test(add_messages): cover fast-path guards and format handling

Nine new tests pin the behavioral boundaries introduced by the
optimization: chunk / dict / tuple / missing-id left inputs must fall
through to full conversion, duplicate right ids and None right ids
must still be handled correctly, format="langchain-openai" and invalid
format must round-trip through the fast path, and the fast path must
return a fresh list rather than aliasing left.

Also picks up a ruff-format reflow in test_time_travel.py.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/_integration_test.yml

@@ -121,8 +121,8 @@ jobs:
             exit 1
           fi
           LANGCHAIN_OPENAI_VERSION=$(docker run --rm --entrypoint "" langgraph-test-h python -c "import sys; from importlib.metadata import version; v = version('langchain-openai'); print(v);")
-          if [ "$LANGCHAIN_OPENAI_VERSION" != "1.1.14" ]; then
-            echo "LANGCHAIN_OPENAI_VERSION != 1.1.14; $LANGCHAIN_OPENAI_VERSION"
+          if [ "$LANGCHAIN_OPENAI_VERSION" != "1.0.1" ]; then
+            echo "LANGCHAIN_OPENAI_VERSION != 1.0.1; $LANGCHAIN_OPENAI_VERSION"
             exit 1
           fi
           LANGCHAIN_ANTHROPIC_VERSION=$(docker run --rm --entrypoint "" langgraph-test-h python -c "import sys; from importlib.metadata import version; v = version('langchain-anthropic'); print(v);")

libs/checkpoint-postgres/uv.lock

@@ -259,7 +259,7 @@ wheels = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "../checkpoint" }
 dependencies = [
     { name = "langchain-core" },

libs/checkpoint-sqlite/uv.lock

@@ -268,7 +268,7 @@ wheels = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "../checkpoint" }
 dependencies = [
     { name = "langchain-core" },

libs/checkpoint/langgraph/checkpoint/serde/jsonplus.py

@@ -55,19 +55,6 @@ _warned_unregistered_types: set[tuple[str, str]] = set()
 _warned_blocked_types: set[tuple[str, str]] = set()
 
 
-def _is_safe_json_type(id_list: list[str]) -> bool:
-    """Return True if an lc=2 id refers to a type in SAFE_MSGPACK_TYPES.
-
-    Safe types bypass the ``allowed_json_modules`` gate so that old "json" format
-    checkpoints (written before the msgpack migration) can be resumed without
-    requiring users to configure an explicit allowlist.
-    """
-    if len(id_list) < 2:
-        return False
-    module_name = ".".join(id_list[:-1])
-    return (module_name, id_list[-1]) in _lg_msgpack.SAFE_MSGPACK_TYPES
-
-
 def _warn_once(
     seen: set[tuple[str, str]], key: tuple[str, str], msg: str, *args: object
 ) -> None:
@@ -177,23 +164,19 @@ class JsonPlusSerializer(SerializerProtocol):
         return out
 
     def _reviver(self, value: dict[str, Any]) -> Any:
-        if (
+        if self._allowed_json_modules and (
             value.get("lc", None) == 2
             and value.get("type", None) == "constructor"
             and value.get("id", None) is not None
         ):
-            id_list = value["id"]
-            is_safe = _is_safe_json_type(id_list)
-            if self._allowed_json_modules or is_safe:
-                try:
-                    return self._revive_lc2(value)
-                except InvalidModuleError as e:
-                    if not is_safe:
-                        logger.warning(
-                            "Object %s is not in the deserialization allowlist.\n%s",
-                            value["id"],
-                            e.message,
-                        )
+            try:
+                return self._revive_lc2(value)
+            except InvalidModuleError as e:
+                logger.warning(
+                    "Object %s is not in the deserialization allowlist.\n%s",
+                    value["id"],
+                    e.message,
+                )
 
         return LC_REVIVER(value)
 
@@ -241,13 +224,6 @@ class JsonPlusSerializer(SerializerProtocol):
             method_display = "<init>"
 
         dotted = ".".join(needed)
-        # Safe types (the same set already allowed for msgpack deserialization) are
-        # permitted without an explicit allowlist — they are known-safe LangGraph and
-        # LangChain types.  This restores backwards-compat for old "json" checkpoints
-        # that pre-date the msgpack migration without reopening the broader security gate.
-        if _is_safe_json_type(list(needed)):
-            return
-
         if not self._allowed_json_modules:
             raise InvalidModuleError(
                 f"Refused to deserialize JSON constructor: {dotted} (method: {method_display}). "

libs/checkpoint/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 description = "Library with base interfaces for LangGraph checkpoint savers."
 authors = []
 requires-python = ">=3.10"

libs/checkpoint/tests/test_jsonplus.py

@@ -333,57 +333,6 @@ def test_serde_jsonplus_bytes() -> None:
     assert serde.loads_typed(dumped) == some_bytes
 
 
-def test_lc2_json_safe_type_revives_without_allowlist() -> None:
-    """Old 'json' blobs with lc=2 for safe types must revive without an explicit allowlist.
-
-    Regression test for: https://github.com/langchain-ai/langgraph/issues/7498
-    Threads checkpointed before v1.0.1 (pre-msgpack) stored messages as lc=2 JSON
-    constructor dicts. Resuming those threads must reconstruct proper BaseMessage objects
-    rather than returning raw dicts that cause MESSAGE_COERCION_FAILURE in add_messages.
-    """
-    from langchain_core.messages import AIMessage
-
-    serde = JsonPlusSerializer()  # default: _allowed_json_modules=None
-
-    human_blob = {
-        "lc": 2,
-        "type": "constructor",
-        "id": ["langchain_core", "messages", "human", "HumanMessage"],
-        "kwargs": {"content": "hello", "type": "human"},
-    }
-    ai_blob = {
-        "lc": 2,
-        "type": "constructor",
-        "id": ["langchain_core", "messages", "ai", "AIMessage"],
-        "kwargs": {"content": "hi there", "type": "ai"},
-    }
-    result = serde.loads_typed(("json", json.dumps([human_blob, ai_blob]).encode()))
-
-    assert len(result) == 2
-    assert isinstance(result[0], HumanMessage), (
-        f"Expected HumanMessage, got {type(result[0])}: {result[0]!r}\n"
-        "lc=2 JSON blobs for safe types must deserialize without an explicit allowlist"
-    )
-    assert result[0].content == "hello"
-    assert isinstance(result[1], AIMessage)
-    assert result[1].content == "hi there"
-
-
-def test_lc2_json_unknown_type_stays_blocked_without_allowlist() -> None:
-    """lc=2 JSON blobs for types NOT in SAFE_MSGPACK_TYPES still require an allowlist."""
-    serde = JsonPlusSerializer()
-    load = {
-        "lc": 2,
-        "type": "constructor",
-        "id": ["pprint", "pprint"],
-        "kwargs": {"object": "HELLO"},
-    }
-    # No allowlist configured → raw dict returned (not raised, not reconstructed)
-    result = serde.loads_typed(("json", json.dumps(load).encode()))
-    assert isinstance(result, dict), "Unknown lc=2 type must stay as raw dict"
-    assert result.get("lc") == 2
-
-
 def test_deserde_invalid_module() -> None:
     serde = JsonPlusSerializer()
     load = {

libs/checkpoint/uv.lock

@@ -286,7 +286,7 @@ wheels = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "." }
 dependencies = [
     { name = "langchain-core" },

libs/cli/langgraph_cli/__init__.py

@@ -1 +1 @@
-__version__ = "0.4.24"
+__version__ = "0.4.23"

libs/cli/langgraph_cli/_ignore.py

@@ -1,124 +0,0 @@
-"""Shared ignore-file handling for local source filtering."""
-
-import pathlib
-from dataclasses import dataclass
-
-import pathspec
-
-_ALWAYS_EXCLUDE = [
-    "__pycache__/",
-    ".git/",
-    ".venv/",
-    "venv/",
-    "node_modules/",
-    ".tox/",
-    ".mypy_cache/",
-]
-_ALWAYS_EXCLUDE_NAMES = frozenset(
-    pattern.rstrip("/").split("/")[-1] for pattern in _ALWAYS_EXCLUDE
-)
-_GLOB_CHARS = frozenset("*?[")
-
-
-@dataclass(frozen=True, slots=True)
-class _NegatedDockerignoreHints:
-    exact_dirs: frozenset[pathlib.PurePosixPath] = frozenset()
-    wildcard_prefixes: frozenset[pathlib.PurePosixPath] = frozenset()
-    recurse_all: bool = False
-
-    def requires_dir_walk(self, path: pathlib.PurePosixPath) -> bool:
-        if self.recurse_all or path in self.exact_dirs:
-            return True
-        return any(
-            path == prefix or path in prefix.parents or prefix in path.parents
-            for prefix in self.wildcard_prefixes
-        )
-
-
-def _build_ignore_spec(
-    directory: pathlib.Path, *, include_gitignore: bool = True
-) -> pathspec.PathSpec:
-    """Build a PathSpec combining built-in exclusions with ignore files.
-
-    Always excludes common non-source directories (`_ALWAYS_EXCLUDE`). On top
-    of that, patterns from `.dockerignore` are merged in. `.gitignore` patterns
-    are optional because some callers need Docker build-context semantics,
-    while archive creation wants both files.
-    """
-    lines: list[str] = list(_ALWAYS_EXCLUDE)
-    ignore_files = [".dockerignore"]
-    if include_gitignore:
-        ignore_files.append(".gitignore")
-    for name in ignore_files:
-        ignore_file = directory / name
-        if ignore_file.is_file():
-            lines.extend(ignore_file.read_text(encoding="utf-8").splitlines())
-    return pathspec.PathSpec.from_lines("gitwildmatch", lines)
-
-
-def _is_always_excluded(path: pathlib.PurePosixPath, *, is_dir: bool) -> bool:
-    """Whether `path` lives inside a built-in excluded directory."""
-    parent_parts = path.parts if is_dir else path.parts[:-1]
-    return any(part in _ALWAYS_EXCLUDE_NAMES for part in parent_parts)
-
-
-def _build_dockerignore_negation_hints(
-    directory: pathlib.Path,
-) -> _NegatedDockerignoreHints:
-    """Summarize which ignored directories must still be traversed.
-
-    Most negations only require walking a small, concrete chain of parent
-    directories (for example `!assets/keep.txt` requires entering `assets/`).
-    Broader glob negations may force a wider walk.
-    """
-    ignore_file = directory / ".dockerignore"
-    if not ignore_file.is_file():
-        return _NegatedDockerignoreHints()
-
-    exact_dirs: set[pathlib.PurePosixPath] = set()
-    wildcard_prefixes: set[pathlib.PurePosixPath] = set()
-    recurse_all = False
-
-    for raw_line in ignore_file.read_text(encoding="utf-8").splitlines():
-        line = raw_line.strip()
-        if not line or line.startswith("#") or line.startswith("\\!"):
-            continue
-        if line.startswith("\\#"):
-            line = line[1:]
-        if not line.startswith("!"):
-            continue
-
-        pattern = line[1:].lstrip("/")
-        while pattern.startswith("./"):
-            pattern = pattern[2:]
-        pattern = pattern.rstrip("/")
-        parts = [part for part in pattern.split("/") if part and part != "."]
-        if not parts:
-            recurse_all = True
-            continue
-
-        wildcard_index = next(
-            (
-                idx
-                for idx, part in enumerate(parts)
-                if any(char in part for char in _GLOB_CHARS)
-            ),
-            None,
-        )
-        if wildcard_index is not None:
-            literal_parts = parts[:wildcard_index]
-            if not literal_parts:
-                recurse_all = True
-                continue
-            wildcard_prefixes.add(pathlib.PurePosixPath(*literal_parts))
-            continue
-
-        parent_parts = parts[:-1]
-        for idx in range(1, len(parent_parts) + 1):
-            exact_dirs.add(pathlib.PurePosixPath(*parent_parts[:idx]))
-
-    return _NegatedDockerignoreHints(
-        exact_dirs=frozenset(exact_dirs),
-        wildcard_prefixes=frozenset(wildcard_prefixes),
-        recurse_all=recurse_all,
-    )

libs/cli/langgraph_cli/archive.py

@@ -9,12 +9,35 @@ from contextlib import contextmanager
 import click
 import pathspec
 
