feat(cli): support layer mode from environment

Add a repository-wide `<corridor>` block to `AGENTS.md` requiring agents
to plan first and run Corridor `analyzePlan` before generating or
modifying code. The tags are explicit and balanced so Corridor-specific
guidance remains scoped.

Validation: `git diff --check` and a tag-balance assertion.

---------

Co-authored-by: langsmith-fleet[bot] <langsmith-fleet[bot]@users.noreply.github.com>

.gitignore

@@ -77,6 +77,10 @@ __pypackages__/
 # Environments
 .env
 .envrc
+*.crt
+*.key
+*.pem
+credentials.json
 .venv
 .venvs
 env/
@@ -98,6 +102,7 @@ dmypy.json
 
 .vercel
 .turbo
+node_modules/
 .editorconfig
 .scratch
 .worktrees/

AGENTS.md

@@ -2,6 +2,14 @@
 
 This repository is a monorepo. Each library lives in a subdirectory under `libs/`.
 
+<corridor>
+
+## Corridor security analysis
+
+When Corridor's `analyzePlan` tool is available, create a plan and use the tool to analyze it before generating or modifying code. Apply the resulting security guidance before writing code.
+
+</corridor>
+
 When you modify code in any library, run the following commands in that library's directory before creating a pull request:
 
 - `make format` – run code formatters

CLAUDE.md

@@ -2,6 +2,14 @@
 
 This repository is a monorepo. Each library lives in a subdirectory under `libs/`.
 
+<corridor>
+
+## Corridor security analysis
+
+Before generating or modifying code, create a plan and use Corridor's `analyzePlan` tool to analyze it. Apply the resulting security guidance before writing code.
+
+</corridor>
+
 When you modify code in any library, run the following commands in that library's directory before creating a pull request:
 
 - `make format` – run code formatters

libs/checkpoint-postgres/langgraph/store/postgres/base.py

@@ -7,7 +7,7 @@ import logging
 import re
 import threading
 from collections import defaultdict
-from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
+from collections.abc import Callable, Iterable, Iterator, Sequence
 from contextlib import contextmanager
 from datetime import datetime
 from typing import (
@@ -354,7 +354,7 @@ class BasePostgresStore(Generic[C]):
                     (
                         _namespace_to_text(op.namespace),
                         op.key,
-                        Jsonb(dict(cast(Mapping[str, Any], op.value))),
+                        Jsonb(cast(dict, op.value)),
                     )
                 )
                 if op.ttl is not None:

libs/checkpoint-sqlite/langgraph/store/sqlite/base.py

@@ -7,7 +7,7 @@ import re
 import sqlite3
 import threading
 from collections import defaultdict
-from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
+from collections.abc import Callable, Iterable, Iterator, Sequence
 from contextlib import contextmanager
 from typing import Any, Literal, NamedTuple, cast
 
@@ -387,7 +387,7 @@ class BaseSqliteStore:
                     [
                         _namespace_to_text(op.namespace),
                         op.key,
-                        orjson.dumps(dict(cast(Mapping[str, Any], op.value))),
+                        orjson.dumps(cast(dict, op.value)),
                         expires_at,
                         op.ttl,
                     ]

libs/checkpoint/langgraph/store/base/__init__.py

@@ -12,7 +12,7 @@ Core types:
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from collections.abc import Iterable, Mapping
+from collections.abc import Iterable
 from datetime import datetime
 from typing import (
     Any,
@@ -473,10 +473,10 @@ class PutOp(NamedTuple):
         the full path would effectively be `"documents/user123/report1"`
     """
 
-    value: Mapping[str, Any] | None
+    value: dict[str, Any] | None
     """The data to store, or `None` to mark the item for deletion.
 
-    The value must be a mapping with string keys and JSON-serializable values.
+    The value must be a dictionary with string keys and JSON-serializable values.
     Setting this to `None` signals that the item should be deleted.
 
     Example:
@@ -857,7 +857,7 @@ class BaseStore(ABC):
         self,
         namespace: tuple[str, ...],
         key: str,
-        value: Mapping[str, Any],
+        value: dict[str, Any],
         index: Literal[False] | list[str] | None = None,
         *,
         ttl: float | None | NotProvided = NOT_PROVIDED,
@@ -869,7 +869,7 @@ class BaseStore(ABC):
                 Example: `("documents", "user123")`
             key: Unique identifier within the namespace. Together with namespace forms
                 the complete path to the item.
-            value: Mapping containing the item's data. Must contain string keys
+            value: Dictionary containing the item's data. Must contain string keys
                 and JSON-serializable values.
             index: Controls how the item's fields are indexed for search:
 
@@ -1110,7 +1110,7 @@ class BaseStore(ABC):
         self,
         namespace: tuple[str, ...],
         key: str,
-        value: Mapping[str, Any],
+        value: dict[str, Any],
         index: Literal[False] | list[str] | None = None,
         *,
         ttl: float | None | NotProvided = NOT_PROVIDED,
@@ -1122,7 +1122,7 @@ class BaseStore(ABC):
                 Example: `("documents", "user123")`
             key: Unique identifier within the namespace. Together with namespace forms
                 the complete path to the item.
-            value: Mapping containing the item's data. Must contain string keys
+            value: Dictionary containing the item's data. Must contain string keys
                 and JSON-serializable values.
             index: Controls how the item's fields are indexed for search:
 

libs/checkpoint/langgraph/store/base/batch.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 import asyncio
 import functools
 import weakref
-from collections.abc import Callable, Iterable, Mapping
+from collections.abc import Callable, Iterable
 from typing import Any, Literal, TypeVar
 
