[BREAKING] Python: Replace RequestInfoExecutor with request_info API and @response_handler (#1466)

* Prototype: Add request_info API and @response_handler

* Add original_request as a parameter to the response handler

* Prototype: request interception in sub workflows

* Prototype: request interception in sub workflows 2

* WIP: Make checkpointing work

* checkpointing with sub workflow

* Fix function executor

* Allow sub-workflow to output directly

* Remove ReqeustInfoExecutor and related classes; Debugging checkpoint_with_human_in_the_loop

* Fix Handoff and sample

* fix pending requests in checkpoint

* Fix unit tests

* Fix formatting

* Resolve comments

* Address comment

* Add checkpoint tests

* Add tests

* misc

* fix mypy

* fix mypy

* Use request type as part of the key

* Log warning if there is not response handler for a request

* Update Internal edge group comments

* REcord message type in executor processing span

* Update sample

* Improve tests
This commit is contained in:
Tao Chen
2025-10-29 16:31:23 -07:00
committed by GitHub
Unverified
parent f6eadd412e
commit 943d92674e
54 changed files with 7532 additions and 6684 deletions
@@ -1,11 +1,13 @@
# Copyright (c) Microsoft. All rights reserved.
import asyncio
from collections.abc import AsyncIterable
from dataclasses import dataclass
from pathlib import Path
from typing import TYPE_CHECKING, Any
# NOTE: the Azure client imports above are real dependencies. When running this
# sample outside of Azure-enabled environments you may wish to swap in the
# `agent_framework.builtin` chat client or mock the writer executor. We keep the
# concrete import here so readers can see an end-to-end configuration.
from agent_framework import (
AgentExecutor,
AgentExecutorRequest,
@@ -14,30 +16,20 @@ from agent_framework import (
Executor,
FileCheckpointStorage,
RequestInfoEvent,
RequestInfoExecutor,
RequestInfoMessage,
RequestResponse,
Role,
Workflow,
WorkflowBuilder,
WorkflowCheckpoint,
WorkflowContext,
WorkflowOutputEvent,
WorkflowRunState,
WorkflowStatusEvent,
get_checkpoint_summary,
handler,
response_handler,
)
from agent_framework.azure import AzureOpenAIChatClient
from azure.identity import AzureCliCredential
# NOTE: the Azure client imports above are real dependencies. When running this
# sample outside of Azure-enabled environments you may wish to swap in the
# `agent_framework.builtin` chat client or mock the writer executor. We keep the
# concrete import here so readers can see an end-to-end configuration.
if TYPE_CHECKING:
from agent_framework import Workflow
from agent_framework._workflows._checkpoint import WorkflowCheckpoint
"""
Sample: Checkpoint + human-in-the-loop quickstart.
@@ -45,17 +37,14 @@ This getting-started sample keeps the moving pieces to a minimum:
1. A brief is turned into a consistent prompt for an AI copywriter.
2. The copywriter (an `AgentExecutor`) drafts release notes.
3. A reviewer gateway routes every draft through `RequestInfoExecutor` so a human
can approve or request tweaks.
3. A reviewer gateway sends a request for approval for every draft.
4. The workflow records checkpoints between each superstep so you can stop the
program, restart later, and optionally pre-supply human answers on resume.
Key concepts demonstrated
-------------------------
- Minimal executor pipeline with checkpoint persistence.
- Human-in-the-loop pause/resume by pairing `RequestInfoExecutor` with
checkpoint restoration.
- Supplying responses at restore time (`run_stream_from_checkpoint(..., responses=...)`).
- Human-in-the-loop pause/resume with checkpoint restoration.
Typical pause/resume flow
-------------------------
@@ -110,8 +99,8 @@ class BriefPreparer(Executor):
@dataclass
class HumanApprovalRequest(RequestInfoMessage):
"""Message sent to the human reviewer via RequestInfoExecutor."""
class HumanApprovalRequest:
"""Request sent to the human reviewer."""
