Replace private encode/decode imports with pickle serialization

examples/spanish/workflow_hitl_checkpoint_pg.py

@@ -10,11 +10,11 @@
 
 import asyncio
 import os
+import pickle  # noqa: S403
 from dataclasses import dataclass
 from typing import Any
 
 import psycopg
-from psycopg.types.json import Jsonb
 from agent_framework import (
     Agent,
     AgentExecutor,
@@ -29,10 +29,6 @@
     response_handler,
 )
 from agent_framework import WorkflowCheckpoint
-
-# Importación privada — aún no hay API pública para la codificación de checkpoints.
-# Ver: https://github.com/microsoft/agent-framework/issues/4428
-from agent_framework._workflows._checkpoint_encoding import decode_checkpoint_value, encode_checkpoint_value
 from agent_framework.exceptions import WorkflowCheckpointException
 from agent_framework.openai import OpenAIChatClient
 from azure.identity.aio import DefaultAzureCredential, get_bearer_token_provider
@@ -51,7 +47,10 @@ class PostgresCheckpointStorage:
     """Almacenamiento de checkpoints respaldado por PostgreSQL.
 
     Guarda checkpoints en una sola tabla con columnas para ID, nombre del workflow,
-    timestamp y los datos JSON codificados. SQL maneja la indexación y el filtrado.
+    timestamp y los datos serializados con pickle. SQL maneja la indexación y el filtrado.
+
+    ADVERTENCIA DE SEGURIDAD: Los checkpoints usan pickle para la serialización.
+    Solo carga checkpoints de fuentes confiables.
     """
 
     def __init__(self, conninfo: str) -> None:
@@ -65,7 +64,7 @@ def _ensure_table(self) -> None:
                     id TEXT PRIMARY KEY,
                     workflow_name TEXT NOT NULL,
                     timestamp TEXT NOT NULL,
-                    data JSONB NOT NULL
+                    data BYTEA NOT NULL
                 )
             """)
             conn.execute("""
@@ -75,14 +74,14 @@ def _ensure_table(self) -> None:
 
     async def save(self, checkpoint: WorkflowCheckpoint) -> str:
         """Guarda un checkpoint en PostgreSQL."""
-        encoded = encode_checkpoint_value(checkpoint.to_dict())
+        data = pickle.dumps(checkpoint, protocol=pickle.HIGHEST_PROTOCOL)  # noqa: S301
         async with await psycopg.AsyncConnection.connect(self._conninfo) as conn:
             await conn.execute(
                 """INSERT INTO workflow_checkpoints (id, workflow_name, timestamp, data)
                    VALUES (%s, %s, %s, %s)
                    ON CONFLICT (id) DO UPDATE SET data = EXCLUDED.data""",
                 (checkpoint.checkpoint_id, checkpoint.workflow_name,
-                 checkpoint.timestamp, Jsonb(encoded)),
+                 checkpoint.timestamp, data),
             )
         return checkpoint.checkpoint_id
 
@@ -94,8 +93,7 @@ async def load(self, checkpoint_id: str) -> WorkflowCheckpoint:
             )).fetchone()
         if row is None:
             raise WorkflowCheckpointException(f"No se encontró checkpoint con ID {checkpoint_id}")
-        decoded = decode_checkpoint_value(row["data"])
-        return WorkflowCheckpoint.from_dict(decoded)
+        return pickle.loads(row["data"])  # noqa: S301
 
     async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoint]:
         """Lista todos los checkpoints de un workflow, ordenados por timestamp."""
@@ -104,7 +102,7 @@ async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoi
                 "SELECT data FROM workflow_checkpoints WHERE workflow_name = %s ORDER BY timestamp",
                 (workflow_name,),
             )).fetchall()
-        return [WorkflowCheckpoint.from_dict(decode_checkpoint_value(r["data"])) for r in rows]
+        return [pickle.loads(r["data"]) for r in rows]  # noqa: S301
 
     async def delete(self, checkpoint_id: str) -> bool:
         """Elimina un checkpoint por ID."""
@@ -124,7 +122,7 @@ async def get_latest(self, *, workflow_name: str) -> WorkflowCheckpoint | None:
             )).fetchone()
         if row is None:
             return None
-        return WorkflowCheckpoint.from_dict(decode_checkpoint_value(row["data"]))
+        return pickle.loads(row["data"])  # noqa: S301
 
     async def list_checkpoint_ids(self, *, workflow_name: str) -> list[str]:
         """Lista los IDs de checkpoints de un workflow."""