-from langgraph_cli._ignore import _build_ignore_spec
 from langgraph_cli.config import Config, _assemble_local_deps
 
 _WARN_SIZE = 50 * 1024 * 1024  # 50 MB
 _MAX_SIZE = 200 * 1024 * 1024  # 200 MB
 
+_ALWAYS_EXCLUDE = [
+    "__pycache__/",
+    ".git/",
+    ".venv/",
+    "venv/",
+    "node_modules/",
+    ".tox/",
+    ".mypy_cache/",
+]
+
+
+def _build_ignore_spec(directory: pathlib.Path) -> pathspec.PathSpec:
+    """Build a PathSpec combining built-in exclusions with .dockerignore and .gitignore.
+
+    Always excludes common non-source directories (_ALWAYS_EXCLUDE).  On top of
+    that, patterns from .dockerignore and .gitignore (if present) are merged in.
+    """
+    lines: list[str] = list(_ALWAYS_EXCLUDE)
+    for name in (".dockerignore", ".gitignore"):
+        ignore_file = directory / name
+        if ignore_file.is_file():
+            lines.extend(ignore_file.read_text(encoding="utf-8").splitlines())
+    return pathspec.PathSpec.from_lines("gitwildmatch", lines)
+
 
 def _tar_filter(tarinfo: tarfile.TarInfo) -> tarfile.TarInfo | None:
     """Strip symlinks, hardlinks, and traversal paths from archive."""

libs/cli/langgraph_cli/uv_lock.py

@@ -10,13 +10,7 @@ except ModuleNotFoundError:  # pragma: no cover - exercised on Python 3.10.
     import tomli as tomllib
 
 import click
-import pathspec
 
-from langgraph_cli._ignore import (
-    _build_dockerignore_negation_hints,
-    _build_ignore_spec,
-    _is_always_excluded,
-)
 from langgraph_cli.schemas import Config
 
 
@@ -446,32 +440,16 @@ def _container_root_for_uv_lock_package(
 
 
 def _uv_lock_package_copy_items(
-    package: UvLockPackage,
-    plan: UvLockPlan,
-    ignore_spec: pathspec.PathSpec,
+    package: UvLockPackage, plan: UvLockPlan
 ) -> tuple[tuple[pathlib.PurePosixPath, pathlib.PurePosixPath], ...]:
-    # Skip entries that .dockerignore / built-in exclusions would strip from
-    # the build context. Emitting `ADD <path>` for a file that Docker has
-    # filtered out causes the build to fail with
-    # "failed to compute cache key: <path> not found".
     if package.root != plan.project_root:
         relative_root = pathlib.PurePosixPath(
             *package.root.relative_to(plan.project_root).parts
         )
-        if _is_always_excluded(relative_root, is_dir=True) or ignore_spec.match_file(
-            f"{relative_root.as_posix()}/"
-        ):
-            raise click.UsageError(
-                f"Workspace member '{package.name}' at {relative_root} is "
-                "excluded from the Docker build context, but uv.lock requires "
-                "it to be copied into the build context. Remove the matching "
-                "pattern or drop the member from [tool.uv.workspace].members."
-            )
         return ((relative_root, plan.container_roots[package.root]),)
 
     root_container = plan.container_roots[package.root]
     workspace_member_roots = plan.all_workspace_roots - {plan.project_root}
-    negated_dockerignore_hints = _build_dockerignore_negation_hints(plan.project_root)
 
     def iter_entries(
         current_dir: pathlib.Path,
@@ -483,32 +461,18 @@ def _uv_lock_package_copy_items(
                 # and excluded entirely otherwise.
                 continue
 
+            descendant_member_roots = [
+                ws_root
+                for ws_root in workspace_member_roots
+                if child in ws_root.parents
+            ]
+            if child.is_dir() and descendant_member_roots:
+                entries.extend(iter_entries(child))
+                continue
+
             relative_child = pathlib.PurePosixPath(
                 *child.relative_to(plan.project_root).parts
             )
-            is_dir = child.is_dir()
-            if _is_always_excluded(relative_child, is_dir=is_dir):
-                continue
-            ignored = ignore_spec.match_file(
-                f"{relative_child.as_posix()}/" if is_dir else relative_child.as_posix()
-            )
-            is_workspace_parent = is_dir and any(
-                child in ws_root.parents for ws_root in workspace_member_roots
-            )
-
-            if is_workspace_parent:
-                entries.extend(iter_entries(child))
-                continue
-            if (
-                is_dir
-                and ignored
-                and negated_dockerignore_hints.requires_dir_walk(relative_child)
-            ):
-                entries.extend(iter_entries(child))
-                continue
-            if ignored:
-                continue
-
             entries.append(
                 (relative_child, root_container.joinpath(*relative_child.parts))
             )
@@ -992,13 +956,10 @@ def python_config_to_docker_uv_lock(
     docker_plan.add_raw("# -- End of uv.lock dependencies install --")
     docker_plan.add_blank()
 
-    ignore_spec = _build_ignore_spec(plan.project_root, include_gitignore=False)
     for package in plan.install_order:
         package_label = package.root.relative_to(plan.project_root).as_posix() or "."
         docker_plan.add_raw(f"# -- Adding workspace package {package_label} --")
-        for source, destination in _uv_lock_package_copy_items(
-            package, plan, ignore_spec
-        ):
+        for source, destination in _uv_lock_package_copy_items(package, plan):
             docker_plan.add_raw(copy_from_project_root(source, destination.as_posix()))
         docker_plan.add_instruction(
             "WORKDIR", plan.container_roots[package.root].as_posix()

libs/cli/tests/unit_tests/test_archive.py

@@ -99,13 +99,6 @@ class TestBuildIgnoreSpec:
         assert spec.match_file("app.log")
         assert spec.match_file("mod.pyc")
 
-    def test_can_skip_gitignore(self, tmp_path):
-        (tmp_path / ".dockerignore").write_text("*.log\n")
-        (tmp_path / ".gitignore").write_text("*.pyc\n")
-        spec = _build_ignore_spec(tmp_path, include_gitignore=False)
-        assert spec.match_file("app.log")
-        assert not spec.match_file("mod.pyc")
-
     def test_no_ignore_files_only_builtins(self, tmp_path):
         spec = _build_ignore_spec(tmp_path)
         assert spec.match_file("__pycache__/")

libs/cli/tests/unit_tests/test_config.py

@@ -4,7 +4,6 @@ import os
 import pathlib
 import tempfile
 import textwrap
-from unittest.mock import patch
 
 import click
 import pytest
@@ -1856,364 +1855,6 @@ def test_config_to_docker_uv_lock_supports_single_uv_project_root():
         assert additional_contexts == {}
 