# These fields are intentionally simple because they are serialised into
# checkpoints. Keeping them primitive types guarantees the new
@@ -124,52 +113,42 @@ class HumanApprovalRequest(RequestInfoMessage):
class ReviewGateway(Executor):
"""Routes agent drafts to humans and optionally back for revisions."""
def __init__(self, id: str, reviewer_id: str, writer_id: str, finalize_id: str) -> None:
def __init__(self, id: str, writer_id: str) -> None:
super().__init__(id=id)
self._reviewer_id = reviewer_id
self._writer_id = writer_id
self._finalize_id = finalize_id
@handler
async def on_agent_response(
self,
response: AgentExecutorResponse,
ctx: WorkflowContext[HumanApprovalRequest, str],
) -> None:
# Capture the agent output so we can surface it to the reviewer and
# persist iterations. The `RequestInfoExecutor` relies on this state to
# rehydrate when checkpoints are restored.
async def on_agent_response(self, response: AgentExecutorResponse, ctx: WorkflowContext) -> None:
# Capture the agent output so we can surface it to the reviewer and persist iterations.
draft = response.agent_run_response.text or ""
iteration = int((await ctx.get_executor_state() or {}).get("iteration", 0)) + 1
await ctx.set_executor_state({"iteration": iteration, "last_draft": draft})
# Emit a human approval request. Because this flows through
# RequestInfoExecutor it will pause the workflow until an answer is
# supplied either interactively or via pre-supplied responses.
await ctx.send_message(
# Emit a human approval request.
await ctx.request_info(
HumanApprovalRequest(
prompt="Review the draft. Reply 'approve' or provide edit instructions.",
draft=draft,
iteration=iteration,
),
target_id=self._reviewer_id,
HumanApprovalRequest,
str,
)
@handler
@response_handler
async def on_human_feedback(
self,
feedback: RequestResponse[HumanApprovalRequest, str],
original_request: HumanApprovalRequest,
feedback: str,
ctx: WorkflowContext[AgentExecutorRequest | str, str],
) -> None:
# The RequestResponse wrapper gives us both the human data and the
# original request message, even when resuming from checkpoints.
reply = (feedback.data or "").strip()
# The `original_request` is the request we sent earlier that is now being answered.
reply = feedback.strip()
state = await ctx.get_executor_state() or {}
draft = state.get("last_draft") or (feedback.original_request.draft if feedback.original_request else "")
draft = state.get("last_draft") or (original_request.draft or "")
if reply.lower() == "approve":
# When the human signs off we can short-circuit the workflow and
# send the approved draft to the final executor.
await ctx.send_message(draft, target_id=self._finalize_id)
# Workflow is completed when the human approves.
await ctx.yield_output(draft)
return
# Any other response loops us back to the writer with fresh guidance.
@@ -187,63 +166,34 @@ class ReviewGateway(Executor):
)
class FinaliseExecutor(Executor):
"""Publishes the approved text."""
@handler
async def publish(self, text: str, ctx: WorkflowContext[Any, str]) -> None:
# Store the output so diagnostics or a UI could fetch the final copy.
await ctx.set_executor_state({"published_text": text})
# Yield the final output so the workflow completes cleanly.
await ctx.yield_output(text)
def create_workflow(*, checkpoint_storage: FileCheckpointStorage | None = None) -> "Workflow":
def create_workflow(checkpoint_storage: FileCheckpointStorage) -> Workflow:
"""Assemble the workflow graph used by both the initial run and resume."""
# The Azure client is created once so our agent executor can issue calls to
# the hosted model. The agent id is stable across runs which keeps
# checkpoints deterministic.
# The Azure client is created once so our agent executor can issue calls to the hosted
# model. The agent id is stable across runs which keeps checkpoints deterministic.
chat_client = AzureOpenAIChatClient(credential=AzureCliCredential())
writer = AgentExecutor(
chat_client.create_agent(
