microsoft/autogen · error · InvalidOperationException

Parameter name cannot be null

Error message

Parameter name cannot be null

What it means

Error "Parameter name cannot be null" thrown in microsoft/autogen.

Source

Thrown at dotnet/src/AutoGen.AzureAIInference/Extension/FunctionContractExtension.cs:34

    /// Convert a <see cref="FunctionContract"/> to a <see cref="FunctionDefinition"/> that can be used in gpt funciton call.
    /// </summary>
    /// <param name="functionContract">function contract</param>
    /// <returns><see cref="FunctionDefinition"/></returns>
    public static FunctionDefinition ToAzureAIInferenceFunctionDefinition(this FunctionContract functionContract)
    {
        var functionDefinition = new FunctionDefinition
        {
            Name = functionContract.Name,
            Description = functionContract.Description,
        };
        var requiredParameterNames = new List<string>();
        var propertiesSchemas = new Dictionary<string, JsonSchema>();
        var propertySchemaBuilder = new JsonSchemaBuilder().Type(SchemaValueType.Object);
        foreach (var param in functionContract.Parameters ?? [])
        {
            if (param.Name is null)
            {
                throw new InvalidOperationException("Parameter name cannot be null");
            }

            var schemaBuilder = new JsonSchemaBuilder().FromType(param.ParameterType ?? throw new ArgumentNullException(nameof(param.ParameterType)));
            if (param.Description != null)
            {
                schemaBuilder = schemaBuilder.Description(param.Description);
            }

            if (param.IsRequired)
            {
                requiredParameterNames.Add(param.Name);
            }

            var schema = schemaBuilder.Build();
            propertiesSchemas[param.Name] = schema;

        }
        propertySchemaBuilder = propertySchemaBuilder.Properties(propertiesSchemas);

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Give every parameter of the function a valid name

Example fix

Annotate the method parameter with a non-null name

When it happens

Trigger: Thrown at dotnet/src/AutoGen.AzureAIInference/Extension/FunctionContractExtension.cs:34 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/eb207b0406e8a504. Report an issue: GitHub.