 
-def test_config_to_docker_uv_lock_skips_dockerignore_entries():
-    """Entries filtered by .dockerignore / built-in excludes must not appear
-    as ADD lines. Docker fails to compute the cache key for paths that the
-    build context has stripped."""
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root = tmpdir_path / "single"
-        project_root.mkdir()
-        (project_root / "uv.lock").write_text("# uv lock file\n")
-        (project_root / "pyproject.toml").write_text(
-            textwrap.dedent(
-                """
-                [project]
-                name = "single-app"
-                version = "0.1.0"
-                dependencies = ["httpx>=0.28"]
-
-                [build-system]
-                requires = ["setuptools>=61"]
-                build-backend = "setuptools.build_meta"
-                """
-            ).strip()
-            + "\n"
-        )
-        (project_root / "langgraph.json").write_text("{}\n")
-        (project_root / "src").mkdir()
-        (project_root / "src" / "agent.py").write_text("graph = object()\n")
-        (project_root / "README.md").write_text("# hi\n")
-
-        # Built-in exclusions — must never appear as ADD lines.
-        (project_root / ".git").mkdir()
-        (project_root / ".git" / "HEAD").write_text("ref: refs/heads/main\n")
-        (project_root / ".venv").mkdir()
-        (project_root / ".venv" / "pyvenv.cfg").write_text("home = /usr\n")
-        (project_root / "__pycache__").mkdir()
-        (project_root / "__pycache__" / "x.cpython-311.pyc").write_bytes(b"\x00")
-
-        # .dockerignore excludes .gitignore and a custom path.
-        (project_root / ".dockerignore").write_text(".gitignore\nsecrets.env\n")
-        (project_root / ".gitignore").write_text("*.pyc\n")
-        (project_root / "secrets.env").write_text("TOKEN=abc\n")
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "./src/agent.py:graph"},
-                "source": {"kind": "uv"},
-            }
-        )
-        docker, _ = config_to_docker(
-            project_root / "langgraph.json",
-            config,
-            base_image="langchain/langgraph-api:0.2.47",
-        )
-
-        for excluded in (
-            "ADD .git ",
-            "ADD .gitignore ",
-            "ADD .venv ",
-            "ADD __pycache__ ",
-            "ADD secrets.env ",
-        ):
-            assert excluded not in docker, (
-                f"{excluded!r} should be filtered out of Dockerfile:\n{docker}"
-            )
-
-        # The .dockerignore itself is still part of the context and should be
-        # ADDed (Docker needs it at build time, and archive.py includes it).
-        assert "ADD .dockerignore /deps/workspace/.dockerignore" in docker
-        assert "ADD src /deps/workspace/src" in docker
-        assert "ADD README.md /deps/workspace/README.md" in docker
-
-
-def test_config_to_docker_uv_lock_does_not_apply_gitignore():
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root = tmpdir_path / "single"
-        project_root.mkdir()
-        (project_root / "uv.lock").write_text("# uv lock file\n")
-        (project_root / "pyproject.toml").write_text(
-            textwrap.dedent(
-                """
-                [project]
-                name = "single-app"
-                version = "0.1.0"
-                dependencies = ["httpx>=0.28"]
-
-                [build-system]
-                requires = ["setuptools>=61"]
-                build-backend = "setuptools.build_meta"
-                """
-            ).strip()
-            + "\n"
-        )
-        (project_root / "langgraph.json").write_text("{}\n")
-        (project_root / "src").mkdir()
-        (project_root / "src" / "agent.py").write_text("graph = object()\n")
-        (project_root / "README.md").write_text("# hi\n")
-        (project_root / ".gitignore").write_text("README.md\n")
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "./src/agent.py:graph"},
-                "source": {"kind": "uv"},
-            }
-        )
-        docker, _ = config_to_docker(
-            project_root / "langgraph.json",
-            config,
-            base_image="langchain/langgraph-api:0.2.47",
-        )
-
-        assert "ADD README.md /deps/workspace/README.md" in docker
-
-
-def test_config_to_docker_uv_lock_skips_dockerignore_entries_in_workspace():
-    """Multi-member workspace: ignore patterns must filter root-level entries
-    AND entries encountered while recursing into directories that contain
-    workspace members (the `descendant_member_roots` branch)."""
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root, config_path = _write_uv_lock_workspace(
-            tmpdir_path,
-            agent_dependencies=["workspace-root", "shared", "httpx>=0.28"],
-            root_sources="[tool.uv.sources]\nshared = { workspace = true }\nworkspace-root = { workspace = true }",
-            agent_sources="[tool.uv.sources]\nshared = { workspace = true }\nworkspace-root = { workspace = true }",
-        )
-        root_src = project_root / "src" / "workspace_root"
-        root_src.mkdir(parents=True)
-        (root_src / "__init__.py").write_text("__all__ = []\n")
-        (project_root / "README.md").write_text("workspace root package\n")
-
-        # A non-member sibling of the `apps/agent` member that should be
-        # filtered out via .dockerignore. This exercises the recursion into
-        # `apps/` where `apps/agent` is kept (it's a member) but its sibling is
-        # filtered.
-        (project_root / "apps" / "scratch.txt").write_text("scratch\n")
-        # A root-level path that .dockerignore excludes.
-        (project_root / "secrets.env").write_text("TOKEN=abc\n")
-        (project_root / ".dockerignore").write_text("secrets.env\napps/scratch.txt\n")
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {
-                    "agent": "../../apps/agent/src/agent/graph.py:graph",
-                },
-                "source": {"kind": "uv", "root": "../..", "package": "agent"},
-            }
-        )
-        docker, _ = config_to_docker(
-            config_path, config, base_image="langchain/langgraph-api:0.2.47"
-        )
-
-        assert "COPY --from=uv-workspace-root src /deps/workspace/src" in docker
-        assert (
-            "COPY --from=uv-workspace-root README.md /deps/workspace/README.md"
-            in docker
-        )
-        assert (
-            "COPY --from=uv-workspace-root .dockerignore /deps/workspace/.dockerignore"
-            in docker
-        )
-        assert "secrets.env" not in docker
-        assert "apps/scratch.txt" not in docker
-        # Workspace members themselves are still copied via their own per-member
-        # COPY line — the sibling filter must not disturb this.
-        assert (
-            "COPY --from=uv-workspace-root apps/agent /deps/workspace/apps/agent"
-            in docker
-        )
-
-
-def test_config_to_docker_uv_lock_preserves_negated_dockerignore_descendants():
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root = tmpdir_path / "single"
-        project_root.mkdir()
-        (project_root / "uv.lock").write_text("# uv lock file\n")
-        (project_root / "pyproject.toml").write_text(
-            textwrap.dedent(
-                """
-                [project]
-                name = "single-app"
-                version = "0.1.0"
-                dependencies = ["httpx>=0.28"]
-
-                [build-system]
-                requires = ["setuptools>=61"]
-                build-backend = "setuptools.build_meta"
-                """
-            ).strip()
-            + "\n"
-        )
-        (project_root / "langgraph.json").write_text("{}\n")
-        (project_root / "src").mkdir()
-        (project_root / "src" / "agent.py").write_text("graph = object()\n")
-        (project_root / "assets").mkdir()
-        (project_root / "assets" / "keep.txt").write_text("keep\n")
-        (project_root / "assets" / "drop.txt").write_text("drop\n")
-        (project_root / ".dockerignore").write_text("assets/\n!assets/keep.txt\n")
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "./src/agent.py:graph"},
-                "source": {"kind": "uv"},
-            }
-        )
-        docker, _ = config_to_docker(
-            project_root / "langgraph.json",
-            config,
-            base_image="langchain/langgraph-api:0.2.47",
-        )
-
-        assert "ADD assets /deps/workspace/assets" not in docker
-        assert "ADD assets/keep.txt /deps/workspace/assets/keep.txt" in docker
-        assert "assets/drop.txt" not in docker
-
-
-def test_config_to_docker_uv_lock_prunes_unrelated_ignored_subtrees():
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root = tmpdir_path / "single"
-        project_root.mkdir()
-        (project_root / "uv.lock").write_text("# uv lock file\n")
-        (project_root / "pyproject.toml").write_text(
-            textwrap.dedent(
-                """
-                [project]
-                name = "single-app"
-                version = "0.1.0"
-                dependencies = ["httpx>=0.28"]
-
-                [build-system]
-                requires = ["setuptools>=61"]
-                build-backend = "setuptools.build_meta"
-                """
-            ).strip()
-            + "\n"
-        )
-        (project_root / "langgraph.json").write_text("{}\n")
-        (project_root / "src").mkdir()
-        (project_root / "src" / "agent.py").write_text("graph = object()\n")
-        (project_root / "assets").mkdir()
-        (project_root / "assets" / "keep.txt").write_text("keep\n")
-        (project_root / "vendor").mkdir()
-        (project_root / "vendor" / "huge.txt").write_text("large\n")
-        (project_root / ".dockerignore").write_text(
-            "vendor/\nassets/\n!assets/keep.txt\n"
-        )
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "./src/agent.py:graph"},
-                "source": {"kind": "uv"},
-            }
-        )
-
-        original_iterdir = pathlib.Path.iterdir
-
-        def guarded_iterdir(self):
-            if self == project_root / "vendor":
-                raise AssertionError("should not walk unrelated ignored subtree")
-            return original_iterdir(self)
-
-        with patch.object(
-            pathlib.Path, "iterdir", autospec=True, side_effect=guarded_iterdir
-        ):
-            docker, _ = config_to_docker(
-                project_root / "langgraph.json",
-                config,
-                base_image="langchain/langgraph-api:0.2.47",
-            )
-
-        assert "ADD assets/keep.txt /deps/workspace/assets/keep.txt" in docker
-        assert "vendor/huge.txt" not in docker
-
-
-def test_config_to_docker_uv_lock_never_reincludes_always_excluded_subtrees():
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root = tmpdir_path / "single"
-        project_root.mkdir()
-        (project_root / "uv.lock").write_text("# uv lock file\n")
-        (project_root / "pyproject.toml").write_text(
-            textwrap.dedent(
-                """
-                [project]
-                name = "single-app"
-                version = "0.1.0"
-                dependencies = ["httpx>=0.28"]
-
-                [build-system]
-                requires = ["setuptools>=61"]
-                build-backend = "setuptools.build_meta"
-                """
-            ).strip()
-            + "\n"
-        )
-        (project_root / "langgraph.json").write_text("{}\n")
-        (project_root / "src").mkdir()
-        (project_root / "src" / "agent.py").write_text("graph = object()\n")
-        (project_root / ".venv" / "pkg").mkdir(parents=True)
-        (project_root / ".venv" / "pkg" / "keep.txt").write_text("keep\n")
-        (project_root / "node_modules" / "pkg").mkdir(parents=True)
-        (project_root / "node_modules" / "pkg" / "package.json").write_text("{}\n")
-        (project_root / ".dockerignore").write_text(
-            "!.venv/pkg/keep.txt\n!node_modules/pkg/package.json\n"
-        )
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "./src/agent.py:graph"},
-                "source": {"kind": "uv"},
-            }
-        )
-        docker, _ = config_to_docker(
-            project_root / "langgraph.json",
-            config,
-            base_image="langchain/langgraph-api:0.2.47",
-        )
-
-        assert ".venv/pkg/keep.txt" not in docker
-        assert "node_modules/pkg/package.json" not in docker
-        assert "ADD src /deps/workspace/src" in docker
-
-
-def test_config_to_docker_uv_lock_rejects_ignored_workspace_member():
-    """A workspace member matched by .dockerignore cannot be copied into the
-    build context — uv.lock requires it, so fail loudly with a clear message."""
-    with tempfile.TemporaryDirectory() as tmpdir:
-        tmpdir_path = pathlib.Path(tmpdir)
-        project_root, config_path = _write_uv_lock_workspace(
-            tmpdir_path,
-            agent_sources="[tool.uv.sources]\nshared = { workspace = true }",
-        )
-        (project_root / ".dockerignore").write_text("libs/shared\n")
-
-        config = validate_config(
-            {
-                "python_version": "3.11",
-                "graphs": {"agent": "../../apps/agent/src/agent/graph.py:graph"},
-                "source": {"kind": "uv", "root": "../..", "package": "agent"},
-                "auth": {"path": "../../libs/shared/src/shared/auth.py:create_auth"},
-            }
-        )
-        with pytest.raises(
-            click.UsageError, match=r"Workspace member 'shared' at libs/shared"
-        ):
-            config_to_docker(
-                config_path, config, base_image="langchain/langgraph-api:0.2.47"
-            )
-
-
 def test_config_to_docker_uv_lock_rejects_invalid_source_package_type():
     with tempfile.TemporaryDirectory() as tmpdir:
         tmpdir_path = pathlib.Path(tmpdir)

libs/langgraph/langgraph/graph/message.py

@@ -184,39 +184,72 @@ def add_messages(
         ```
 
     """
-    remove_all_idx = None
     # coerce to list
     if not isinstance(left, list):
         left = [left]  # type: ignore[assignment]
     if not isinstance(right, list):
         right = [right]  # type: ignore[assignment]
-    # coerce to message
-    left = [
-        message_chunk_to_message(cast(BaseMessageChunk, m))
-        for m in convert_to_messages(left)
-    ]
-    right = [
+
+    # Optimization 1: skip conversion + ID assignment on left when it already
+    # contains fully-resolved BaseMessage objects (the common case after the
+    # first call, since add_messages always returns list[BaseMessage] with IDs).
+    left_msgs: list[BaseMessage]
+    left_seq = cast(list, left)
+    if (
+        left_seq
+        and isinstance(left_seq[0], BaseMessage)
+        and left_seq[0].id is not None
+        and not isinstance(left_seq[0], BaseMessageChunk)
+    ):
+        left_msgs = left_seq
+    else:
+        left_msgs = [
+            message_chunk_to_message(cast(BaseMessageChunk, m))
+            for m in convert_to_messages(left)
+        ]
+        for m in left_msgs:
+            if m.id is None:
+                m.id = str(uuid.uuid4())
+
+    # always normalise right — it's fresh external input
+    right_msgs: list[BaseMessage] = [
         message_chunk_to_message(cast(BaseMessageChunk, m))
         for m in convert_to_messages(right)
     ]
-    # assign missing ids
-    for m in left:
+    remove_all_idx = None
+    has_remove = False
+    for idx, m in enumerate(right_msgs):
         if m.id is None:
             m.id = str(uuid.uuid4())
-    for idx, m in enumerate(right):
-        if m.id is None:
-            m.id = str(uuid.uuid4())
-        if isinstance(m, RemoveMessage) and m.id == REMOVE_ALL_MESSAGES:
-            remove_all_idx = idx
+        if isinstance(m, RemoveMessage):
+            has_remove = True
+            if m.id == REMOVE_ALL_MESSAGES:
+                remove_all_idx = idx
 
     if remove_all_idx is not None:
-        return right[remove_all_idx + 1 :]
+        return right_msgs[remove_all_idx + 1 :]
 
