Python: support checkpoints for workflow orchestrations and sub-workflows (#863)

* Magentic checkpoint wip

* Magentic checkpoint updates

* Support checkpointing for magentic orchestration.

* Checkpointing for sub-workflows

* Use _execute_contexts instead of _pending_requests

* Remove unnecessary type ignores

* Support checkpoints for other orchestrations, refactor some code.

* Regenerate uv.lock
This commit is contained in:
Evan Mattson
2025-09-26 11:21:06 +09:00
committed by GitHub
Unverified
parent 4b743ea62a
commit 2cd7ab342b
22 changed files with 2005 additions and 277 deletions
@@ -249,7 +249,7 @@ async def main():
line += f" messages={msg_count}"
print(line)
user_input = input(
user_input = input( # noqa: ASYNC250
"\nEnter checkpoint index (or paste checkpoint id) to resume from, or press Enter to skip resume: "
).strip()
@@ -0,0 +1,370 @@
# Copyright (c) Microsoft. All rights reserved.
import asyncio
import contextlib
import json
from dataclasses import dataclass, field, replace
from datetime import datetime, timedelta
from pathlib import Path
from agent_framework import (
Executor,
FileCheckpointStorage,
RequestInfoEvent,
RequestInfoExecutor,
RequestInfoMessage,
RequestResponse,
Workflow,
WorkflowBuilder,
WorkflowContext,
WorkflowExecutor,
WorkflowOutputEvent,
WorkflowRunState,
WorkflowStatusEvent,
handler,
)
CHECKPOINT_DIR = Path(__file__).with_suffix("").parent / "tmp" / "sub_workflow_checkpoints"
"""
Sample: Checkpointing for workflows that embed sub-workflows.
This sample shows how a parent workflow that wraps a sub-workflow can:
- run until the sub-workflow emits a human approval request via RequestInfoExecutor
- persist a checkpoint that captures the pending request (including complex payloads)
- resume later, supplying the human decision directly at restore time
It is intentionally similar in spirit to the orchestration checkpoint sample but
uses ``WorkflowExecutor`` so we exercise the full parent/sub-workflow round-trip.
"""
def _utc_now() -> datetime:
return datetime.now()
# ---------------------------------------------------------------------------
# Messages exchanged inside the sub-workflow
# ---------------------------------------------------------------------------
@dataclass
class DraftTask:
"""Task handed from the parent to the sub-workflow writer."""
topic: str
due: datetime
iteration: int = 1
@dataclass
class DraftPackage:
"""Intermediate draft produced by the sub-workflow writer."""
topic: str
content: str
iteration: int
created_at: datetime = field(default_factory=_utc_now)
@dataclass
class FinalDraft:
"""Final deliverable returned to the parent workflow."""
topic: str
content: str
iterations: int
approved_at: datetime
@dataclass
class ReviewRequest(RequestInfoMessage):
"""Human approval request surfaced via RequestInfoExecutor."""
topic: str = ""
iteration: int = 1
draft_excerpt: str = ""
due_iso: str = ""
reviewer_guidance: list[str] = field(default_factory=list) # type: ignore
# ---------------------------------------------------------------------------
# Sub-workflow executors
# ---------------------------------------------------------------------------
class DraftWriter(Executor):
"""Produces an initial draft for the supplied topic."""
def __init__(self) -> None:
super().__init__(id="draft_writer")
@handler
async def create_draft(self, task: DraftTask, ctx: WorkflowContext[DraftPackage]) -> None:
draft = DraftPackage(
topic=task.topic,
content=(
f"Launch plan for {task.topic}.\n\n"
"- Outline the customer message.\n"
"- Highlight three differentiators.\n"
"- Close with a next-step CTA.\n"
f"(iteration {task.iteration})"
),
iteration=task.iteration,
)
await ctx.send_message(draft, target_id="draft_review")
class DraftReviewRouter(Executor):
"""Turns draft packages into human approval requests."""
def __init__(self) -> None:
super().__init__(id="draft_review")
@handler
async def request_review(self, draft: DraftPackage, ctx: WorkflowContext[ReviewRequest]) -> None:
excerpt = draft.content.splitlines()[0]
request = ReviewRequest(
topic=draft.topic,
iteration=draft.iteration,
draft_excerpt=excerpt,
due_iso=draft.created_at.isoformat(),
reviewer_guidance=[
"Ensure tone matches launch messaging",
"Confirm CTA is action-oriented",
],
)
await ctx.send_message(request, target_id="sub_review_requests")
@handler
async def forward_decision(
self,
decision: RequestResponse[ReviewRequest, str],
ctx: WorkflowContext[RequestResponse[ReviewRequest, str]],
) -> None:
await ctx.send_message(decision, target_id="draft_finaliser")
class DraftFinaliser(Executor):
"""Applies the human decision and emits the final draft."""
def __init__(self) -> None:
super().__init__(id="draft_finaliser")
@handler
async def on_review_decision(
self,
decision: RequestResponse[ReviewRequest, str],
ctx: WorkflowContext[DraftTask, FinalDraft],
) -> None:
reply = (decision.data or "").strip().lower()
original = decision.original_request
topic = original.topic if original else "unknown topic"
iteration = original.iteration if original else 1
if reply != "approve":
# Loop back with a follow-up task. In a real workflow you would
# incorporate the human guidance; here we just increment the counter.
next_task = DraftTask(
topic=topic,
due=_utc_now() + timedelta(hours=1),
iteration=iteration + 1,
)
await ctx.send_message(next_task, target_id="draft_writer")
return
final = FinalDraft(
topic=topic,
content=f"Approved launch narrative for {topic} (iteration {iteration}).",
iterations=iteration,
approved_at=_utc_now(),
)
await ctx.yield_output(final)
# ---------------------------------------------------------------------------
# Parent workflow executors
# ---------------------------------------------------------------------------
class LaunchCoordinator(Executor):
"""Owns the top-level workflow and collects the final draft."""
def __init__(self) -> None:
super().__init__(id="launch_coordinator")
self._final: FinalDraft | None = None
@handler
async def kick_off(self, topic: str, ctx: WorkflowContext[DraftTask]) -> None:
task = DraftTask(topic=topic, due=_utc_now() + timedelta(hours=2))
await ctx.send_message(task, target_id="launch_subworkflow")
@handler
async def collect_final(self, draft: FinalDraft, ctx: WorkflowContext[None, FinalDraft]) -> None:
approved_at = draft.approved_at
normalised = draft
if isinstance(approved_at, str):
with contextlib.suppress(ValueError):
parsed = datetime.fromisoformat(approved_at)
normalised = replace(draft, approved_at=parsed)
approved_at = parsed
self._final = normalised
approved_display = approved_at.isoformat() if hasattr(approved_at, "isoformat") else str(approved_at)
print("\n>>> Parent workflow received approved draft:")
print(f"- Topic: {normalised.topic}")
print(f"- Iterations: {normalised.iterations}")
print(f"- Approved at: {approved_display}")
print(f"- Content: {normalised.content}\n")
await ctx.yield_output(normalised)
@property
def final_result(self) -> FinalDraft | None:
return self._final
# ---------------------------------------------------------------------------
# Workflow construction helpers
# ---------------------------------------------------------------------------
def build_sub_workflow() -> WorkflowExecutor:
writer = DraftWriter()
router = DraftReviewRouter()
request_info = RequestInfoExecutor(id="sub_review_requests")
finaliser = DraftFinaliser()
sub_workflow = (
WorkflowBuilder()
.set_start_executor(writer)
.add_edge(writer, router)
.add_edge(router, request_info)
.add_edge(request_info, router, condition=lambda msg: isinstance(msg, RequestResponse))
.add_edge(router, finaliser, condition=lambda msg: isinstance(msg, RequestResponse))
.add_edge(request_info, finaliser)
.add_edge(finaliser, writer) # permits revision loops
.build()
)
return WorkflowExecutor(sub_workflow, id="launch_subworkflow")
def build_parent_workflow(storage: FileCheckpointStorage) -> tuple[LaunchCoordinator, Workflow]:
coordinator = LaunchCoordinator()
sub_executor = build_sub_workflow()
parent_request_info = RequestInfoExecutor(id="parent_review_gateway")
workflow = (
WorkflowBuilder()
.set_start_executor(coordinator)
.add_edge(coordinator, sub_executor)
.add_edge(sub_executor, coordinator, condition=lambda msg: isinstance(msg, FinalDraft))
.add_edge(
sub_executor,
parent_request_info,
condition=lambda msg: isinstance(msg, RequestInfoMessage),
)
.add_edge(parent_request_info, sub_executor)
.with_checkpointing(storage)
.build()
)
return coordinator, workflow
async def main() -> None:
CHECKPOINT_DIR.mkdir(parents=True, exist_ok=True)
for file in CHECKPOINT_DIR.glob("*.json"):
file.unlink()
storage = FileCheckpointStorage(CHECKPOINT_DIR)
_, workflow = build_parent_workflow(storage)
print("\n=== Stage 1: run until sub-workflow requests human review ===")
request_id: str | None = None
async for event in workflow.run_stream("Contoso Gadget Launch"):
if isinstance(event, RequestInfoEvent) and request_id is None:
request_id = event.request_id
print(f"Captured review request id: {request_id}")
if isinstance(event, WorkflowStatusEvent) and event.state is WorkflowRunState.IDLE_WITH_PENDING_REQUESTS:
break
if request_id is None:
print("Sub-workflow completed without requesting review.")
return
checkpoints = await storage.list_checkpoints(workflow.id)
if not checkpoints:
print("No checkpoints written.")
return
checkpoints.sort(key=lambda cp: cp.timestamp)
resume_checkpoint = checkpoints[-1]
print(f"Using checkpoint {resume_checkpoint.checkpoint_id} at iteration {resume_checkpoint.iteration_count}")
checkpoint_path = storage.storage_path / f"{resume_checkpoint.checkpoint_id}.json"
if checkpoint_path.exists():
snapshot = json.loads(checkpoint_path.read_text())
exec_states = snapshot.get("executor_states", {})
sub_pending = exec_states.get("sub_review_requests", {}).get("request_events", {})
parent_pending = exec_states.get("parent_review_gateway", {}).get("request_events", {})
print(f"Pending review requests (sub executor snapshot): {list(sub_pending.keys())}")
print(f"Pending review requests (parent executor snapshot): {list(parent_pending.keys())}")
print("\n=== Stage 2: resume from checkpoint and approve draft ===")
# Rebuild fresh instances to mimic a separate process resuming
coordinator2, workflow2 = build_parent_workflow(storage)
approval_response = "approve"
final_event: WorkflowOutputEvent | None = None
async for event in workflow2.run_stream_from_checkpoint(
resume_checkpoint.checkpoint_id,
responses={request_id: approval_response},
):
if isinstance(event, WorkflowOutputEvent):
final_event = event
if final_event is None:
print("Workflow did not complete after resume.")
return
final = final_event.data
print("\n=== Final Draft (from resumed run) ===")
print(final)
if coordinator2.final_result is None:
print("Coordinator did not capture final result via handler.")
else:
print("Coordinator stored final draft successfully.")
""""
Sample Output:
=== Stage 1: run until sub-workflow requests human review ===
Captured review request id: 032c9f3a-ad1b-4a52-89be-a168d6663011
Using checkpoint 54f376c2-f849-44e4-9d8d-e627fd27ab96 at iteration 2
Pending review requests (sub executor snapshot): []
Pending review requests (parent executor snapshot): ['032c9f3a-ad1b-4a52-89be-a168d6663011']
=== Stage 2: resume from checkpoint and approve draft ===
>>> Parent workflow received approved draft:
- Topic: Contoso Gadget Launch
- Iterations: 1
- Approved at: 2025-09-25T14:29:34.479164
- Content: Approved launch narrative for Contoso Gadget Launch (iteration 1).
=== Final Draft (from resumed run) ===
FinalDraft(topic='Contoso Gadget Launch', content='Approved launch narrative for Contoso
Gadget Launch (iteration 1).', iterations=1, approved_at=datetime.datetime(2025, 9, 25, 14, 29, 34, 479164))
Coordinator stored final draft successfully.
"""
if __name__ == "__main__":
asyncio.run(main())