examples/workflow_hitl_checkpoint_pg.py

@@ -10,11 +10,11 @@
 
 import asyncio
 import os
+import pickle  # noqa: S403
 from dataclasses import dataclass
 from typing import Any
 
 import psycopg
-from psycopg.types.json import Jsonb
 from agent_framework import (
     Agent,
     AgentExecutor,
@@ -29,10 +29,6 @@
     response_handler,
 )
 from agent_framework import WorkflowCheckpoint
-
-# Private import — no public API for checkpoint encoding yet.
-# See: https://github.com/microsoft/agent-framework/issues/4428
-from agent_framework._workflows._checkpoint_encoding import decode_checkpoint_value, encode_checkpoint_value
 from agent_framework.exceptions import WorkflowCheckpointException
 from agent_framework.openai import OpenAIChatClient
 from azure.identity.aio import DefaultAzureCredential, get_bearer_token_provider
@@ -51,7 +47,10 @@ class PostgresCheckpointStorage:
     """PostgreSQL-backed checkpoint storage.
 
     Stores checkpoints in a single table with columns for ID, workflow name,
-    timestamp, and the encoded JSON data. SQL handles indexing and filtering.
+    timestamp, and the pickled checkpoint data. SQL handles indexing and filtering.
+
+    SECURITY WARNING: Checkpoints use pickle for serialization. Only load
+    checkpoints from trusted sources.
     """
 
     def __init__(self, conninfo: str) -> None:
@@ -65,7 +64,7 @@ def _ensure_table(self) -> None:
                     id TEXT PRIMARY KEY,
                     workflow_name TEXT NOT NULL,
                     timestamp TEXT NOT NULL,
-                    data JSONB NOT NULL
+                    data BYTEA NOT NULL
                 )
             """)
             conn.execute("""
@@ -75,14 +74,14 @@ def _ensure_table(self) -> None:
 
     async def save(self, checkpoint: WorkflowCheckpoint) -> str:
         """Save a checkpoint to PostgreSQL."""
-        encoded = encode_checkpoint_value(checkpoint.to_dict())
+        data = pickle.dumps(checkpoint, protocol=pickle.HIGHEST_PROTOCOL)  # noqa: S301
         async with await psycopg.AsyncConnection.connect(self._conninfo) as conn:
             await conn.execute(
                 """INSERT INTO workflow_checkpoints (id, workflow_name, timestamp, data)
                    VALUES (%s, %s, %s, %s)
                    ON CONFLICT (id) DO UPDATE SET data = EXCLUDED.data""",
                 (checkpoint.checkpoint_id, checkpoint.workflow_name,
-                 checkpoint.timestamp, Jsonb(encoded)),
+                 checkpoint.timestamp, data),
             )
         return checkpoint.checkpoint_id
 
@@ -94,8 +93,7 @@ async def load(self, checkpoint_id: str) -> WorkflowCheckpoint:
             )).fetchone()
         if row is None:
             raise WorkflowCheckpointException(f"No checkpoint found with ID {checkpoint_id}")
-        decoded = decode_checkpoint_value(row["data"])
-        return WorkflowCheckpoint.from_dict(decoded)
+        return pickle.loads(row["data"])  # noqa: S301
 
     async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoint]:
         """List all checkpoints for a workflow, ordered by timestamp."""
@@ -104,7 +102,7 @@ async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoi
                 "SELECT data FROM workflow_checkpoints WHERE workflow_name = %s ORDER BY timestamp",
                 (workflow_name,),
             )).fetchall()
-        return [WorkflowCheckpoint.from_dict(decode_checkpoint_value(r["data"])) for r in rows]
+        return [pickle.loads(r["data"]) for r in rows]  # noqa: S301
 
     async def delete(self, checkpoint_id: str) -> bool:
         """Delete a checkpoint by ID."""
@@ -124,7 +122,7 @@ async def get_latest(self, *, workflow_name: str) -> WorkflowCheckpoint | None:
             )).fetchone()
         if row is None:
             return None
-        return WorkflowCheckpoint.from_dict(decode_checkpoint_value(row["data"]))
+        return pickle.loads(row["data"])  # noqa: S301
 
     async def list_checkpoint_ids(self, *, workflow_name: str) -> list[str]:
         """List checkpoint IDs for a workflow."""