Python: [Bug]: AG-UI workflow runner ignores "intermediate" events

[savannahknight]

Description

What happened?

The agent-framework-ag-ui package only processes output and data event types in workflows, meaning intermediate events produced by agent-framework WorkflowAgent are NOT handled and fall through to custom events instead of being converted to the appropriate AGUI Reasoning* event types.

Location:

agent-framework/python/packages/ag-ui/agent_framework_ag_ui/_workflow_run.py

Line 1277 in baf0ea5

if event_type in {"output", "data"}:

This causes intermediate workflow events to be emitted as generic AGUI CustomEvent instead of proper reasoning events.

What did you expect to happen?

1. agent-framework-ag-ui should handle "intermediate" events

Since AGENT_FORWARDED_EVENT_TYPES defines "intermediate" as the modern standard (with "data" as deprecated):

# python/packages/core/agent_framework/_workflows/_events.py:L138
AGENT_FORWARDED_EVENT_TYPES: frozenset[str] = frozenset({
    "output",
    "intermediate",  # ← The new standard
    "data",  # deprecated alias for intermediate; retained for backward compat
    "request_info",
})

The AG-UI workflow runner should handle all forwarded event types:

# _workflow_run.py:L1277 (proposed fix)
if event_type in {"output", "intermediate", "data"}:
    # ... process as AG-UI events

2. Intermediate event content should be displayed as reasoning
   When workflows emit intermediate events with text content, the AG-UI layer should automatically convert that content to text_reasoning type so it displays as reasoning in the UI (collapsible "thinking" sections), not as final assistant messages.
   This could be handled in either:

• Option A: WorkflowAgent._convert_workflow_event_to_agent_response_updates() - auto-convert text content in intermediate events to text_reasoning before forwarding
• Option B: agent-framework-ag-ui/_workflow_run.py - detect intermediate events and convert their text content to text_reasoning before calling _emit_content()

Steps to reproduce the issue

@executor(id="thinking_executor")
async def thinking_executor(
    msgs: list[Message], 
    ctx: WorkflowContext[None, str]
) -> None:
    """Emit intermediate output that should display as reasoning."""
    # This should appear as reasoning/thinking in the UI
    await ctx.yield_output("Analyzing the problem...", type="intermediate")
    # This should appear as final response
    await ctx.yield_output("Here's my answer!", type="output")

# Create workflow with intermediate output enabled
builder = WorkflowBuilder(
    name="test_workflow",
    start_executor=thinking_executor,
    intermediate_output_from=[thinking_executor],
)
workflow = builder.build()

# Wrap in AG-UI
agui_workflow = AgentFrameworkWorkflow(
    workflow=workflow,
    name="test-reasoning",
    description="Test intermediate events",
)

# Run it - intermediate events will NOT display as reasoning
# They fall through to CustomEvent instead of ReasoningMessageContentEvent

Code Sample

Error Messages / Stack Traces

Package Versions

agent-framework-core 1.13.0; agent-framework-ag-ui 1.0.1

Python Version

python 3.12

Additional Context

No response

[github-actions]

🤖 Automated triage reproduction notes (agent-authored — trust but verify)

Agent analysis

The bug occurs in python/packages/ag-ui/agent_framework_ag_ui/_workflow_run.py::run_workflow_stream, where an event produced by an executor designated through intermediate_output_from reaches the generic custom-event fallback. Minimal repro: stream a two-executor workflow with intermediate text from the first executor and final output from the second; the intermediate text produces CUSTOM(name="intermediate") instead of REASONING_MESSAGE_CONTENT.

• Failing test: python/packages/ag-ui/tests/ag_ui/test_workflow_run.py::test_workflow_run_maps_intermediate_text_to_reasoning_events
• Files examined: python/packages/ag-ui/agent_framework_ag_ui/_workflow_run.py, python/packages/ag-ui/tests/ag_ui/test_workflow_run.py, python/packages/core/agent_framework/_workflows/_events.py, python/packages/core/agent_framework/_workflows/_agent.py, python/packages/core/tests/workflow/test_output_designation.py, python/packages/ag-ui/pyproject.toml
• Tests run: test_workflow_run_maps_custom_and_text_events, test_workflow_run_maps_intermediate_text_to_reasoning_events
• Reported version: 1.0.1
• Current version: 1.2.1