Reports

I also find the answer to this question.

This below URL is able to get the pipeline definition.

POST https://api.fabric.microsoft.com/v1/workspaces/{workspaceId}/items/{itemId}/getDefinition

{
    "definition": {
        "parts": [
            {
                "path": "pipeline-content.json",
                "payload": "ewogsdfsdfsdf7sdfICJwcm9wZXJ0aWVz",
                "payloadType": "InlineBase64"
            },
            {
                "path": ".platform",
                "payload": "ewogIasdfsdf7sdfCIkc2NoZW",
                "payloadType": "InlineBase64"
            }
        ]
    }
}

Here, "payload" properties contain the definition of items in the encoded format. So, we need to decode it to see the proper output in JSON format.

79502660