cr

libs/core/langchain_core/language_models/chat_model_stream.py

@@ -575,7 +575,7 @@ class _ChatModelStreamBase:
 
     # -- Event ingestion (public) ------------------------------------------
 
-    def dispatch(self, event: MessagesData) -> None:
+    def dispatch(self, event: Mapping[str, Any]) -> None:
         """Route a protocol event to the appropriate internal handler.
 
         Public entry point for feeding events into the stream. Called by
@@ -598,9 +598,9 @@ class _ChatModelStreamBase:
 
     # -- Internal push API (called by dispatch) ----------------------------
 
-    def _record_event(self, event: MessagesData) -> None:
+    def _record_event(self, event: Mapping[str, Any]) -> None:
         """Append a raw event to the replay buffer."""
-        self._events.append(event)
+        self._events.append(cast("MessagesData", event))
 
     def _push_message_start(self, data: MessageStartData) -> None:
         """Process a `message-start` event."""

libs/core/tests/unit_tests/language_models/test_chat_model_stream.py

@@ -16,7 +16,7 @@ from langchain_core.language_models.chat_model_stream import (
 )
 
 if TYPE_CHECKING:
-    from langchain_protocol.protocol import ContentBlockFinishData, MessagesData
+    from langchain_protocol.protocol import ContentBlockFinishData
 
 # ---------------------------------------------------------------------------
 # Projection unit tests
@@ -244,7 +244,7 @@ class TestAsyncProjection:
         """Concurrent `stream.text` + `await stream.output` both drive the pump."""
         stream = AsyncChatModelStream(message_id="m1")
 
-        events: list[MessagesData] = [
+        events: list[dict[str, Any]] = [
             {
                 "event": "message-start",
                 "role": "ai",
@@ -313,7 +313,7 @@ class TestChatModelStream:
 
     def test_text_deltas_via_pump(self) -> None:
         stream = ChatModelStream()
-        events: list[MessagesData] = [
+        events: list[dict[str, Any]] = [
             {"event": "message-start", "role": "ai"},
             {
                 "event": "content-block-delta",
@@ -363,7 +363,7 @@ class TestChatModelStream:
             }
         )
         stream.dispatch(
-            {  # type: ignore[arg-type,misc]
+            {
                 "event": "content-block-delta",
                 "index": 0,
                 "content_block": {

libs/core/tests/unit_tests/language_models/test_compat_bridge.py

@@ -28,6 +28,11 @@ if TYPE_CHECKING:
     )
 
 
+def _event_metadata(event: Any) -> dict[str, Any]:
+    """Return event metadata for protocol versions that type it as extensible."""
+    return cast("dict[str, Any]", cast("dict[str, Any]", event).get("metadata") or {})
+
+
 # ---------------------------------------------------------------------------
 # Pure helpers
 # ---------------------------------------------------------------------------
@@ -134,7 +139,7 @@ def test_chunks_to_events_text_only() -> None:
     # No provider finish_reason in fixtures — metadata carries no
     # `finish_reason` key (the bridge passes response_metadata through
     # unchanged).
-    assert "finish_reason" not in (finish.get("metadata") or {})
+    assert "finish_reason" not in _event_metadata(finish)
 
 
 def test_chunks_to_events_empty_iterator() -> None:
@@ -291,9 +296,7 @@ def test_chunks_to_events_tool_call_multichunk() -> None:
     # not synthesize one. It deliberately does not infer `"tool_use"`
     # from the presence of a valid tool_call either; terminal reasons
     # are provider-specific (see `_build_message_finish`).
-    assert "finish_reason" not in (
-        cast("MessageFinishData", events[-1]).get("metadata") or {}
-    )
+    assert "finish_reason" not in _event_metadata(events[-1])
 
 
 def test_chunks_to_events_invalid_tool_call_keeps_stop_reason() -> None:
@@ -323,9 +326,7 @@ def test_chunks_to_events_invalid_tool_call_keeps_stop_reason() -> None:
     ]
     assert len(finish_events) == 1
     assert finish_events[0]["content"]["type"] == "invalid_tool_call"
-    assert "finish_reason" not in (
-        cast("MessageFinishData", events[-1]).get("metadata") or {}
-    )
+    assert "finish_reason" not in _event_metadata(events[-1])
 
 
 def test_chunks_to_events_anthropic_server_tool_use_routes_through_translator() -> None:
@@ -453,7 +454,7 @@ def test_message_to_events_text_only() -> None:
     assert delta_event["delta"] == {"type": "text-delta", "text": "Hello world"}
 
     final = cast("MessageFinishData", events[-1])
-    assert "finish_reason" not in (final.get("metadata") or {})
+    assert "finish_reason" not in _event_metadata(final)
 
