diff --git a/include/ground.h b/include/ground.h
index 8c41538..691d8c0 100644
--- a/include/ground.h
+++ b/include/ground.h
@@ -127,6 +127,7 @@ struct GroundError {
 // --- Program structure types definitions ---
 
 enum GroundTypeType {
+    GroundType_Undefined,
     GroundType_Int, GroundType_Double, GroundType_Char, GroundType_Bool,
     GroundType_String, GroundType_List,
     GroundType_Function, GroundType_Struct, GroundType_Object,
diff --git a/src/Bytecode/Instruction/execute.c b/src/Bytecode/Instruction/execute.c
index 6555b0d..42da74d 100644
--- a/src/Bytecode/Instruction/execute.c
+++ b/src/Bytecode/Instruction/execute.c
@@ -888,6 +888,137 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
         return CONTINUE;
     }
     CALLMETHOD: {
+        // bytecode: object_offset, field0_offset, ..., fieldN_offset, method_offset, arg0_offset, ..., argM_offset, output_offset
+        GroundSize len = instruction->args.len;
+
+        // Navigate the object through field path to find the containing object and method
+        GroundBytecodeValue* current = HEAP_GET(heap, instruction->args.at[0]);
+
+        // Walk the field path to find the containing object
+        GroundSize fieldPairsCount = 0;
+        for (GroundSize fi = 1; fi < len - 1; fi++) {
+            if (current->type.type != GroundType_Object) break;
+            GroundBytecodeValue* next = &current->as.Object.values[instruction->args.at[fi]];
+            if (next->type.type == GroundType_Function) {
+                // This is the method
+                break;
+            }
+            current = next;
+            fieldPairsCount++;
+        }
+
+        // The method is at index 1 + fieldPairsCount
+        GroundSize methodFieldIdx = 1 + fieldPairsCount;
+        GroundSize methodArgCount = len - methodFieldIdx - 2; // subtract method and output
+
+        if (current->type.type != GroundType_Object) {
+            Ground.Log.Error("CALLMETHOD on non-object value in Ground.Bytecode.Instruction.execute");
+            Ground.Flags.error = true;
+            return CONTINUE;
+        }
+
+        GroundBytecodeFunction* method = &current->as.Object.values[instruction->args.at[methodFieldIdx]].as.Function;
+
+        if (method->isNativeFunction) {
+            // Native method handling (same as CALL native path but with self appended)
+            ffi_type* argTypes[methodArgCount + 1];
+            void* args[methodArgCount + 1];
+
+            // Self is the first arg for native methods
+            argTypes[0] = ffiTypeFromGroundType(&(GroundType){.type = GroundType_Object});
+            args[0] = current;
+
+            for (GroundSize i = 0; i < methodArgCount; i++) {
+                GroundBytecodeValue* val = HEAP_GET(heap, instruction->args.at[methodFieldIdx + 1 + i]);
+                argTypes[i + 1] = ffiTypeFromGroundType(&val->type);
+                switch (val->type.type) {
+                    case GroundType_Int:    args[i + 1] = &val->as.Int; break;
+                    case GroundType_Double: args[i + 1] = &val->as.Double; break;
+                    case GroundType_Char:   args[i + 1] = &val->as.Char; break;
+                    case GroundType_Bool:   args[i + 1] = &val->as.Bool; break;
+                    case GroundType_String: args[i + 1] = &val->as.String.cstr; break;
+                    default: args[i + 1] = val; break;
+                }
+            }
+
+            ffi_cif cif;
+            ffi_status status = ffi_prep_cif(
+                &cif, FFI_DEFAULT_ABI, methodArgCount + 1,
+                ffiTypeFromGroundType(method->returnType), argTypes
+            );
+
+            if (status != FFI_OK) {
+                Ground.Log.Error("ffi CIF preparation failed in Ground.Bytecode.Instruction.execute");
+                Ground.Flags.error = true;
+                return CONTINUE;
+            }
+
+            union {
+                GroundInt    Int;
+                GroundDouble Double;
+                GroundChar   Char;
+                GroundBool   Bool;
+                char*        String;
+            } result;
+
+            ffi_call(&cif, method->program.native, &result, args);
+
+            switch (method->returnType->type) {
+                case GroundType_Int:    HEAP_SET(heap, instruction->args.at[len - 1], Ground.New.BytecodeValue(Ground.New.Value.Int(result.Int))); break;
+                case GroundType_Char:   HEAP_SET(heap, instruction->args.at[len - 1], Ground.New.BytecodeValue(Ground.New.Value.Char(result.Char))); break;
