diff --git a/convert/convert.go b/convert/convert.go
index 21306e9..d6e80f7 100644
--- a/convert/convert.go
+++ b/convert/convert.go
@@ -44,3 +44,18 @@ func IntToString(i int) string {
 
 	return string(result)
 }
+
+// WasmPtrToBytes returns a slice of bytes from WebAssembly compatible numeric types
+// representing its pointer and length.
+func WasmPtrToBytes(ptr uint32, size uint32) []byte {
+	return unsafe.Slice((*byte)(unsafe.Pointer(uintptr(ptr))), size)
+}
+
+// BytesToWasmPtr returns a pointer and size pair for the given string in a way
+// compatible with WebAssembly numeric types.
+// The returned pointer aliases the string hence the string must be kept alive
+// until ptr is no longer needed.
+func BytesToWasmPtr(b []byte) (uint32, uint32) {
+	ptr := uintptr(unsafe.Pointer(unsafe.SliceData(b)))
+	return uint32(ptr), uint32(len(b))
+}
diff --git a/engine/engine_test.go b/engine/engine_test.go
index dea2992..55a357d 100644
--- a/engine/engine_test.go
+++ b/engine/engine_test.go
@@ -1,8 +1,6 @@
 package engine
 
-import (
-	"testing"
-)
+import "testing"
 
 func TestEngine(t *testing.T) {
 	t.Run("cannot init without interpreter", func(t *testing.T) {
@@ -53,3 +51,7 @@ func (i *mockInterpreter) DefineFunc(modulename, funcname string, f interface{})
 func (i *mockInterpreter) MemoryData(ptr, sz uint32) ([]byte, error) {
 	return nil, nil
 }
+
+func (i *mockInterpreter) References() *ExternalReferences {
+	return nil
+}
diff --git a/engine/interp.go b/engine/interp.go
index bfbc81d..b1572a2 100644
--- a/engine/interp.go
+++ b/engine/interp.go
@@ -15,4 +15,6 @@ type Interpreter interface {
 	DefineFunc(module, name string, f interface{}) error
 	// MemoryData returns a slice of memory data from the memory managed by the host.
 	MemoryData(ptr, sz uint32) ([]byte, error)
+	// References are the external references managed by the host module.
+	References() *ExternalReferences
 }
diff --git a/engine/references.go b/engine/references.go
index 0f8594a..78bc944 100644
--- a/engine/references.go
+++ b/engine/references.go
@@ -12,8 +12,8 @@ type ExternalReferences struct {
 }
 
 // NewReferences creates a new ExternalReferences store.
-func NewReferences() *ExternalReferences {
-	return &ExternalReferences{
+func NewReferences() ExternalReferences {
+	return ExternalReferences{
 		refs: make(map[int32]uintptr),
 	}
 }
diff --git a/go.mod b/go.mod
index 0ddbb18..5ab870a 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.22.0
 replace github.com/tetratelabs/wazero => github.com/orsinium-forks/wazero v0.0.0-20240217173836-b12c024bcbe4
 
