diff --git a/tests/native.test.ts b/tests/native.test.ts
index 04bd664..887b32f 100644
--- a/tests/native.test.ts
+++ b/tests/native.test.ts
@@ -1011,7 +1011,7 @@ test("Native function calls multiple Reef functions", async () => {
     const doubled = await this.call('double', n)
     const tripled = await this.call('triple', n)
 
-    return doubled + tripled  // 10 + 15 = 25
+    return doubled + tripled
   })
 
   const result = await vm.run()
@@ -1327,4 +1327,306 @@ test("Native function calls Reef function with named arguments", async () => {
 
   const result = await vm.run()
   expect(result).toEqual({ type: 'string', value: "Hi Alice!" })
-})
\ No newline at end of file
+})
+test("vm.call() with only named arguments", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function with default parameters
+    MAKE_FUNCTION (name greeting='Hello') .greet_body
+    STORE greet
+    JUMP .skip_greet
+    .greet_body:
+      LOAD greeting
+      PUSH " "
+      LOAD name
+      PUSH "!"
+      STR_CONCAT #4
+      RETURN
+    .skip_greet:
+
+    LOAD call_greet
+    PUSH 0
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode, {
+    call_greet: async function () {
+      // Call with ONLY named arguments (no positional)
+      return await this.call('greet', { name: "Bob", greeting: "Hey" })
+    }
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'string', value: "Hey Bob!" })
+})
+
+test("Native function receives Reef closure with default params - calls with named args", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function with default parameters
+    MAKE_FUNCTION (x multiplier=2) .transform_body
+    STORE transform
+    JUMP .skip_transform
+    .transform_body:
+      LOAD x
+      LOAD multiplier
+      MUL
+      RETURN
+    .skip_transform:
+
+    ; Pass to native map function
+    LOAD map
+    PUSH 1
+    PUSH 2
+    PUSH 3
+    MAKE_ARRAY #3
+    LOAD transform
+    PUSH 2
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode)
+
+  // Native function that calls the Reef closure with named arguments
+  vm.registerFunction('map', async (array: any[], callback: Function) => {
+    const results = []
+    for (const item of array) {
+      // Call with named argument to override the default
+      results.push(await callback(item, { multiplier: 10 }))
+    }
+    return results
+  })
+
+  const result = await vm.run()
+  expect(result.type).toBe('array')
+  if (result.type === 'array') {
+    expect(result.value).toEqual([
+      toValue(10),  // 1 * 10
+      toValue(20),  // 2 * 10
+      toValue(30)   // 3 * 10
+    ])
+  }
+})
+
+test("Native function receives Reef closure with variadic parameters", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function with variadic params
+    MAKE_FUNCTION (...nums) .sum_body
+    STORE sum_all
+    JUMP .skip_sum
+    .sum_body:
+      PUSH 0
+      STORE total
+      LOAD nums
+      STORE items
+      PUSH 0
+      STORE idx
+
+      .loop:
+        LOAD idx
+        LOAD items
+        ARRAY_LEN
+        LT
+        JUMP_IF_FALSE .done
+
+        LOAD total
+        LOAD items
+        LOAD idx
+        ARRAY_GET
+        ADD
+        STORE total
+
+        LOAD idx
+        PUSH 1
+        ADD
+        STORE idx
+        JUMP .loop
+
+      .done:
+        LOAD total
+        RETURN
+    .skip_sum:
+
+    ; Pass to native function
+    LOAD process
+    LOAD sum_all
+    PUSH 1
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode)
+
+  // Native function that calls the variadic Reef closure with multiple args
+  vm.registerFunction('process', async (callback: Function) => {
+    // Call with varying number of arguments
+    const result1 = await callback(1, 2, 3)
+    const result2 = await callback(10, 20)
+    return result1 + result2
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'number', value: 36 })  // (1+2+3) + (10+20) = 6 + 30
+})
+