+                case GroundType_Double: HEAP_SET(heap, instruction->args.at[len - 1], Ground.New.BytecodeValue(Ground.New.Value.Double(result.Double))); break;
+                case GroundType_Bool:   HEAP_SET(heap, instruction->args.at[len - 1], Ground.New.BytecodeValue(Ground.New.Value.Bool(result.Bool))); break;
+                case GroundType_String: HEAP_SET(heap, instruction->args.at[len - 1], Ground.New.BytecodeValue(Ground.New.Value.String(Ground.New.String(result.String)))); break;
+                default: break;
+            }
+
+            return CONTINUE;
+        }
+
+        if (method->closure == NULL) {
+            Ground.Log.Error("unexpected NULL closure in Ground.Bytecode.Instruction.execute");
+            Ground.Flags.error = true;
+            return CONTINUE;
+        }
+
+        // Total args for method: methodArgCount explicit + 1 self
+        GroundSize totalArgs = methodArgCount + 1;
+        GroundSize heapSize = totalArgs + method->closure->len;
+
+        GroundBytecodeHeap newHeap = { malloc(sizeof(GroundBytecodeValue) * heapSize), heapSize, heapSize };
+        if (newHeap.heap == NULL) {
+            Ground.Log.Error("malloc failed in Ground.Bytecode.Instruction.execute");
+            Ground.Flags.error = true;
+            return CONTINUE;
+        }
+
+        // Load explicit method arguments into the heap
+        for (GroundSize i = 0; i < methodArgCount; i++) {
+            newHeap.heap[i] = Ground.Copy.BytecodeValue(HEAP_GET(heap, instruction->args.at[methodFieldIdx + 1 + i]));
+        }
+
+        // Self (the containing object) is the last argument
+        newHeap.heap[methodArgCount] = Ground.Copy.BytecodeValue(current);
+
+        // Copy closure variables after arguments
+        for (GroundSize i = totalArgs; i < newHeap.len; i++) {
+            newHeap.heap[i] = Ground.Copy.BytecodeValue(&method->closure->heap[i - totalArgs]);
+        }
+
+        // Execute the method
+        GroundBytecodeValue result = Ground.Bytecode.Program.execute(method->program.ground, &newHeap);
+
+        GroundBytecodeValue resultCopy = Ground.Copy.BytecodeValue(&result);
+
+        // Clean up
+        for (GroundSize i = 0; i < newHeap.len; i++) {
+            Ground.Free.BytecodeValue(&newHeap.heap[i]);
+        }
+        free(newHeap.heap);
+
+        // Store the result
+        HEAP_SET(heap, instruction->args.at[len - 1], resultCopy);
+
         return CONTINUE;
     }
     STRUCT: {
diff --git a/src/New/Bytecode.c b/src/New/Bytecode.c
index d5e93cb..a166d4a 100644
--- a/src/New/Bytecode.c
+++ b/src/New/Bytecode.c
@@ -457,6 +457,158 @@ static inline GroundSize doOffsets(GroundProgram* gp, GroundState* state, Ground
                 continue;
             }
             case GroundInstruction_CALLMETHOD: {
+                // callmethod &object -type (&field -type)... !methodName $args... &output
+                // Bytecode: object_offset, field0_offset, ..., fieldN_offset, method_offset, arg0_offset, ..., argM_offset, output_offset
+                GroundInstruction* inst = &gp->at[i];
+
+                // Find the methodName (FunctionRef) to determine the field path length
+                GroundSize methodIdx = 0;
+                for (GroundSize j = 0; j < inst->args.len; j++) {
+                    if (inst->args.at[j].type == GroundArg_FunctionRef) {
+                        methodIdx = j;
+                        break;
+                    }
+                }
+
+                GroundSize fieldPairs = (methodIdx - 2) / 2;
+                GroundSize methodArgs = inst->args.len - methodIdx - 2;
+                GroundSize gbiSize = 1 + fieldPairs + 1 + methodArgs + 1;
+
+                GroundBytecodeInstruction newInst = {
+                    .type = GroundInstruction_CALLMETHOD,
+                    .args = {
+                        .at = malloc(sizeof(GroundSize) * gbiSize),
+                        .capacity = gbiSize,
+                        .len = gbiSize
+                    }
+                };
+
+                if (newInst.args.at == NULL) {
+                    Ground.Log.Error("malloc failed in Ground.New.Bytecode -> doOffsets");
+                    Ground.Flags.error = true;
+                    return 0;
+                }
+
+                // Resolve the object variable to a heap offset
+                GroundArg* arg = &inst->args.at[0];
+                GroundVariable* item = NULL;