 from langgraph.store.base import (
@@ -132,7 +132,7 @@ class AsyncBatchedBaseStore(BaseStore):
         self,
         namespace: tuple[str, ...],
         key: str,
-        value: Mapping[str, Any],
+        value: dict[str, Any],
         index: Literal[False] | list[str] | None = None,
         *,
         ttl: float | None | NotProvided = NOT_PROVIDED,
@@ -231,7 +231,7 @@ class AsyncBatchedBaseStore(BaseStore):
         self,
         namespace: tuple[str, ...],
         key: str,
-        value: Mapping[str, Any],
+        value: dict[str, Any],
         index: Literal[False] | list[str] | None = None,
         *,
         ttl: float | None | NotProvided = NOT_PROVIDED,

libs/checkpoint/langgraph/store/memory/__init__.py

@@ -408,7 +408,7 @@ class InMemoryStore(BaseStore):
                 self._vectors[namespace].pop(key, None)
             else:
                 self._data[namespace][key] = Item(
-                    value=dict(op.value),
+                    value=op.value,
                     key=key,
                     namespace=namespace,
                     created_at=datetime.now(timezone.utc),

libs/cli/langgraph_cli/cli.py

@@ -408,6 +408,12 @@ For production use, requires a license key in env var LANGGRAPH_CLOUD_LICENSE_KE
     "--build-command",
     help="Custom build command to run from the langgraph.json directory. If not provided, uses default build process.",
 )
+@click.option(
+    "--single-user-layer",
+    is_flag=True,
+    envvar="LANGGRAPH_CLI_SINGLE_USER_LAYER",
+    help="Combine generated Python build steps into one image layer when supported.",
+)
 @click.argument("docker_build_args", nargs=-1, type=click.UNPROCESSED)
 @cli.command(
     help="📦 Build LangGraph API server Docker image.",
@@ -426,6 +432,7 @@ def build(
     tag: str,
     install_command: str | None,
     build_command: str | None,
+    single_user_layer: bool,
 ):
     if install_command and langgraph_cli.config.has_disallowed_build_command_content(
         install_command
@@ -461,6 +468,7 @@ def build(
             docker_build_args,
             install_command,
             build_command,
+            single_user_layer=single_user_layer,
         )
 
 

libs/cli/langgraph_cli/config.py

@@ -1267,6 +1267,7 @@ def python_config_to_docker(
     api_version: str | None = None,
     *,
     escape_variables: bool = False,
+    single_user_layer: bool = False,
 ) -> tuple[str, dict[str, str]]:
     """Generate a Dockerfile from the configuration."""
     source_kind = _get_source_kind(config)
@@ -1428,6 +1429,91 @@ ADD {relpath} /deps/{name}
             ]
         )
     image_str = docker_tag(config, base_image, api_version)
+    dep_vname = "$$dep" if escape_variables else "$dep"
+    local_deps_install_str = f"""RUN for dep in /deps/*; do \
+            echo "Installing {dep_vname}"; \
+            if [ -d "{dep_vname}" ]; then \
+                echo "Installing {dep_vname}"; \
+                (cd "{dep_vname}" && {global_reqs_pip_install} -e .); \
+            fi; \
+        done"""
+
+    if (
+        single_user_layer
+        and not config["dockerfile_lines"]
+        and not local_deps.additional_contexts
+        and not config.get("ui")
+        and not config.get("node_version")
+        and not escape_variables
+    ):
+        commands = ["set -eu"]
+        context = pathlib.PurePosixPath("/__build_context")
+        if pip_config_file := config.get("pip_config_file"):
+            commands.append(
+                f"cp {shlex.quote(str(context / pip_config_file))} /pipconfig.txt"
+            )
+        if pypi_deps:
+            commands.append(f"{local_reqs_pip_install} {' '.join(pypi_deps)}")
+        for reqpath, destpath in local_deps.pip_reqs:
+            source = context / reqpath.relative_to(config_path.parent)
+            commands.extend(
+                [
+                    f"mkdir -p {shlex.quote(str(pathlib.PurePosixPath(destpath).parent))}",
+                    f"cp {shlex.quote(str(source))} {shlex.quote(destpath)}",
+                ]
+            )
+        if local_deps.pip_reqs:
+            commands.append(
+                f"{local_reqs_pip_install} "
+                + " ".join(f"-r {path}" for _, path in local_deps.pip_reqs)
+            )
+        for _, (relpath, name) in local_deps.real_pkgs.items():
+            destination = f"/deps/{name}"
+            source = f"{context / relpath}/."
+            commands.extend(
+                [
+                    f"mkdir -p {shlex.quote(destination)}",
+                    f"cp -a {shlex.quote(source)} {shlex.quote(destination)}/",
+                ]
+            )
+        for fullpath, (relpath, destpath) in local_deps.faux_pkgs.items():
+            source = f"{context / relpath}/."
+            pyproject = shlex.quote(f"/deps/outer-{fullpath.name}/pyproject.toml")
+            commands.extend(
+                [
+                    f"mkdir -p {shlex.quote(destpath)}",
+                    f"cp -a {shlex.quote(source)} {shlex.quote(destpath)}/",
+                    "for line in '[project]' "
+                    f"'name = \"{fullpath.name}\"' "
+                    "'version = \"0.1\"' "
+                    "'[tool.setuptools.package-data]' "
+                    '\'"*" = ["**/*"]\' '
+                    "'[build-system]' "
+                    "'requires = [\"setuptools>=61\"]' "
+                    "'build-backend = \"setuptools.build_meta\"'; do "
+                    f'echo "$line" >> {pyproject}; done',
+                ]
+            )
+        commands.append(local_deps_install_str.removeprefix("RUN "))
+        commands.extend(
+            line.removeprefix("RUN ")
+            for line in _get_pip_cleanup_lines(
+                install_cmd=install_cmd,
+                to_uninstall=build_tools_to_uninstall,
+                pip_installer=pip_installer,
+            ).splitlines()
+            if line and not line.startswith("#")
+        )
+        docker_file_contents = [
+            "# syntax=docker/dockerfile:1.7",
+            f"FROM {image_str}",
+            "RUN --mount=type=bind,target=/__build_context,readonly <<'USER_LAYER'",
+            *commands,
+            "USER_LAYER",
+            *env_vars,
+            f"WORKDIR {local_deps.working_dir}" if local_deps.working_dir else "",
+        ]
+        return os.linesep.join(docker_file_contents), additional_contexts
 
