feat(langgraph): drop tags from TracePolicy (#8402)

libs/langgraph/langgraph/graph/state.py

@@ -700,8 +700,7 @@ class StateGraph(Generic[StateT, ContextT, InputT, OutputT]):
             trace_policy: Optional policy controlling how this node's run is traced. Its
                 `process_inputs` callable transforms the node's input before it is
                 recorded (e.g. to omit or summarize large message history) without
-                changing the value passed to the node, and `tags` attaches tags to the
+                changing the value passed to the node. Does not affect execution.
-                run (e.g. to hide it from the trace tree). Does not affect execution.
             destinations: Destinations that indicate where a node can route to.
 
                 Useful for edgeless graphs with nodes that return `Command` objects.
@@ -1529,7 +1528,6 @@ class CompiledStateGraph(
                 if node.defer
                 else EphemeralValue(Any, guard=False)
             )
-            trace_tags = node.trace_policy.tags if node.trace_policy else None
             self.nodes[key] = PregelNode(
                 triggers=[branch_channel],
                 # read state keys and managed values
@@ -1538,7 +1536,6 @@ class CompiledStateGraph(
                 mapper=mapper,
                 # publish to state keys
                 writers=[ChannelWrite(write_entries)],
-                tags=list(trace_tags) if trace_tags else None,
                 metadata=node.metadata,
                 retry_policy=node.retry_policy,
                 cache_policy=node.cache_policy,

libs/langgraph/langgraph/types.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 import sys
 from collections import deque
 from collections.abc import Callable, Hashable, Sequence
-from dataclasses import asdict, dataclass, field
+from dataclasses import asdict, dataclass
 from datetime import timedelta
 from typing import (
     TYPE_CHECKING,
@@ -547,9 +547,6 @@ class TracePolicy:
     node's trace run. Use to omit or summarize large payloads (e.g. message history).
     Does not affect the value passed to the node."""
 
-    tags: list[str] = field(default_factory=list)
-    """Tags to attach to this node's trace run."""
-
 
 _DEFAULT_INTERRUPT_ID = "placeholder-id"
 

libs/langgraph/tests/test_trace_policy.py

@@ -1,4 +1,4 @@
-"""End-to-end tests for `TracePolicy` (input processing + hidden tag) on node runs."""
+"""End-to-end tests for `TracePolicy` input processing on node trace runs."""
 
 from typing import Any
 
@@ -86,24 +86,3 @@ async def test_trace_policy_transforms_recorded_inputs_async() -> None:
     run = _node_run(tracer, "n")
     assert run.inputs == {"scrubbed_in": True}
     assert run.outputs == {"value": 6}
-
-
-def test_trace_policy_tags_applied_to_run() -> None:
-    graph = (
-        StateGraph(State)
-        .add_node("shown", _incr)
-        .add_node(
-            "hush", _incr, trace_policy=TracePolicy(tags=["langsmith:hidden_middleware"])
-        )
-        .add_edge(START, "shown")
-        .add_edge("shown", "hush")
-        .add_edge("hush", END)
-        .compile()
-    )
-
-    tracer = FakeTracer()
-    graph.invoke({"value": 0}, {"callbacks": [tracer]})
-
-    # the policy's tags land on the node's run; other nodes are unaffected
-    assert "langsmith:hidden_middleware" in _node_run(tracer, "hush").tags
-    assert "langsmith:hidden_middleware" not in _node_run(tracer, "shown").tags