+                HASH_FIND_STR(state->variables, arg->as.ref->string, item);
+                if (item == NULL) {
+                    item = malloc(sizeof(GroundVariable));
+                    if (item == NULL) {
+                        Ground.Log.Error("malloc failed in Ground.New.Bytecode -> doOffsets");
+                        Ground.Flags.error = true;
+                        return 0;
+                    }
+                    item->value = Ground.New.Value.Int(0);
+                    strncpy(item->name, arg->as.ref->string, 2047);
+                    item->_offset = size++;
+                    HASH_ADD_STR(state->variables, name, item);
+                }
+                arg->_offset = item->_offset;
+                newInst.args.at[0] = arg->_offset;
+
+                // Get the type of the object (type annotation is at args[1])
+                GroundVariable* var = NULL;
+                HASH_FIND_STR(state->variables, inst->args.at[1].as.ref->string, var);
+                if (var == NULL || var->value.type.type != GroundType_Struct) {
+                    Ground.Log.Error("unknown struct name in Ground.New.Bytecode -> doOffsets");
+                    Ground.Flags.error = true;
+                    return 0;
+                }
+                GroundStruct* currentType = &var->value.as.Struct;
+
+                // Resolve each field's offset within its containing struct
+                for (GroundSize j = 0; j < fieldPairs; j++) {
+                    GroundArg* fieldArg = &inst->args.at[2 + (j * 2)];
+                    GroundObjectField* field;
+                    HASH_FIND_STR(currentType->fields, fieldArg->as.ref->string, field);
+                    if (field == NULL) {
+                        Ground.Log.Error("unknown field in struct in Ground.New.Bytecode -> doOffsets");
+                        Ground.Flags.error = true;
+                        return 0;
+                    }
+                    newInst.args.at[1 + j] = field->offset;
+
+                    // Resolve the type for the next field
+                    GroundVariable* typeVar = NULL;
+                    HASH_FIND_STR(state->variables, inst->args.at[3 + j * 2].as.ref->string, typeVar);
+                    if (typeVar == NULL || typeVar->value.type.type != GroundType_Struct) {
+                        Ground.Log.Error("field type is not a struct in Ground.New.Bytecode -> doOffsets");
+                        Ground.Flags.error = true;
+                        return 0;
+                    }
+                    currentType = &typeVar->value.as.Struct;
+                }
+
+                // Resolve the method name to a field offset
+                GroundArg* methodArg = &inst->args.at[methodIdx];
+                GroundObjectField* methodField;
+                HASH_FIND_STR(currentType->fields, methodArg->as.ref->string, methodField);
+                if (methodField == NULL) {
+                    Ground.Log.Error("unknown method in struct in Ground.New.Bytecode -> doOffsets");
+                    Ground.Flags.error = true;
+                    return 0;
+                }
+                newInst.args.at[1 + fieldPairs] = methodField->offset;
+
+                // Resolve the method arguments
+                for (GroundSize j = 0; j < methodArgs; j++) {
+                    GroundArg* arg = &inst->args.at[methodIdx + 1 + j];
+                    if (arg->type == GroundArg_Value) {
+                        GroundVariable* constItem = malloc(sizeof(GroundVariable));
+                        if (constItem == NULL) {
+                            Ground.Log.Error("malloc failed in Ground.New.Bytecode -> doOffsets");
+                            Ground.Flags.error = true;
+                            return 0;
+                        }
+                        constItem->value = Ground.Copy.Value(&arg->as.value);
+                        if (Ground.Flags.error) return 0;
+                        constItem->_offset = size++;
+                        snprintf(constItem->name, sizeof(constItem->name) - 1, "_._.ground_internal_constant_%zu", constItem->_offset);
+                        HASH_ADD_STR(state->variables, name, constItem);
+                        newInst.args.at[2 + fieldPairs + j] = constItem->_offset;
+                    } else {
+                        GroundVariable* argItem = NULL;
+                        HASH_FIND_STR(state->variables, arg->as.ref->string, argItem);
