diff --git a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/DocumentAggregatedClientGenerator.java b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/DocumentAggregatedClientGenerator.java
index 398838d14d24..b832cbd76b8e 100644
--- a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/DocumentAggregatedClientGenerator.java
+++ b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/DocumentAggregatedClientGenerator.java
@@ -23,6 +23,7 @@
 import software.amazon.smithy.codegen.core.SymbolReference;
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.knowledge.TopDownIndex;
+import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.OperationShape;
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.typescript.codegen.ApplicationProtocol;
@@ -113,40 +114,49 @@ private void generateOperations() {
 
                 // Generate a multiple overloaded methods for each command.
                 writer.writeDocs(DocumentClientUtils.getCommandDocs(operationSymbol.getName()));
-                writer.write("public $L(\n"
-                            + "  args: $L,\n"
-                            + "  options?: $T,\n"
-                            + "): Promise<$L>;", methodName, input, options, output);
-                writer.write("public $L(\n"
-                             + "  args: $L,\n"
-                             + "  cb: (err: any, data?: $L) => void\n"
-                             + "): void;", methodName, input, output);
-                writer.write("public $L(\n"
-                            + "  args: $L,\n"
-                            + "  options: $T,\n"
-                            + "  cb: (err: any, data?: $L) => void\n"
-                            + "): void;", methodName, input, options, output);
-                writer.openBlock("public $1L(\n"
-                                 + "  args: $2L,\n"
-                                 + "  optionsOrCb?: $3T | ((err: any, data?: $4L) => void),\n"
-                                 + "  cb?: (err: any, data?: $4L) => void\n"
-                                 + "): Promise<$4L> | void { ", "}",
-                        methodName,
-                        input,
-                        options,
-                        output,
-                        () -> {
-                    writer.write("const command = new $L(args);\n"
-                                 + "if (typeof optionsOrCb === \"function\") {\n"
-                                 + "  this.send(command, optionsOrCb)\n"
-                                 + "} else if (typeof cb === \"function\") {\n"
-                                 + "  if (typeof optionsOrCb !== \"object\")\n"
-                                 + "    throw new Error(`Expect http options but get $${typeof optionsOrCb}`)\n"
-                                 + "  this.send(command, optionsOrCb || {}, cb)\n"
-                                 + "} else {\n"
-                                 + "  return this.send(command, optionsOrCb);\n"
-                                 + "}", name);
-                });
+                boolean inputOptional = model.getShape(operation.getInputShape()).map(
+                    shape -> shape.getAllMembers().values().stream().noneMatch(MemberShape::isRequired)
+                ).orElse(true);
+                if (inputOptional) {
+                    writer.write("$L(): Promise<$T>;", methodName, output);
+                }
+                writer.write("""
+                    public $1L(
+                      args: $2L,
+                      options?: $3T,
+                    ): Promise<$4L>;
+                    public $1L(
+                      args: $2L,
+                      cb: (err: any, data?: $4L) => void
+                    ): void;
+                    public $1L(
+                      args: $2L,
+                      options: $3T,
+                      cb: (err: any, data?: $4L) => void
+                    ): void;
+                    public $1L(
+                      args: $2L,
+                      optionsOrCb?: $3T | ((err: any, data?: $4L) => void),
+                      cb?: (err: any, data?: $4L) => void
+                    ): Promise<$4L> | void {
+                        const command = new $5L(args);
+                        if (typeof optionsOrCb === "function") {
+                          this.send(command, optionsOrCb);
+                        } else if (typeof cb === "function") {
+                          if (typeof optionsOrCb !== "object") {
+                            throw new Error(`Expect http options but get $${typeof optionsOrCb}`)
+                          }
+                          this.send(command, optionsOrCb || {}, cb);
+                        } else {
+                          return this.send(command, optionsOrCb);
+                        }
+                    }""",
+                    methodName,
+                    input,
+                    options,
+                    output,
+                    name
+                );
                 writer.write("");
             }
         }
diff --git a/lib/lib-dynamodb/src/DynamoDBDocument.ts b/lib/lib-dynamodb/src/DynamoDBDocument.ts
index 408e1c1d2136..7e3143875fbb 100644
--- a/lib/lib-dynamodb/src/DynamoDBDocument.ts
+++ b/lib/lib-dynamodb/src/DynamoDBDocument.ts
@@ -113,7 +113,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -143,7 +145,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -173,7 +177,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -203,7 +209,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -239,7 +247,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -275,7 +285,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -305,7 +317,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -335,7 +349,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -365,7 +381,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -395,7 +413,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -425,7 +445,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -461,7 +483,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);
@@ -491,7 +515,9 @@ export class DynamoDBDocument extends DynamoDBDocumentClient {
     if (typeof optionsOrCb === "function") {
       this.send(command, optionsOrCb);
     } else if (typeof cb === "function") {
-      if (typeof optionsOrCb !== "object") throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      if (typeof optionsOrCb !== "object") {
+        throw new Error(`Expect http options but get ${typeof optionsOrCb}`);
+      }
       this.send(command, optionsOrCb || {}, cb);
     } else {
       return this.send(command, optionsOrCb);