diff --git a/packages/frontend-plugin-api/src/wiring/createExtension.test.ts b/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
index ab6a6c19a5..8da3504434 100644
--- a/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
+++ b/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
@@ -561,4 +561,35 @@ describe('createExtension', () => {
       }),
     ).toMatchObject({ version: 'v2' });
   });
+
+  describe('overrides', () => {
+    it('should allow overriding of the default factory', () => {
+      const testExtension = createExtension({
+        namespace: 'test',
+        attachTo: { id: 'root', input: 'blob' },
+        output: [stringDataRef],
+        config: {
+          schema: {
+            foo: z => z.string().optional(),
+          },
+        },
+        factory() {
+          return [stringDataRef('default')];
+        },
+      });
+
+      testExtension.override({
+        config: {
+          schema: {
+            bar: z => z.string().optional(),
+          },
+        },
+        factory(_, { config }) {
+          return [stringDataRef(config.foo ?? config.bar ?? 'default')];
+        },
+      });
+
+      expect(true).toBe(true);
+    });
+  });
 });
diff --git a/packages/frontend-plugin-api/src/wiring/createExtension.ts b/packages/frontend-plugin-api/src/wiring/createExtension.ts
index 6684323b51..f1db16b4d2 100644
--- a/packages/frontend-plugin-api/src/wiring/createExtension.ts
+++ b/packages/frontend-plugin-api/src/wiring/createExtension.ts
@@ -247,6 +247,10 @@ export type OverrideExtensionOptions<
   TConfigInput,
   TConfigSchema extends { [key: string]: (zImpl: typeof z) => z.ZodType },
   UFactoryOutput extends ExtensionDataValue<any, any>,
+  TConfigSchemaOverrides extends {
+    [key: string]: (zImpl: typeof z) => z.ZodType;
+  },
+  UOutputOverrides extends AnyExtensionDataRef = UOutput,
 > = {
   kind?: string;
   namespace?: string;
@@ -254,11 +258,11 @@ export type OverrideExtensionOptions<
   attachTo?: { id: string; input: string };
   disabled?: boolean;
   inputs?: TInputs;
-  output: Array<UOutput>;
+  output?: Array<UOutputOverrides>;
   /** @deprecated - use `config.schema` instead */
   configSchema?: PortableSchema<TConfig, TConfigInput>;
   config?: {
-    schema: TConfigSchema;
+    schema: TConfigSchemaOverrides;
   };
   factory?(
     originalFactory: (context?: {
@@ -273,6 +277,10 @@ export type OverrideExtensionOptions<
         (string extends keyof TConfigSchema
           ? {}
           : {
+              [key in keyof TConfigSchemaOverrides]: z.infer<
+                ReturnType<TConfigSchemaOverrides[key]>
+              >;
+            } & {
               [key in keyof TConfigSchema]: z.infer<
                 ReturnType<TConfigSchema[key]>
               >;
@@ -280,7 +288,7 @@ export type OverrideExtensionOptions<
       inputs: Expand<ResolvedExtensionInputs<TInputs>>;
     },
   ): Iterable<UFactoryOutput>;
-} & VerifyExtensionFactoryOutput<UOutput, UFactoryOutput>;
+} & VerifyExtensionFactoryOutput<UOutput & UOutputOverrides, UFactoryOutput>;
 
 /** @public */
 export type OverridableExtension<
@@ -296,14 +304,19 @@ export type OverridableExtension<
   TConfigSchema extends { [key: string]: (zImpl: typeof z) => z.ZodType },
   UFactoryOutput extends ExtensionDataValue<any, any>,
 > = {
-  override(
+  override<
+    TConfigSchemaOverrides extends {
+      [key in string]: (zImpl: typeof z) => z.ZodType;
+    },
+  >(
     options: OverrideExtensionOptions<
       UOutput,
       TInputs,
       TConfig,
       TConfigInput,
       TConfigSchema,
-      UFactoryOutput
+      UFactoryOutput,
+      TConfigSchemaOverrides
     >,
   ): ExtensionDefinition<TConfig, TConfigInput>;
 };
@@ -540,6 +553,9 @@ export function createExtension<
       parts.push(`attachTo=${options.attachTo.id}@${options.attachTo.input}`);
       return `ExtensionDefinition{${parts.join(',')}}`;
     },
+    override() {
+      // todo(blam): implement.
+    },
   } as InternalExtensionDefinition<
     TConfig &
       (string extends keyof TConfigSchema