doesn't exist.
400080 Transliteration isn't supported for the language or script.
401000 The request isn't authorized because credentials are missing or invalid.
401015 "The credentials provided are for the Speech API. This request requires credentials for the Text API. Use a subscription to Translator."
403000 The operation isn't allowed.
403001 The operation isn't allowed because the subscription has exceeded its free quota.
405000 The request method isn't supported for the requested resource.
408001 The translation system requested is being prepared. Retry in a few minutes.
408002 Request timed out waiting on incoming stream. The client didn't produce a request within the time that the server was prepared to wait. The client may repeat the request without modifications at any later time.
415000 The Content-Type header is missing or invalid.
429000, 429001, 429002 The server rejected the request because the client has exceeded request limits.
500000 An unexpected error occurred. If the error persists, report it with date/time of error, request identifier from response header X-RequestId, and client identifier from request header X-ClientTraceId.
503000 Service is temporarily unavailable. Retry. If the error persists, report it with date/time of error, request identifier from response header X-RequestId, and client identifier from request header X-ClientTraceId.

Metrics

Metrics allow you to view the translator usage and availability information in Azure portal, under metrics section as shown in the below screenshot. For more information, see Data and platform metrics.

Translator Metrics

This table lists available metrics with description of how they're used to monitor translation API calls.

Metrics Description
TotalCalls Total number of API calls.
TotalTokenCalls Total number of API calls via token service using authentication token.
SuccessfulCalls Number of successful calls.
TotalErrors Number of calls with error response.
BlockedCalls Number of calls that exceeded rate or quota limit.
ServerErrors Number of calls with server internal error(5XX).
ClientErrors Number of calls with client-side error(4XX).
Latency Duration to complete request in milliseconds.
CharactersTranslated Total number of characters in incoming text request.