instructions="Write concise, warm release notes that sound human and helpful.",
),
id="writer",
)
# RequestInfoExecutor is the lynchpin for human-in-the-loop: every draft is
# routed through it so checkpoints can pause while waiting for responses.
review = RequestInfoExecutor(id="request_info")
finalise = FinaliseExecutor(id="finalise")
gateway = ReviewGateway(
id="review_gateway",
reviewer_id=review.id,
writer_id=writer.id,
finalize_id=finalise.id,
)
agent = chat_client.create_agent(instructions="Write concise, warm release notes that sound human and helpful.")
writer = AgentExecutor(agent, id="writer")
gateway = ReviewGateway(id="review_gateway", writer_id=writer.id)
prepare = BriefPreparer(id="prepare_brief", agent_id=writer.id)
# Wire the workflow DAG. Edges mirror the numbered steps described in the
# module docstring. Because `WorkflowBuilder` is declarative, reading these
# edges is often the quickest way to understand execution order.
builder = (
workflow_builder = (
WorkflowBuilder(max_iterations=6)
.set_start_executor(prepare)
.add_edge(prepare, writer)
.add_edge(writer, gateway)
.add_edge(gateway, review)
.add_edge(review, gateway) # human resumes loop
.add_edge(gateway, writer) # revisions
.add_edge(gateway, finalise)
.add_edge(gateway, writer) # revisions loop
.with_checkpointing(checkpoint_storage=checkpoint_storage)
)
# Opt-in to persistence when the caller provides storage. The workflow
# object itself is identical whether or not checkpointing is enabled.
if checkpoint_storage:
builder = builder.with_checkpointing(checkpoint_storage=checkpoint_storage)
return builder.build()
return workflow_builder.build()
def _render_checkpoint_summary(checkpoints: list["WorkflowCheckpoint"]) -> None:
def render_checkpoint_summary(checkpoints: list["WorkflowCheckpoint"]) -> None:
"""Pretty-print saved checkpoints with the new framework summaries."""
print("\nCheckpoint summary:")
@@ -251,166 +201,83 @@ def _render_checkpoint_summary(checkpoints: list["WorkflowCheckpoint"]) -> None:
# Compose a single line per checkpoint so the user can scan the output
# and pick the resume point that still has outstanding human work.
line = (
f"- {summary.checkpoint_id} | iter={summary.iteration_count} "
f"- {summary.checkpoint_id} | timestamp={summary.timestamp} | iter={summary.iteration_count} "
f"| targets={summary.targets} | states={summary.executor_ids}"
)
if summary.status:
line += f" | status={summary.status}"
if summary.draft_preview:
line += f" | draft_preview={summary.draft_preview}"
if summary.pending_requests:
line += f" | pending_request_id={summary.pending_requests[0].request_id}"
if summary.pending_request_info_events:
line += f" | pending_request_id={summary.pending_request_info_events[0].request_id}"
print(line)
def _print_events(events: list[Any]) -> tuple[str | None, list[tuple[str, HumanApprovalRequest]]]:
"""Echo workflow events to the console and collect outstanding requests."""
completed_output: str | None = None
requests: list[tuple[str, HumanApprovalRequest]] = []
for event in events:
print(f"Event: {event}")
if isinstance(event, WorkflowOutputEvent):
completed_output = event.data
if isinstance(event, RequestInfoEvent) and isinstance(event.data, HumanApprovalRequest):
# Capture pending human approvals so the caller can ask the user for
# input after the current batch of events is processed.
requests.append((event.request_id, event.data))
elif isinstance(event, WorkflowStatusEvent) and event.state in {
WorkflowRunState.IN_PROGRESS_PENDING_REQUESTS,
WorkflowRunState.IDLE_WITH_PENDING_REQUESTS,
}:
print(f"Workflow state: {event.state.name}")
return completed_output, requests
def _prompt_for_responses(requests: list[tuple[str, HumanApprovalRequest]]) -> dict[str, str] | None:
def prompt_for_responses(requests: dict[str, HumanApprovalRequest]) -> dict[str, str]:
"""Interactive CLI prompt for any live RequestInfo requests."""
if not requests:
return None
answers: dict[str, str] = {}
for request_id, request in requests:
# Keep the prompt conversational so testers can use the script without
# memorising the workflow APIs.
responses: dict[str, str] = {}
for request_id, request in requests.items():
print("\n=== Human approval needed ===")
print(f"request_id: {request_id}")
if request.iteration:
print(f"Iteration: {request.iteration}")
print(f"Iteration: {request.iteration}")
print(request.prompt)
print("Draft: \n---\n" + request.draft + "\n---")
answer = input("Type 'approve' or enter revision guidance (or 'exit' to quit): ").strip() # noqa: ASYNC250
if answer.lower() == "exit":
response = input("Type 'approve' or enter revision guidance (or 'exit' to quit): ").strip()
if response.lower() == "exit":
raise SystemExit("Stopped by user.")
answers[request_id] = answer
return answers
responses[request_id] = response
return responses
def _maybe_pre_supply_responses(cp: "WorkflowCheckpoint") -> dict[str, str] | None:
"""Offer to collect responses before resuming a checkpoint."""
pending = get_checkpoint_summary(cp).pending_requests
if not pending:
return None
print(
"This checkpoint still has pending human input. Provide the responses now so the resume step "
"applies them immediately and does not re-emit the original RequestInfo event."
)
choice = input("Pre-supply responses for this checkpoint? [y/N]: ").strip().lower() # noqa: ASYNC250
if choice not in {"y", "yes"}:
return None
answers: dict[str, str] = {}
for item in pending:
iteration = item.iteration or 0
print(f"\nPending draft (iteration {iteration} | request_id={item.request_id}):")
draft_text = (item.draft or "").strip()
if draft_text:
# The shortened preview in the summary may truncate text; here we
# show the full draft so the reviewer can make an informed choice.
print("Draft:\n---\n" + draft_text + "\n---")
else:
print("Draft: [not captured in checkpoint payload - refer to your notes/log]")
prompt_text = (item.prompt or "Review the draft").strip()
print(prompt_text)
answer = input("Response ('approve' or guidance, 'exit' to abort): ").strip() # noqa: ASYNC250
if answer.lower() == "exit":
raise SystemExit("Resume aborted by user.")
answers[item.request_id] = answer
return answers
async def _consume(stream: AsyncIterable[Any]) -> list[Any]:
"""Materialise an async event stream into a list."""
return [event async for event in stream]
async def run_interactive_session(workflow: "Workflow", initial_message: str) -> str | None:
async def run_interactive_session(
workflow: Workflow,
initial_message: str | None = None,
checkpoint_id: str | None = None,
) -> str:
"""Run the workflow until it either finishes or pauses for human input."""
pending_responses: dict[str, str] | None = None
requests: dict[str, HumanApprovalRequest] = {}
responses: dict[str, str] | None = None
completed_output: str | None = None
first = True
while completed_output is None:
if first:
# Kick off the workflow with the initial brief. The returned events
# include RequestInfo events when the agent produces a draft.
events = await _consume(workflow.run_stream(initial_message))
first = False
elif pending_responses:
# Feed any answers the user just typed back into the workflow.
events = await _consume(workflow.send_responses_streaming(pending_responses))
while True:
if responses:
event_stream = workflow.send_responses_streaming(responses)
requests.clear()
responses = None
else:
if initial_message:
print(f"\nStarting workflow with brief: {initial_message}\n")
event_stream = workflow.run_stream(initial_message)
elif checkpoint_id:
print("\nStarting workflow from checkpoint...\n")
event_stream = workflow.run_stream_from_checkpoint(checkpoint_id)
else:
raise ValueError("Either initial_message or checkpoint_id must be provided")
async for event in event_stream:
if isinstance(event, WorkflowStatusEvent):
print(event)
if isinstance(event, WorkflowOutputEvent):
completed_output = event.data
if isinstance(event, RequestInfoEvent):
if isinstance(event.data, HumanApprovalRequest):