     # Prepare docker file contents
     docker_file_contents = []
@@ -1442,14 +1528,6 @@ ADD {relpath} /deps/{name}
         )
 
     # Add main dockerfile content
-    dep_vname = "$$dep" if escape_variables else "$dep"
-    local_deps_install_str = f"""RUN for dep in /deps/*; do \
-            echo "Installing {dep_vname}"; \
-            if [ -d "{dep_vname}" ]; then \
-                echo "Installing {dep_vname}"; \
-                (cd "{dep_vname}" && {global_reqs_pip_install} -e .); \
-            fi; \
-        done"""
     docker_file_contents.extend(
         [
             f"FROM {image_str}",
@@ -1625,6 +1703,7 @@ def config_to_docker(
     build_command: str | None = None,
     build_context: str | None = None,
     escape_variables: bool = False,
+    single_user_layer: bool = False,
 ) -> tuple[str, dict[str, str]]:
     base_image = base_image or default_base_image(config)
 
@@ -1645,6 +1724,7 @@ def config_to_docker(
         base_image=base_image,
         api_version=api_version,
         escape_variables=escape_variables,
+        single_user_layer=single_user_layer,
     )
 
 

libs/cli/langgraph_cli/docker.py

@@ -345,6 +345,7 @@ def build_docker_image(
     docker_command: Sequence[str] | None = None,
     extra_flags: Sequence[str] = (),
     verbose: bool = True,
+    single_user_layer: bool = False,
 ):
     """Build a Docker image from a LangGraph config."""
     # pull latest images
@@ -387,6 +388,7 @@ def build_docker_image(
         install_command=install_command,
         build_command=build_command,
         build_context=build_context,
+        single_user_layer=single_user_layer,
     )
     # add additional_contexts
     if additional_contexts:

libs/cli/langgraph_cli/uv_lock.py

@@ -970,6 +970,22 @@ def python_config_to_docker_uv_lock(
             f"{uv_export_project_dir}/uv.lock",
         )
     )
+    for package_root in sorted(
+        plan.all_workspace_roots,
+        key=lambda root: root.as_posix(),
+    ):
+        if package_root == plan.project_root:
+            continue
+        package_relative_path = pathlib.PurePosixPath(
+            package_root.relative_to(plan.project_root).as_posix()
+        )
+        package_pyproject_path = package_relative_path / "pyproject.toml"
+        docker_plan.add_raw(
+            copy_from_project_root(
+                package_pyproject_path,
+                f"{uv_export_project_dir}/{package_pyproject_path.as_posix()}",
+            )
+        )
     docker_plan.add_instruction("WORKDIR", uv_export_project_dir)
     docker_plan.add_instruction(
         "RUN",

libs/cli/tests/unit_tests/test_config.py

@@ -723,6 +723,23 @@ WORKDIR /deps/outer-unit_tests/unit_tests\
     }
 
 
+def test_config_to_docker_single_user_layer():
+    dockerfile, additional_contexts = config_to_docker(
+        PATH_TO_CONFIG,
+        validate_config(
+            {"dependencies": ["."], "graphs": {"agent": "./agent.py:graph"}}
+        ),
+        base_image="langchain/langgraph-api",
+        single_user_layer=True,
+    )
+
+    assert additional_contexts == {}
+    assert dockerfile.count("\nRUN ") == 1
+    assert "--mount=type=bind" in dockerfile
+    assert "cp -a /__build_context/. /deps/outer-unit_tests/unit_tests/" in dockerfile
+    assert dockerfile.endswith("WORKDIR /deps/outer-unit_tests/unit_tests")
+
+
 def test_config_to_docker_outside_path():
     graphs = {"agent": "./agent.py:graph"}
     actual_docker_stdin, additional_contexts = config_to_docker(
@@ -1403,6 +1420,19 @@ def test_config_to_docker_uv_lock():
             "COPY --from=uv-workspace-root uv.lock /tmp/uv_export/project/uv.lock"
             in docker
         )
+        workspace_pyprojects = [
+            "apps/agent/pyproject.toml",
+            "libs/extra/pyproject.toml",
+            "libs/shared/pyproject.toml",
+        ]
+        export_instruction = "RUN uv export --package agent"
+        for pyproject_path in workspace_pyprojects:
+            copy_instruction = (
+                "COPY --from=uv-workspace-root "
+                f"{pyproject_path} /tmp/uv_export/project/{pyproject_path}"
+            )
+            assert copy_instruction in docker
+            assert docker.index(copy_instruction) < docker.index(export_instruction)
         assert additional_contexts == {"uv-workspace-root": str(project_root.resolve())}
 
