feat: add on_tool_progress hook for mid-execution tool progress updates

Author: 0xSudoSSH

examples/basic/stream_tool_progress.py

@@ -0,0 +1,86 @@
+"""Example: tool progress via on_tool_progress hooks.
+
+Demonstrates how tools can emit intermediate progress updates using
+await ctx.send_progress(data), consumed via RunHooks.on_tool_progress.
+"""
+
+import asyncio
+
+from agents import Agent, RunHooks, Runner, function_tool
+from agents.tool import Tool
+from agents.tool_context import ToolContext
+
+
+@function_tool
+async def analyze_data(ctx: ToolContext, query: str) -> str:
+    """Simulate a long-running data analysis task with progress updates."""
+    await ctx.send_progress({"status": "starting", "query": query})
+    await asyncio.sleep(1)
+
+    await ctx.send_progress({"status": "fetching_data", "progress": 0.25})
+    await asyncio.sleep(1)
+
+    await ctx.send_progress({"status": "processing", "progress": 0.5})
+    await asyncio.sleep(1)
+
+    await ctx.send_progress({"status": "finalizing", "progress": 1.0})
+    await asyncio.sleep(0.5)
+
+    return f"Analysis complete for '{query}': found 42 results with 95% confidence."
+
+
+@function_tool
+async def quick_lookup(ctx: ToolContext, term: str) -> str:
+    """A faster tool that also emits progress."""
+    await ctx.send_progress({"status": "searching", "term": term})
+    await asyncio.sleep(0.5)
+    return f"Found definition for '{term}': a common search term."
+
+
+class ProgressHooks(RunHooks):
+    async def on_tool_progress(self, ctx, agent, tool: Tool, data):
+        print(f"  [progress] {tool.name}: {data}")
+
+
+async def main():
+    agent = Agent(
+        name="Analyst",
+        instructions=(
+            "You are a data analyst. Use the analyze_data tool for complex queries "
+            "and quick_lookup for simple lookups. Always use the tools when asked."
+        ),
+        tools=[analyze_data, quick_lookup],
+    )
+
+    hooks = ProgressHooks()
+
+    print("Interactive tool progress example (hooks-based).")
+    print("Type a message to chat, or 'quit' to exit.\n")
+
+    while True:
+        user_input = input("You: ").strip()
+        if not user_input or user_input.lower() == "quit":
+            print("Goodbye!")
+            break
+
+        result = Runner.run_streamed(agent, input=user_input, hooks=hooks)
+        async for event in result.stream_events():
+            if event.type == "raw_response_event":
+                data = event.data
+                if getattr(data, "type", None) == "response.output_text.delta":
+                    print(data.delta, end="", flush=True)
+            elif event.type == "agent_updated_stream_event":
+                print(f"Agent: {event.new_agent.name}")
+            elif event.type == "run_item_stream_event":
+                if event.item.type == "tool_call_item":
+                    print(f"\n-- Tool called: {getattr(event.item.raw_item, 'name', '?')}")
+                elif event.item.type == "tool_call_output_item":
+                    print(f"\n-- Tool output: {event.item.output}")
+                elif event.item.type == "message_output_item":
+                    print()  # newline after streamed tokens
+
+        print()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

src/agents/lifecycle.py

@@ -98,6 +98,21 @@ async def on_tool_end(
         """
         pass
 
+    async def on_tool_progress(
+        self,
+        context: RunContextWrapper[TContext],
+        agent: TAgent,
+        tool: Tool,
+        data: Any,
+    ) -> None:
+        """Called when a tool emits a progress update via ``send_progress()``.
+
+        Unlike ``on_tool_start``/``on_tool_end`` which fire at lifecycle boundaries,
+        this fires from inside the tool body at arbitrary points.  For function-tool
+        invocations, ``context`` is typically a ``ToolContext``.
+        """
+        pass
+
 
 class AgentHooksBase(Generic[TContext, TAgent]):
     """A class that receives callbacks on various lifecycle events for a specific agent. You can
@@ -172,6 +187,21 @@ async def on_tool_end(
         """
         pass
 
+    async def on_tool_progress(
+        self,
+        context: RunContextWrapper[TContext],
+        agent: TAgent,
+        tool: Tool,
+        data: Any,
+    ) -> None:
+        """Called when a tool emits a progress update via ``send_progress()``.
+
+        Unlike ``on_tool_start``/``on_tool_end`` which fire at lifecycle boundaries,
+        this fires from inside the tool body at arbitrary points.  For function-tool
+        invocations, ``context`` is typically a ``ToolContext``.
+        """
+        pass
+
     async def on_llm_start(
         self,
         context: RunContextWrapper[TContext],

src/agents/run_internal/tool_execution.py

@@ -1582,6 +1582,21 @@ async def _run_single_tool(
                 run_config=self.config,
             )
             agent_hooks = self.public_agent.hooks
+
+            async def _send_progress(data: Any) -> None:
+                await asyncio.gather(
+                    self.hooks.on_tool_progress(tool_context, self.public_agent, func_tool, data),
+                    (
+                        agent_hooks.on_tool_progress(
+                            tool_context, self.public_agent, func_tool, data
+                        )
+                        if agent_hooks
+                        else _coro.noop_coroutine()
+                    ),
+                )
+
+            tool_context.set_progress_fn(_send_progress)
+
             if self.config.trace_include_sensitive_data:
                 span_fn.span_data.input = tool_call.arguments
 

src/agents/tool_context.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from collections.abc import Awaitable, Callable
 from dataclasses import dataclass, field, fields
 from typing import TYPE_CHECKING, Any, cast
 
@@ -104,11 +105,25 @@ def __init__(
         self.agent = agent
         self.run_config = run_config
 
+    _progress_fn: Callable[[Any], Awaitable[None]] | None = None
+
     @property
     def qualified_tool_name(self) -> str:
         """Return the tool name qualified by namespace when available."""
         return tool_trace_name(self.tool_name, self.tool_namespace) or self.tool_name
 
+    async def send_progress(self, data: Any) -> None:
+        """Emit a progress update, firing ``on_tool_progress`` hooks.
+
+        No-op if no progress handler has been set by the framework.
+        """
+        if self._progress_fn is not None:
+            await self._progress_fn(data)
+
+    def set_progress_fn(self, fn: Callable[[Any], Awaitable[None]]) -> None:
+        """Set the progress handler. Called by the framework during tool invocation."""
+        self._progress_fn = fn
+
     @classmethod
     def from_agent_context(
         cls,