requests[event.request_id] = event.data
else:
raise ValueError("Unexpected request data type")
if completed_output:
break
completed_output, requests = _print_events(events)
if completed_output is None:
pending_responses = _prompt_for_responses(requests)
if requests:
responses = prompt_for_responses(requests)
continue
raise RuntimeError("Workflow stopped without completing or requesting input")
return completed_output
async def resume_from_checkpoint(
workflow: "Workflow",
checkpoint_id: str,
storage: FileCheckpointStorage,
pre_supplied: dict[str, str] | None,
) -> None:
"""Resume a stored checkpoint and continue until completion or another pause."""
print(f"\nResuming from checkpoint: {checkpoint_id}")
events = await _consume(
workflow.run_stream_from_checkpoint(
checkpoint_id,
checkpoint_storage=storage,
responses=pre_supplied,
)
)
completed_output, requests = _print_events(events)
if pre_supplied and not requests and completed_output is None:
# When the checkpoint only needed the provided answers we let the user
# know the workflow is waiting for the next superstep (usually another
# agent response).
print("Pre-supplied responses applied automatically; workflow is now waiting for the next step.")
pending = _prompt_for_responses(requests)
while completed_output is None and pending:
events = await _consume(workflow.send_responses_streaming(pending))
completed_output, requests = _print_events(events)
if completed_output is None:
pending = _prompt_for_responses(requests)
else:
break
if completed_output:
print(f"Workflow completed with: {completed_output}")
async def main() -> None:
"""Entry point used by both the initial run and subsequent resumes."""
@@ -428,11 +295,8 @@ async def main() -> None:
)
print("Running workflow (human approval required)...")
completed = await run_interactive_session(workflow, initial_message=brief)
if completed:
print(f"Initial run completed with final copy: {completed}")
else:
print("Initial run paused for human input.")
result = await run_interactive_session(workflow, initial_message=brief)
print(f"Workflow completed with: {result}")
checkpoints = await storage.list_checkpoints()
if not checkpoints:
@@ -441,7 +305,7 @@ async def main() -> None:
# Show the user what is available before we prompt for the index. The
# summary helper keeps this output consistent with other tooling.
_render_checkpoint_summary(checkpoints)
render_checkpoint_summary(checkpoints)
sorted_cps = sorted(checkpoints, key=lambda c: c.timestamp)
print("\nAvailable checkpoints:")
@@ -472,14 +336,11 @@ async def main() -> None:
print("Selected checkpoint already reflects a completed workflow; nothing to resume.")
return
# If the user wants, capture their decisions now so the resume call can
# push them into the workflow and avoid re-prompting.
pre_responses = _maybe_pre_supply_responses(chosen)
resumed_workflow = create_workflow()
new_workflow = create_workflow(checkpoint_storage=storage)
# Resume with a fresh workflow instance. The checkpoint carries the
# persistent state while this object holds the runtime wiring.
await resume_from_checkpoint(resumed_workflow, chosen.checkpoint_id, storage, pre_responses)
result = await run_interactive_session(new_workflow, checkpoint_id=chosen.checkpoint_id)
print(f"Workflow completed with: {result}")
if __name__ == "__main__":
@@ -3,6 +3,7 @@
import asyncio
import contextlib
import json
import uuid
from dataclasses import dataclass, field, replace
from datetime import datetime, timedelta
from pathlib import Path
@@ -11,9 +12,8 @@ from agent_framework import (
Executor,
FileCheckpointStorage,
RequestInfoEvent,
RequestInfoExecutor,
RequestInfoMessage,
RequestResponse,
SubWorkflowRequestMessage,
SubWorkflowResponseMessage,
Workflow,
WorkflowBuilder,
WorkflowContext,
@@ -22,6 +22,7 @@ from agent_framework import (
WorkflowRunState,
WorkflowStatusEvent,
handler,
response_handler,
)
CHECKPOINT_DIR = Path(__file__).with_suffix("").parent / "tmp" / "sub_workflow_checkpoints"