+test("Native function receives Reef closure with @named parameter", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function with @named parameter
+    MAKE_FUNCTION (message @options) .format_body
+    STORE format_message
+    JUMP .skip_format
+    .format_body:
+      ; Get uppercase option (default false)
+      LOAD options
+      PUSH "uppercase"
+      DICT_GET
+      STORE use_upper
+
+      ; Get prefix option (default empty)
+      LOAD options
+      PUSH "prefix"
+      DICT_GET
+      STORE prefix_val
+
+      ; Build result
+      LOAD prefix_val
+      LOAD message
+      STR_CONCAT #2
+      RETURN
+    .skip_format:
+
+    ; Pass to native function
+    LOAD format_messages
+    PUSH "hello"
+    PUSH "world"
+    MAKE_ARRAY #2
+    LOAD format_message
+    PUSH 2
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode)
+
+  // Native function that calls Reef closure with named arguments
+  vm.registerFunction('format_messages', async (messages: any[], formatter: Function) => {
+    const results = []
+    for (const msg of messages) {
+      // Call with named arguments
+      results.push(await formatter(msg, { prefix: "[LOG] ", uppercase: true }))
+    }
+    return results
+  })
+
+  const result = await vm.run()
+  expect(result.type).toBe('array')
+  if (result.type === 'array') {
+    expect(result.value).toEqual([
+      toValue('[LOG] hello'),
+      toValue('[LOG] world')
+    ])
+  }
+})
+
+test("Native function receives Reef closure - calls with only named arguments", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function expecting named arguments
+    MAKE_FUNCTION (x=0 y=0 z=0) .add_body
+    STORE add_coords
+    JUMP .skip_add
+    .add_body:
+      LOAD x
+      LOAD y
+      ADD
+      LOAD z
+      ADD
+      RETURN
+    .skip_add:
+
+    ; Pass to native function
+    LOAD compute
+    LOAD add_coords
+    PUSH 1
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode)
+
+  // Native function that calls Reef closure with ONLY named arguments
+  vm.registerFunction('compute', async (callback: Function) => {
+    // First call with all named args
+    const result1 = await callback({ x: 10, y: 20, z: 30 })
+
+    // Second call with partial named args (rest use defaults)
+    const result2 = await callback({ x: 5, z: 15 })
+
+    return result1 + result2
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'number', value: 80 })  // (10+20+30) + (5+0+15) = 60 + 20
+})
+
+test("Native function receives Reef closure with mixed positional and variadic", async () => {
+  const bytecode = toBytecode(`
+    ; Reef function with fixed param and variadic
+    MAKE_FUNCTION (multiplier ...nums) .scale_body
+    STORE scale_numbers
+    JUMP .skip_scale
+    .scale_body:
+      PUSH 0
+      STORE total
+      LOAD nums
+      STORE items
+      PUSH 0
+      STORE idx
+
+      .loop:
+        LOAD idx
+        LOAD items
+        ARRAY_LEN
+        LT
+        JUMP_IF_FALSE .done
+
+        LOAD total
+        LOAD items
+        LOAD idx
+        ARRAY_GET
+        LOAD multiplier
+        MUL
+        ADD
+        STORE total
+
+        LOAD idx
+        PUSH 1
+        ADD
+        STORE idx
+        JUMP .loop
+
+      .done:
+        LOAD total
+        RETURN
+    .skip_scale:
+
+    ; Pass to native function
+    LOAD process_numbers
+    LOAD scale_numbers
+    PUSH 1
+    PUSH 0
+    CALL
+  `)
+
+  const vm = new VM(bytecode)
+
+  // Native function that calls Reef closure with mixed args
+  vm.registerFunction('process_numbers', async (calculator: Function) => {
+    // Call with fixed multiplier and variadic numbers
+    const result1 = await calculator(10, 1, 2, 3)  // 10 * (1+2+3) = 60
+    const result2 = await calculator(5, 4, 6)      // 5 * (4+6) = 50
+    return result1 + result2
+  })
+
+  const result = await vm.run()
+  expect(result).toEqual({ type: 'number', value: 110 })  // 60 + 50
+})