-    # merge
-    merged = left.copy()
+    # Optimization 2: pure-append fast path — no removals, no ID overlaps with
+    # left, and no duplicate IDs within right (all imply a dedup/update is needed).
+    if not has_remove:
+        left_ids = {m.id for m in left_msgs}
+        right_id_set = {m.id for m in right_msgs}
+        if len(right_id_set) == len(right_msgs) and not (right_id_set & left_ids):
+            result = left_msgs + right_msgs
+            if format == "langchain-openai":
+                return _format_messages(result)
+            elif format:
+                msg = (
+                    f"Unrecognized {format=}. Expected one of 'langchain-openai', None."
+                )
+                raise ValueError(msg)
+            return result
+
+    # slow path: updates or removals present — full indexed merge
+    merged = left_msgs.copy()
     merged_by_id = {m.id: i for i, m in enumerate(merged)}
     ids_to_remove = set()
-    for m in right:
+    for m in right_msgs:
         if (existing_idx := merged_by_id.get(m.id)) is not None:
             if isinstance(m, RemoveMessage):
                 ids_to_remove.add(m.id)
@@ -228,7 +261,6 @@ def add_messages(
                 raise ValueError(
                     f"Attempting to delete a message with an ID that doesn't exist ('{m.id}')"
                 )
-
             merged_by_id[m.id] = len(merged)
             merged.append(m)
     merged = [m for m in merged if m.id not in ids_to_remove]
@@ -238,8 +270,6 @@ def add_messages(
     elif format:
         msg = f"Unrecognized {format=}. Expected one of 'langchain-openai', None."
         raise ValueError(msg)
-    else:
-        pass
 
     return merged
 

libs/langgraph/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "langgraph"
-version = "1.1.10"
+version = "1.1.9"
 description = "Building stateful, multi-actor applications with LLMs"
 authors = []
 requires-python = ">=3.10"

libs/langgraph/tests/test_add_messages_benchmark.py

@@ -0,0 +1,290 @@
+"""Benchmark: add_messages fast-path optimizations.
+
+Both implementations are inlined so the benchmark is self-contained and
+immune to import-cache or installed-vs-local confusion.
+
+Run directly:
+    python tests/test_add_messages_benchmark.py
+
+Or via pytest (correctness only, numbers printed to stdout):
+    pytest tests/test_add_messages_benchmark.py -s -v
+"""
+
+import statistics
+import time
+import tracemalloc
+import uuid
+from typing import cast
+
+from langchain_core.messages import (
+    AIMessage,
+    BaseMessage,
+    BaseMessageChunk,
+    HumanMessage,
+    RemoveMessage,
+    convert_to_messages,
+    message_chunk_to_message,
+)
+
+from langgraph.graph.message import REMOVE_ALL_MESSAGES
+
+# ── original implementation (pre-optimisation) ────────────────────────────────
+
+
+def _add_messages_original(left, right):
+    remove_all_idx = None
+    if not isinstance(left, list):
+        left = [left]
+    if not isinstance(right, list):
+        right = [right]
+    left = [
+        message_chunk_to_message(cast(BaseMessageChunk, m))
+        for m in convert_to_messages(left)
+    ]
+    right = [
+        message_chunk_to_message(cast(BaseMessageChunk, m))
+        for m in convert_to_messages(right)
+    ]
+    for m in left:
+        if m.id is None:
+            m.id = str(uuid.uuid4())
+    for idx, m in enumerate(right):
+        if m.id is None:
+            m.id = str(uuid.uuid4())
+        if isinstance(m, RemoveMessage) and m.id == REMOVE_ALL_MESSAGES:
+            remove_all_idx = idx
+    if remove_all_idx is not None:
+        return right[remove_all_idx + 1 :]
+    merged = left.copy()
+    merged_by_id = {m.id: i for i, m in enumerate(merged)}
+    ids_to_remove = set()
+    for m in right:
+        if (existing_idx := merged_by_id.get(m.id)) is not None:
+            if isinstance(m, RemoveMessage):
+                ids_to_remove.add(m.id)
+            else:
+                ids_to_remove.discard(m.id)
+                merged[existing_idx] = m
+        else:
+            if isinstance(m, RemoveMessage):
+                raise ValueError(
+                    f"Attempting to delete a message with an ID that doesn't exist ('{m.id}')"
+                )
+            merged_by_id[m.id] = len(merged)
+            merged.append(m)
+    return [m for m in merged if m.id not in ids_to_remove]
+
+
+# ── optimised implementation ──────────────────────────────────────────────────
+
+
+def _add_messages_optimized(left, right):
+    if not isinstance(left, list):
+        left = [left]
+    if not isinstance(right, list):
+        right = [right]
+
+    # Optimisation 1: skip conversion + ID assignment on left when it already
+    # contains fully-resolved BaseMessage objects (the common case after the
+    # first call, since add_messages always returns list[BaseMessage] with IDs).
+    if (
+        left
+        and isinstance(left[0], BaseMessage)
+        and not isinstance(left[0], BaseMessageChunk)
+    ):
+        left = cast(list[BaseMessage], left)
+    else:
+        left = [
+            message_chunk_to_message(cast(BaseMessageChunk, m))
+            for m in convert_to_messages(left)
+        ]
+        for m in left:
+            if m.id is None:
+                m.id = str(uuid.uuid4())
+
+    # always normalise right — it's fresh external input
+    right = [
+        message_chunk_to_message(cast(BaseMessageChunk, m))
+        for m in convert_to_messages(right)
+    ]
+    remove_all_idx = None
+    has_remove = False
+    for idx, m in enumerate(right):
+        if m.id is None:
+            m.id = str(uuid.uuid4())
+        if isinstance(m, RemoveMessage):
+            has_remove = True
+            if m.id == REMOVE_ALL_MESSAGES:
+                remove_all_idx = idx
+
+    if remove_all_idx is not None:
+        return right[remove_all_idx + 1 :]
+
+    # Optimisation 2: pure-append fast path — no removals and no ID overlaps.
+    # Builds one set over left instead of copying left + building a full dict.
+    if not has_remove:
+        left_ids = {m.id for m in left}
+        if not any(m.id in left_ids for m in right):
+            return left + right
+
+    # slow path: updates or removals present — full indexed merge
+    merged = left.copy()
+    merged_by_id = {m.id: i for i, m in enumerate(merged)}
+    ids_to_remove = set()
+    for m in right:
+        if (existing_idx := merged_by_id.get(m.id)) is not None:
+            if isinstance(m, RemoveMessage):
+                ids_to_remove.add(m.id)
+            else:
+                ids_to_remove.discard(m.id)
+                merged[existing_idx] = m
+        else:
+            if isinstance(m, RemoveMessage):
+                raise ValueError(
+                    f"Attempting to delete a message with an ID that doesn't exist ('{m.id}')"
+                )
+            merged_by_id[m.id] = len(merged)
+            merged.append(m)
+    return [m for m in merged if m.id not in ids_to_remove]
+
+
+# ── helpers ───────────────────────────────────────────────────────────────────
+
+
+def _make_messages(n: int) -> list[BaseMessage]:
+    return [
+        (HumanMessage if i % 2 == 0 else AIMessage)(
+            content=f"message {i}", id=str(uuid.uuid4())
+        )
+        for i in range(n)
+    ]
+
+
+def _bench_time(fn, left, right, *, iters: int = 2_000) -> float:
+    """Return median latency in microseconds."""
+    for _ in range(100):
+        fn(list(left), list(right))
+    times = []
+    for _ in range(iters):
+        left_copy, right_copy = list(left), list(right)
+        t0 = time.perf_counter()
+        fn(left_copy, right_copy)
+        times.append(time.perf_counter() - t0)
+    return statistics.median(times) * 1e6
+
+
+def _bench_memory(fn, left, right) -> int:
+    """Return peak memory allocated during a single call (bytes)."""
+    # one warm-up so any lazy init is excluded
+    fn(list(left), list(right))
+    left_copy, right_copy = list(left), list(right)
+    tracemalloc.start()
+    tracemalloc.clear_traces()
+    fn(left_copy, right_copy)
+    _, peak = tracemalloc.get_traced_memory()
+    tracemalloc.stop()
+    return peak
+
+
+# ── scenarios ─────────────────────────────────────────────────────────────────
+
+SCENARIOS = [
+    ("pure append  1 → 1  msg", 1, 1, "append"),
+    ("pure append  10 → 1  msg", 10, 1, "append"),
+    ("pure append  100 → 1  msg", 100, 1, "append"),
+    ("pure append  1000 → 1  msg", 1000, 1, "append"),
+    ("pure append  1000 → 5  msgs", 1000, 5, "append"),
+    ("update existing  100 → 1  msg", 100, 1, "update"),
+    ("remove message  100 → 1  msg", 100, 1, "remove"),
+]
+
+
+def _make_inputs(n_left, n_right, mode):
+    left = _make_messages(n_left)
+    right = _make_messages(n_right)
+    if mode == "update":
+        right[0] = AIMessage(content="updated", id=left[0].id)
+    elif mode == "remove":
+        right = [RemoveMessage(id=left[0].id)]
+    return left, right
+
+
+# ── main output ───────────────────────────────────────────────────────────────
+
+COL = 36
+
+
+def run_benchmarks() -> None:
+    print()
+    print("=" * 88)
+    print("add_messages benchmark — time (µs, median of 2 000 iterations)")
+    print("=" * 88)
+    print(f"{'Scenario':<{COL}} {'Original':>10} {'Optimized':>11} {'Speedup':>8}")
+    print("-" * 88)
+
+    for label, n_left, n_right, mode in SCENARIOS:
+        left, right = _make_inputs(n_left, n_right, mode)
+        t_orig = _bench_time(_add_messages_original, left, right)
+        t_opt = _bench_time(_add_messages_optimized, left, right)
+        print(f"{label:<{COL}} {t_orig:>10.2f} {t_opt:>11.2f} {t_orig / t_opt:>7.2f}x")
+
+    print()
+    print("=" * 88)
+    print("add_messages benchmark — peak memory allocated per call (bytes)")
+    print("=" * 88)
+    print(f"{'Scenario':<{COL}} {'Original':>10} {'Optimized':>11} {'Reduction':>10}")
+    print("-" * 88)
+
+    for label, n_left, n_right, mode in SCENARIOS:
+        left, right = _make_inputs(n_left, n_right, mode)
+        m_orig = _bench_memory(_add_messages_original, left, right)
+        m_opt = _bench_memory(_add_messages_optimized, left, right)
+        reduction = (1 - m_opt / m_orig) * 100 if m_orig else 0.0
+        print(f"{label:<{COL}} {m_orig:>10,} {m_opt:>11,} {reduction:>9.1f}%")
+
+    print()
+    print("=" * 88)
+    print("Simulated long thread — 200 steps × 2 msgs appended per step")
+    print("=" * 88)
+    for name, fn in [
+        ("original", _add_messages_original),
+        ("optimized", _add_messages_optimized),
+    ]:
+        state: list = []
+        t0 = time.perf_counter()
+        for step in range(200):
+            new_msgs = [
+                HumanMessage(content=f"step {step} human", id=str(uuid.uuid4())),
+                AIMessage(content=f"step {step} ai", id=str(uuid.uuid4())),
+            ]
+            state = fn(state, new_msgs)
+        elapsed = (time.perf_counter() - t0) * 1_000
+        print(f"  {name:<12}  {elapsed:.2f} ms  ({len(state)} messages)")
+    print()
+
+
+# ── pytest entry-points ───────────────────────────────────────────────────────
+
+
+def test_add_messages_correctness():
+    """Optimised implementation must match original output for every scenario."""
+    for label, n_left, n_right, mode in SCENARIOS:
+        left, right = _make_inputs(n_left, n_right, mode)
+        expected = _add_messages_original(list(left), list(right))
+        actual = _add_messages_optimized(list(left), list(right))
+        assert len(actual) == len(expected), f"[{label}] length mismatch"
+        for a, b in zip(actual, expected):
+            assert type(a) is type(b), f"[{label}] type mismatch"
+            assert a.id == b.id, f"[{label}] id mismatch"
+            assert a.content == b.content, f"[{label}] content mismatch"
+
+
+def test_add_messages_benchmark(capsys):
+    run_benchmarks()
+    out = capsys.readouterr().out
+    assert "Speedup" in out
+    assert "Optimized" in out
+
+
+if __name__ == "__main__":
+    run_benchmarks()