@@ -30,7 +31,7 @@ CHECKPOINT_DIR = Path(__file__).with_suffix("").parent / "tmp" / "sub_workflow_c
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
- run until the sub-workflow emits a human approval request
- persist a checkpoint that captures the pending request (including complex payloads)
- resume later, supplying the human decision directly at restore time
@@ -78,9 +79,10 @@ class FinalDraft:
@dataclass
class ReviewRequest(RequestInfoMessage):
"""Human approval request surfaced via RequestInfoExecutor."""
class ReviewRequest:
"""Human approval request surfaced via `request_info`."""
id: str = str(uuid.uuid4())
topic: str = ""
iteration: int = 1
draft_excerpt: str = ""
@@ -88,6 +90,14 @@ class ReviewRequest(RequestInfoMessage):
reviewer_guidance: list[str] = field(default_factory=list) # type: ignore
@dataclass
class ReviewDecision:
"""The review decision to be sent to downstream executors along with the original request."""
decision: str
original_request: ReviewRequest
# ---------------------------------------------------------------------------
# Sub-workflow executors
# ---------------------------------------------------------------------------
@@ -122,7 +132,8 @@ class DraftReviewRouter(Executor):
super().__init__(id="draft_review")
@handler
async def request_review(self, draft: DraftPackage, ctx: WorkflowContext[ReviewRequest]) -> None:
async def request_review(self, draft: DraftPackage, ctx: WorkflowContext) -> None:
"""Request a review upon receiving a draft."""
excerpt = draft.content.splitlines()[0]
request = ReviewRequest(
topic=draft.topic,
@@ -134,15 +145,17 @@ class DraftReviewRouter(Executor):
"Confirm CTA is action-oriented",
],
)
await ctx.send_message(request, target_id="sub_review_requests")
await ctx.request_info(request, ReviewRequest, str)
@handler
@response_handler
async def forward_decision(
self,
decision: RequestResponse[ReviewRequest, str],
ctx: WorkflowContext[RequestResponse[ReviewRequest, str]],
original_request: ReviewRequest,
decision: str,
ctx: WorkflowContext[ReviewDecision],
) -> None:
await ctx.send_message(decision, target_id="draft_finaliser")
"""Route the decision to the next executor."""
await ctx.send_message(ReviewDecision(decision=decision, original_request=original_request))
class DraftFinaliser(Executor):
@@ -154,11 +167,11 @@ class DraftFinaliser(Executor):
@handler
async def on_review_decision(
self,
decision: RequestResponse[ReviewRequest, str],
review_decision: ReviewDecision,
ctx: WorkflowContext[DraftTask, FinalDraft],
) -> None:
reply = (decision.data or "").strip().lower()
original = decision.original_request
reply = review_decision.decision.strip().lower()
original = review_decision.original_request
topic = original.topic if original else "unknown topic"
iteration = original.iteration if original else 1
@@ -192,12 +205,11 @@ class LaunchCoordinator(Executor):
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")
await ctx.send_message(task)
@handler
async def collect_final(self, draft: FinalDraft, ctx: WorkflowContext[None, FinalDraft]) -> None:
@@ -209,8 +221,6 @@ class LaunchCoordinator(Executor):
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:")
@@ -221,9 +231,50 @@ class LaunchCoordinator(Executor):
await ctx.yield_output(normalised)
@property
def final_result(self) -> FinalDraft | None:
return self._final
@handler
async def handler_sub_workflow_request(
self,
request: SubWorkflowRequestMessage,
ctx: WorkflowContext,
) -> None:
"""Handle requests from the sub-workflow.
Note that the message type must be SubWorkflowRequestMessage to intercept the request.
"""
if not isinstance(request.source_event.data, ReviewRequest):
raise TypeError(f"Expected 'ReviewRequest', got {type(request.source_event.data)}")
# Record the request to response matching
review_request = request.source_event.data
executor_state = await ctx.get_executor_state() or {}
executor_state[review_request.id] = request
