diff --git a/cairo0-bootloader/bootloader/objects.py b/cairo0-bootloader/bootloader/objects.py
index 95f6179..137a564 100644
--- a/cairo0-bootloader/bootloader/objects.py
+++ b/cairo0-bootloader/bootloader/objects.py
@@ -1,4 +1,16 @@
+import tempfile
+import subprocess
+import dataclasses
+from abc import abstractmethod
+from dataclasses import field
+from typing import ClassVar, Dict, List, Optional, Type
+import marshmallow
+import marshmallow.fields as mfields
 import marshmallow_dataclass
+from marshmallow_oneofschema import OneOfSchema
+from starkware.cairo.lang.compiler.program import Program, ProgramBase, StrippedProgram
+from starkware.cairo.lang.vm.cairo_pie import CairoPie
+from starkware.starkware_utils.marshmallow_dataclass_fields import additional_metadata
 from starkware.starkware_utils.validated_dataclass import ValidatedMarshmallowDataclass
 from contract_class.contract_class import (
     CompiledClass,
@@ -8,6 +20,167 @@
 )
 
 
+class TaskSpec(ValidatedMarshmallowDataclass):
+    """
+    Contains task's specification.
+    """
+
+    @abstractmethod
+    def load_task(self, memory=None, args_start=None, args_len=None) -> "Task":
+        """
+        Returns the corresponding task.
+        """
+
+
+class Task:
+    @abstractmethod
+    def get_program(self) -> ProgramBase:
+        """
+        Returns the task's Cairo program.
+        """
+
+
+@marshmallow_dataclass.dataclass(frozen=True)
+class RunProgramTask(TaskSpec, Task):
+    TYPE: ClassVar[str] = "RunProgramTask"
+    program: Program
+    program_input: dict
+    use_poseidon: bool
+
+    def get_program(self) -> Program:
+        return self.program
+
+    def load_task(self, memory=None, args_start=None, args_len=None) -> "Task":
+        return self
+
+
+@marshmallow_dataclass.dataclass(frozen=True)
+class CairoPiePath(TaskSpec):
+    TYPE: ClassVar[str] = "CairoPiePath"
+    path: str
+    use_poseidon: bool
+
+    def load_task(self, memory=None, args_start=None, args_len=None) -> "CairoPieTask":
+        """
+        Loads the PIE to memory.
+        """
+        return CairoPieTask(
+            cairo_pie=CairoPie.from_file(self.path), use_poseidon=self.use_poseidon
+        )
+
+
+@marshmallow_dataclass.dataclass(frozen=True)
+class Cairo1ProgramPath(TaskSpec):
+    TYPE: ClassVar[str] = "Cairo1ProgramPath"
+    path: str
+    use_poseidon: bool
+
+    def load_task(self, memory=None, args_start=None, args_len=None) -> "CairoPieTask":
+        """
+        Builds and Loads the PIE to memory.
+        """
+        with tempfile.NamedTemporaryFile() as cairo_pie_file:
+            cairo_pie_file_path = cairo_pie_file.name
+
+            args = [memory[args_start.address_ + i] for i in range(args_len)]
+            formatted_args = f'[{" ".join(map(str, args))}]'
+
+            subprocess.run(
+                [
+                    "cairo1-run",
+                    self.path,
+                    "--layout",
+                    "all_cairo",
+                    "--args",
+                    formatted_args,
+                    "--cairo_pie_output",
+                    cairo_pie_file_path,
+                    "--append_return_values",
+                ],
+                check=True,
+            )
+
+            return CairoPieTask(
+                cairo_pie=CairoPie.from_file(cairo_pie_file_path),
+                use_poseidon=self.use_poseidon,
+            )
+
+
+@marshmallow_dataclass.dataclass(frozen=True)
+class CairoSierra(TaskSpec):
+    TYPE: ClassVar[str] = "CairoSierra"
+    path: str
+    use_poseidon: bool
+
+    def load_task(self, memory=None, args_start=None, args_len=None) -> "CairoPieTask":
+        """
+        Builds and Loads the PIE to memory.
+        """
+        with tempfile.NamedTemporaryFile() as cairo_pie_file:
+            cairo_pie_file_path = cairo_pie_file.name
+
+            args = [memory[args_start.address_ + i] for i in range(args_len)]
+            formatted_args = f'[{" ".join(map(str, args))}]'
+
+            subprocess.run(
+                [
+                    "runner",
+                    "--sierra_program",
+                    self.path,
+                    "--args",
+                    formatted_args,
+                    "--cairo_pie_output",
+                    cairo_pie_file_path,
+                ],
+                check=True,
+            )
+
+            return CairoPieTask(
+                cairo_pie=CairoPie.from_file(cairo_pie_file_path),
+                use_poseidon=self.use_poseidon,
+            )
+
+
+class TaskSchema(OneOfSchema):
+    """
+    Schema for Task/CairoPiePath/Cairo1ProgramPath/CairoSierra
+    OneOfSchema adds a "type" field.
+    """
+
+    type_schemas: Dict[str, Type[marshmallow.Schema]] = {
+        RunProgramTask.TYPE: RunProgramTask.Schema,
+        CairoPiePath.TYPE: CairoPiePath.Schema,
+        Cairo1ProgramPath.TYPE: Cairo1ProgramPath.Schema,
+        CairoSierra.TYPE: CairoSierra.Schema,
+    }
+
+    def get_obj_type(self, obj):
+        return obj.TYPE
+
+
+@dataclasses.dataclass(frozen=True)
+class CairoPieTask(Task):
+    cairo_pie: CairoPie
+    use_poseidon: bool
+
+    def get_program(self) -> StrippedProgram:
+        return self.cairo_pie.program
+
+
+@marshmallow_dataclass.dataclass(frozen=True)
+class SimpleBootloaderInput(ValidatedMarshmallowDataclass):
+    tasks: List[TaskSpec] = field(
+        metadata=additional_metadata(
+            marshmallow_field=mfields.List(mfields.Nested(TaskSchema))
+        )
+    )
+    fact_topologies_path: Optional[str]
+
+    # If true, the bootloader will put all the outputs in a single page, ignoring the
+    # tasks' fact topologies.
+    single_page: bool
+
+
 @marshmallow_dataclass.dataclass(frozen=True)
 class ContractBootloaderInput(ValidatedMarshmallowDataclass):
     compiled_class: CompiledClass = CompiledClass