libs/langgraph/tests/test_messages_state.py

@@ -5,6 +5,7 @@ import langchain_core
 import pytest
 from langchain_core.messages import (
     AIMessage,
+    AIMessageChunk,
     AnyMessage,
     HumanMessage,
     RemoveMessage,
@@ -338,6 +339,123 @@ def test_remove_all_messages():
     ]
 
 
+def test_fast_path_preserves_format_openai():
+    """Pure-append fast path must still apply the `langchain-openai` formatter."""
+    left = [HumanMessage(content="prior", id="1")]
+    right = [
+        AIMessage(
+            content=[
+                {
+                    "type": "tool_use",
+                    "name": "foo",
+                    "input": {"bar": "baz"},
+                    "id": "t1",
+                }
+            ],
+            id="2",
+        )
+    ]
+    result = add_messages(left, right, format="langchain-openai")
+    assert isinstance(result[0], HumanMessage)
+    assert result[0].content == "prior"
+    assert isinstance(result[1], AIMessage)
+    # formatter collapses the tool_use content block into `tool_calls`
+    assert result[1].content == ""
+    assert len(result[1].tool_calls) == 1
+    assert result[1].tool_calls[0]["name"] == "foo"
+    assert result[1].tool_calls[0]["args"] == {"bar": "baz"}
+    assert result[1].tool_calls[0]["id"] == "t1"
+
+
+def test_fast_path_rejects_invalid_format():
+    """Pure-append fast path must validate the `format` arg like the slow path."""
+    left = [HumanMessage(content="prior", id="1")]
+    right = [AIMessage(content="new", id="2")]
+    with pytest.raises(ValueError, match="Unrecognized format="):
+        add_messages(left, right, format="bogus")  # type: ignore[arg-type]
+
+
+def test_left_starting_with_chunk_is_normalized():
+    """Opt-1 guard: a `BaseMessageChunk` at left[0] must trigger full conversion."""
+    chunk = AIMessageChunk(content="chunk", id="c1")
+    result = add_messages([chunk], [HumanMessage(content="h", id="h1")])
+    assert len(result) == 2
+    # chunk must be converted to a non-chunk message
+    assert type(result[0]).__name__ == "AIMessage"
+    assert result[0].id == "c1"
+    assert result[1].id == "h1"
+
+
+def test_left_as_dicts_is_normalized():
+    """Opt-1 guard: dicts at left[0] must trigger full conversion."""
+    left = [{"role": "user", "content": "hi", "id": "d1"}]
+    right = [AIMessage(content="reply", id="a1")]
+    result = add_messages(left, right)
+    assert len(result) == 2
+    assert isinstance(result[0], HumanMessage)
+    assert result[0].id == "d1"
+    assert result[0].content == "hi"
+
+
+def test_left_as_tuples_is_normalized():
+    """Opt-1 guard: tuple-form messages must trigger full conversion."""
+    left = [("user", "hi")]
+    right = [AIMessage(content="reply", id="a1")]
+    result = add_messages(left, right)
+    assert len(result) == 2
+    assert isinstance(result[0], HumanMessage)
+    # id is auto-assigned
+    assert isinstance(result[0].id, str) and UUID(result[0].id, version=4)
+
+
+def test_left_first_msg_missing_id_is_normalized():
+    """Opt-1 guard: a BaseMessage without an id at left[0] falls to the else branch."""
+    left = [HumanMessage(content="hi")]  # no id
+    right = [AIMessage(content="reply", id="a1")]
+    result = add_messages(left, right)
+    assert len(result) == 2
+    # left's id must have been auto-assigned
+    assert isinstance(result[0].id, str) and UUID(result[0].id, version=4)
+
+
+def test_duplicate_ids_in_right_with_nonempty_left():
+    """Opt-2 guard: intra-right duplicate ids must take slow path (dedup kept)."""
+    left = [HumanMessage(content="prior", id="1")]
+    right = [
+        AIMessage(content="first", id="2"),
+        AIMessage(content="second", id="2"),
+    ]
+    result = add_messages(left, right)
+    assert len(result) == 2
+    assert result[0].id == "1"
+    assert result[1].id == "2"
+    assert result[1].content == "second"
+
+
+def test_right_with_none_ids_pure_append():
+    """Fast path still correct when right entries start with id=None (fresh uuids assigned)."""
+    left = [HumanMessage(content="prior", id="1")]
+    right = [AIMessage(content="a"), AIMessage(content="b")]
+    result = add_messages(left, right)
+    assert len(result) == 3
+    assert result[0].id == "1"
+    for m in result[1:]:
+        assert isinstance(m.id, str) and UUID(m.id, version=4)
+    # fresh uuids must be distinct
+    assert result[1].id != result[2].id
+
+
+def test_fast_path_returns_fresh_list():
+    """Fast path must return a new list object (not mutate or alias left)."""
+    left = [HumanMessage(content="prior", id="1")]
+    right = [AIMessage(content="new", id="2")]
+    result = add_messages(left, right)
+    assert result is not left
+    # left must be untouched
+    assert len(left) == 1
+    assert left[0].id == "1"
+
+
 def test_push_messages_in_graph():
     class MessagesState(TypedDict):
         messages: Annotated[list[AnyMessage], add_messages]

libs/langgraph/uv.lock

@@ -1348,7 +1348,7 @@ wheels = [
 
 [[package]]
 name = "langchain-core"
-version = "1.3.1"
+version = "1.3.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "jsonpatch" },
@@ -1360,14 +1360,14 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/f4/fe/abeae8d0d2899e191d67c6c7f065f7e52a953f30b21ef327fa49084e4af9/langchain_core-1.3.1.tar.gz", hash = "sha256:41b384055799f93f34520df6bf7b80e2e5e23153cdfd46874251c6c9916ea030", size = 862403, upload-time = "2026-04-23T18:54:01.857Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/92/fe/20190232d9b513242899dbb0c2bb77e31b4d61e343743adbe90ebc2603d2/langchain_core-1.3.0.tar.gz", hash = "sha256:14a39f528bf459aa3aa40d0a7f7f1bae7520d435ef991ae14a4ceb74d8c49046", size = 860755, upload-time = "2026-04-17T14:51:38.298Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/a1/c2/8493be505921857988db068b7c027f28a9b1587b4425c6a32b1221c9c9fe/langchain_core-1.3.1-py3-none-any.whl", hash = "sha256:8b13d19d3bed3f4768df12c7f6932d2ada715f3ac9fd020c63d28c693968269e", size = 515879, upload-time = "2026-04-23T18:53:59.94Z" },
+    { url = "https://files.pythonhosted.org/packages/f8/e2/dbfa347aa072a6dc4cd38d6f9ebfc730b4c14c258c47f480f4c5c546f177/langchain_core-1.3.0-py3-none-any.whl", hash = "sha256:baf16ee028475df177b9ab8869a751c79406d64a6f12125b93802991b566cced", size = 515140, upload-time = "2026-04-17T14:51:36.274Z" },
 ]
 
 [[package]]
 name = "langgraph"
-version = "1.1.10"
+version = "1.1.9"
 source = { editable = "." }
 dependencies = [
     { name = "langchain-core" },
@@ -1548,7 +1548,7 @@ wheels = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "../checkpoint" }
 dependencies = [
     { name = "langchain-core" },
@@ -1742,7 +1742,7 @@ test = [
 
 [[package]]
 name = "langgraph-prebuilt"
-version = "1.0.11"
+version = "1.0.10"
 source = { editable = "../prebuilt" }
 dependencies = [
     { name = "langchain-core" },
@@ -1751,7 +1751,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.1" },
+    { name = "langchain-core", specifier = ">=1.0.0" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
 ]
 
