fix(api-extractor): preserve export keyword for namespace re-exports

apps/api-extractor/src/generators/ApiReportGenerator.ts

@@ -302,6 +302,23 @@ export class ApiReportGenerator {
         break;
 
       case ts.SyntaxKind.ExportKeyword:
+        // Check if this export keyword is part of an ExportDeclaration inside a namespace
+        // (e.g., "export { Foo, Bar };" inside "declare namespace SDK { ... }")
+        // In that case, we must preserve the export keyword, otherwise the output is invalid TypeScript.
+        if (span.node.parent && ts.isExportDeclaration(span.node.parent)) {
+          const moduleBlock: ts.ModuleBlock | undefined = TypeScriptHelpers.findFirstParent(
+            span.node,
+            ts.SyntaxKind.ModuleBlock
+          );
+          if (moduleBlock) {
+            // This is an export declaration inside a namespace - preserve the export keyword
+            break;
+          }
+        }
+        // Otherwise, delete the export keyword -- we will re-add it below
+        span.modification.skipAll();
+        break;
+
       case ts.SyntaxKind.DefaultKeyword:
       case ts.SyntaxKind.DeclareKeyword:
         // Delete any explicit "export" or "declare" keywords -- we will re-add them below

apps/api-extractor/src/generators/DtsRollupGenerator.ts

@@ -270,6 +270,23 @@ export class DtsRollupGenerator {
         break;
 
       case ts.SyntaxKind.ExportKeyword:
+        // Check if this export keyword is part of an ExportDeclaration inside a namespace
+        // (e.g., "export { Foo, Bar };" inside "declare namespace SDK { ... }")
+        // In that case, we must preserve the export keyword, otherwise the output is invalid TypeScript.
+        if (span.node.parent && ts.isExportDeclaration(span.node.parent)) {
+          const moduleBlock: ts.ModuleBlock | undefined = TypeScriptHelpers.findFirstParent(
+            span.node,
+            ts.SyntaxKind.ModuleBlock
+          );
+          if (moduleBlock) {
+            // This is an export declaration inside a namespace - preserve the export keyword
+            break;
+          }
+        }
+        // Otherwise, delete the export keyword -- we will re-add it below
+        span.modification.skipAll();
+        break;
+
       case ts.SyntaxKind.DefaultKeyword:
       case ts.SyntaxKind.DeclareKeyword:
         // Delete any explicit "export" or "declare" keywords -- we will re-add them below

build-tests/api-extractor-scenarios/etc/apiItemKinds/api-extractor-scenarios.api.md

@@ -51,7 +51,7 @@ export namespace n1 {
     // (undocumented)
     export class SomeClass2 extends SomeClass1 {
     }
-        {};
+    export {};
 }
 
 // @public (undocumented)

build-tests/api-extractor-scenarios/etc/apiItemKinds/rollup.d.ts

@@ -36,7 +36,7 @@ export declare namespace n1 {
         export class SomeClass3 {
         }
     }
-        {};
+    export {};
 }
 
 /** @public */

build-tests/api-extractor-scenarios/etc/includeForgottenExports/api-extractor-scenarios.api.md

@@ -86,7 +86,7 @@ export namespace SomeNamespace1 {
     }
     // (undocumented)
     export function someFunction3(): ForgottenExport3;
-        {};
+    export {};
 }
 
 // (No @packageDocumentation comment for this package)

build-tests/api-extractor-scenarios/etc/includeForgottenExports/rollup.d.ts

@@ -80,7 +80,7 @@ export declare namespace SomeNamespace1 {
     export class ForgottenExport3 {
     }
     export function someFunction3(): ForgottenExport3;
-        {};
+    export {};
 }
 
 export { }

build-tests/api-extractor-scenarios/etc/referenceTokens/api-extractor-scenarios.api.md

@@ -21,13 +21,13 @@ export namespace n1 {
         export function someFunction2(): SomeType2;
         // (undocumented)
         export type SomeType2 = number;
-            {};
+        export {};
     }
     // (undocumented)
     export function someFunction1(): SomeType1;
     // (undocumented)
     export type SomeType1 = number;
-        {};
+    export {};
 }
 
 // @public (undocumented)

build-tests/api-extractor-scenarios/etc/referenceTokens/rollup.d.ts

@@ -14,9 +14,9 @@ export declare namespace n1 {
             export type SomeType3 = number;
             export function someFunction3(): n2.n3.SomeType3;
         }
-            {};
+        export {};
     }
-        {};
+    export {};
 }
 
 /** @public */

common/changes/@microsoft/api-extractor/fix-namespace-export-keyword_2025-12-24-17-25.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Fix missing 'export' keyword for namespace re-exports that produced invalid TypeScript output",
+      "type": "patch",
+      "packageName": "@microsoft/api-extractor"
+    }
+  ],
+  "packageName": "@microsoft/api-extractor",
+  "email": "chris@matterport.com"
+}