+                        if (argItem == NULL) {
+                            argItem = malloc(sizeof(GroundVariable));
+                            if (argItem == NULL) {
+                                Ground.Log.Error("malloc failed in Ground.New.Bytecode -> doOffsets");
+                                Ground.Flags.error = true;
+                                return 0;
+                            }
+                            argItem->value = Ground.New.Value.Int(0);
+                            strncpy(argItem->name, arg->as.ref->string, 2047);
+                            argItem->_offset = size++;
+                            HASH_ADD_STR(state->variables, name, argItem);
+                        }
+                        arg->_offset = argItem->_offset;
+                        newInst.args.at[2 + fieldPairs + j] = argItem->_offset;
+                    }
+                }
+
+                // Resolve the output variable
+                GroundArg* outputArg = &inst->args.at[inst->args.len - 1];
+                GroundVariable* outputItem = NULL;
+                HASH_FIND_STR(state->variables, outputArg->as.ref->string, outputItem);
+                if (outputItem == NULL) {
+                    outputItem = malloc(sizeof(GroundVariable));
+                    if (outputItem == NULL) {
+                        Ground.Log.Error("malloc failed in Ground.New.Bytecode -> doOffsets");
+                        Ground.Flags.error = true;
+                        return 0;
+                    }
+                    outputItem->value = Ground.New.Value.Int(0);
+                    strncpy(outputItem->name, outputArg->as.ref->string, 2047);
+                    outputItem->_offset = size++;
+                    HASH_ADD_STR(state->variables, name, outputItem);
+                }
+                outputArg->_offset = outputItem->_offset;
+                newInst.args.at[gbiSize - 1] = outputArg->_offset;
+
+                gbp->at[i] = newInst;
+                gbp->len++;
 
                 continue;
             }
diff --git a/src/Program/preprocess.c b/src/Program/preprocess.c
index f3cfee2..75edd2e 100644
--- a/src/Program/preprocess.c
+++ b/src/Program/preprocess.c
@@ -222,15 +222,40 @@ static void doStruct(GroundProgram* program, GroundProgram* newProgram, GroundSt
             case GroundInstruction_FUN: {
                 // Parse the function itself
                 doFunction(program, newProgram, state, i);
+
+                // Add hidden "self" parameter to the method
+                GroundVariable* fnVar = NULL;
+                HASH_FIND_STR(state->variables, newProgram->at[newProgram->len - 1].args.at[0].as.ref->string, fnVar);
+                if (fnVar != NULL && fnVar->value.type.type == GroundType_Function) {
+                    Ground.Function.appendArg(&fnVar->value.as.Function, "self");
+
+                    GroundVariable* selfVar = malloc(sizeof(GroundVariable));
+                    if (selfVar != NULL) {
+                        snprintf(selfVar->name, 2047, "self");
+                        selfVar->value = Ground.New.Value.Int(0);
+                        HASH_ADD_STR(fnVar->value.as.Function.closure->variables, name, selfVar);
+                    }
+                }
+
+                // Add it to the struct
+                GroundObjectField* field = malloc(sizeof(GroundObjectField));
+                if (field == NULL) {
+                    Ground.Log.Error("malloc failed in Ground.Program.preprocess -> doStruct");
+                    Ground.Flags.error = true;
+                    return;
+                } 
+
+                snprintf(field->name, 2047, "%s", instruction->args.at[0].as.ref->string);
+                field->offset = fieldCount++;
+
+                HASH_ADD_STR(gs.fields, name, field);
+
                 // Read and remove the emitted instruction 
                 GroundInstruction* inst = &newProgram->at[newProgram->len - 1];
                 Ground.Instruction.append(&output, Ground.New.Arg.FunctionRef(Ground.Copy.Identifier(inst->args.at[0].as.ref)));
                 Ground.Free.Instruction(inst);
                 newProgram->len--;
 
-                // TODO do the rest of this 
-                // for some reason I haven't done it yet?? oh well who cares
-
                 // Add 3 to signal addition of closure 
                 Ground.Instruction.append(&output, (GroundArg) {.type = GroundArg_DirectRef, ._offset = 3});
                 break;