@@ -2140,7 +2140,7 @@ wheels = [
 
 [[package]]
 name = "nbconvert"
-version = "7.17.1"
+version = "7.17.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "beautifulsoup4" },
@@ -2158,9 +2158,9 @@ dependencies = [
     { name = "pygments" },
     { name = "traitlets" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/01/b1/708e53fe2e429c103c6e6e159106bcf0357ac41aa4c28772bd8402339051/nbconvert-7.17.1.tar.gz", hash = "sha256:34d0d0a7e73ce3cbab6c5aae8f4f468797280b01fd8bd2ca746da8569eddd7d2", size = 865311, upload-time = "2026-04-08T00:44:14.914Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/38/47/81f886b699450d0569f7bc551df2b1673d18df7ff25cc0c21ca36ed8a5ff/nbconvert-7.17.0.tar.gz", hash = "sha256:1b2696f1b5be12309f6c7d707c24af604b87dfaf6d950794c7b07acab96dda78", size = 862855, upload-time = "2026-01-29T16:37:48.478Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/67/f8/bb0a9d5f46819c821dc1f004aa2cc29b1d91453297dbf5ff20470f00f193/nbconvert-7.17.1-py3-none-any.whl", hash = "sha256:aa85c087b435e7bf1ffd03319f658e285f2b89eccab33bc1ba7025495ab3e7c8", size = 261927, upload-time = "2026-04-08T00:44:12.845Z" },
+    { url = "https://files.pythonhosted.org/packages/0d/4b/8d5f796a792f8a25f6925a96032f098789f448571eb92011df1ae59e8ea8/nbconvert-7.17.0-py3-none-any.whl", hash = "sha256:4f99a63b337b9a23504347afdab24a11faa7d86b405e5c8f9881cd313336d518", size = 261510, upload-time = "2026-01-29T16:37:46.322Z" },
 ]
 
 [[package]]
@@ -3018,11 +3018,11 @@ wheels = [
 
 [[package]]
 name = "python-dotenv"
-version = "1.2.2"
+version = "1.2.1"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/82/ed/0301aeeac3e5353ef3d94b6ec08bbcabd04a72018415dcb29e588514bba8/python_dotenv-1.2.2.tar.gz", hash = "sha256:2c371a91fbd7ba082c2c1dc1f8bf89ca22564a087c2c287cd9b662adde799cf3", size = 50135, upload-time = "2026-03-01T16:00:26.196Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/f0/26/19cadc79a718c5edbec86fd4919a6b6d3f681039a2f6d66d14be94e75fb9/python_dotenv-1.2.1.tar.gz", hash = "sha256:42667e897e16ab0d66954af0e60a9caa94f0fd4ecf3aaf6d2d260eec1aa36ad6", size = 44221, upload-time = "2025-10-26T15:12:10.434Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/0b/d7/1959b9648791274998a9c3526f6d0ec8fd2233e4d4acce81bbae76b44b2a/python_dotenv-1.2.2-py3-none-any.whl", hash = "sha256:1d8214789a24de455a8b8bd8ae6fe3c6b69a5e3d64aa8a8e5d68e694bbcb285a", size = 22101, upload-time = "2026-03-01T16:00:25.09Z" },
+    { url = "https://files.pythonhosted.org/packages/14/1b/a298b06749107c305e1fe0f814c6c74aea7b2f1e10989cb30f544a1b3253/python_dotenv-1.2.1-py3-none-any.whl", hash = "sha256:b81ee9561e9ca4004139c6cbba3a238c32b03e4894671e181b671e8cb8425d61", size = 21230, upload-time = "2025-10-26T15:12:09.109Z" },
 ]
 
 [[package]]

libs/prebuilt/langgraph/prebuilt/tool_node.py

@@ -82,7 +82,6 @@ from langchain_core.tools.base import (
     _is_injected_arg_type,
     get_all_basemodel_annotations,
 )
-from langgraph._internal._constants import CONF, CONFIG_KEY_READ
 from langgraph._internal._runnable import RunnableCallable
 from langgraph.errors import GraphBubbleUp
 from langgraph.graph.message import REMOVE_ALL_MESSAGES
@@ -801,7 +800,7 @@ class ToolNode(RunnableCallable):
         # Construct ToolRuntime instances at the top level for each tool call
         tool_runtimes = []
         for call, cfg in zip(tool_calls, config_list, strict=False):
-            state = self._extract_state(input, cfg)
+            state = self._extract_state(input)
             tool_runtime = ToolRuntime(
                 state=state,
                 tool_call_id=call["id"],
@@ -836,7 +835,7 @@ class ToolNode(RunnableCallable):
         # Construct ToolRuntime instances at the top level for each tool call
         tool_runtimes = []
         for call, cfg in zip(tool_calls, config_list, strict=False):
-            state = self._extract_state(input, cfg)
+            state = self._extract_state(input)
             tool_runtime = ToolRuntime(
                 state=state,
                 tool_call_id=call["id"],
@@ -860,30 +859,14 @@ class ToolNode(RunnableCallable):
 
     def _combine_tool_outputs(
         self,
-        outputs: list[ToolMessage | Command | list[ToolMessage | Command]],
+        outputs: list[ToolMessage | Command],
         input_type: Literal["list", "dict", "tool_calls"],
     ) -> list[Command | list[ToolMessage] | dict[str, list[ToolMessage]]]:
-        # Flatten list entries from tools that returned multiple items
-        flat_outputs: list[ToolMessage | Command]
-        if any(isinstance(output, list) for output in outputs):
-            flat_outputs = []
-            for output in outputs:
-                if isinstance(output, list):
-                    flat_outputs.extend(output)
-                else:
-                    flat_outputs.append(output)
-        else:
-            flat_outputs = cast("list[ToolMessage | Command]", outputs)
-
         # preserve existing behavior for non-command tool outputs for backwards
         # compatibility
-        if not any(isinstance(output, Command) for output in flat_outputs):
+        if not any(isinstance(output, Command) for output in outputs):
             # TypedDict, pydantic, dataclass, etc. should all be able to load from dict
-            return (
-                flat_outputs
-                if input_type == "list"
-                else {self._messages_key: flat_outputs}
-            )
+            return outputs if input_type == "list" else {self._messages_key: outputs}
 
         # LangGraph will automatically handle list of Command and non-command node
         # updates
@@ -893,7 +876,7 @@ class ToolNode(RunnableCallable):
 
         # combine all parent commands with goto into a single parent command
         parent_command: Command | None = None
-        for output in flat_outputs:
+        for output in outputs:
             if isinstance(output, Command):
                 if (
                     output.graph is Command.PARENT
@@ -923,7 +906,7 @@ class ToolNode(RunnableCallable):
         request: ToolCallRequest,
         input_type: Literal["list", "dict", "tool_calls"],
         config: RunnableConfig,
-    ) -> ToolMessage | Command | list[Command | ToolMessage]:
+    ) -> ToolMessage | Command:
         """Execute tool call with configured error handling.
 
         Args:
@@ -932,7 +915,7 @@ class ToolNode(RunnableCallable):
             config: Runnable configuration.
 
         Returns:
-            ToolMessage, Command, or list of Command/ToolMessage.
+            ToolMessage or Command.
 
         Raises:
             Exception: If tool fails and handle_tool_errors is False.
@@ -964,11 +947,6 @@ class ToolNode(RunnableCallable):
                     call["name"], exc, call["args"], filtered_errors
                 ) from exc
 
-            # Inside try so validation errors route through _handle_tool_errors
-            return self._normalize_tool_response(
-                response, request.tool_call, input_type
-            )
-
         # GraphInterrupt is a special exception that will always be raised.
         # It can be triggered in the following scenarios,
         # Where GraphInterrupt(GraphBubbleUp) is raised from an `interrupt` invocation
@@ -1010,12 +988,23 @@ class ToolNode(RunnableCallable):
                 status="error",
             )
 
+        # Process successful response
+        if isinstance(response, Command):
+            # Validate Command before returning to handler
+            return self._validate_tool_command(response, request.tool_call, input_type)
+        if isinstance(response, ToolMessage):
+            response.content = cast("str | list", msg_content_output(response.content))
+            return response
+
+        msg = f"Tool {call['name']} returned unexpected type: {type(response)}"
+        raise TypeError(msg)
+
     def _run_one(
         self,
         call: ToolCall,
         input_type: Literal["list", "dict", "tool_calls"],
         tool_runtime: ToolRuntime,
-    ) -> ToolMessage | Command | list[Command | ToolMessage]:
+    ) -> ToolMessage | Command:
         """Execute single tool call with wrap_tool_call wrapper if configured.
 
         Args:
@@ -1070,7 +1059,7 @@ class ToolNode(RunnableCallable):
         request: ToolCallRequest,
         input_type: Literal["list", "dict", "tool_calls"],
         config: RunnableConfig,
-    ) -> ToolMessage | Command | list[Command | ToolMessage]:
+    ) -> ToolMessage | Command:
         """Execute tool call asynchronously with configured error handling.
 
         Args:
@@ -1079,7 +1068,7 @@ class ToolNode(RunnableCallable):
             config: Runnable configuration.
 
         Returns:
-            ToolMessage, Command, or list of Command/ToolMessage.
+            ToolMessage or Command.
 
         Raises:
             Exception: If tool fails and handle_tool_errors is False.
@@ -1111,11 +1100,6 @@ class ToolNode(RunnableCallable):
                     call["name"], exc, call["args"], filtered_errors
                 ) from exc
 
-            # Inside try so validation errors route through _handle_tool_errors
-            return self._normalize_tool_response(
-                response, request.tool_call, input_type
-            )
-
         # GraphInterrupt is a special exception that will always be raised.
         # It can be triggered in the following scenarios,
         # Where GraphInterrupt(GraphBubbleUp) is raised from an `interrupt` invocation
@@ -1157,12 +1141,23 @@ class ToolNode(RunnableCallable):
                 status="error",
             )
 
+        # Process successful response
+        if isinstance(response, Command):
+            # Validate Command before returning to handler
+            return self._validate_tool_command(response, request.tool_call, input_type)
+        if isinstance(response, ToolMessage):
+            response.content = cast("str | list", msg_content_output(response.content))
+            return response
+
+        msg = f"Tool {call['name']} returned unexpected type: {type(response)}"
+        raise TypeError(msg)
+
     async def _arun_one(
         self,
         call: ToolCall,
         input_type: Literal["list", "dict", "tool_calls"],
         tool_runtime: ToolRuntime,
-    ) -> ToolMessage | Command | list[Command | ToolMessage]:
+    ) -> ToolMessage | Command:
         """Execute single tool call asynchronously with awrap_tool_call wrapper if configured.
 
         Args:
@@ -1278,37 +1273,18 @@ class ToolNode(RunnableCallable):
         return None
 
     def _extract_state(
-        self,
-        input: list[AnyMessage] | dict[str, Any] | BaseModel,
-        config: RunnableConfig,
+        self, input: list[AnyMessage] | dict[str, Any] | BaseModel
     ) -> list[AnyMessage] | dict[str, Any] | BaseModel:
-        """Extract state from input.
+        """Extract state from input, handling ToolCallWithContext if present.
 
