DAX REST API

Base URL: http://localhost:3000

These endpoints let you run and validate DAX queries directly over HTTP — no Power BI, Excel, or XMLA client in the loop. Point any HTTP client at your model and get results back as JSON.

Evaluate DAX

POST /models/{id}/dax/evaluate
Content-Type: text/plain

Executes a DAX query against the model and returns the tabular result. A query may contain multiple EVALUATE statements; each produces one result table in the response array.

Path parameters

Request body

Raw DAX query text:

EVALUATE
SUMMARIZECOLUMNS(
    'Product'[Color],
    "Revenue", [Total Sales]
)

Response 200 OK

An array — one entry per EVALUATE statement in the query:

[
  {
    "columns": [
      { "name": "Product[Color]", "data_type": "string" },
      { "name": "Revenue",        "data_type": "double" }
    ],
    "rows": [
      ["Blue", "1234.50"],
      ["Red",  null],
      ["Green","780.00"]
    ]
  }
]

All values are serialised as strings. null indicates a blank or missing cell. Column data_type values match those used by the List tables endpoint (string, integer, double, boolean, dateTime, etc.).

Response 400 Bad Request

Returned when the DAX engine rejects the query (parse failure, evaluation error, etc.):

{ "error": "Unknown column: Sales.Amountt" }

Response 404 Not Found — model ID does not exist.

Validate DAX

POST /models/{id}/dax/validate
Content-Type: text/plain

Validates a DAX query against the model without executing it. Three phases run in order — a later phase only runs if the earlier one passes:

1. Syntax — the query must be parseable DAX (EVALUATE ..., optionally with a DEFINE block).
2. Semantic — all column references (Table[Column]), table references, and function names must exist in the model.
3. Type — argument types must satisfy each function’s signature.

Path parameters

Request body

Raw DAX query text, for example:

EVALUATE
SUMMARIZECOLUMNS(
    'Product'[Color],
    "Revenue", [Total Sales]
)

Response 200 OK — valid query

{
  "valid": true,
  "errors": []
}

Response 200 OK — invalid query

{
  "valid": false,
  "errors": [
    {
      "kind": "syntax",
      "message": " --> 1:9\n  |\n1 | EVALUTE ...\n  |         ^---\n  |\n  = expected ..."
    },
    {
      "kind": "semantic",
      "message": "Unknown column: Sales.Amountt"
    },
    {
      "kind": "type",
      "message": "Type error: ..."
    }
  ]
}

The endpoint always returns 200 OK. Errors are reported in the body, not via HTTP status codes. Multiple errors can be returned when more than one expression fails to bind.

Error kind values

Response 404 Not Found — model ID does not exist.