 require (
-	github.com/hybridgroup/wasman v0.0.0-20240228124029-ecd9fd3f900a
+	github.com/hybridgroup/wasman v0.0.0-20240229144219-f3288962ab34
 	github.com/tetratelabs/wazero v1.6.0
 	github.com/urfave/cli/v2 v2.27.1
 	tinygo.org/x/tinyfs v0.3.1-0.20231212053859-32ae3f6bbad9
diff --git a/go.sum b/go.sum
index 45ce827..ada22ad 100644
--- a/go.sum
+++ b/go.sum
@@ -2,6 +2,8 @@ github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHH
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/hybridgroup/wasman v0.0.0-20240228124029-ecd9fd3f900a h1:6q1Gn1MR643sBn4PnvgX40jCCXmAyjuNXFfk8wirpds=
 github.com/hybridgroup/wasman v0.0.0-20240228124029-ecd9fd3f900a/go.mod h1:rLavUo4P0xVcDeDnViYEpPQPoACmp1py9UTLPY/R7Lg=
+github.com/hybridgroup/wasman v0.0.0-20240229144219-f3288962ab34 h1:XGX7Qt+ylSTF7VrwfXePwXAy2cK2iB6At+Ni/PcaNok=
+github.com/hybridgroup/wasman v0.0.0-20240229144219-f3288962ab34/go.mod h1:rLavUo4P0xVcDeDnViYEpPQPoACmp1py9UTLPY/R7Lg=
 github.com/orsinium-forks/wazero v0.0.0-20240217173836-b12c024bcbe4 h1:MUh9e2izck9aROiwDsDm24UU7kHieYM2911U1t+NASs=
 github.com/orsinium-forks/wazero v0.0.0-20240217173836-b12c024bcbe4/go.mod h1:0U0G41+ochRKoPKCJlh0jMg1CHkyfK8kDqiirMmKY8A=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
diff --git a/interp/tester/interp.go b/interp/tester/interp.go
index 1b14081..ab70a53 100644
--- a/interp/tester/interp.go
+++ b/interp/tester/interp.go
@@ -2,6 +2,7 @@ package tester
 
 import (
 	"testing"
+	"unsafe"
 
 	"github.com/hybridgroup/mechanoid/engine"
 )
@@ -11,6 +12,14 @@ func InitTest(t *testing.T, i engine.Interpreter) {
 	if err != nil {
 		t.Errorf("Interpreter.Init() failed: %v", err)
 	}
+
+	if i.Name() == "" {
+		t.Errorf("Interpreter.Name() failed: %v", i.Name())
+	}
+
+	if i.References() == nil {
+		t.Errorf("Interpreter.References() failed: %v", i.References())
+	}
 }
 
 func LoadTest(t *testing.T, i engine.Interpreter) {
@@ -51,3 +60,53 @@ func HaltTest(t *testing.T, i engine.Interpreter) {
 		t.Errorf("Interpreter.Halt() failed: %v", err)
 	}
 }
+
+func ReferencesTest(t *testing.T, i engine.Interpreter) {
+	err := i.Init()
+	if err != nil {
+		t.Errorf("Interpreter.Init() failed: %v", err)
+	}
+	if i.References() == nil {
+		t.Errorf("Interpreter.References() failed: %v", i.References())
+	}
+
+	var id1, id2 int32
+	thing1 := &testingType{
+		val1: "hello",
+		val2: "world",
+	}
+	thing2 := &testingType{
+		val1: "hola",
+		val2: "mundo",
+	}
+
+	t.Run("add references", func(t *testing.T) {
+		id1 = i.References().Add(unsafe.Pointer(&thing1))
+		id2 = i.References().Add(unsafe.Pointer(&thing2))
+
+		if id1 == id2 {
+			t.Errorf("id1 and id2 should not be the same")
+		}
+	})
+
+	t.Run("get references", func(t *testing.T) {
+		if i.References().Get(id1) != uintptr(unsafe.Pointer(&thing1)) {
+			t.Errorf("refs.Get(id1) failed")
+		}
+		if i.References().Get(id2) != uintptr(unsafe.Pointer(&thing2)) {
+			t.Errorf("refs.Get(id2) failed")
+		}
+	})
+
+	t.Run("remove references", func(t *testing.T) {
+		i.References().Remove(id1)
+		i.References().Remove(id2)
+
+		if i.References().Get(id1) != uintptr(0) {
+			t.Errorf("refs.Get(id1) failed")
+		}
+		if i.References().Get(id2) != uintptr(0) {
+			t.Errorf("refs.Get(id2) failed")
+		}
+	})
+}
diff --git a/interp/wasman/interp.go b/interp/wasman/interp.go
index 6dc6eab..1186f09 100644
--- a/interp/wasman/interp.go
+++ b/interp/wasman/interp.go
@@ -14,6 +14,8 @@ type Interpreter struct {
 	module   *wasmaneng.Module
 	instance *wasmaneng.Instance
 	Memory   []byte
+
+	references engine.ExternalReferences
 }
 
 func (i *Interpreter) Name() string {
@@ -34,6 +36,8 @@ func (i *Interpreter) Init() error {
 		}
 	}
 