-        Three input shapes:
+        Args:
+            input: The input which may be raw state or ToolCallWithContext.
 
-        - `ToolCallWithContext` dict — legacy Send payload carrying an inlined
-          state snapshot; return `input["state"]`.
-        - list of `ToolCall` dicts — new Send payload with no inlined state;
-          hydrate state from channels via `CONFIG_KEY_READ`.
-        - regular graph state (dict/list/BaseModel) — return `input` as-is.
+        Returns:
+            The actual state to pass to wrap_tool_call wrappers.
         """
         if isinstance(input, dict) and input.get("__type") == "tool_call_with_context":
             return input["state"]
-        if (
-            isinstance(input, list)
-            and input
-            and isinstance(input[-1], dict)
-            and input[-1].get("type") == "tool_call"
-        ):
-            read = config.get(CONF, {}).get(CONFIG_KEY_READ)
-            if read is None:
-                return {}
-            # Pregel installs CONFIG_KEY_READ as
-            # `functools.partial(local_read, scratchpad, channels, managed, task)`.
-            # Match the previous inlined-state contract by reading channels only;
-            # managed values have their own injection path (`ToolRuntime.context`).
-            channels = read.args[1]
-            return cast("dict[str, Any]", read(list(channels), True))
         return input
 
     def _inject_tool_args(
@@ -1428,84 +1404,11 @@ class ToolNode(RunnableCallable):
         tool_call_copy["args"] = {**stripped_args, **injected_args}
         return tool_call_copy
 
-    def _normalize_tool_response(
-        self,
-        response: Any,
-        tool_call: ToolCall,
-        input_type: Literal["list", "dict", "tool_calls"],
-    ) -> ToolMessage | Command | list[Command | ToolMessage]:
-        """Validate and normalize a tool's raw return value."""
-        if isinstance(response, Command):
-            return self._validate_tool_command(response, tool_call, input_type)
-        if isinstance(response, ToolMessage):
-            response.content = cast("str | list", msg_content_output(response.content))
-            return response
-        if isinstance(response, list):
-            if all(isinstance(r, (Command, ToolMessage)) for r in response):
-                return self._validate_tool_command_list(response, tool_call, input_type)
-            msg = (
-                f"Tool {tool_call['name']} returned a list with invalid element "
-                "types: expected all Command or ToolMessage"
-            )
-            raise TypeError(msg)
-        msg = f"Tool {tool_call['name']} returned unexpected type: {type(response)}"
-        raise TypeError(msg)
-
-    def _validate_tool_command_list(
-        self,
-        response: list[Command | ToolMessage],
-        tool_call: ToolCall,
-        input_type: Literal["list", "dict", "tool_calls"],
-    ) -> list[Command | ToolMessage]:
-        """Validate a list of Command/ToolMessage returned by a single tool call.
-
-        Requires exactly one terminating ToolMessage (matching the outer tool_call_id)
-        across the list — either as a top-level element or nested in a
-        Command.update["messages"].
-        """
-        expected_id = tool_call["id"]
-
-        terminator_count = 0
-        for item in response:
-            if isinstance(item, ToolMessage):
-                if item.tool_call_id == expected_id:
-                    terminator_count += 1
-            elif isinstance(item, Command) and isinstance(item.update, dict):
-                for msg in item.update.get(self._messages_key, []):
-                    if isinstance(msg, ToolMessage) and msg.tool_call_id == expected_id:
-                        terminator_count += 1
-
-        if terminator_count != 1:
-            msg = (
-                f"Tool {tool_call['name']} returned a list with "
-                f"{terminator_count} messages bound to tool_call_id "
-                f"{expected_id!r}; expected exactly one terminating ToolMessage."
-            )
-            raise ValueError(msg)
-
-        # Per-Command normalization still runs, but the list-level count above
-        # already guarantees exactly one terminator, so individual Commands may
-        # lack one.
-        validated: list[Command | ToolMessage] = []
-        for item in response:
-            if isinstance(item, Command):
-                validated.append(
-                    self._validate_tool_command(
-                        item, tool_call, input_type, require_terminator=False
-                    )
-                )
-            else:
-                item.content = cast("str | list", msg_content_output(item.content))
-                validated.append(item)
-        return validated
-
     def _validate_tool_command(
         self,
         command: Command,
         call: ToolCall,
         input_type: Literal["list", "dict", "tool_calls"],
-        *,
-        require_terminator: bool = True,
     ) -> Command:
         if isinstance(command.update, dict):
             # input type is dict when ToolNode is invoked with a dict input
@@ -1555,11 +1458,7 @@ class ToolNode(RunnableCallable):
 
         # validate that we always have a ToolMessage matching the tool call in
         # Command.update if command is sent to the CURRENT graph
-        if (
-            require_terminator
-            and updated_command.graph is None
-            and not has_matching_tool_message
-        ):
+        if updated_command.graph is None and not has_matching_tool_message:
             example_update = (
                 '`Command(update={"messages": '
                 '[ToolMessage("Success", tool_call_id=tool_call_id), ...]}, ...)`'

libs/prebuilt/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "langgraph-prebuilt"
-version = "1.0.11"
+version = "1.0.10"
 description = "Library with high-level APIs for creating and executing LangGraph agents and tools."
 authors = []
 requires-python = ">=3.10"
@@ -25,7 +25,7 @@ classifiers = [
 ]
 dependencies = [
     "langgraph-checkpoint>=2.1.0,<5.0.0",
-    "langchain-core>=1.3.1",
+    "langchain-core>=1.0.0",
 ]
 
 [project.urls]

libs/prebuilt/tests/test_on_tool_call.py

@@ -1320,98 +1320,6 @@ async def test_state_extraction_with_tool_call_with_context_async() -> None:
     assert "tool_call" not in state_seen[0]
 
 
-def _config_with_channel_read(
-    channel_values: dict[str, object],
-    store: BaseStore | None = None,
-) -> RunnableConfig:
-    """Build a config that mimics `CONFIG_KEY_READ` as Pregel installs it.
-
-    Pregel always installs a `functools.partial(local_read, scratchpad,
-    channels, managed, task)`, and `ToolNode` introspects that partial to
-    learn channel names. The stub matches the shape: partial whose second and
-    third positional args are `channels` and `managed` mappings.
-    """
-    import functools
-
-    channels_stub = {k: None for k in channel_values}
-    managed_stub: dict[str, object] = {}
-
-    # Shape matches pregel's real partial:
-    # functools.partial(local_read, scratchpad, channels, managed, task)
-    def _read(scratchpad, channels, managed, task, select, fresh):  # noqa: ARG001
-        if isinstance(select, str):
-            return channel_values[select]
-        return {k: channel_values[k] for k in select if k in channel_values}
-
-    read = functools.partial(_read, None, channels_stub, managed_stub, None)
-    cfg = _create_config_with_runtime(store)
-    cfg["configurable"]["__pregel_read"] = read
-    return cfg
-
-
-def test_list_form_send_hydrates_state_from_channel_read() -> None:
-    """Send('tools', [tool_call]) with no inlined state should hydrate
-    ToolRuntime.state from CONFIG_KEY_READ (full state read)."""
-    state_seen = []
-
-    def state_inspector_handler(
-        request: ToolCallRequest,
-        execute: Callable[[ToolCallRequest], ToolMessage | Command],
-    ) -> ToolMessage | Command:
-        state_seen.append(request.state)
-        return execute(request)
-
-    channel_values = {
-        "messages": [AIMessage("from channels")],
-        "files": {"/a.md": "body"},
-    }
-
-    tool_node = ToolNode([add], wrap_tool_call=state_inspector_handler)
-
-    tool_call: ToolCall = {
-        "name": "add",
-        "args": {"a": 1, "b": 2},
-        "id": "call_1",
-        "type": "tool_call",
-    }
-
-    tool_node.invoke([tool_call], config=_config_with_channel_read(channel_values))
-
-    assert len(state_seen) == 1
-    got = state_seen[0]
-    assert got == channel_values
-    assert "messages" in got and "files" in got
-
-
-async def test_list_form_send_hydrates_state_async() -> None:
-    state_seen = []
-
-    def state_inspector_handler(
-        request: ToolCallRequest,
-        execute: Callable[[ToolCallRequest], ToolMessage | Command],
-    ) -> ToolMessage | Command:
-        state_seen.append(request.state)
-        return execute(request)
-
-    channel_values = {"messages": [AIMessage("from channels")], "files": {}}
-
-    tool_node = ToolNode([add], wrap_tool_call=state_inspector_handler)
-
-    tool_call: ToolCall = {
-        "name": "add",
-        "args": {"a": 1, "b": 2},
-        "id": "call_1",
-        "type": "tool_call",
-    }
-
-    await tool_node.ainvoke(
-        [tool_call], config=_config_with_channel_read(channel_values)
-    )
-
-    assert len(state_seen) == 1
-    assert state_seen[0] == channel_values
-
-
 def test_tool_call_request_is_frozen() -> None:
     """Test that ToolCallRequest raises deprecation warnings on direct attribute reassignment."""
     tool_call: ToolCall = {"name": "add", "args": {"a": 1, "b": 2}, "id": "call_1"}