         assert (

libs/cli/uv-examples/monorepo/uv.lock

@@ -266,20 +266,20 @@ wheels = [
 
 [[package]]
 name = "langgraph-checkpoint"
-version = "4.0.1"
+version = "4.2.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "langchain-core" },
     { name = "ormsgpack" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/b1/44/a8df45d1e8b4637e29789fa8bae1db022c953cc7ac80093cfc52e923547e/langgraph_checkpoint-4.0.1.tar.gz", hash = "sha256:b433123735df11ade28829e40ce25b9be614930cd50245ff2af60629234befd9", size = 158135, upload-time = "2026-02-27T21:06:16.092Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/dc/e1/089c4c9e0a2fec7f883f82ae8e6a727138d50074cfeb6644bc2d13b1019b/langgraph_checkpoint-4.2.0.tar.gz", hash = "sha256:51a593b6bee684b0818e5d6e58e28ab340c6db7794575056ce7bd1b746a84ed7", size = 180239, upload-time = "2026-08-07T20:05:03.756Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/65/4c/09a4a0c42f5d2fc38d6c4d67884788eff7fd2cfdf367fdf7033de908b4c0/langgraph_checkpoint-4.0.1-py3-none-any.whl", hash = "sha256:e3adcd7a0e0166f3b48b8cf508ce0ea366e7420b5a73aa81289888727769b034", size = 50453, upload-time = "2026-02-27T21:06:14.293Z" },
+    { url = "https://files.pythonhosted.org/packages/05/71/3b475f09bd57d3a5649792c66353312b4432afd843f301739dfcebd157f0/langgraph_checkpoint-4.2.0-py3-none-any.whl", hash = "sha256:0547fd228935a0b758865de3a3d6d7a2537c308895d0f9ab092ce9151b5da942", size = 56833, upload-time = "2026-08-07T20:05:02.655Z" },
 ]
 
 [[package]]
 name = "langgraph-checkpoint-postgres"
-version = "3.0.5"
+version = "3.1.1"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "langgraph-checkpoint" },
@@ -287,9 +287,9 @@ dependencies = [
     { name = "psycopg" },
     { name = "psycopg-pool" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/95/7a/8f439966643d32111248a225e6cb33a182d07c90de780c4dbfc1e0377832/langgraph_checkpoint_postgres-3.0.5.tar.gz", hash = "sha256:a8fd7278a63f4f849b5cbc7884a15ca8f41e7d5f7467d0a66b31e8c24492f7eb", size = 127856, upload-time = "2026-03-18T21:25:29.785Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/06/92/1e8959f8cd1b56e672fde3227f6fd642be85af6c5fd662d73921074aa39d/langgraph_checkpoint_postgres-3.1.1.tar.gz", hash = "sha256:d320e147ddad8c374cd546df0b52b532dd54d0541dd9fd23fc738cbd5de76f41", size = 150413, upload-time = "2026-07-30T19:15:39.014Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/e8/87/b0f98b33a67204bca9d5619bcd9574222f6b025cf3c125eedcec9a50ecbc/langgraph_checkpoint_postgres-3.0.5-py3-none-any.whl", hash = "sha256:86d7040a88fd70087eaafb72251d796696a0a2d856168f5c11ef620771411552", size = 42907, upload-time = "2026-03-18T21:25:28.75Z" },
+    { url = "https://files.pythonhosted.org/packages/03/32/ba457698a48a0e18d786caa770033067049fbe36d6846f8e50f13b594b51/langgraph_checkpoint_postgres-3.1.1-py3-none-any.whl", hash = "sha256:6e353aecd8150de144fef8e51a49076f58b7d6830d4cf51392b7ad4d79832ba7", size = 50778, upload-time = "2026-07-30T19:15:37.405Z" },
 ]
 
 [[package]]

libs/langgraph/langgraph/pregel/_utils.py

@@ -1,11 +1,10 @@
 from __future__ import annotations
 
-import ast
-import inspect
+import dis
 import re
-import textwrap
 from collections.abc import Callable, Sequence
 from functools import partial
+from types import CodeType, FunctionType
 from typing import Any
 
 from langchain_core.runnables import (
@@ -17,7 +16,6 @@ from langchain_core.runnables import (
 from langchain_core.runnables.base import RunnableBindingBase
 from langchain_core.runnables.config import run_in_executor
 from langgraph.checkpoint.base import ChannelVersions
-from typing_extensions import override
 
 from langgraph._internal._runnable import RunnableCallable, RunnableSeq
 from langgraph._internal._timeout import sync_timeout_unsupported
@@ -137,155 +135,87 @@ def validate_timeout_supported(runnable: Runnable, *, name: str) -> None:
         raise sync_timeout_unsupported(name)
 
 
+# Values treated as dead ends when deciding whether to walk a function's
+# bytecode. A container can hold a graph, but `find_subgraph_pregel` does not
+# look inside one, so skipping it costs nothing while that holds. Matched by
+# exact type, since a subclass of a builtin can carry attributes.
+_LEAF_TYPES = frozenset(
+    {
+        int,
+        float,
+        complex,
+        bool,
+        str,
+        bytes,
+        bytearray,
+        list,
+        tuple,
+        dict,
+        set,
+        frozenset,
+        type(None),
+    }
+)
+
+
 def get_function_nonlocals(func: Callable) -> list[Any]:
-    """Get the nonlocal variables accessed by a function.
+    """Get the values a function reaches from outside its own scope.
 
     Args:
         func: The function to check.
 