 
 def test_message_to_events_empty_content_yields_start_finish_only() -> None:
@@ -512,7 +513,7 @@ def test_message_to_events_tool_call_skips_delta() -> None:
     # bridge does not synthesize one and does not second-guess based on
     # the presence of a tool_call.
     final = cast("MessageFinishData", events[-1])
-    assert "finish_reason" not in (final.get("metadata") or {})
+    assert "finish_reason" not in _event_metadata(final)
 
 
 def test_message_to_events_invalid_tool_calls_surfaced_from_field() -> None:
@@ -557,7 +558,7 @@ def test_message_to_events_preserves_finish_reason_and_metadata() -> None:
     # Passthrough: response_metadata lands on `metadata` unchanged,
     # including the raw provider `finish_reason`.
     final = cast("MessageFinishData", events[-1])
-    assert final["metadata"] == {
+    assert _event_metadata(final) == {
         "finish_reason": "length",
         "model_name": "test-model",
         "stop_sequence": "</end>",

libs/core/tests/unit_tests/language_models/test_stream_v2.py

@@ -389,14 +389,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=TextContentBlock(type="text", text="A"),
+                delta={"type": "text-delta", "text": "A"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=0,
-                content_block=TextContentBlock(type="text", text="A"),
+                content=TextContentBlock(type="text", text="A"),
             )
         )
         # Block 1: "B"
@@ -404,14 +404,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=1,
-                content_block=TextContentBlock(type="text", text="B"),
+                delta={"type": "text-delta", "text": "B"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=1,
-                content_block=TextContentBlock(type="text", text="B"),
+                content=TextContentBlock(type="text", text="B"),
             )
         )
         stream.dispatch(MessageFinishData(event="message-finish"))
@@ -435,14 +435,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=ReasoningContentBlock(type="reasoning", reasoning="one"),
+                delta={"type": "reasoning-delta", "reasoning": "one"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=0,
-                content_block=ReasoningContentBlock(type="reasoning", reasoning="one"),
+                content=ReasoningContentBlock(type="reasoning", reasoning="one"),
             )
         )
         # Block 1: "two"
@@ -450,14 +450,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=1,
-                content_block=ReasoningContentBlock(type="reasoning", reasoning="two"),
+                delta={"type": "reasoning-delta", "reasoning": "two"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=1,
-                content_block=ReasoningContentBlock(type="reasoning", reasoning="two"),
+                content=ReasoningContentBlock(type="reasoning", reasoning="two"),
             )
         )
         stream.dispatch(MessageFinishData(event="message-finish"))
@@ -482,14 +482,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=TextContentBlock(type="text", text="hel"),
+                delta={"type": "text-delta", "text": "hel"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=0,
-                content_block=TextContentBlock(type="text", text="hello"),
+                content=TextContentBlock(type="text", text="hello"),
             )
         )
         stream.dispatch(MessageFinishData(event="message-finish"))
@@ -520,7 +520,7 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=TextContentBlock(type="text", text="aaa"),
+                delta={"type": "text-delta", "text": "aaa"},
             )
         )
         # Block 1 streams deltas before block 0 finishes.
@@ -528,7 +528,7 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=1,
-                content_block=TextContentBlock(type="text", text="bb"),
+                delta={"type": "text-delta", "text": "bb"},
             )
         )
         # Block 0 finishes with authoritative text different from deltas.
@@ -536,14 +536,14 @@ class TestPerBlockAccumulation:
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=0,
-                content_block=TextContentBlock(type="text", text="XXX"),
+                content=TextContentBlock(type="text", text="XXX"),
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=1,
-                content_block=TextContentBlock(type="text", text="bb"),
+                content=TextContentBlock(type="text", text="bb"),
             )
         )
         stream.dispatch(MessageFinishData(event="message-finish"))
@@ -566,7 +566,7 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=ReasoningContentBlock(type="reasoning", reasoning="thi"),
+                delta={"type": "reasoning-delta", "reasoning": "thi"},
             )
         )
         stream.dispatch(
@@ -594,14 +594,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=0,
-                content_block=TextContentBlock(type="text", text="before"),
+                delta={"type": "text-delta", "text": "before"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=0,
-                content_block=TextContentBlock(type="text", text="before"),
+                content=TextContentBlock(type="text", text="before"),
             )
         )
         # Block 1: tool_call
@@ -609,7 +609,7 @@ class TestPerBlockAccumulation:
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=1,
-                content_block=ToolCall(
+                content=ToolCall(
                     type="tool_call",
                     id="tc1",
                     name="search",
@@ -622,14 +622,14 @@ class TestPerBlockAccumulation:
             ContentBlockDeltaData(
                 event="content-block-delta",
                 index=2,
-                content_block=TextContentBlock(type="text", text="after"),
+                delta={"type": "text-delta", "text": "after"},
             )
         )
         stream.dispatch(
             ContentBlockFinishData(
                 event="content-block-finish",
                 index=2,
-                content_block=TextContentBlock(type="text", text="after"),
+                content=TextContentBlock(type="text", text="after"),
             )
         )
         stream.dispatch(MessageFinishData(event="message-finish"))