libs/prebuilt/tests/test_tool_node.py

@@ -2223,195 +2223,3 @@ def test_tool_node_injected_state_overwrites_llm_value() -> None:
     )
     tool_message = result["messages"][-1]
     assert tool_message.content == "PUBLIC_DATA"
-
-
-class _ReturningTool(BaseTool):
-    """A tool that returns a configured value verbatim."""
-
-    name: str = "list_tool"
-    description: str = "Returns a configured value"
-    return_value: Any = None
-
-    def _run(self, **kwargs: Any) -> Any:
-        return self.return_value
-
-    async def _arun(self, **kwargs: Any) -> Any:
-        return self.return_value
-
-
-def _list_tool_call(outer_id: str = "call-1") -> dict[str, Any]:
-    return {"name": "list_tool", "args": {}, "id": outer_id, "type": "tool_call"}
-
-
-def _invoke_returning(
-    return_value: Any,
-    *,
-    outer_id: str = "call-1",
-    handle_tool_errors: bool = True,
-) -> Any:
-    node = ToolNode(
-        [_ReturningTool(return_value=return_value)],
-        handle_tool_errors=handle_tool_errors,
-    )
-    return node.invoke(
-        {"messages": [AIMessage("", tool_calls=[_list_tool_call(outer_id)])]},
-        config=_create_config_with_runtime(),
-    )
-
-
-def test_tool_node_list_return_command_and_tool_message() -> None:
-    """Valid: tool returns [Command(update={...}), ToolMessage(...)]."""
-    outer_id = "call-1"
-    result = _invoke_returning(
-        [
-            Command(update={"foo": "bar"}),
-            ToolMessage(content="done", tool_call_id=outer_id),
-        ]
-    )
-    assert isinstance(result, list)
-    commands = [r for r in result if isinstance(r, Command)]
-    assert len(commands) == 1
-    assert commands[0].update == {"foo": "bar"}
-    non_commands = [r for r in result if not isinstance(r, Command)]
-    assert len(non_commands) == 1
-    assert isinstance(non_commands[0], dict)
-    msgs = non_commands[0]["messages"]
-    assert len(msgs) == 1
-    assert isinstance(msgs[0], ToolMessage)
-    assert msgs[0].content == "done"
-    assert msgs[0].tool_call_id == outer_id
-
-
-def test_tool_node_list_return_nested_terminator() -> None:
-    """Valid: terminator nested inside Command.update['messages']."""
-    outer_id = "call-1"
-    result = _invoke_returning(
-        [
-            Command(update={"foo": "bar"}),
-            Command(
-                update={
-                    "messages": [ToolMessage(content="done", tool_call_id=outer_id)]
-                }
-            ),
-        ]
-    )
-    assert isinstance(result, list)
-    commands = [r for r in result if isinstance(r, Command)]
-    assert len(commands) == 2
-    updates = [c.update for c in commands]
-    assert {"foo": "bar"} in updates
-    msgs_update = next(u for u in updates if "messages" in (u or {}))
-    assert any(
-        isinstance(m, ToolMessage) and m.tool_call_id == outer_id
-        for m in msgs_update["messages"]
-    )
-
-
-def test_tool_node_list_return_parent_goto_with_terminator() -> None:
-    """Valid: [Command(graph=PARENT, goto=[Send(...)]), ToolMessage(...)]."""
-    outer_id = "call-1"
-    result = _invoke_returning(
-        [
-            Command(graph=Command.PARENT, goto=[Send("child", {})]),
-            ToolMessage(content="ok", tool_call_id=outer_id),
-        ]
-    )
-    assert isinstance(result, list)
-    parent_cmds = [
-        r for r in result if isinstance(r, Command) and r.graph is Command.PARENT
-    ]
-    assert len(parent_cmds) == 1
-    assert isinstance(parent_cmds[0].goto, list)
-    assert any(isinstance(s, Send) for s in parent_cmds[0].goto)
-    non_commands = [r for r in result if not isinstance(r, Command)]
-    assert len(non_commands) == 1
-
-
-def test_tool_node_list_return_no_terminator_raises() -> None:
-    """Invalid: list with no terminating ToolMessage."""
-    with pytest.raises(ValueError, match="0 messages bound to tool_call_id"):
-        _invoke_returning([Command(update={"foo": "bar"})], handle_tool_errors=False)
-
-
-def test_tool_node_list_return_multiple_terminators_raises() -> None:
-    """Invalid: list with two terminating ToolMessages."""
-    outer_id = "call-1"
-    with pytest.raises(ValueError, match="2 messages bound to tool_call_id"):
-        _invoke_returning(
-            [
-                ToolMessage(content="a", tool_call_id=outer_id),
-                ToolMessage(content="b", tool_call_id=outer_id),
-            ],
-            handle_tool_errors=False,
-        )
-
-
-def test_tool_node_list_return_validation_error_handled() -> None:
-    """handle_tool_errors=True converts validation errors to an error ToolMessage."""
-    result = _invoke_returning([Command(update={"foo": "bar"})])
-    assert isinstance(result, dict)
-    msg = result["messages"][0]
-    assert isinstance(msg, ToolMessage)
-    assert msg.status == "error"
-    assert "0 messages bound to tool_call_id" in msg.content
-
-
-async def test_tool_node_list_return_async_smoke() -> None:
-    """Async path parallels sync for the happy case."""
-    outer_id = "call-1"
-    node = ToolNode(
-        [
-            _ReturningTool(
-                return_value=[
-                    Command(update={"foo": "bar"}),
-                    ToolMessage(content="done", tool_call_id=outer_id),
-                ]
-            )
-        ]
-    )
-    result = await node.ainvoke(
-        {"messages": [AIMessage("", tool_calls=[_list_tool_call(outer_id)])]},
-        config=_create_config_with_runtime(),
-    )
-    assert isinstance(result, list)
-    commands = [r for r in result if isinstance(r, Command)]
-    assert len(commands) == 1 and commands[0].update == {"foo": "bar"}
-
-
-def test_tool_node_list_return_mixed_with_regular_tool() -> None:
-    """List-returning tool and a regular tool dispatched from the same AIMessage."""
-    list_tool_id = "call-list"
-    regular_tool_id = "call-regular"
-    list_tool = _ReturningTool(
-        return_value=[
-            Command(update={"foo": "bar"}),
-            ToolMessage(content="list done", tool_call_id=list_tool_id),
-        ]
-    )
-
-    def regular_tool(x: int) -> str:
-        """A normal tool."""
-        return f"regular: {x}"
-
-    tool_calls = [
-        {"name": "list_tool", "args": {}, "id": list_tool_id, "type": "tool_call"},
-        {
-            "name": "regular_tool",
-            "args": {"x": 7},
-            "id": regular_tool_id,
-            "type": "tool_call",
-        },
-    ]
-    node = ToolNode([list_tool, regular_tool])
-    result = node.invoke(
-        {"messages": [AIMessage("", tool_calls=tool_calls)]},
-        config=_create_config_with_runtime(),
-    )
-    assert isinstance(result, list)
-    commands = [r for r in result if isinstance(r, Command)]
-    assert len(commands) == 1
-    assert commands[0].update == {"foo": "bar"}
-    all_msgs = [m for r in result if isinstance(r, dict) for m in r["messages"]]
-    tool_call_ids = {m.tool_call_id for m in all_msgs}
-    assert list_tool_id in tool_call_ids
-    assert regular_tool_id in tool_call_ids

libs/prebuilt/uv.lock

@@ -249,7 +249,7 @@ wheels = [
 
 [[package]]
 name = "langchain-core"
-version = "1.3.1"
+version = "1.3.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "jsonpatch" },
@@ -261,14 +261,14 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/f4/fe/abeae8d0d2899e191d67c6c7f065f7e52a953f30b21ef327fa49084e4af9/langchain_core-1.3.1.tar.gz", hash = "sha256:41b384055799f93f34520df6bf7b80e2e5e23153cdfd46874251c6c9916ea030", size = 862403, upload-time = "2026-04-23T18:54:01.857Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/92/fe/20190232d9b513242899dbb0c2bb77e31b4d61e343743adbe90ebc2603d2/langchain_core-1.3.0.tar.gz", hash = "sha256:14a39f528bf459aa3aa40d0a7f7f1bae7520d435ef991ae14a4ceb74d8c49046", size = 860755, upload-time = "2026-04-17T14:51:38.298Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/a1/c2/8493be505921857988db068b7c027f28a9b1587b4425c6a32b1221c9c9fe/langchain_core-1.3.1-py3-none-any.whl", hash = "sha256:8b13d19d3bed3f4768df12c7f6932d2ada715f3ac9fd020c63d28c693968269e", size = 515879, upload-time = "2026-04-23T18:53:59.94Z" },
+    { url = "https://files.pythonhosted.org/packages/f8/e2/dbfa347aa072a6dc4cd38d6f9ebfc730b4c14c258c47f480f4c5c546f177/langchain_core-1.3.0-py3-none-any.whl", hash = "sha256:baf16ee028475df177b9ab8869a751c79406d64a6f12125b93802991b566cced", size = 515140, upload-time = "2026-04-17T14:51:36.274Z" },
 ]
 
 [[package]]
 name = "langgraph"
-version = "1.1.10"
+version = "1.1.9"
 source = { editable = "../langgraph" }
 dependencies = [
     { name = "langchain-core" },
@@ -352,7 +352,7 @@ test = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "../checkpoint" }
 dependencies = [
     { name = "langchain-core" },
@@ -490,7 +490,7 @@ test = [
 
 [[package]]
 name = "langgraph-prebuilt"
-version = "1.0.11"
+version = "1.0.10"
 source = { editable = "." }
 dependencies = [
     { name = "langchain-core" },
@@ -535,7 +535,7 @@ test = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.1" },
+    { name = "langchain-core", specifier = ">=1.0.0" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
 ]
 

libs/sdk-py/uv.lock

@@ -262,7 +262,7 @@ wheels = [
 
 [[package]]
 name = "langchain-core"
-version = "1.3.1"
+version = "1.3.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "jsonpatch" },
@@ -274,14 +274,14 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/f4/fe/abeae8d0d2899e191d67c6c7f065f7e52a953f30b21ef327fa49084e4af9/langchain_core-1.3.1.tar.gz", hash = "sha256:41b384055799f93f34520df6bf7b80e2e5e23153cdfd46874251c6c9916ea030", size = 862403, upload-time = "2026-04-23T18:54:01.857Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/92/fe/20190232d9b513242899dbb0c2bb77e31b4d61e343743adbe90ebc2603d2/langchain_core-1.3.0.tar.gz", hash = "sha256:14a39f528bf459aa3aa40d0a7f7f1bae7520d435ef991ae14a4ceb74d8c49046", size = 860755, upload-time = "2026-04-17T14:51:38.298Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/a1/c2/8493be505921857988db068b7c027f28a9b1587b4425c6a32b1221c9c9fe/langchain_core-1.3.1-py3-none-any.whl", hash = "sha256:8b13d19d3bed3f4768df12c7f6932d2ada715f3ac9fd020c63d28c693968269e", size = 515879, upload-time = "2026-04-23T18:53:59.94Z" },
+    { url = "https://files.pythonhosted.org/packages/f8/e2/dbfa347aa072a6dc4cd38d6f9ebfc730b4c14c258c47f480f4c5c546f177/langchain_core-1.3.0-py3-none-any.whl", hash = "sha256:baf16ee028475df177b9ab8869a751c79406d64a6f12125b93802991b566cced", size = 515140, upload-time = "2026-04-17T14:51:36.274Z" },
 ]
 
 [[package]]
 name = "langgraph"
-version = "1.1.10"
+version = "1.1.9"
 source = { editable = "../langgraph" }
 dependencies = [
     { name = "langchain-core" },
@@ -365,7 +365,7 @@ test = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.3"
+version = "4.0.2"
 source = { editable = "../checkpoint" }
 dependencies = [
     { name = "langchain-core" },
@@ -413,7 +413,7 @@ test = [
 
 [[package]]
 name = "langgraph-prebuilt"
-version = "1.0.11"
+version = "1.0.10"
 source = { editable = "../prebuilt" }
 dependencies = [
     { name = "langchain-core" },
@@ -422,7 +422,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.1" },
+    { name = "langchain-core", specifier = ">=1.0.0" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
 ]