Preview Reports with AI-generated Test Data in Visual Studio Report Designer

• Sep 18, 2025
• 3 minutes to read

With the DevExpress AI-powered Assistant, you can generate AI-powered test data to preview reports without connecting to a live data source directly within the Visual Studio Report Designer. This feature uses the report’s data source schema and expression bindings to create a JSON test data set.

DevExpress AI Assistant for Visual Studio

The DevExpress Unified Component Installer installs the AI-powered Assistant for Visual Studio extension.

Configure AI Services

Go to Tools → Options → DevExpress → AI Assistant to open AI Assistant options.

Option	Description
Endpoint URL	The service endpoint used to connect to Azure OpenAI. For OpenAI connections, this option must be empty.
API Key	A personal access key required to authenticate requests to the AI service.
Model Name	The identifier of the AI model (for example, gpt-4o-mini).
Enable Logging	If enabled, the extension records request and response details for diagnostic purposes. Logs are stored in the following folder: C:\Documents and Settings<UserName>\AppData\Local\DevExpress\AI_Assistant_VSIX
Enable Prompt Caching	If enabled, previously used prompts and responses are cached to improve performance and reduce repeated requests.

Warning

Some OpenAI models (for example, GPT-5, o1, and o3 series) do not support the Temperature parameter. To avoid runtime exceptions when targeting these models, set the Temperature to 1. The value is ignored by the service, but this setting prevents validation/compatibility errors.

Configure Test DataSource Options

Option	Description
Row Count	Specifies the number of rows/records the AI service generates for the test data source.
Temperature	Controls randomness in AI output and produces more deterministic results. Higher values increase variation. The default value is 0.

Preview Reports with AI-generated Test Data

Click the Test Data tab to preview the report with AI-generated test data. The Report Designer requests data from an LLM and populates the report with meaningful values for preview.

Troubleshooting

Test Data Tab Is Not Displayed

Possible Cause

The DevExpress AI-powered Assistant for Visual Studio extension is disabled.

Solution

Open the Extension Manager in Visual Studio (Extensions → Manage Extensions…). Switch to the Installed tab and enable the DevExpress AI-powered Assistant for Visual Studio extension. Restart Visual Studio.

HTTP 400 (Unsupported Value)

Possible Cause

Some OpenAI models (for example, GPT-5, o1, and o3 series) do not support the Temperature parameter.

Solution

Open AI Assistant Options and check Model Name and Temperature settings. If the selected model does not accept the Temperature, set the Temperature to 1 to avoid errors, or switch to a supported model (for example, gpt-4o-mini).

HTTP 404 (Deployment Not Found)

Possible Cause

The specified model deployment does not exist. This may happen if the deployment name is incorrect, if the deployment was recently created and is not yet active, or if it was deleted.

Solution

Open AI Assistant Options and check the Model Name setting.