microsoft/autogen · critical · ConfigurationErrorsException

Orleans:CosmosDBConnectionString is missing from configurati

Error message

Orleans:CosmosDBConnectionString is missing from configuration. This is required for persistence in production environments.

What it means

ConfigurationErrorsException thrown by the Orleans runtime hosting extension when the environment is not development and 'Orleans:CosmosDBConnectionString' is absent from configuration. In production mode the silo is configured with Cosmos DB clustering/persistence, which is impossible without the connection string, so startup aborts.

Source

Thrown at dotnet/src/Microsoft.AutoGen/RuntimeGateway.Grpc/Services/Orleans/OrleansRuntimeHostingExtenions.cs:41

        {
            // Development mode or local mode uses in-memory storage and streams
            if (builder.Environment.IsDevelopment())
            {
                siloBuilder.UseLocalhostClustering()
                       .AddMemoryStreams("StreamProvider")
                       .AddMemoryGrainStorage("PubSubStore")
                       .AddMemoryGrainStorage("AgentRegistryStore")
                       .AddMemoryGrainStorage("AgentStateStore");

                siloBuilder.UseInMemoryReminderService();
                siloBuilder.UseDashboard(x => x.HostSelf = true);

                siloBuilder.UseInMemoryReminderService();
            }
            else
            {
                var cosmosDbconnectionString = builder.Configuration.GetValue<string>("Orleans:CosmosDBConnectionString") ??
                    throw new ConfigurationErrorsException(
                        "Orleans:CosmosDBConnectionString is missing from configuration. This is required for persistence in production environments.");

                siloBuilder.Configure<SiloMessagingOptions>(options =>
                {
                    options.ResponseTimeout = TimeSpan.FromMinutes(3);
                    options.SystemResponseTimeout = TimeSpan.FromMinutes(3);
                });
                siloBuilder.Configure<ClientMessagingOptions>(options =>
                {
                    options.ResponseTimeout = TimeSpan.FromMinutes(3);
                });
                siloBuilder.UseCosmosClustering(o =>
                {
                    o.ConfigureCosmosClient(cosmosDbconnectionString);
                    o.ContainerName = "AutoGen";
                    o.DatabaseName = "clustering";
                    o.IsResourceCreationEnabled = true;
                });

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Provide the key exactly as 'Orleans:CosmosDBConnectionString' in the production configuration source (appsettings.Production.json, environment variable Orleans__CosmosDBConnectionString, or KeyVault).
2. Verify with a startup log or config dump (never log the value) that the key resolves before the silo builder runs.
3. For local non-development testing, either set the connection string or keep the environment as Development to get the in-memory stores.

Example fix

# before
export ASPNETCORE_ENVIRONMENT=Production
# Orleans:CosmosDBConnectionString unset -> startup throws

# after
export ASPNETCORE_ENVIRONMENT=Production
export Orleans__CosmosDBConnectionString="AccountEndpoint=...;AccountKey=...;"

var connectionString = builder.Configuration.GetValue<string>("Orleans:CosmosDBConnectionString");
if (!builder.Environment.IsDevelopment() && string.IsNullOrWhiteSpace(connectionString))
{
    throw new InvalidOperationException(
        "Refusing to start in production without Orleans:CosmosDBConnectionString. Set Orleans__CosmosDBConnectionString or configure KeyVault.");
}

When it happens

Trigger: Running the Grpc runtime gateway with ASPNETCORE_ENVIRONMENT set to Production (anything other than the development branch) while the Orleans:CosmosDBConnectionString configuration key is missing from appsettings, environment variables, user secrets, or KeyVault.

Common situations: Deploying to a container or Azure App Service where the environment flips to Production but secrets were only in local user-secrets; a typo in the key (e.g. 'Orleans:CosmosDbConnectionString'); KeyVault configuration provider not registered in the production host; CI smoke tests that set Production without secrets.

Related errors

• Please set OPENAI_API_KEY environment variable.
• Please set OPENAI_API_KEY environment variable.
• BING_API_KEY environment variable is not set
• Missing MISTRAL_API_KEY environment variable.
• Please set OPENAI_API_KEY environment variable.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/35586b1bc4f5514f. Report an issue: GitHub.