     Returns:
-        List[Any]: The nonlocal variables accessed by the function.
+        Every captured cell value, the globals the function names, and each
+        value along an attribute path it loads. Over-approximates: a value can
+        come back without the function reaching it at runtime.
     """
-    try:
-        code = inspect.getsource(func)
-        tree = ast.parse(textwrap.dedent(code))
-        visitor = FunctionNonLocals()
-        visitor.visit(tree)
-        values: list[Any] = []
-        closure = (
-            inspect.getclosurevars(func.__wrapped__)
-            if hasattr(func, "__wrapped__") and callable(func.__wrapped__)
-            else inspect.getclosurevars(func)
-        )
-        candidates = {**closure.globals, **closure.nonlocals}
-        for k, v in candidates.items():
-            if k in visitor.nonlocals:
-                values.append(v)
-            for kk in visitor.nonlocals:
-                if "." in kk and kk.startswith(k):
-                    vv = v
-                    for part in kk.split(".")[1:]:
-                        if vv is None:
-                            break
-                        else:
-                            try:
-                                vv = getattr(vv, part)
-                            except AttributeError:
-                                break
-                    else:
-                        values.append(vv)
-    except (SyntaxError, TypeError, OSError, SystemError):
+    func = getattr(func, "__func__", func)  # bound method -> function
+    wrapped = getattr(func, "__wrapped__", None)
+    if callable(wrapped):
+        func = getattr(wrapped, "__func__", wrapped)
+    if not isinstance(func, FunctionType):
         return []
+    code = func.__code__
 
+    cells: dict[str, Any] = {}
+    for name, cell in zip(code.co_freevars, func.__closure__ or ()):
+        try:
+            cells[name] = cell.cell_contents
+        except ValueError:
+            continue  # empty cell: a recursive def not yet bound
+
+    # Every captured value counts, referenced or not: over-declaring costs an
+    # introspection entry, under-declaring drops the subgraph's checkpoints and
+    # stream events. Checking each cell against the bytecode would cost more and
+    # only trade the cheap error for the expensive one.
+    values: list[Any] = list(cells.values())
+    global_ns = func.__globals__
+    globals_ = {name: global_ns[name] for name in code.co_names if name in global_ns}
+    if all(type(v) in _LEAF_TYPES for v in (*cells.values(), *globals_.values())):
+        return values
+
+    # Nested code objects hold the references made by inner defs, lambdas and
+    # comprehensions, which resolve against the namespaces gathered above.
+    codes = [code]
+    for c in codes:
+        codes.extend(k for k in c.co_consts if isinstance(k, CodeType))
+        value: Any = None
+        for instruction in dis.get_instructions(c):
+            opname = instruction.opname
+            if opname == "LOAD_GLOBAL":
+                value = globals_.get(instruction.argval)
+            elif opname == "LOAD_DEREF":
+                value = cells.get(instruction.argval)
+            elif opname in ("LOAD_ATTR", "LOAD_METHOD"):
+                value = getattr(value, instruction.argval, None)
+            else:
+                value = None  # anything else ends the chain: `a, b.c` is not `a.c`
+                continue
+            if value is not None:
+                values.append(value)
     return values
 
 
-class FunctionNonLocals(ast.NodeVisitor):
-    """Get the nonlocal variables accessed of a function."""
-
-    def __init__(self) -> None:
-        self.nonlocals: set[str] = set()
-
-    @override
-    def visit_FunctionDef(self, node: ast.FunctionDef) -> Any:
-        """Visit a function definition.
-
-        Args:
-            node: The node to visit.
-
-        Returns:
-            Any: The result of the visit.
-        """
-        visitor = NonLocals()
-        visitor.visit(node)
-        self.nonlocals.update(visitor.loads - visitor.stores)
-
-    @override
-    def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef) -> Any:
-        """Visit an async function definition.
-
-        Args:
-            node: The node to visit.
-
-        Returns:
-            Any: The result of the visit.
-        """
-        visitor = NonLocals()
-        visitor.visit(node)
-        self.nonlocals.update(visitor.loads - visitor.stores)
-
-    @override
-    def visit_Lambda(self, node: ast.Lambda) -> Any:
-        """Visit a lambda function.
-
-        Args:
-            node: The node to visit.
-
-        Returns:
-            Any: The result of the visit.
-        """
-        visitor = NonLocals()
-        visitor.visit(node)
-        self.nonlocals.update(visitor.loads - visitor.stores)
-
-
-class NonLocals(ast.NodeVisitor):
-    """Get nonlocal variables accessed."""
-
-    def __init__(self) -> None:
-        self.loads: set[str] = set()
-        self.stores: set[str] = set()
-
-    @override
-    def visit_Name(self, node: ast.Name) -> Any:
-        """Visit a name node.
-
-        Args:
-            node: The node to visit.
-
-        Returns:
-            Any: The result of the visit.
-        """
-        if isinstance(node.ctx, ast.Load):
-            self.loads.add(node.id)
-        elif isinstance(node.ctx, ast.Store):
-            self.stores.add(node.id)
-
-    @override
-    def visit_Attribute(self, node: ast.Attribute) -> Any:
-        """Visit an attribute node.
-
-        Args:
-            node: The node to visit.
-
-        Returns:
-            Any: The result of the visit.
-        """
-        if isinstance(node.ctx, ast.Load):
-            parent = node.value
-            attr_expr = node.attr
-            while isinstance(parent, ast.Attribute):
-                attr_expr = parent.attr + "." + attr_expr
-                parent = parent.value
-            if isinstance(parent, ast.Name):
-                self.loads.add(parent.id + "." + attr_expr)
-                self.loads.discard(parent.id)
-            elif isinstance(parent, ast.Call):
-                if isinstance(parent.func, ast.Name):
-                    self.loads.add(parent.func.id)
-                else:
-                    parent = parent.func
-                    attr_expr = ""
-                    while isinstance(parent, ast.Attribute):
-                        if attr_expr:
-                            attr_expr = parent.attr + "." + attr_expr
-                        else:
-                            attr_expr = parent.attr
-                        parent = parent.value
-                    if isinstance(parent, ast.Name):
-                        self.loads.add(parent.id + "." + attr_expr)
-
-
 def is_xxh3_128_hexdigest(value: str) -> bool:
     """Check if the given string matches the format of xxh3_128_hexdigest."""
     return bool(re.fullmatch(r"[0-9a-f]{32}", value))

libs/langgraph/tests/test_subgraph_detection.py

@@ -0,0 +1,286 @@
+"""Tests for subgraph auto-detection (`pregel/_utils.py`).
+
+Detection failing is silent — the graph still runs, only introspection goes
+quiet — so every shape a node can hold a graph in is pinned here. The expected
+values are what the source-parsing implementation this replaced produced for
+the same shapes, except for `sourceless`, whose source it could not read,
+`empty_closure_cell`, on which it raised, and `unreachable_attribute_chain`,
+where it reported a graph that dropped code could never invoke.
+"""
+
+import functools
+import operator
+from typing import Annotated, Any
+
+import pytest
+from typing_extensions import TypedDict
+
+from langgraph.graph import END, START, StateGraph
+from langgraph.pregel._utils import get_function_nonlocals
+
+
+class State(TypedDict):
+    log: Annotated[list, operator.add]
+
+
+def _leaf(tag: str) -> Any:
+    """Return a compiled graph that reports itself as `tag`."""
+    builder = StateGraph(State)
+    builder.add_node(tag, lambda s: {"log": [tag]})
+    builder.add_edge(START, tag)
+    builder.add_edge(tag, END)
+    compiled = builder.compile()
+    compiled.name = tag
+    return compiled
+
+
+def _detect(node: Any) -> str | None:
+    """Return the name of the subgraph detected for `node`, or None."""
+    builder = StateGraph(State)
+    builder.add_node("n", node)
+    builder.add_edge(START, "n")
+    builder.add_edge("n", END)
+    subgraphs = builder.compile().nodes["n"].subgraphs
+    return getattr(subgraphs[0], "name", "?") if subgraphs else None
+
+
+class _Box:
+    def __init__(self, payload: Any) -> None:
+        self.payload = payload
+
+
+class _ListSubclass(list):
+    pass
+
+
+class _MethodHolder:
+    def __init__(self) -> None:
+        self.graph = _leaf("via_self")
+
+    def as_node(self, state: State) -> Any:
+        return self.graph.invoke(state)
+
+
+MODULE_GRAPH = _leaf("module_global")
+CHAIN = _Box(_Box(_leaf("attr_chain")))
+GRAPH_IN_PLAIN_LIST = [_leaf("in_list")]
+METHOD_HOLDER = _MethodHolder()
+
+
+def closure_capture() -> Any:
+    sub = _leaf("closure")
+
+    def node(state: State) -> Any:
+        return sub.invoke(state)
+
+    return node
+
+
+def module_global() -> Any:
+    def node(state: State) -> Any:
+        return MODULE_GRAPH.invoke(state)
+
+    return node
+
+
+def attribute_chain() -> Any:
+    def node(state: State) -> Any:
+        return CHAIN.payload.payload.invoke(state)
+
+    return node
+
+
+def nested_def_captured_attribute() -> Any:
+    """A chain on a captured holder, named only inside a nested code object.
+
+    The captured value is the holder, not the graph, so the chain itself has to
+    be recovered from the nested scope.
+    """
+    holder = _Box(_leaf("nested_captured"))
+
+    def node(state: State) -> Any:
+        def inner() -> Any:
+            return holder.payload.invoke(state)
+
+        return inner()
+
+    return node
+
+
+def unreachable_branch() -> Any:
+    """A captured graph referenced only from code the compiler removes."""
+    sub = _leaf("unreachable")
+
+    def node(state: State) -> Any:
+        if False:
+            sub.invoke(state)
+        return {"log": []}
+
+    return node
+
+
+def unreachable_attribute_chain() -> Any:
+    """A graph named only along an attribute path the compiler dropped.
+
+    The closure keeps `holder`, but the `.payload` load is gone. The source
+    parser reported this one; dropped code cannot invoke anything, so that was
+    a phantom rather than a detection.
+    """
+    holder = _Box(_leaf("unreachable_attr"))
+
+    def node(state: State) -> Any:
+        if False:
+            holder.payload.invoke(state)
+        return {"log": []}
+
+    return node
+
+
+def wrapper_referencing_nothing() -> Any:
+    """A wrapper whose own scope holds nothing, so only `__wrapped__` leads on.
+
+    `functools.wraps` would leave the wrapper closing over the inner function;
+    setting the attribute by hand does not.
+    """
+    sub = _leaf("via_wrapped")
+
+    def inner(state: State) -> Any:
+        return sub.invoke(state)
+
+    def wrapper(state: State) -> Any:
+        return {"log": []}
+
+    wrapper.__wrapped__ = inner
+    return wrapper
+
+
+def captured_list_subclass() -> Any:
+    """A `list` subclass is not a leaf: it can carry a graph as an attribute."""
+    holder = _ListSubclass()
+    holder.payload = _leaf("list_subclass")
+
+    def node(state: State) -> Any:
+        return holder.payload.invoke(state)
+
+    return node
+
+
+def empty_closure_cell() -> Any:
+    """An unassigned closure variable leaves a cell that cannot be read."""
+    sub = _leaf("beside_empty_cell")
+
+    def node(state: State) -> Any:
+        return unassigned, sub.invoke(state)
+
+    return node
+    unassigned = 1  # never runs, so the cell it creates is never filled
+
+
+def sourceless() -> Any:
+    """A node compiled without a source file, which `getsource` could not read."""
+    namespace: dict[str, Any] = {"SOURCELESS": _leaf("sourceless")}
+    exec(
+        compile(
+            "def node(state):\n    return SOURCELESS.invoke(state)", "<test>", "exec"
+        ),
+        namespace,
+    )
+    return namespace["node"]
+
+
+async def _async_node(state: State) -> Any:
+    return await MODULE_GRAPH.ainvoke(state)
+
+
+def async_node() -> Any:
+    return _async_node
+
+
+def no_subgraph() -> Any:
+    """Nothing but leaf values in reach, so the bytecode walk is skipped."""
+
+    def node(state: State) -> Any:
+        return {"log": [len("abc") + 1]}
+
+    return node
+
+
+def recombined_names() -> Any:
+    """Loads `CHAIN.payload` and `local.payload`, never `CHAIN.payload.payload`."""
+
+    def node(state: State) -> Any:
+        local = _Box("not a graph")
+        return {"log": [CHAIN.payload, local.payload]}
+
+    return node
+
+
+def broken_attribute_chain() -> Any:
+    holder = _Box("a string, so `.payload.missing` cannot resolve")
+
+    def node(state: State) -> Any:
+        return holder.payload.missing.invoke(state)
+
+    return node
+
+
+def nested_def_global() -> Any:
+    """A global named only in a nested code object: out of reach, as before."""
+
+    def node(state: State) -> Any:
+        def inner() -> Any:
+            return MODULE_GRAPH.invoke(state)
+
+        return inner()
+
+    return node
+
+
+def graph_in_plain_list() -> Any:
+    def node(state: State) -> Any:
+        return GRAPH_IN_PLAIN_LIST[0].invoke(state)
+
+    return node
+
+
+def bound_method_self() -> Any:
+    return METHOD_HOLDER.as_node
+
+
+@pytest.mark.parametrize(
+    ("factory", "expected"),
+    [
+        (closure_capture, "closure"),
+        (module_global, "module_global"),
+        (attribute_chain, "attr_chain"),
+        (nested_def_captured_attribute, "nested_captured"),
+        (unreachable_branch, "unreachable"),
+        (wrapper_referencing_nothing, "via_wrapped"),
+        (captured_list_subclass, "list_subclass"),
+        (empty_closure_cell, "beside_empty_cell"),
+        (sourceless, "sourceless"),
+        (async_node, "module_global"),
+        # Shapes no reference chain reaches: a subscript, an instance attribute
+        # of `self`, a global named only in a nested scope, and an attribute
+        # path the compiler dropped.
+        (no_subgraph, None),
+        (recombined_names, None),
+        (broken_attribute_chain, None),
+        (nested_def_global, None),
+        (graph_in_plain_list, None),
+        (bound_method_self, None),
+        (unreachable_attribute_chain, None),
+    ],
+    ids=lambda value: value.__name__ if callable(value) else str(value),
+)
+def test_subgraph_detection(factory: Any, expected: str | None) -> None:
+    assert _detect(factory()) == expected
+
+
+@pytest.mark.parametrize(
+    "candidate",
+    [functools.partial(lambda state, extra: {"log": [extra]}, extra="x"), len],
+    ids=["partial", "builtin"],
+)
+def test_callables_without_a_code_object_are_handled(candidate: Any) -> None:
+    assert get_function_nonlocals(candidate) == []

libs/sdk-py/langgraph_sdk/__init__.py

@@ -1,8 +1,15 @@
 from langgraph_sdk.auth import Auth
 from langgraph_sdk.client import get_client, get_sync_client
 from langgraph_sdk.encryption import Encryption
-from langgraph_sdk.encryption.types import EncryptionContext
+from langgraph_sdk.encryption.types import DecryptResult, EncryptionContext
 
-__version__ = "0.4.2"
+__version__ = "0.4.3"
 
-__all__ = ["Auth", "Encryption", "EncryptionContext", "get_client", "get_sync_client"]
+__all__ = [
+    "Auth",
+    "DecryptResult",
+    "Encryption",
+    "EncryptionContext",
+    "get_client",
+    "get_sync_client",
+]

libs/sdk-py/langgraph_sdk/encryption/__init__.py

@@ -18,6 +18,9 @@ import warnings
 
 from langgraph_sdk.encryption import types
 
+_BlobDecryptorT = typing.TypeVar("_BlobDecryptorT", bound=types.BlobDecryptor)
+_JsonDecryptorT = typing.TypeVar("_JsonDecryptorT", bound=types.JsonDecryptor)
+
 
 class LangGraphBetaWarning(UserWarning):
     """Warning for beta features in LangGraph SDK."""
@@ -141,7 +144,7 @@ class _DecryptDecorators:
     def __init__(self, parent: Encryption):
         self._parent = parent
 
-    def blob(self, fn: types.BlobDecryptor) -> types.BlobDecryptor:
+    def blob(self, fn: _BlobDecryptorT) -> _BlobDecryptorT:
         """Register a blob decryption handler.
 
         The handler will be called to decrypt opaque data like checkpoint blobs.
@@ -149,7 +152,9 @@ class _DecryptDecorators:
         Example:
             ```python
             @encryption.decrypt.blob
-            async def decrypt_blob(ctx: EncryptionContext, blob: bytes) -> bytes:
+            async def decrypt_blob(
+                ctx: EncryptionContext, blob: bytes
+            ) -> bytes | DecryptResult[bytes]:
                 # Decrypt the blob using your encryption service
                 return decrypted_blob
             ```
@@ -170,13 +175,15 @@ class _DecryptDecorators:
         self._parent._blob_decryptor = fn
         return fn
 
-    def json(self, fn: types.JsonDecryptor) -> types.JsonDecryptor:
+    def json(self, fn: _JsonDecryptorT) -> _JsonDecryptorT:
         """Register the JSON decryption handler.
 
         Example:
             ```python
             @encryption.decrypt.json
-            async def decrypt_json(ctx: EncryptionContext, data: dict) -> dict:
+            async def decrypt_json(
+                ctx: EncryptionContext, data: dict
+            ) -> dict | DecryptResult[dict]:
                 # Decrypt the data
                 return decrypt_data(data)
             ```
@@ -369,7 +376,7 @@ class Encryption:
     """Reference to encryption type definitions.
 
     Provides access to all type definitions used in the encryption system,
-    including EncryptionContext, BlobEncryptor, BlobDecryptor,
+    including EncryptionContext, DecryptResult, BlobEncryptor, BlobDecryptor,
     JsonEncryptor, and JsonDecryptor.
     """
 

libs/sdk-py/langgraph_sdk/encryption/types.py

@@ -9,10 +9,30 @@ from __future__ import annotations
 
 import typing
 from collections.abc import Awaitable, Callable
+from dataclasses import dataclass
 
 Json = dict[str, typing.Any]
 """JSON-serializable dictionary type for structured data encryption."""
 
+T = typing.TypeVar("T")
+
+
+@dataclass(frozen=True, slots=True)
+class DecryptResult(typing.Generic[T]):
+    """Decrypted data and optional replacement ciphertext.
+
+    Return this from a decrypt handler when encrypted data should be replaced,
+    such as after rotating its encryption key. Returning plaintext directly
+    remains supported when no replacement is needed.
+
+    Attributes:
+        plaintext: Decrypted data returned to the caller
+        replacement: New encrypted data to persist in place of the input
+    """
+
+    plaintext: T
+    replacement: T | None = None
+
 
 class EncryptionContext:
     """Context passed to encryption/decryption handlers.
@@ -57,7 +77,9 @@ Returns:
     Awaitable that resolves to encrypted bytes
 """
 
-BlobDecryptor = Callable[[EncryptionContext, bytes], Awaitable[bytes]]
+BlobDecryptor = Callable[
+    [EncryptionContext, bytes], Awaitable[bytes | DecryptResult[bytes]]
+]
 """Handler for decrypting opaque blob data like checkpoints.
 
 Note: Must be an async function. Decryption typically involves I/O operations
@@ -68,7 +90,8 @@ Args:
     blob: The encrypted bytes to decrypt
 
 Returns:
-    Awaitable that resolves to decrypted bytes
+    Awaitable that resolves to decrypted bytes, or a DecryptResult containing
+    decrypted bytes and replacement ciphertext
 """
 
 JsonEncryptor = Callable[[EncryptionContext, Json], Awaitable[Json]]
@@ -101,7 +124,9 @@ Returns:
     Awaitable that resolves to encrypted JSON dictionary
 """
 
-JsonDecryptor = Callable[[EncryptionContext, Json], Awaitable[Json]]
+JsonDecryptor = Callable[
+    [EncryptionContext, Json], Awaitable[Json | DecryptResult[Json]]
+]
 """Handler for decrypting structured JSON data.
 
 Note: Must be an async function. Decryption typically involves I/O operations
@@ -115,7 +140,8 @@ Args:
     data: The encrypted JSON dictionary
 
 Returns:
-    Awaitable that resolves to decrypted JSON dictionary
+    Awaitable that resolves to a decrypted JSON dictionary, or a DecryptResult
+    containing decrypted JSON and replacement ciphertext
 """
 
 if typing.TYPE_CHECKING:

libs/sdk-py/tests/test_encryption.py

@@ -1,8 +1,40 @@
+from collections.abc import Awaitable, Callable
+
 import pytest
 
+from langgraph_sdk import DecryptResult, EncryptionContext
 from langgraph_sdk.encryption import DuplicateHandlerError, Encryption
 
 
+def test_decrypt_result():
+    result = DecryptResult(plaintext=b"plain", replacement=b"rotated")
+
+    assert result.plaintext == b"plain"
+    assert result.replacement == b"rotated"
+    assert DecryptResult(plaintext={"plain": True}).replacement is None
+
+
+def test_decrypt_decorators_preserve_return_types():
+    encryption = Encryption()
+
+    @encryption.decrypt.blob
+    async def blob_dec(_ctx: EncryptionContext, data: bytes) -> bytes:
+        return data
+
+    @encryption.decrypt.json
+    async def json_dec(
+        _ctx: EncryptionContext, data: dict[str, object]
+    ) -> dict[str, object]:
+        return data
+
+    blob_handler: Callable[[EncryptionContext, bytes], Awaitable[bytes]] = blob_dec
+    json_handler: Callable[
+        [EncryptionContext, dict[str, object]], Awaitable[dict[str, object]]
+    ] = json_dec
+    assert blob_handler is blob_dec
+    assert json_handler is json_dec
+
+
 class TestHandlerValidation:
     """Test duplicate handler and signature validation."""