Query/management HTTP request

Request verb and resource

Action HTTP verb HTTP resource
Query GET /v1/rest/query
Query POST /v1/rest/query
Query v2 GET /v2/rest/query
Query v2 POST /v2/rest/query
Management POST /v1/rest/mgmt

For example, to send a management command ("management") to a service endpoint, use the following request line:

POST https://help.kusto.windows.net/v1/rest/mgmt HTTP/1.1

See below for the request headers and body to include.

Request headers

The following table contains the common headers used for query and management operations.

Standard header Description Required/Optional
Accept Set to application/json Required
Accept-Encoding Supported encodings are gzip and deflate Optional
Authorization See authentication Required
Connection We recommend that you enable Keep-Alive Optional
Content-Length We recommend that you specify the request body length when known Optional
Content-Type Set to application/json with charset=utf-8 Required
Expect Can be set to 100-Continue Optional
Host Set to the qualified domain name that the request was sent to (for example, help.kusto.windows.net) Required

The following table contains the common custom headers used for query and management operations. Unless otherwise indicated, these headers are used for telemetry purposes only, and have no functionality impact.

All headers are optional. We recommend that you specify the x-ms-client-request-id custom header. In some scenarios, such as canceling a running query, this header is required because it's used to identify the request.

Custom header Description
x-ms-app The (friendly) name of the application making the request
x-ms-user The (friendly) name of the user making the request
x-ms-user-id Same as x-ms-user
x-ms-client-request-id A unique identifier for the request
x-ms-client-version The (friendly) version identifier for the client making the request
x-ms-readonly If specified, forces the request to run in read-only mode, preventing it from making long-lasting changes

Request parameters

The following parameters can be passed in the request. They're encoded in the request as query parameters or as part of the body, depending on whether GET or POST is used.

Parameter Description Required/Optional
csl Text of the query or management command to execute Required
db Name of the database in scope that is the target of the query or management command Optional for some management commands.
Required for other commands and all queries.
properties Provides request properties that modify how the request is processed and its results. For more information, see Request properties Optional

GET query parameters

When GET is used, the query parameters of the request specify the request parameters.


When POST is used, the body of the request is a single JSON document encoded in UTF-8, with the values of the request parameters.


This example shows the HTTP POST request for a query.

POST https://help.kusto.windows.net/v2/rest/query HTTP/1.1

Request headers

Accept: application/json
Authorization: Bearer ...AzureActiveDirectoryAccessToken...
Accept-Encoding: deflate
Content-Type: application/json; charset=utf-8
Host: help.kusto.windows.net
x-ms-client-request-id: MyApp.Query;e9f884e4-90f0-404a-8e8b-01d883023bf1
x-ms-user-id: EARTH\davidbg
x-ms-app: MyApp

Request body

  "csl":"print Test=\"Hello, World!\"",

This example shows how to create a request that sends the query above, using curl.

  1. Obtain a token for authentication.

    Replace AAD_TENANT_NAME_OR_ID, AAD_APPLICATION_ID, and AAD_APPLICATION_KEY with the relevant values, after having set up Microsoft Entra application authentication

    curl "https://login.microsoftonline.com/AAD_TENANT_NAME_OR_ID/oauth2/token" \
      -F "grant_type=client_credentials" \
      -F "resource=https://help.kusto.windows.net" \
      -F "client_id=AAD_APPLICATION_ID" \
      -F "client_secret=AAD_APPLICATION_KEY"

    This code snippet will provide you with the bearer token.

      "token_type": "Bearer",
      "expires_in": "3599",
  2. Use the bearer token in your request to the query endpoint.

    curl -d '{"db":"Samples","csl":"print Test=\"Hello, World!\"","properties":"{\"Options\":{\"queryconsistency\":\"strongconsistency\"}}"}"' \
    -H "Accept: application/json" \
    -H "Authorization: Bearer eyJ0...uXOQ" \
    -H "Content-Type: application/json; charset=utf-8" \
    -H "Host: help.kusto.windows.net" \
    -H "x-ms-client-request-id: MyApp.Query;e9f884e4-90f0-404a-8e8b-01d883023bf1" \
    -H "x-ms-user-id: EARTH\davidbg" \
    -H "x-ms-app: MyApp" \
    -X POST https://help.kusto.windows.net/v2/rest/query
  3. Read the response according to this specification.

Set client request properties and query parameters

In the following example body, the query in the csl field declares two parameters named n and d. The values for those query parameters are specified within the Parameters field under the properties field in the request body. The Options field defines client request properties.


Non-string and non-long parameters must be expressed as KQL literals in string format.

    "db": "Samples",
    "csl": "declare query_parameters (n:long, d:dynamic); StormEvents | where State in (d) | top n by StartTime asc",
    "properties": {
        "Options": {
            "maxmemoryconsumptionperiterator": 68719476736,
            "max_memory_consumption_per_query_per_node": 68719476736,
            "servertimeout": "50m"
        "Parameters": {
            "n": 10, "d": "dynamic([\"ATLANTIC SOUTH\"])"

For more information, see Query parameters.