+	i.references = engine.NewReferences()
+
 	return nil
 }
 
@@ -100,6 +104,8 @@ func (i *Interpreter) DefineFunc(moduleName, funcName string, f any) error {
 		return wasmaneng.DefineFunc20(i.linker, moduleName, funcName, tf)
 	case func(uint32, uint32) uint32:
 		return wasmaneng.DefineFunc21(i.linker, moduleName, funcName, tf)
+	case func(uint32, uint32, uint32) uint32:
+		return wasmaneng.DefineFunc31(i.linker, moduleName, funcName, tf)
 	default:
 		return engine.ErrInvalidFuncType
 	}
@@ -115,3 +121,8 @@ func (i *Interpreter) MemoryData(ptr, sz uint32) ([]byte, error) {
 
 	return i.instance.Memory.Value[ptr : ptr+sz], nil
 }
+
+// References are the external references managed by the host module.
+func (i *Interpreter) References() *engine.ExternalReferences {
+	return &i.references
+}
diff --git a/interp/wasman/interp_test.go b/interp/wasman/interp_test.go
index 2eb0476..f6b6266 100644
--- a/interp/wasman/interp_test.go
+++ b/interp/wasman/interp_test.go
@@ -29,6 +29,10 @@ func TestHalt(t *testing.T) {
 	tester.HaltTest(t, &Interpreter{})
 }
 
+func TestExternalReferences(t *testing.T) {
+	tester.ReferencesTest(t, &Interpreter{})
+}
+
 func TestDefineFunc(t *testing.T) {
 	t.Skip("TODO: implement TestDefineFunc")
 }
diff --git a/interp/wazero/interp.go b/interp/wazero/interp.go
index f35dab7..58bb25d 100644
--- a/interp/wazero/interp.go
+++ b/interp/wazero/interp.go
@@ -14,6 +14,8 @@ type Interpreter struct {
 	runtime wazero.Runtime
 	defs    map[string]map[string]any
 	module  api.Module
+
+	references engine.ExternalReferences
 }
 
 func (i *Interpreter) Name() string {
@@ -26,6 +28,7 @@ func (i *Interpreter) Init() error {
 	conf = conf.WithDebugInfoEnabled(false)
 	conf = conf.WithMemoryLimitPages(1)
 	i.runtime = wazero.NewRuntimeWithConfig(ctx, conf)
+	i.references = engine.NewReferences()
 	return nil
 }
 
@@ -95,6 +98,11 @@ func (i *Interpreter) MemoryData(ptr, sz uint32) ([]byte, error) {
 	return data, nil
 }
 
+// References are the external references managed by the host module.
+func (i *Interpreter) References() *engine.ExternalReferences {
+	return &i.references
+}
+
 // A fake RandSource for having fewer memory allocations.
 //
 // Should not be used with modules that do need an access to random functions.
diff --git a/interp/wazero/interp_test.go b/interp/wazero/interp_test.go
index 5a723ca..a908456 100644
--- a/interp/wazero/interp_test.go
+++ b/interp/wazero/interp_test.go
@@ -29,6 +29,10 @@ func TestHalt(t *testing.T) {
 	tester.HaltTest(t, &Interpreter{})
 }
 
+func TestExternalReferences(t *testing.T) {
+	tester.ReferencesTest(t, &Interpreter{})
+}
+
 func TestDefineFunc(t *testing.T) {
 	t.Skip("TODO: implement TestDefineFunc")
 }