diff --git a/packages/core/src/lib/functional-extensions/filter.ts b/packages/core/src/lib/functional-extensions/filter.ts
index b6341be5..f4ee3cdd 100644
--- a/packages/core/src/lib/functional-extensions/filter.ts
+++ b/packages/core/src/lib/functional-extensions/filter.ts
@@ -16,7 +16,7 @@ export interface FunctionalFilterOptions {
 
 export type FunctionalFilter = (
   options: FunctionalFilterOptions
-) => Promise<string>;
+) => Promise<any>;
 
 export const createFilterExtension = (
   name: string,
diff --git a/packages/core/test/functional-extensions/filter.spec.ts b/packages/core/test/functional-extensions/filter.spec.ts
index edca3386..3b09914a 100644
--- a/packages/core/test/functional-extensions/filter.spec.ts
+++ b/packages/core/test/functional-extensions/filter.spec.ts
@@ -43,3 +43,31 @@ it('The extensions created by createFilter function should work with template en
   expect(queries[0]).toBe('SELECT $1');
   expect(bindings[0].get('$1')).toBe('QAQ3QQQQ');
 });
+
+it('The extensions can return arbitrary value', async () => {
+  // Arrange
+  const testFilter: FunctionalFilter = async ({ args, value }) =>
+    ({id: args['aa'], text: `QAQ${args['aa']}${value}`});
+  const [Builder, Runner] = createFilterExtension('test', testFilter);
+  const builder = new Builder({}, '');
+  const runner = new Runner({}, '');
+  const {
+    compiler,
+    loader,
+    executeTemplate,
+    getCreatedQueries,
+    getCreatedBinding,
+  } = await createTestCompiler({ additionalExtensions: [builder, runner] });
+  const { compiledData } = await compiler.compile(
+    `SELECT {{ (context.params.id | test(aa=3)).id }}, {{ (context.params.id | test(aa=3)).text }}`
+  );
+  loader.setSource('test', compiledData);
+  // Act
+  await executeTemplate('test', { id: 'QQQQ' });
+  const queries = await getCreatedQueries();
+  const bindings = await getCreatedBinding();
+  // Assert
+  expect(queries[0]).toBe('SELECT $1, $2');
+  expect(bindings[0].get('$1')).toBe(3);
+  expect(bindings[0].get('$2')).toBe('QAQ3QQQQ');
+});
diff --git a/packages/extension-api-caller/README.md b/packages/extension-api-caller/README.md
index 7ec66959..fb281a3d 100644
--- a/packages/extension-api-caller/README.md
+++ b/packages/extension-api-caller/README.md
@@ -23,26 +23,26 @@ To pass the path parameters:
 
 ```sql
 {% set a_variable_you_can_define = { "path": { "id": 1 } } %}
-SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/:id') }}
+SELECT {{ (a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/:id')).id }}
 ```
 
 To pass the query parameters:
 
 ```sql
 {% set a_variable_you_can_define = { "query": { "q": "phone" }  } %}
-SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/search') }}
+SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/search') | dump }}
 ```
 
 To issue the POST request:
 
 ```sql
 {% set a_variable_you_can_define = { "body": { "title": "BMW Pencil" } } %}
-SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/add', method='POST') }}
+SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/add', method='POST') | dump }}
 ```
 
 To pass the headers and multiple fields:
 
 ```sql
 {% set a_variable_you_can_define = { "headers": { "Content-Type": "application/json" }, "body": { "title": "BMW Pencil" } } %}
-SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/add', method='POST') }}
+SELECT {{ a_variable_you_can_define | rest_api(url='https://dummyjson.com/products/add', method='POST') | dump }}
 ```
\ No newline at end of file
diff --git a/packages/extension-api-caller/src/lib/filters/restApiCaller.ts b/packages/extension-api-caller/src/lib/filters/restApiCaller.ts
index 842fd74a..56f6861e 100644
--- a/packages/extension-api-caller/src/lib/filters/restApiCaller.ts
+++ b/packages/extension-api-caller/src/lib/filters/restApiCaller.ts
@@ -48,7 +48,7 @@ export const RestApiCallerFilter: FunctionalFilter = async ({
     logger.info('API request:', options);
     const results = await axios(options);
     logger.info('API response:', results.data);
-    return JSON.stringify(results.data);
+    return results.data;
   } catch (error: any) {
     const message = error.response
       ? `response status: ${error.response.status}, response data: ${JSON.stringify(error.response.data)}`
diff --git a/packages/extension-api-caller/test/restApiCaller.spec.ts b/packages/extension-api-caller/test/restApiCaller.spec.ts
index bff23980..fcc230c5 100644
--- a/packages/extension-api-caller/test/restApiCaller.spec.ts
+++ b/packages/extension-api-caller/test/restApiCaller.spec.ts
@@ -50,7 +50,7 @@ describe('Test "rest_api" filter', () => {
         extensions: { rest_api: path.join(__dirname, '..', 'src') },
       });
 
-      const sql = `{% set value = { "path": { "id": 1 } } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/:id') }}`;
+      const sql = `{% set value = { "path": { "id": 1 } } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/:id') | dump }}`;
 
       // Act
       await compileAndLoad(sql);
@@ -155,7 +155,7 @@ describe('Test "rest_api" filter', () => {
         extensions: { rest_api: path.join(__dirname, '..', 'src') },
       });
 
-      const sql = `{% set value = { "query": { "q": "phone" }  } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/search') }}`;
+      const sql = `{% set value = { "query": { "q": "phone" }  } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/search') | dump }}`;
 
       // Act
       await compileAndLoad(sql);
@@ -183,7 +183,35 @@ describe('Test "rest_api" filter', () => {
         extensions: { rest_api: path.join(__dirname, '..', 'src') },
       });
 
-      const sql = `{% set value = { "body": { "title": "BMW Pencil" }, "headers": { "Content-Type": "application/json" } } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/add', method='POST') }}`;
+      const sql = `{% set value = { "body": { "title": "BMW Pencil" }, "headers": { "Content-Type": "application/json" } } %}SELECT {{ value | rest_api(url='https://dummyjson.com/products/add', method='POST') | dump }}`;
+
+      // Act
+      await compileAndLoad(sql);
+      await execute({});
+
+      // Assert
+      const queries = await getExecutedQueries();
+      const bindings = await getCreatedBinding();
+
+      expect(queries[0]).toBe('SELECT $1');
+      expect(bindings[0].get('$1')).toEqual(expected);
+    },
+    50 * 1000
+  )
+
+  it(
+    'Should work with template engine with field access',
+    async () => {
+      const expected = {
+        id: 101,
+        title: 'BMW Pencil'
+      }.id;
+
+      const { compileAndLoad, execute, getExecutedQueries, getCreatedBinding } = await getTestCompiler({
+        extensions: { rest_api: path.join(__dirname, '..', 'src') },
+      });
+
+      const sql = `{% set value = { "body": { "title": "BMW Pencil" }, "headers": { "Content-Type": "application/json" } } %}SELECT {{ (value | rest_api(url='https://dummyjson.com/products/add', method='POST')).id }}`;
 
       // Act
       await compileAndLoad(sql);