Fix router path detection for listener methods with @human_feedback

[m-k8s]

Summary

Fix incorrect router path detection when combining @listen and @human_feedback(emit=...) decorators.

Problem

When a listener method is decorated with both @listen and @human_feedback with emit, the Flow metaclass incorrectly detects router paths by parsing the method's source code instead of using the __router_paths__ attribute set by @human_feedback.

Example:

@listen("begin")
@human_feedback(
    message="Review this:",
    emit=["approved", "rejected"],
    llm="gpt-4o-mini",
)
def review(self):
    return "content to review"

Before fix: _router_paths["review"] = ["content to review"] (wrong - parsed from return statement)

After fix: _router_paths["review"] = ["approved", "rejected"] (correct - from emit parameter)

This bug could also cause IndentationError when parsing source code of multi-decorated methods, because inspect.getsource() includes decorators with class-level indentation which can confuse ast.parse().

Root Cause

In FlowMeta.__new__, the code for listener methods that are also routers directly calls get_possible_return_constants() without first checking the __router_paths__ attribute:

# Before (buggy)
if hasattr(attr_value, "__is_router__") and attr_value.__is_router__:
    routers.add(attr_name)
    possible_returns = get_possible_return_constants(attr_value)  # Parses source!
    ...

However, the code for start methods that are routers correctly checks __router_paths__ first:

# Existing code for start methods (correct)
if hasattr(attr_value, "__router_paths__") and attr_value.__router_paths__:
    router_paths[attr_name] = attr_value.__router_paths__
else:
    possible_returns = get_possible_return_constants(attr_value)
    ...

Solution

Apply the same pattern to listener methods: check __router_paths__ first before falling back to source parsing.

Files Changed

• lib/crewai/src/crewai/flow/flow.py - Fix router path detection for listeners
• lib/crewai/tests/test_human_feedback_decorator.py - Add regression tests

Tests

Added TestListenerRouterPathDetection class with 2 tests:

• test_listener_with_human_feedback_emit_has_router_paths - Basic case
• test_multiple_listener_routers_detected - Multiple listener-routers in same flow

Test results:

• Without fix: 2 FAILED
• With fix: 2 PASSED

Related Documentation

This is a documented use case per docs/en/learn/human-feedback-in-flows.mdx:

Combining with Other Decorators

The @human_feedback decorator works with other flow decorators. Place it as the innermost decorator (closest to the function):

@listen(other_method)
@human_feedback(message="Review this too:")
def my_listener(self, data):
    return f"processed: {data}"

---

Note

Ensures correct router path detection for listener methods decorated with @human_feedback(emit=...), avoiding brittle source parsing and potential IndentationError.

• In flow.py (FlowMeta.__new__), when a listener is also a router, first use __router_paths__ from the decorator; fall back to get_possible_return_constants only if absent
• Adds TestListenerRouterPathDetection in test_human_feedback_decorator.py with cases for single and multiple listener-routers

^{Written by Cursor Bugbot for commit 59118dc. This will update automatically on new commits. Configure here.}