Azure Search Service REST

Azure Search is a fully managed cloud search service that provides a rich search experience to custom applications. One way to add search capability is through a REST API, with operations that create and manage indexes, load data, implement search features, execute queries, and handle results.

Version 2016-09-01 is the second generally available release of the Azure Search Service REST API. New features in this API version include:

  • Custom analyzers, which allow you to take control over the process of converting text into indexable and searchable terms.
  • Azure Blob Storage and Azure Table Storage indexers, which allow you to easily import data from Azure storage into Azure Search on a schedule or on-demand.
  • Field mappings, which allow you to customize how indexers import data into Azure Search.
  • ETags, which allow you to update the definitions of indexes, indexers, and data sources in a concurrency-safe manner.

For details on how to upgrade to version 2016-09-01 from the previous GA version, see Upgrading to the Azure Search Service REST API version 2016-09-01.


Azure Search has the concepts of search services and indexes and documents, where a search service contains one or more indexes that provides persistent storage of searchable data, and data is loaded in the form of JSON documents. Data is typically pushed to an index from an external data source, but if you use an indexer, it's possible to crawl a data source to extract and load data into an index.

There are three types of operations that can be executed against the service:

  • Index management operations. Create, delete, update, or configure a search index.

  • Document operations. Add, update, or delete documents in the index, query the index, or look up specific documents by ID.

  • Indexer operations. Automate aspects of an indexing operation by configuring a data source and an indexer that you can schedule or run on demand. This feature is supported for a limited number of data source types.

    A separate REST API is provided for service administration, including provisioning the service or altering capacity. For more information, see Azure Search Management REST.

    The APIs documented in this section provide access to operations on search data, such as index creation and population, document upload, and queries. When calling the API, keep the following points in mind:

  • All APIs must be issued over HTTPS (on the default port 443).

  • Your search service is uniquely identified by a fully-qualified domain name (for example: ``).

  • All API requests must include an api-key that was generated for the Search service you provisioned. Having a valid key establishes trust, on a per request basis, between the application sending the request and the service that handles it.

  • All API requests must include the api-version in the URI. Its value must be set to the version of the current service release, shown in the following example:

    GET https://[search service name]

  • All API requests can optionally set the Accept HTTP header. If the header is not set, the default is assumed to be application/json.


The endpoint for service operations is the URL of the Azure Search service you provisioned: https://<yourService>


api-version=2016-09-01 is the general release version. This version operates under an Azure service level agreement (SLA).

Preview versions of the REST API are used to collect community feedback on new features before adding them to the general release. See API versions in Azure Search for details.

Authentication and Authorization

Every HTTP request to your search service is authenticated based on two pieces of information: a Search service URL and an api-key that provides proof the request is from a trusted entity. There are two types of api-keys for different levels of operation.

Key Description Limits
Admin Admin keys grant full rights to all operations, including the ability to manage the service, create and delete indexes, indexers, and data sources.

Two admin api-keys, referred to as primary and secondary keys in the portal, are generated when the service is created and can be individually regenerated on demand. Having two keys allows you to roll over one key while using the second key for continued access to the service.

Admin keys are only specified in HTTP request headers. You cannot place an admin api-key in a URL.
Maximum of 2 per service
Query Query keys grant read-only access to indexes and documents, and are typically distributed to client applications that issue search requests.

Query keys are created on demand. You can create them manually in the portal or programmatically via the Management REST API.

Query keys can be specified in an HTTP request header for search, suggestion, or lookup operation. Alternatively, you can pass a query key as a parameter on a URL. Depending on how your client application formulates the request, it might be easier to pass the key as a query parameter:

GET /indexes/hotels/docs?search=*&$orderby=lastRenovationDate desc&api-version=2016-09-01&api-key=A8DA81E03F809FE166ADDB183E9ED84D
50 per service

Visually, there is no distinction between an admin key or query key. Both keys are strings composed of 32 randomly-generated alpha-numeric characters. If you lose track of what type of key is specified in your application, you can check the key values in the portal or use the REST API to return the value and key type.


It is considered a poor security practice to pass sensitive data such as an api-key in the request URI. For this reason, Azure Search will only accept a query key as an api-key in the query string, and you should avoid doing so unless the contents of your index should be publicly available. As a general rule, we recommend passing your api-key as a request header.

Authorization in Azure Search

Authorization is available for administrative operations via the role-based access controls (RBAC) provided in the Azure portal. RBAC roles are used to set levels of access for service administration in a way that is consistent across all services. For example, viewing sensitive data, such as the admin key, is restricted to the Owner and Contributor roles, whereas viewing service status is available to members of any role.

For its own search-centric operations, Azure Search does not provide an authorization model. However, if you have the ability to load an index with document and user associations, you can filter search results based on user identity. For more information, see Security filters for trimming results in Azure Search.

Azure Search Operations

Azure Search service API supports two URL syntaxes for API operations: Simple query syntax in Azure Search and OData syntax (see Support for OData (Azure Search) for details). The following list shows the simple syntax

To create the service, see Create an Azure Search service. followed by How to build a .NET application with Azure Search.

See also

Azure Search: tutorials, video demos, and samples
Supported data types (Azure Search)
Create an Azure Search service
Pricing Details
Manage your search service on Microsoft Azure
Naming rules (Azure Search)
Common HTTP request and response headers used in Azure Search
Azure Search Management REST Azure Search .NET SDK