clockworklabs/SpacetimeDB · error · InvalidOperationException

Building DbConnection with a null nameOrAddress. Call WithDa

Error message

Building DbConnection with a null nameOrAddress. Call WithDatabaseName() first.

What it means

The second precondition in DbConnectionBuilder.Build(): the database name or address must be supplied via WithDatabaseName before connecting. Build throws InvalidOperationException when nameOrAddress is still null, after the uri check has passed.

Source

Thrown at sdks/csharp/src/SpacetimeDBClient.cs:37

    {
        readonly DbConnection conn = new();

        string? uri;
        string? nameOrAddress;
        string? token;
        Compression? compression;
        bool light;
        bool? confirmedReads;

        public DbConnection Build()
        {
            if (uri == null)
            {
                throw new InvalidOperationException("Building DbConnection with a null uri. Call WithUri() first.");
            }
            if (nameOrAddress == null)
            {
                throw new InvalidOperationException("Building DbConnection with a null nameOrAddress. Call WithDatabaseName() first.");
            }
            conn.Connect(token, uri, nameOrAddress, compression ?? Compression.Brotli, light, confirmedReads);
#if UNITY_5_3_OR_NEWER
            if (SpacetimeDBNetworkManager._instance != null)
            {
                SpacetimeDBNetworkManager._instance.AddConnection(conn);
            }
#endif
            return conn;
        }

        public DbConnectionBuilder<DbConnection> WithUri(string uri)
        {
            this.uri = uri;
            return this;
        }

        public DbConnectionBuilder<DbConnection> WithDatabaseName(string nameOrAddress)

View on GitHub (pinned to 524b4487d9)

Solutions

1. Call WithDatabaseName("mydb") (database name or published address) before Build()
2. Validate required config values up front and fail with your own error naming the missing key
3. Centralize builder construction so both WithUri and WithDatabaseName are always supplied together

Example fix

// before
var conn = builder
    .WithUri("https://maincloud.spacetimedb.com")
    .Build(); // no WithDatabaseName -> throws

// after
var conn = builder
    .WithUri("https://maincloud.spacetimedb.com")
    .WithDatabaseName(dbName ?? "mydb")
    .Build();

var dbName = config["SpacetimeDB:Database"];
if (string.IsNullOrWhiteSpace(dbName))
    throw new ConfigException("SpacetimeDB:Database is required before building a connection");

try { var conn = builder.Build(); }
catch (InvalidOperationException e) when (e.Message.Contains("null nameOrAddress"))
{ /* resolve the database name and rebuild */ }

When it happens

Trigger: Calling builder.WithUri(...).Build() without WithDatabaseName(...), or the database-name branch being skipped when the value comes from config/env that is unset.

Common situations: Database name moved to an env var that is missing in a deploy environment; typos between WithDatabaseName and a similarly named setter; per-tenant connection loops where one tenant row has a null name.

Related errors

• Building DbConnection with a null uri. Call WithUri() first.
• URI is required to connect to SpacetimeDB
• Database name or address is required to connect to Spacetime
• never types are not yet supported in C# output
• Unsupported --dotnet-version {version}. Supported values: 8,

AI-assisted analysis of clockworklabs/SpacetimeDB@524b4487d9 (2026-08-16). Data as JSON: /api/errors/0187af3fd71b9dad. Report an issue: GitHub.