await ctx.set_executor_state(executor_state)
# Send the request without modification
await ctx.request_info(review_request, ReviewRequest, str)
@response_handler
async def handle_request_response(
self,
original_request: ReviewRequest,
response: str,
ctx: WorkflowContext[SubWorkflowResponseMessage],
) -> None:
"""Process the response and send it back to the sub-workflow.
Note that the response must be sent back using SubWorkflowResponseMessage to route
the response back to the sub-workflow.
"""
executor_state = await ctx.get_executor_state() or {}
request_message = executor_state.pop(original_request.id, None)
# Save the executor state back to the context
await ctx.set_executor_state(executor_state)
if request_message is None:
raise ValueError("No matching pending request found for the resource response")
await ctx.send_message(request_message.create_response(response))
# ---------------------------------------------------------------------------
@@ -234,17 +285,13 @@ class LaunchCoordinator(Executor):
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(router, finaliser)
.add_edge(finaliser, writer) # permits revision loops
.build()
)
@@ -252,28 +299,19 @@ def build_sub_workflow() -> WorkflowExecutor:
return WorkflowExecutor(sub_workflow, id="launch_subworkflow")
def build_parent_workflow(storage: FileCheckpointStorage) -> tuple[LaunchCoordinator, Workflow]:
def build_parent_workflow(storage: FileCheckpointStorage) -> Workflow:
coordinator = LaunchCoordinator()
sub_executor = build_sub_workflow()
parent_request_info = RequestInfoExecutor(id="parent_review_gateway")
workflow = (
return (
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)
.add_edge(sub_executor, coordinator)
.with_checkpointing(storage)
.build()
)
return coordinator, workflow
async def main() -> None:
CHECKPOINT_DIR.mkdir(parents=True, exist_ok=True)
@@ -282,9 +320,10 @@ async def main() -> None:
storage = FileCheckpointStorage(CHECKPOINT_DIR)
_, workflow = build_parent_workflow(storage)
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:
@@ -294,52 +333,52 @@ async def main() -> None:
break
if request_id is None:
print("Sub-workflow completed without requesting review.")
return
raise RuntimeError("Sub-workflow completed without requesting review.")
checkpoints = await storage.list_checkpoints(workflow.id)
if not checkpoints:
print("No checkpoints written.")
return
raise RuntimeError("No checkpoints found.")
# Print the checkpoint to show pending requests
# We didn't handle the request above so the request is still pending the last checkpoint
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())}")
checkpoint_content_dict = json.loads(checkpoint_path.read_text())
print(f"Pending review requests: {checkpoint_content_dict.get('pending_request_info_events', {})}")
print("\n=== Stage 2: resume from checkpoint ===")
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)
workflow2 = build_parent_workflow(storage)
approval_response = "approve"
final_event: WorkflowOutputEvent | None = None
request_info_event: RequestInfoEvent | None = None
async for event in workflow2.run_stream_from_checkpoint(
resume_checkpoint.checkpoint_id,
responses={request_id: approval_response},
):
if isinstance(event, RequestInfoEvent):
request_info_event = event
if request_info_event is None:
raise RuntimeError("No request_info_event captured.")
print("\n=== Stage 3: approve draft ==")
approval_response = "approve"
output_event: WorkflowOutputEvent | None = None
async for event in workflow2.send_responses_streaming({request_info_event.request_id: approval_response}):
if isinstance(event, WorkflowOutputEvent):
final_event = event
output_event = event
if final_event is None:
print("Workflow did not complete after resume.")
return
if output_event is None:
raise RuntimeError("Workflow did not complete after resume.")
final = final_event.data
output = output_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.")
print(output)
""""
Sample Output: