Add files using upload-large-folder tool

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/cache/base/__init__.py

@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from collections.abc import Mapping, Sequence
+from typing import Generic, TypeVar
+
+from langgraph.checkpoint.serde.base import SerializerProtocol
+from langgraph.checkpoint.serde.jsonplus import JsonPlusSerializer
+
+ValueT = TypeVar("ValueT")
+Namespace = tuple[str, ...]
+FullKey = tuple[Namespace, str]
+
+
+class BaseCache(ABC, Generic[ValueT]):
+    """Base class for a cache."""
+
+    serde: SerializerProtocol = JsonPlusSerializer(pickle_fallback=False)
+
+    def __init__(self, *, serde: SerializerProtocol | None = None) -> None:
+        """Initialize the cache with a serializer."""
+        self.serde = serde or self.serde
+
+    @abstractmethod
+    def get(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Get the cached values for the given keys."""
+
+    @abstractmethod
+    async def aget(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Asynchronously get the cached values for the given keys."""
+
+    @abstractmethod
+    def set(self, pairs: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Set the cached values for the given keys and TTLs."""
+
+    @abstractmethod
+    async def aset(self, pairs: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Asynchronously set the cached values for the given keys and TTLs."""
+
+    @abstractmethod
+    def clear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+
+    @abstractmethod
+    async def aclear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Asynchronously delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/cache/memory/__init__.py

@@ -0,0 +1,73 @@
+from __future__ import annotations
+
+import datetime
+import threading
+from collections.abc import Mapping, Sequence
+
+from langgraph.cache.base import BaseCache, FullKey, Namespace, ValueT
+from langgraph.checkpoint.serde.base import SerializerProtocol
+
+
+class InMemoryCache(BaseCache[ValueT]):
+    def __init__(self, *, serde: SerializerProtocol | None = None):
+        super().__init__(serde=serde)
+        self._cache: dict[Namespace, dict[str, tuple[str, bytes, float | None]]] = {}
+        self._lock = threading.RLock()
+
+    def get(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Get the cached values for the given keys."""
+        with self._lock:
+            if not keys:
+                return {}
+            now = datetime.datetime.now(datetime.timezone.utc).timestamp()
+            values: dict[FullKey, ValueT] = {}
+            for ns_tuple, key in keys:
+                ns = Namespace(ns_tuple)
+                if ns in self._cache and key in self._cache[ns]:
+                    enc, val, expiry = self._cache[ns][key]
+                    if expiry is None or now < expiry:
+                        values[(ns, key)] = self.serde.loads_typed((enc, val))
+                    else:
+                        del self._cache[ns][key]
+            return values
+
+    async def aget(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Asynchronously get the cached values for the given keys."""
+        return self.get(keys)
+
+    def set(self, keys: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Set the cached values for the given keys."""
+        with self._lock:
+            now = datetime.datetime.now(datetime.timezone.utc)
+            for (ns, key), (value, ttl) in keys.items():
+                if ttl is not None:
+                    delta = datetime.timedelta(seconds=ttl)
+                    expiry: float | None = (now + delta).timestamp()
+                else:
+                    expiry = None
+                if ns not in self._cache:
+                    self._cache[ns] = {}
+                self._cache[ns][key] = (
+                    *self.serde.dumps_typed(value),
+                    expiry,
+                )
+
+    async def aset(self, keys: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Asynchronously set the cached values for the given keys."""
+        self.set(keys)
+
+    def clear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        with self._lock:
+            if namespaces is None:
+                self._cache.clear()
+            else:
+                for ns in namespaces:
+                    if ns in self._cache:
+                        del self._cache[ns]
+
+    async def aclear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Asynchronously delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        self.clear(namespaces)

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/cache/redis/__init__.py

@@ -0,0 +1,144 @@
+from __future__ import annotations
+
+from collections.abc import Mapping, Sequence
+from typing import Any
+
+from langgraph.cache.base import BaseCache, FullKey, Namespace, ValueT
+from langgraph.checkpoint.serde.base import SerializerProtocol
+
+
+class RedisCache(BaseCache[ValueT]):
+    """Redis-based cache implementation with TTL support."""
+
+    def __init__(
+        self,
+        redis: Any,
+        *,
+        serde: SerializerProtocol | None = None,
+        prefix: str = "langgraph:cache:",
+    ) -> None:
+        """Initialize the cache with a Redis client.
+
+        Args:
+            redis: Redis client instance (sync or async)
+            serde: Serializer to use for values
+            prefix: Key prefix for all cached values
+        """
+        super().__init__(serde=serde)
+        self.redis = redis
+        self.prefix = prefix
+
+    def _make_key(self, ns: Namespace, key: str) -> str:
+        """Create a Redis key from namespace and key."""
+        ns_str = ":".join(ns) if ns else ""
+        return f"{self.prefix}{ns_str}:{key}" if ns_str else f"{self.prefix}{key}"
+
+    def _parse_key(self, redis_key: str) -> tuple[Namespace, str]:
+        """Parse a Redis key back to namespace and key."""
+        if not redis_key.startswith(self.prefix):
+            raise ValueError(
+                f"Key {redis_key} does not start with prefix {self.prefix}"
+            )
+
+        remaining = redis_key[len(self.prefix) :]
+        if ":" in remaining:
+            parts = remaining.split(":")
+            key = parts[-1]
+            ns_parts = parts[:-1]
+            return (tuple(ns_parts), key)
+        else:
+            return (tuple(), remaining)
+
+    def get(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Get the cached values for the given keys."""
+        if not keys:
+            return {}
+
+        # Build Redis keys
+        redis_keys = [self._make_key(ns, key) for ns, key in keys]
+
+        # Get values from Redis using MGET
+        try:
+            raw_values = self.redis.mget(redis_keys)
+        except Exception:
+            # If Redis is unavailable, return empty dict
+            return {}
+
+        values: dict[FullKey, ValueT] = {}
+        for i, raw_value in enumerate(raw_values):
+            if raw_value is not None:
+                try:
+                    # Deserialize the value
+                    encoding, data = raw_value.split(b":", 1)
+                    values[keys[i]] = self.serde.loads_typed((encoding.decode(), data))
+                except Exception:
+                    # Skip corrupted entries
+                    continue
+
+        return values
+
+    async def aget(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Asynchronously get the cached values for the given keys."""
+        return self.get(keys)
+
+    def set(self, mapping: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Set the cached values for the given keys and TTLs."""
+        if not mapping:
+            return
+
+        # Use pipeline for efficient batch operations
+        pipe = self.redis.pipeline()
+
+        for (ns, key), (value, ttl) in mapping.items():
+            redis_key = self._make_key(ns, key)
+            encoding, data = self.serde.dumps_typed(value)
+
+            # Store as "encoding:data" format
+            serialized_value = f"{encoding}:".encode() + data
+
+            if ttl is not None:
+                pipe.setex(redis_key, ttl, serialized_value)
+            else:
+                pipe.set(redis_key, serialized_value)
+
+        try:
+            pipe.execute()
+        except Exception:
+            # Silently fail if Redis is unavailable
+            pass
+
+    async def aset(self, mapping: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Asynchronously set the cached values for the given keys and TTLs."""
+        self.set(mapping)
+
+    def clear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        try:
+            if namespaces is None:
+                # Clear all keys with our prefix
+                pattern = f"{self.prefix}*"
+                keys = self.redis.keys(pattern)
+                if keys:
+                    self.redis.delete(*keys)
+            else:
+                # Clear specific namespaces
+                keys_to_delete = []
+                for ns in namespaces:
+                    ns_str = ":".join(ns) if ns else ""
+                    pattern = (
+                        f"{self.prefix}{ns_str}:*" if ns_str else f"{self.prefix}*"
+                    )
+                    keys = self.redis.keys(pattern)
+                    keys_to_delete.extend(keys)
+
+                if keys_to_delete:
+                    self.redis.delete(*keys_to_delete)
+        except Exception:
+            # Silently fail if Redis is unavailable
+            pass
+
+    async def aclear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Asynchronously delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        self.clear(namespaces)

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/cache/sqlite/__init__.py

@@ -0,0 +1,120 @@
+from __future__ import annotations
+
+import asyncio
+import datetime
+import sqlite3
+import threading
+from collections.abc import Mapping, Sequence
+
+from langgraph.cache.base import BaseCache, FullKey, Namespace, ValueT
+from langgraph.checkpoint.serde.base import SerializerProtocol
+
+
+class SqliteCache(BaseCache[ValueT]):
+    """File-based cache using SQLite."""
+
+    def __init__(
+        self,
+        *,
+        path: str,
+        serde: SerializerProtocol | None = None,
+    ) -> None:
+        """Initialize the cache with a file path."""
+        super().__init__(serde=serde)
+        # SQLite backing store
+        self._conn = sqlite3.connect(
+            path,
+            check_same_thread=False,
+        )
+        # Serialize access to the shared connection across threads
+        self._lock = threading.RLock()
+        # Better concurrency & atomicity
+        self._conn.execute("PRAGMA journal_mode=WAL;")
+        # Schema: key -> (expiry, encoding, value)
+        self._conn.execute(
+            """CREATE TABLE IF NOT EXISTS cache (
+                ns TEXT,
+                key TEXT,
+                expiry REAL,
+                encoding TEXT NOT NULL,
+                val BLOB NOT NULL,
+                PRIMARY KEY (ns, key)
+            )"""
+        )
+        self._conn.commit()
+
+    def get(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Get the cached values for the given keys."""
+        with self._lock, self._conn:
+            now = datetime.datetime.now(datetime.timezone.utc).timestamp()
+            if not keys:
+                return {}
+            placeholders = ",".join("(?, ?)" for _ in keys)
+            params: list[str] = []
+            for ns_tuple, key in keys:
+                params.extend((",".join(ns_tuple), key))
+            cursor = self._conn.execute(
+                f"SELECT ns, key, expiry, encoding, val FROM cache WHERE (ns, key) IN ({placeholders})",
+                tuple(params),
+            )
+            values: dict[FullKey, ValueT] = {}
+            rows = cursor.fetchall()
+            for ns, key, expiry, encoding, raw in rows:
+                if expiry is not None and now > expiry:
+                    # purge expired entry
+                    self._conn.execute(
+                        "DELETE FROM cache WHERE (ns, key) = (?, ?)", (ns, key)
+                    )
+                    continue
+                values[(tuple(ns.split(",")), key)] = self.serde.loads_typed(
+                    (encoding, raw)
+                )
+            return values
+
+    async def aget(self, keys: Sequence[FullKey]) -> dict[FullKey, ValueT]:
+        """Asynchronously get the cached values for the given keys."""
+        return await asyncio.to_thread(self.get, keys)
+
+    def set(self, mapping: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Set the cached values for the given keys and TTLs."""
+        with self._lock, self._conn:
+            now = datetime.datetime.now(datetime.timezone.utc)
+            for key, (value, ttl) in mapping.items():
+                if ttl is not None:
+                    delta = datetime.timedelta(seconds=ttl)
+                    expiry: float | None = (now + delta).timestamp()
+                else:
+                    expiry = None
+                encoding, raw = self.serde.dumps_typed(value)
+                self._conn.execute(
+                    "INSERT OR REPLACE INTO cache (ns, key, expiry, encoding, val) VALUES (?, ?, ?, ?, ?)",
+                    (",".join(key[0]), key[1], expiry, encoding, raw),
+                )
+
+    async def aset(self, mapping: Mapping[FullKey, tuple[ValueT, int | None]]) -> None:
+        """Asynchronously set the cached values for the given keys and TTLs."""
+        await asyncio.to_thread(self.set, mapping)
+
+    def clear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        with self._lock, self._conn:
+            if namespaces is None:
+                self._conn.execute("DELETE FROM cache")
+            else:
+                placeholders = ",".join("?" for _ in namespaces)
+                self._conn.execute(
+                    f"DELETE FROM cache WHERE (ns) IN ({placeholders})",
+                    tuple(",".join(key) for key in namespaces),
+                )
+
+    async def aclear(self, namespaces: Sequence[Namespace] | None = None) -> None:
+        """Asynchronously delete the cached values for the given namespaces.
+        If no namespaces are provided, clear all cached values."""
+        await asyncio.to_thread(self.clear, namespaces)
+
+    def __del__(self) -> None:
+        try:
+            self._conn.close()
+        except Exception:
+            pass

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/checkpoint/base/__init__.py

@@ -0,0 +1,860 @@
+from __future__ import annotations
+
+import copy
+import logging
+from collections.abc import AsyncIterator, Collection, Iterator, Mapping, Sequence
+from typing import (
+    Any,
+    Generic,
+    Literal,
+    NamedTuple,
+    TypedDict,
+    TypeVar,
+)
+
+from langchain_core.runnables import RunnableConfig
+from typing_extensions import NotRequired
+
+from langgraph.checkpoint.base.id import uuid6
+from langgraph.checkpoint.serde.base import SerializerProtocol, maybe_add_typed_methods
+from langgraph.checkpoint.serde.encrypted import EncryptedSerializer
+from langgraph.checkpoint.serde.jsonplus import JsonPlusSerializer
+from langgraph.checkpoint.serde.types import (
+    ERROR,
+    INTERRUPT,
+    RESUME,
+    SCHEDULED,
+    ChannelProtocol,
+)
+
+V = TypeVar("V", int, float, str)
+PendingWrite = tuple[str, str, Any]
+
+
+logger = logging.getLogger(__name__)
+
+
+# Marked as total=False to allow for future expansion.
+class CheckpointMetadata(TypedDict, total=False):
+    """Metadata associated with a checkpoint."""
+
+    source: Literal["input", "loop", "update", "fork"]
+    """The source of the checkpoint.
+
+    - `"input"`: The checkpoint was created from an input to invoke/stream/batch.
+    - `"loop"`: The checkpoint was created from inside the pregel loop.
+    - `"update"`: The checkpoint was created from a manual state update.
+    - `"fork"`: The checkpoint was created as a copy of another checkpoint.
+    """
+    step: int
+    """The step number of the checkpoint.
+
+    `-1` for the first `"input"` checkpoint.
+    `0` for the first `"loop"` checkpoint.
+    `...` for the `nth` checkpoint afterwards.
+    """
+    parents: dict[str, str]
+    """The IDs of the parent checkpoints.
+
+    Mapping from checkpoint namespace to checkpoint ID.
+    """
+    run_id: str
+    """The ID of the run that created this checkpoint."""
+    counters_since_delta_snapshot: dict[str, tuple[int, int]]
+    """Per-channel counters since the last `_DeltaSnapshot` was written.
+
+    !!! warning "Beta"
+
+        This metadata field backs `DeltaChannel` (beta). The key name and
+        contents may change while the delta-channel design stabilizes.
+
+    Maps channel name -> `(updates, supersteps)`:
+
+    - index 0 (`updates`): number of supersteps that wrote to this channel
+      since its last snapshot blob.
+    - index 1 (`supersteps`): total supersteps elapsed since this channel's
+      last snapshot, regardless of whether the channel was written.
+
+    A snapshot fires when EITHER `updates >= ch.snapshot_frequency` OR
+    `supersteps >= DELTA_MAX_SUPERSTEPS_SINCE_SNAPSHOT` (system-wide bound,
+    default 5000, env `LANGGRAPH_DELTA_MAX_SUPERSTEPS_SINCE_SNAPSHOT`).
+    The supersteps bound prevents unbounded ancestor walks on threads where
+    a delta channel exists but is no longer being updated.
+
+    Absent on threads that don't use delta channels. Persisted as a
+    2-element list in JSON (no native tuple).
+    """
+
+
+ChannelVersions = dict[str, str | int | float]
+
+
+class Checkpoint(TypedDict):
+    """State snapshot at a given point in time."""
+
+    v: int
+    """The version of the checkpoint format. Currently `1`."""
+    id: str
+    """The ID of the checkpoint.
+    
+    This is both unique and monotonically increasing, so can be used for sorting
+    checkpoints from first to last."""
+    ts: str
+    """The timestamp of the checkpoint in ISO 8601 format."""
+    channel_values: dict[str, Any]
+    """The values of the channels at the time of the checkpoint.
+    
+    Mapping from channel name to deserialized channel snapshot value.
+    """
+    channel_versions: ChannelVersions
+    """The versions of the channels at the time of the checkpoint.
+    
+    The keys are channel names and the values are monotonically increasing
+    version strings for each channel.
+    """
+    versions_seen: dict[str, ChannelVersions]
+    """Map from node ID to map from channel name to version seen.
+    
+    This keeps track of the versions of the channels that each node has seen.
+    Used to determine which nodes to execute next.
+    """
+    updated_channels: list[str] | None
+    """The channels that were updated in this checkpoint.
+    """
+
+
+def copy_checkpoint(checkpoint: Checkpoint) -> Checkpoint:
+    return Checkpoint(
+        v=checkpoint["v"],
+        ts=checkpoint["ts"],
+        id=checkpoint["id"],
+        channel_values=checkpoint["channel_values"].copy(),
+        channel_versions=checkpoint["channel_versions"].copy(),
+        versions_seen={k: v.copy() for k, v in checkpoint["versions_seen"].items()},
+        pending_sends=checkpoint.get("pending_sends", []).copy(),
+        updated_channels=checkpoint.get("updated_channels", None),
+    )
+
+
+class CheckpointTuple(NamedTuple):
+    """A tuple containing a checkpoint and its associated data."""
+
+    config: RunnableConfig
+    checkpoint: Checkpoint
+    metadata: CheckpointMetadata
+    parent_config: RunnableConfig | None = None
+    pending_writes: list[PendingWrite] | None = None
+
+
+class DeltaChannelHistory(TypedDict):
+    """Per-channel result entry from `BaseCheckpointSaver.get_delta_channel_history`.
+
+    !!! warning "Beta"
+
+        Part of the `DeltaChannel` support surface; in beta. Field names and
+        semantics may change.
+
+    Storage-level view of what one channel contributed across the ancestor
+    chain of a target checkpoint:
+
+    * `writes` — on-path deltas oldest→newest as `PendingWrite` tuples.
+      Always present; possibly empty. Already filtered to one channel.
+      Writes stored at the target checkpoint itself are pending for the
+      next super-step and are excluded.
+    * `seed` — the stored value at the nearest ancestor whose
+      `channel_values[ch]` is populated. Omitted if the walk reached the
+      root without finding any stored value (consumer treats absence as
+      "start empty"). Typically a `_DeltaSnapshot` for delta channels with
+      finite snapshot frequency, or a plain value for threads migrated
+      from a pre-delta channel type.
+    """
+
+    writes: list[PendingWrite]
+    seed: NotRequired[Any]
+
+
+class BaseCheckpointSaver(Generic[V]):
+    """Base class for creating a graph checkpointer.
+
+    Checkpointers allow LangGraph agents to persist their state
+    within and across multiple interactions.
+
+    When a checkpointer is configured, you should pass a `thread_id` in the config when
+    invoking the graph:
+
+    ```python
+    config = {"configurable": {"thread_id": "my-thread"}}
+    graph.invoke(inputs, config)
+    ```
+
+    The `thread_id` is the primary key used to store and retrieve checkpoints. Without
+    it, the checkpointer cannot save state, resume from interrupts, or enable
+    time-travel debugging.
+
+    How you choose ``thread_id`` depends on your use case:
+
+    - **Single-shot workflows**: Use a unique ID (e.g., uuid4) for each run when
+        executions are independent.
+    - **Conversational memory**: Reuse the same `thread_id` across invocations
+        to accumulate state (e.g., chat history) within a conversation.
+
+    Attributes:
+        serde (SerializerProtocol): Serializer for encoding/decoding checkpoints.
+
+    Note:
+        When creating a custom checkpoint saver, consider implementing async
+        versions to avoid blocking the main thread.
+    """
+
+    serde: SerializerProtocol = JsonPlusSerializer()
+
+    def __init__(
+        self,
+        *,
+        serde: SerializerProtocol | None = None,
+    ) -> None:
+        self.serde = maybe_add_typed_methods(serde or self.serde)
+
+    @property
+    def config_specs(self) -> list:
+        """Define the configuration options for the checkpoint saver.
+
+        Returns:
+            list: List of configuration field specs.
+        """
+        return []
+
+    def get(self, config: RunnableConfig) -> Checkpoint | None:
+        """Fetch a checkpoint using the given configuration.
+
+        Args:
+            config: Configuration specifying which checkpoint to retrieve.
+
+        Returns:
+            The requested checkpoint, or `None` if not found.
+        """
+        if value := self.get_tuple(config):
+            return value.checkpoint
+
+    def get_tuple(self, config: RunnableConfig) -> CheckpointTuple | None:
+        """Fetch a checkpoint tuple using the given configuration.
+
+        Args:
+            config: Configuration specifying which checkpoint to retrieve.
+
+        Returns:
+            The requested checkpoint tuple, or `None` if not found.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    def list(
+        self,
+        config: RunnableConfig | None,
+        *,
+        filter: dict[str, Any] | None = None,
+        before: RunnableConfig | None = None,
+        limit: int | None = None,
+    ) -> Iterator[CheckpointTuple]:
+        """List checkpoints that match the given criteria.
+
+        Args:
+            config: Base configuration for filtering checkpoints.
+            filter: Additional filtering criteria.
+            before: List checkpoints created before this configuration.
+            limit: Maximum number of checkpoints to return.
+
+        Returns:
+            Iterator of matching checkpoint tuples.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    def put(
+        self,
+        config: RunnableConfig,
+        checkpoint: Checkpoint,
+        metadata: CheckpointMetadata,
+        new_versions: ChannelVersions,
+    ) -> RunnableConfig:
+        """Store a checkpoint with its configuration and metadata.
+
+        Args:
+            config: Configuration for the checkpoint.
+            checkpoint: The checkpoint to store.
+            metadata: Additional metadata for the checkpoint.
+            new_versions: New channel versions as of this write.
+
+        Returns:
+            RunnableConfig: Updated configuration after storing the checkpoint.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    def put_writes(
+        self,
+        config: RunnableConfig,
+        writes: Sequence[tuple[str, Any]],
+        task_id: str,
+        task_path: str = "",
+    ) -> None:
+        """Store intermediate writes linked to a checkpoint.
+
+        Args:
+            config: Configuration of the related checkpoint.
+            writes: List of writes to store.
+            task_id: Identifier for the task creating the writes.
+            task_path: Path of the task creating the writes.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    def delete_thread(
+        self,
+        thread_id: str,
+    ) -> None:
+        """Delete all checkpoints and writes associated with a specific thread ID.
+
+        Args:
+            thread_id: The thread ID whose checkpoints should be deleted.
+        """
+        raise NotImplementedError
+
+    def delete_for_runs(
+        self,
+        run_ids: Sequence[str],
+    ) -> None:
+        """Delete all checkpoints and writes associated with the given run IDs.
+
+        Args:
+            run_ids: The run IDs whose checkpoints should be deleted.
+
+        !!! warning "DeltaChannel"
+
+            Deleting a run that produced ancestor `checkpoint_writes` — or
+            the only `_DeltaSnapshot` blob — for a still-live thread will
+            break reconstruction of any `DeltaChannel` whose history
+            depended on those rows. See the `DeltaChannel` note on `prune`
+            for safe-recovery strategies.
+        """
+        raise NotImplementedError
+
+    def copy_thread(
+        self,
+        source_thread_id: str,
+        target_thread_id: str,
+    ) -> None:
+        """Copy all checkpoints and writes from one thread to another.
+
+        Args:
+            source_thread_id: The thread ID to copy from.
+            target_thread_id: The thread ID to copy to.
+
+        !!! warning "DeltaChannel"
+
+            Implementations must copy the **complete** parent chain (all
+            ancestor checkpoints and their `checkpoint_writes`) — copying
+            only the head checkpoint will leave the target thread with
+            `DeltaChannel` state that cannot be reconstructed (no path back
+            to a `_DeltaSnapshot` ancestor). Equivalently, the copy must
+            include enough ancestors that every `DeltaChannel`-backed key
+            has either a `_DeltaSnapshot` in `channel_values` somewhere in
+            the chain, or a complete write history back to the chain root.
+        """
+        raise NotImplementedError
+
+    def prune(
+        self,
+        thread_ids: Sequence[str],
+        *,
+        strategy: str = "keep_latest",
+    ) -> None:
+        """Prune checkpoints for the given threads.
+
+        Args:
+            thread_ids: The thread IDs to prune.
+            strategy: The pruning strategy. `"keep_latest"` retains only the most
+                recent checkpoint per namespace. `"delete"` removes all checkpoints.
+
+        !!! warning "DeltaChannel"
+
+            Custom implementations must be `DeltaChannel`-aware. `DeltaChannel`
+            stores only a sentinel in `channel_values` for non-snapshot steps;
+            reconstruction walks the parent chain via
+            `get_delta_channel_history`, accumulating rows from
+            `checkpoint_writes` until it reaches an ancestor whose
+            `channel_values` contains a `_DeltaSnapshot` blob (written every
+            `snapshot_frequency` updates).
+
+            A naive `"keep_latest"` that drops intermediate checkpoints and
+            their writes can sever that chain: the surviving "latest"
+            checkpoint is rarely a snapshot point itself, so its delta
+            channels would silently reconstruct as empty (no error raised —
+            `get_delta_channel_history` simply returns no `seed`). Safe
+            options when the graph uses `DeltaChannel`:
+
+            * Walk back from each kept checkpoint and preserve every
+              ancestor (plus its `checkpoint_writes`) up to the nearest one
+              whose `channel_values` already contains a `_DeltaSnapshot` for
+              every `DeltaChannel`-backed key.
+            * Force a fresh snapshot on the kept checkpoint before deleting
+              ancestors — rewrite `channel_values[k] = _DeltaSnapshot(value)`
+              for each delta channel `k` (resolving `value` via the existing
+              ancestor walk first), then prune.
+            * Skip pruning threads whose graph uses `DeltaChannel` until one
+              of the above is implemented.
+        """
+        raise NotImplementedError
+
+    async def aget(self, config: RunnableConfig) -> Checkpoint | None:
+        """Asynchronously fetch a checkpoint using the given configuration.
+
+        Args:
+            config: Configuration specifying which checkpoint to retrieve.
+
+        Returns:
+            The requested checkpoint, or `None` if not found.
+        """
+        if value := await self.aget_tuple(config):
+            return value.checkpoint
+
+    async def aget_tuple(self, config: RunnableConfig) -> CheckpointTuple | None:
+        """Asynchronously fetch a checkpoint tuple using the given configuration.
+
+        Args:
+            config: Configuration specifying which checkpoint to retrieve.
+
+        Returns:
+            The requested checkpoint tuple, or `None` if not found.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    async def alist(
+        self,
+        config: RunnableConfig | None,
+        *,
+        filter: dict[str, Any] | None = None,
+        before: RunnableConfig | None = None,
+        limit: int | None = None,
+    ) -> AsyncIterator[CheckpointTuple]:
+        """Asynchronously list checkpoints that match the given criteria.
+
+        Args:
+            config: Base configuration for filtering checkpoints.
+            filter: Additional filtering criteria for metadata.
+            before: List checkpoints created before this configuration.
+            limit: Maximum number of checkpoints to return.
+
+        Returns:
+            Async iterator of matching checkpoint tuples.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+        yield
+
+    async def aput(
+        self,
+        config: RunnableConfig,
+        checkpoint: Checkpoint,
+        metadata: CheckpointMetadata,
+        new_versions: ChannelVersions,
+    ) -> RunnableConfig:
+        """Asynchronously store a checkpoint with its configuration and metadata.
+
+        Args:
+            config: Configuration for the checkpoint.
+            checkpoint: The checkpoint to store.
+            metadata: Additional metadata for the checkpoint.
+            new_versions: New channel versions as of this write.
+
+        Returns:
+            RunnableConfig: Updated configuration after storing the checkpoint.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    async def aput_writes(
+        self,
+        config: RunnableConfig,
+        writes: Sequence[tuple[str, Any]],
+        task_id: str,
+        task_path: str = "",
+    ) -> None:
+        """Asynchronously store intermediate writes linked to a checkpoint.
+
+        Args:
+            config: Configuration of the related checkpoint.
+            writes: List of writes to store.
+            task_id: Identifier for the task creating the writes.
+            task_path: Path of the task creating the writes.
+
+        Raises:
+            NotImplementedError: Implement this method in your custom checkpoint saver.
+        """
+        raise NotImplementedError
+
+    async def adelete_thread(
+        self,
+        thread_id: str,
+    ) -> None:
+        """Delete all checkpoints and writes associated with a specific thread ID.
+
+        Args:
+            thread_id: The thread ID whose checkpoints should be deleted.
+        """
+        raise NotImplementedError
+
+    async def adelete_for_runs(
+        self,
+        run_ids: Sequence[str],
+    ) -> None:
+        """Asynchronously delete all checkpoints and writes for the given run IDs.
+
+        Args:
+            run_ids: The run IDs whose checkpoints should be deleted.
+
+        !!! warning "DeltaChannel"
+
+            See `delete_for_runs` — deleting rows a still-live thread's
+            `DeltaChannel` reconstruction depends on (writes between the
+            head and its nearest `_DeltaSnapshot` ancestor) will silently
+            corrupt that channel's state.
+        """
+        raise NotImplementedError
+
+    async def acopy_thread(
+        self,
+        source_thread_id: str,
+        target_thread_id: str,
+    ) -> None:
+        """Asynchronously copy all checkpoints and writes from one thread to another.
+
+        Args:
+            source_thread_id: The thread ID to copy from.
+            target_thread_id: The thread ID to copy to.
+
+        !!! warning "DeltaChannel"
+
+            See `copy_thread` — the copy must carry the complete parent
+            chain (or at least back to a `_DeltaSnapshot` ancestor for every
+            `DeltaChannel`) so the target thread can reconstruct delta
+            state.
+        """
+        raise NotImplementedError
+
+    async def aprune(
+        self,
+        thread_ids: Sequence[str],
+        *,
+        strategy: str = "keep_latest",
+    ) -> None:
+        """Asynchronously prune checkpoints for the given threads.
+
+        Args:
+            thread_ids: The thread IDs to prune.
+            strategy: The pruning strategy. `"keep_latest"` retains only the most
+                recent checkpoint per namespace. `"delete"` removes all checkpoints.
+
+        !!! warning "DeltaChannel"
+
+            See `prune` for the full `DeltaChannel` caveat. In short:
+            `"keep_latest"` must not drop ancestor checkpoints / writes that
+            sit between the kept checkpoint and the nearest `_DeltaSnapshot`
+            ancestor, or delta channels will silently reconstruct as empty.
+        """
+        raise NotImplementedError
+
+    def get_delta_channel_history(
+        self, *, config: RunnableConfig, channels: Sequence[str]
+    ) -> Mapping[str, DeltaChannelHistory]:
+        """Walk the parent chain returning per-channel writes + seed.
+
+        !!! warning "Beta"
+
+            This method is part of the `DeltaChannel` support surface and is
+            in beta. The signature, return shape (`DeltaChannelHistory`), and
+            interaction with `_DeltaSnapshot` blobs may change. Override at
+            your own risk; the default implementation will continue to work
+            against the public `BaseCheckpointSaver` contract.
+
+        For each requested channel, walks ancestors of the checkpoint
+        identified by `config` (following `parent_config`) and accumulates
+        `pending_writes` for that channel. The walk terminates per-channel
+        at the nearest ancestor whose `channel_values[ch]` is populated;
+        that value is returned as `seed`. If the walk reaches the root
+        without finding a stored value, `seed` is omitted from that
+        channel's entry — the consumer treats the absence as "start
+        empty."
+
+        Walks the **parent chain** (not `list(before=...)`): for forked
+        threads, only on-path ancestors contribute.
+
+        The default implementation walks `get_tuple` + `parent_config`
+        once for all channels — each ancestor visited once, not once per
+        channel. Savers with direct storage access (`InMemorySaver`,
+        `PostgresSaver`) override for performance; the return contract is
+        fixed here.
+
+        Args:
+            config: Configuration identifying the target checkpoint.
+            channels: Channel names to walk for. Empty → empty mapping.
+
+        Returns:
+            Per-channel `DeltaChannelHistory` for every name in `channels`.
+        """
+        if not channels:
+            return {}
+        collected_by_ch: dict[str, list[PendingWrite]] = {c: [] for c in channels}
+        seed_by_ch: dict[str, Any] = {}
+        remaining: set[str] = set(channels)
+        target_tuple = self.get_tuple(config)
+        cursor_config: RunnableConfig | None = (
+            target_tuple.parent_config if target_tuple else None
+        )
+        while cursor_config is not None and remaining:
+            tup = self.get_tuple(cursor_config)
+            if tup is None:
+                break
+            if tup.pending_writes:
+                for write in reversed(tup.pending_writes):
+                    ch = write[1]
+                    if ch in remaining:
+                        collected_by_ch[ch].append(write)
+            for ch in list(remaining):
+                if ch in tup.checkpoint["channel_values"]:
+                    seed_by_ch[ch] = tup.checkpoint["channel_values"][ch]
+                    remaining.discard(ch)
+            cursor_config = tup.parent_config
+        result: dict[str, DeltaChannelHistory] = {}
+        for ch in channels:
+            entry: DeltaChannelHistory = {"writes": list(reversed(collected_by_ch[ch]))}
+            if ch in seed_by_ch:
+                entry["seed"] = seed_by_ch[ch]
+            result[ch] = entry
+        return result
+
+    async def aget_delta_channel_history(
+        self, *, config: RunnableConfig, channels: Sequence[str]
+    ) -> Mapping[str, DeltaChannelHistory]:
+        """Async version of `get_delta_channel_history`.
+
+        !!! warning "Beta"
+
+            This method is part of the `DeltaChannel` support surface and is
+            in beta. See `get_delta_channel_history` for caveats.
+        """
+        if not channels:
+            return {}
+        collected_by_ch: dict[str, list[PendingWrite]] = {c: [] for c in channels}
+        seed_by_ch: dict[str, Any] = {}
+        remaining: set[str] = set(channels)
+        target_tuple = await self.aget_tuple(config)
+        cursor_config: RunnableConfig | None = (
+            target_tuple.parent_config if target_tuple else None
+        )
+        while cursor_config is not None and remaining:
+            tup = await self.aget_tuple(cursor_config)
+            if tup is None:
+                break
+            if tup.pending_writes:
+                for write in reversed(tup.pending_writes):
+                    ch = write[1]
+                    if ch in remaining:
+                        collected_by_ch[ch].append(write)
+            for ch in list(remaining):
+                if ch in tup.checkpoint["channel_values"]:
+                    seed_by_ch[ch] = tup.checkpoint["channel_values"][ch]
+                    remaining.discard(ch)
+            cursor_config = tup.parent_config
+        result: dict[str, DeltaChannelHistory] = {}
+        for ch in channels:
+            entry: DeltaChannelHistory = {"writes": list(reversed(collected_by_ch[ch]))}
+            if ch in seed_by_ch:
+                entry["seed"] = seed_by_ch[ch]
+            result[ch] = entry
+        return result
+
+    def get_next_version(self, current: V | None, channel: None) -> V:
+        """Generate the next version ID for a channel.
+
+        Default is to use integer versions, incrementing by `1`.
+
+        If you override, you can use `str`/`int`/`float` versions, as long as they are monotonically increasing.
+
+        Args:
+            current: The current version identifier (`int`, `float`, or `str`).
+            channel: Deprecated argument, kept for backwards compatibility.
+
+        Returns:
+            V: The next version identifier, which must be increasing.
+        """
+        if isinstance(current, str):
+            raise NotImplementedError
+        elif current is None:
+            return 1
+        else:
+            return current + 1
+
+    def with_allowlist(
+        self, extra_allowlist: Collection[tuple[str, ...]]
+    ) -> BaseCheckpointSaver[V]:
+        """Return a shallow clone with a derived msgpack allowlist."""
+        serde = _with_msgpack_allowlist(self.serde, extra_allowlist)
+        if serde is self.serde:
+            return self
+        clone = copy.copy(self)
+        clone.serde = maybe_add_typed_methods(serde)
+        return clone
+
+
+def _with_msgpack_allowlist(
+    serde: SerializerProtocol, extra_allowlist: Collection[tuple[str, ...]]
+) -> SerializerProtocol:
+    if isinstance(serde, JsonPlusSerializer):
+        return serde.with_msgpack_allowlist(extra_allowlist)
+    if isinstance(serde, EncryptedSerializer):
+        inner = serde.serde
+        if isinstance(inner, JsonPlusSerializer):
+            updated_inner = inner.with_msgpack_allowlist(extra_allowlist)
+            if updated_inner is inner:
+                return serde
+            return EncryptedSerializer(serde.cipher, updated_inner)
+    logger.warning(
+        "Serializer %s does not support msgpack allowlist. "
+        "Strict msgpack deserialization will not be enforced.",
+        type(serde).__name__,
+    )
+    return serde
+
+
+class EmptyChannelError(Exception):
+    """Raised when attempting to get the value of a channel that hasn't been updated
+    for the first time yet."""
+
+    pass
+
+
+def get_checkpoint_id(config: RunnableConfig) -> str | None:
+    """Get checkpoint ID."""
+    return config["configurable"].get("checkpoint_id")
+
+
+def get_checkpoint_metadata(
+    config: RunnableConfig, metadata: CheckpointMetadata
+) -> CheckpointMetadata:
+    """Get checkpoint metadata in a backwards-compatible manner."""
+    metadata = {
+        k: v.replace("\u0000", "") if isinstance(v, str) else v
+        for k, v in metadata.items()
+    }
+    for obj in (config.get("metadata"), config.get("configurable")):
+        if not obj:
+            continue
+        for key, v in obj.items():
+            if key in metadata or key in EXCLUDED_METADATA_KEYS or key.startswith("__"):
+                continue
+            elif isinstance(v, str):
+                metadata[key] = v.replace("\u0000", "")
+            elif isinstance(v, (int, bool, float)):
+                metadata[key] = v
+    return metadata
+
+
+def get_serializable_checkpoint_metadata(
+    config: RunnableConfig, metadata: CheckpointMetadata
+) -> CheckpointMetadata:
+    """Get checkpoint metadata in a backwards-compatible manner."""
+    checkpoint_metadata = get_checkpoint_metadata(config, metadata)
+    if "writes" in checkpoint_metadata:
+        checkpoint_metadata.pop("writes")
+    return checkpoint_metadata
+
+
+"""
+Mapping from error type to error index.
+Regular writes just map to their index in the list of writes being saved.
+Special writes (e.g. errors) map to negative indices, to avoid those writes from
+conflicting with regular writes.
+Each Checkpointer implementation should use this mapping in put_writes.
+"""
+WRITES_IDX_MAP = {ERROR: -1, SCHEDULED: -2, INTERRUPT: -3, RESUME: -4}
+
+EXCLUDED_METADATA_KEYS = {
+    "thread_id",
+    "checkpoint_id",
+    "checkpoint_ns",
+    "checkpoint_map",
+    "langgraph_step",
+    "langgraph_node",
+    "langgraph_triggers",
+    "langgraph_path",
+    "langgraph_checkpoint_ns",
+}
+
+# --- below are deprecated utilities used by past versions of LangGraph ---
+
+LATEST_VERSION = 2
+
+
+def empty_checkpoint() -> Checkpoint:
+    from datetime import datetime, timezone
+
+    return Checkpoint(
+        v=LATEST_VERSION,
+        id=str(uuid6(clock_seq=-2)),
+        ts=datetime.now(timezone.utc).isoformat(),
+        channel_values={},
+        channel_versions={},
+        versions_seen={},
+        pending_sends=[],
+        updated_channels=None,
+    )
+
+
+def create_checkpoint(
+    checkpoint: Checkpoint,
+    channels: Mapping[str, ChannelProtocol] | None,
+    step: int,
+    *,
+    id: str | None = None,
+) -> Checkpoint:
+    """Create a checkpoint for the given channels."""
+    from datetime import datetime, timezone
+
+    ts = datetime.now(timezone.utc).isoformat()
+    if channels is None:
+        values = checkpoint["channel_values"]
+    else:
+        values = {}
+        for k, v in channels.items():
+            if k not in checkpoint["channel_versions"]:
+                continue
+            try:
+                values[k] = v.checkpoint()
+            except EmptyChannelError:
+                pass
+    return Checkpoint(
+        v=LATEST_VERSION,
+        ts=ts,
+        id=id or str(uuid6(clock_seq=step)),
+        channel_values=values,
+        channel_versions=checkpoint["channel_versions"],
+        versions_seen=checkpoint["versions_seen"],
+        pending_sends=checkpoint.get("pending_sends", []),
+        updated_channels=None,
+    )

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/checkpoint/base/id.py

@@ -0,0 +1,109 @@
+"""Adapted from
+https://github.com/oittaa/uuid6-python/blob/main/src/uuid6/__init__.py#L95
+Bundled in to avoid install issues with uuid6 package
+"""
+
+from __future__ import annotations
+
+import random
+import time
+import uuid
+
+_last_v6_timestamp = None
+
+
+class UUID(uuid.UUID):
+    r"""UUID draft version objects"""
+
+    __slots__ = ()
+
+    def __init__(
+        self,
+        hex: str | None = None,
+        bytes: bytes | None = None,
+        bytes_le: bytes | None = None,
+        fields: tuple[int, int, int, int, int, int] | None = None,
+        int: int | None = None,
+        version: int | None = None,
+        *,
+        is_safe: uuid.SafeUUID = uuid.SafeUUID.unknown,
+    ) -> None:
+        r"""Create a UUID."""
+
+        if int is None or [hex, bytes, bytes_le, fields].count(None) != 4:
+            return super().__init__(
+                hex=hex,
+                bytes=bytes,
+                bytes_le=bytes_le,
+                fields=fields,
+                int=int,
+                version=version,
+                is_safe=is_safe,
+            )
+        if not 0 <= int < 1 << 128:
+            raise ValueError("int is out of range (need a 128-bit value)")
+        if version is not None:
+            if not 6 <= version <= 8:
+                raise ValueError("illegal version number")
+            # Set the variant to RFC 4122.
+            int &= ~(0xC000 << 48)
+            int |= 0x8000 << 48
+            # Set the version number.
+            int &= ~(0xF000 << 64)
+            int |= version << 76
+        super().__init__(int=int, is_safe=is_safe)
+
+    @property
+    def subsec(self) -> int:
+        return ((self.int >> 64) & 0x0FFF) << 8 | ((self.int >> 54) & 0xFF)
+
+    @property
+    def time(self) -> int:
+        if self.version == 6:
+            return (
+                (self.time_low << 28)
+                | (self.time_mid << 12)
+                | (self.time_hi_version & 0x0FFF)
+            )
+        if self.version == 7:
+            return self.int >> 80
+        if self.version == 8:
+            return (self.int >> 80) * 10**6 + _subsec_decode(self.subsec)
+        return super().time
+
+
+def _subsec_decode(value: int) -> int:
+    return -(-value * 10**6 // 2**20)
+
+
+def uuid6(node: int | None = None, clock_seq: int | None = None) -> UUID:
+    r"""UUID version 6 is a field-compatible version of UUIDv1, reordered for
+    improved DB locality. It is expected that UUIDv6 will primarily be
+    used in contexts where there are existing v1 UUIDs. Systems that do
+    not involve legacy UUIDv1 SHOULD consider using UUIDv7 instead.
+
+    If 'node' is not given, a random 48-bit number is chosen.
+
+    If 'clock_seq' is given, it is used as the sequence number;
+    otherwise a random 14-bit sequence number is chosen."""
+
+    global _last_v6_timestamp
+
+    nanoseconds = time.time_ns()
+    # 0x01b21dd213814000 is the number of 100-ns intervals between the
+    # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.
+    timestamp = nanoseconds // 100 + 0x01B21DD213814000
+    if _last_v6_timestamp is not None and timestamp <= _last_v6_timestamp:
+        timestamp = _last_v6_timestamp + 1
+    _last_v6_timestamp = timestamp
+    if clock_seq is None:
+        clock_seq = random.getrandbits(14)  # instead of stable storage
+    if node is None:
+        node = random.getrandbits(48)
+    time_high_and_time_mid = (timestamp >> 12) & 0xFFFFFFFFFFFF
+    time_low_and_version = timestamp & 0x0FFF
+    uuid_int = time_high_and_time_mid << 80
+    uuid_int |= time_low_and_version << 64
+    uuid_int |= (clock_seq & 0x3FFF) << 48
+    uuid_int |= node & 0xFFFFFFFFFFFF
+    return UUID(int=uuid_int, version=6)

data/conda_envs/evalclaw/lib/python3.11/site-packages/langgraph/checkpoint/memory/__init__.py

@@ -0,0 +1,704 @@
+from __future__ import annotations
+
+import logging
+import os
+import pickle
+import random
+import shutil
+from collections import defaultdict
+from collections.abc import AsyncIterator, Iterator, Mapping, Sequence
+from contextlib import AbstractAsyncContextManager, AbstractContextManager, ExitStack
+from types import TracebackType
+from typing import Any
+
+from langchain_core.runnables import RunnableConfig
+
+from langgraph.checkpoint.base import (
+    WRITES_IDX_MAP,
+    BaseCheckpointSaver,
+    ChannelVersions,
+    Checkpoint,
+    CheckpointMetadata,
+    CheckpointTuple,
+    DeltaChannelHistory,
+    PendingWrite,
+    SerializerProtocol,
+    get_checkpoint_id,
+    get_checkpoint_metadata,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class InMemorySaver(
+    BaseCheckpointSaver[str], AbstractContextManager, AbstractAsyncContextManager
+):
+    """An in-memory checkpoint saver.
+
+    This checkpoint saver stores checkpoints in memory using a `defaultdict`.
+
+    Note:
+        Only use `InMemorySaver` for debugging or testing purposes.
+        For production use cases we recommend installing [langgraph-checkpoint-postgres](https://pypi.org/project/langgraph-checkpoint-postgres/) and using `PostgresSaver` / `AsyncPostgresSaver`.
+
+        If you are using LangSmith Deployment, no checkpointer needs to be specified. The correct managed checkpointer will be used automatically.
+
+    Args:
+        serde: The serializer to use for serializing and deserializing checkpoints.
+
+    Example:
+        ```python
+        import asyncio
+
+        from langgraph.checkpoint.memory import InMemorySaver
+        from langgraph.graph import StateGraph
+
+        builder = StateGraph(int)
+        builder.add_node("add_one", lambda x: x + 1)
+        builder.set_entry_point("add_one")
+        builder.set_finish_point("add_one")
+
+        memory = InMemorySaver()
+        graph = builder.compile(checkpointer=memory)
+        coro = graph.ainvoke(1, {"configurable": {"thread_id": "thread-1"}})
+        asyncio.run(coro)  # Output: 2
+        ```
+    """
+
+    # thread ID ->  checkpoint NS -> checkpoint ID -> checkpoint mapping
+    storage: defaultdict[
+        str,
+        dict[str, dict[str, tuple[tuple[str, bytes], tuple[str, bytes], str | None]]],
+    ]
+    # (thread ID, checkpoint NS, checkpoint ID) -> (task ID, write idx)
+    writes: defaultdict[
+        tuple[str, str, str],
+        dict[tuple[str, int], tuple[str, str, tuple[str, bytes], str]],
+    ]
+    blobs: dict[
+        tuple[
+            str, str, str, str | int | float
+        ],  # thread id, checkpoint ns, channel, version
+        tuple[str, bytes],
+    ]
+
+    def __init__(
+        self,
+        *,
+        serde: SerializerProtocol | None = None,
+        factory: type[defaultdict] = defaultdict,
+    ) -> None:
+        super().__init__(serde=serde)
+        self.storage = factory(lambda: defaultdict(dict))
+        self.writes = factory(dict)
+        self.blobs = factory()
+        self.stack = ExitStack()
+        if factory is not defaultdict:
+            self.stack.enter_context(self.storage)  # type: ignore[arg-type]
+            self.stack.enter_context(self.writes)  # type: ignore[arg-type]
+            self.stack.enter_context(self.blobs)  # type: ignore[arg-type]
+
+    def __enter__(self) -> InMemorySaver:
+        self.stack.__enter__()
+        return self
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_value: BaseException | None,
+        traceback: TracebackType | None,
+    ) -> bool | None:
+        return self.stack.__exit__(exc_type, exc_value, traceback)
+
+    async def __aenter__(self) -> InMemorySaver:
+        self.stack.__enter__()
+        return self
+
+    async def __aexit__(
+        self,
+        __exc_type: type[BaseException] | None,
+        __exc_value: BaseException | None,
+        __traceback: TracebackType | None,
+    ) -> bool | None:
+        return self.stack.__exit__(__exc_type, __exc_value, __traceback)
+
+    def _load_blobs(
+        self,
+        thread_id: str,
+        checkpoint_ns: str,
+        versions: ChannelVersions,
+    ) -> dict[str, Any]:
+        result: dict[str, Any] = {}
+        for k, ver in versions.items():
+            kk = (thread_id, checkpoint_ns, k, ver)
+            if kk not in self.blobs:
+                continue
+            vv = self.blobs[kk]
+            if vv[0] == "empty":
+                continue
+            result[k] = self.serde.loads_typed(vv)
+        return result
+
+    def get_delta_channel_history(
+        self, *, config: RunnableConfig, channels: Sequence[str]
+    ) -> Mapping[str, DeltaChannelHistory]:
+        """Override: walk the parent chain ONCE for all requested channels.
+
+        Each channel terminates independently at the nearest ancestor
+        whose stored blob is non-empty. Other channels keep walking until
+        they find their own terminator or hit the root.
+
+        Pre-delta plain-value blobs subsume their ancestor's pending
+        writes (the value already includes them); `_DeltaSnapshot` blobs
+        do not (snapshot is the value AT that ancestor, prior to its own
+        pending writes that produce the child).
+        """
+        if not channels:
+            return {}
+        # Imported lazily to avoid a hard checkpoint→serde-types coupling at
+        # module import; only this override needs the runtime check.
+        from langgraph.checkpoint.serde.types import _DeltaSnapshot
+
+        thread_id = config["configurable"]["thread_id"]
+        checkpoint_ns = config["configurable"].get("checkpoint_ns", "")
+        checkpoint_id = config["configurable"].get("checkpoint_id", "")
+        ns_storage = self.storage.get(thread_id, {}).get(checkpoint_ns, {})
+
+        chain: list[str] = []
+        target_entry = ns_storage.get(checkpoint_id)
+        current: str | None = target_entry[2] if target_entry is not None else None
+        while current is not None:
+            entry = ns_storage.get(current)
+            if entry is None:
+                break
+            chain.append(current)
+            _, _, parent = entry
+            current = parent
+
+        collected_by_ch: dict[str, list[PendingWrite]] = {c: [] for c in channels}
+        seed_by_ch: dict[str, Any] = {}
+        remaining: set[str] = set(channels)
+
+        for cp_id in chain:
+            if not remaining:
+                break
+            entry = ns_storage.get(cp_id)
+            ckpt = self.serde.loads_typed(entry[0]) if entry is not None else None
+
+            terminated_here: set[str] = set()
+            blob_value_by_ch: dict[str, Any] = {}
+            if ckpt is not None:
+                versions = ckpt.get("channel_versions", {})
+                for ch in remaining:
+                    ver = versions.get(ch)
+                    if ver is None:
+                        continue
+                    blob_entry = self.blobs.get((thread_id, checkpoint_ns, ch, ver))
+                    if blob_entry is None or blob_entry[0] == "empty":
+                        continue
+                    blob_value_by_ch[ch] = self.serde.loads_typed(blob_entry)
+                    terminated_here.add(ch)
+
+            step_writes = self.writes.get((thread_id, checkpoint_ns, cp_id), {})
+            for (_task_id, _idx), (tid, ch, serialized, _) in sorted(
+                step_writes.items(), reverse=True
+            ):
+                if ch not in remaining:
+                    continue
+                blob_value = blob_value_by_ch.get(ch)
+                if blob_value is not None and not isinstance(
+                    blob_value, _DeltaSnapshot
+                ):
+                    continue
+                collected_by_ch[ch].append(
+                    (tid, ch, self.serde.loads_typed(serialized))
+                )
+
+            for ch in terminated_here:
+                seed_by_ch[ch] = blob_value_by_ch[ch]
+                remaining.discard(ch)
+
+        result: dict[str, DeltaChannelHistory] = {}
+        for ch in channels:
+            entry_h: DeltaChannelHistory = {
+                "writes": list(reversed(collected_by_ch[ch]))
+            }
+            if ch in seed_by_ch:
+                entry_h["seed"] = seed_by_ch[ch]
+            result[ch] = entry_h
+        return result
+
+    async def aget_delta_channel_history(
+        self, *, config: RunnableConfig, channels: Sequence[str]
+    ) -> Mapping[str, DeltaChannelHistory]:
+        return self.get_delta_channel_history(config=config, channels=channels)
+
+    def get_tuple(self, config: RunnableConfig) -> CheckpointTuple | None:
+        """Get a checkpoint tuple from the in-memory storage.
+
+        This method retrieves a checkpoint tuple from the in-memory storage based on the
+        provided config. If the config contains a `checkpoint_id` key, the checkpoint with
+        the matching thread ID and timestamp is retrieved. Otherwise, the latest checkpoint
+        for the given thread ID is retrieved.
+
+        Args:
+            config: The config to use for retrieving the checkpoint.
+
+        Returns:
+            The retrieved checkpoint tuple, or None if no matching checkpoint was found.
+        """
+        thread_id: str = config["configurable"]["thread_id"]
+        checkpoint_ns: str = config["configurable"].get("checkpoint_ns", "")
+        if checkpoint_id := get_checkpoint_id(config):
+            if saved := self.storage[thread_id][checkpoint_ns].get(checkpoint_id):
+                checkpoint, metadata, parent_checkpoint_id = saved
+                writes = self.writes[(thread_id, checkpoint_ns, checkpoint_id)].values()
+                checkpoint_: Checkpoint = self.serde.loads_typed(checkpoint)
+                return CheckpointTuple(
+                    config=config,
+                    checkpoint={
+                        **checkpoint_,
+                        "channel_values": self._load_blobs(
+                            thread_id, checkpoint_ns, checkpoint_["channel_versions"]
+                        ),
+                    },
+                    metadata=self.serde.loads_typed(metadata),
+                    pending_writes=[
+                        (id, c, self.serde.loads_typed(v)) for id, c, v, _ in writes
+                    ],
+                    parent_config=(
+                        {
+                            "configurable": {
+                                "thread_id": thread_id,
+                                "checkpoint_ns": checkpoint_ns,
+                                "checkpoint_id": parent_checkpoint_id,
+                            }
+                        }
+                        if parent_checkpoint_id
+                        else None
+                    ),
+                )
+        else:
+            if checkpoints := self.storage[thread_id][checkpoint_ns]:
+                checkpoint_id = max(checkpoints.keys())
+                checkpoint, metadata, parent_checkpoint_id = checkpoints[checkpoint_id]
+                writes = self.writes[(thread_id, checkpoint_ns, checkpoint_id)].values()
+                checkpoint_ = self.serde.loads_typed(checkpoint)
+                return CheckpointTuple(
+                    config={
+                        "configurable": {
+                            "thread_id": thread_id,
+                            "checkpoint_ns": checkpoint_ns,
+                            "checkpoint_id": checkpoint_id,
+                        }
+                    },
+                    checkpoint={
+                        **checkpoint_,
+                        "channel_values": self._load_blobs(
+                            thread_id, checkpoint_ns, checkpoint_["channel_versions"]
+                        ),
+                    },
+                    metadata=self.serde.loads_typed(metadata),
+                    pending_writes=[
+                        (id, c, self.serde.loads_typed(v)) for id, c, v, _ in writes
+                    ],
+                    parent_config=(
+                        {
+                            "configurable": {
+                                "thread_id": thread_id,
+                                "checkpoint_ns": checkpoint_ns,
+                                "checkpoint_id": parent_checkpoint_id,
+                            }
+                        }
+                        if parent_checkpoint_id
+                        else None
+                    ),
+                )
+
+    def list(
+        self,
+        config: RunnableConfig | None,
+        *,
+        filter: dict[str, Any] | None = None,
+        before: RunnableConfig | None = None,
+        limit: int | None = None,
+    ) -> Iterator[CheckpointTuple]:
+        """List checkpoints from the in-memory storage.
+
+        This method retrieves a list of checkpoint tuples from the in-memory storage based
+        on the provided criteria.
+
+        Args:
+            config: Base configuration for filtering checkpoints.
+            filter: Additional filtering criteria for metadata.
+            before: List checkpoints created before this configuration.
+            limit: Maximum number of checkpoints to return.
+
+        Yields:
+            An iterator of matching checkpoint tuples.
+        """
+        thread_ids = (config["configurable"]["thread_id"],) if config else self.storage
+        config_checkpoint_ns = (
+            config["configurable"].get("checkpoint_ns") if config else None
+        )
+        config_checkpoint_id = get_checkpoint_id(config) if config else None
+        for thread_id in thread_ids:
+            for checkpoint_ns in self.storage[thread_id].keys():
+                if (
+                    config_checkpoint_ns is not None
+                    and checkpoint_ns != config_checkpoint_ns
+                ):
+                    continue
+
+                for checkpoint_id, (
+                    checkpoint,
+                    metadata_b,
+                    parent_checkpoint_id,
+                ) in sorted(
+                    self.storage[thread_id][checkpoint_ns].items(),
+                    key=lambda x: x[0],
+                    reverse=True,
+                ):
+                    # filter by checkpoint ID from config
+                    if config_checkpoint_id and checkpoint_id != config_checkpoint_id:
+                        continue
+
+                    # filter by checkpoint ID from `before` config
+                    if (
+                        before
+                        and (before_checkpoint_id := get_checkpoint_id(before))
+                        and checkpoint_id >= before_checkpoint_id
+                    ):
+                        continue
+
+                    # filter by metadata
+                    metadata = self.serde.loads_typed(metadata_b)
+                    if filter and not all(
+                        query_value == metadata.get(query_key)
+                        for query_key, query_value in filter.items()
+                    ):
+                        continue
+
+                    # limit search results
+                    if limit is not None and limit <= 0:
+                        break
+                    elif limit is not None:
+                        limit -= 1
+
+                    writes = self.writes[
+                        (thread_id, checkpoint_ns, checkpoint_id)
+                    ].values()
+
+                    checkpoint_: Checkpoint = self.serde.loads_typed(checkpoint)
+
+                    yield CheckpointTuple(
+                        config={
+                            "configurable": {
+                                "thread_id": thread_id,
+                                "checkpoint_ns": checkpoint_ns,
+                                "checkpoint_id": checkpoint_id,
+                            }
+                        },
+                        checkpoint={
+                            **checkpoint_,
+                            "channel_values": self._load_blobs(
+                                thread_id,
+                                checkpoint_ns,
+                                checkpoint_["channel_versions"],
+                            ),
+                        },
+                        metadata=metadata,
+                        parent_config=(
+                            {
+                                "configurable": {
+                                    "thread_id": thread_id,
+                                    "checkpoint_ns": checkpoint_ns,
+                                    "checkpoint_id": parent_checkpoint_id,
+                                }
+                            }
+                            if parent_checkpoint_id
+                            else None
+                        ),
+                        pending_writes=[
+                            (id, c, self.serde.loads_typed(v)) for id, c, v, _ in writes
+                        ],
+                    )
+
+    def put(
+        self,
+        config: RunnableConfig,
+        checkpoint: Checkpoint,
+        metadata: CheckpointMetadata,
+        new_versions: ChannelVersions,
+    ) -> RunnableConfig:
+        """Save a checkpoint to the in-memory storage.
+
+        This method saves a checkpoint to the in-memory storage. The checkpoint is associated
+        with the provided config.
+
+        Args:
+            config: The config to associate with the checkpoint.
+            checkpoint: The checkpoint to save.
+            metadata: Additional metadata to save with the checkpoint.
+            new_versions: New versions as of this write
+
+        Returns:
+            RunnableConfig: The updated config containing the saved checkpoint's timestamp.
+        """
+        c = checkpoint.copy()
+        thread_id = config["configurable"]["thread_id"]
+        checkpoint_ns = config["configurable"]["checkpoint_ns"]
+        values: dict[str, Any] = c.pop("channel_values")  # type: ignore[misc]
+        for k, v in new_versions.items():
+            self.blobs[(thread_id, checkpoint_ns, k, v)] = (
+                self.serde.dumps_typed(values[k]) if k in values else ("empty", b"")
+            )
+        self.storage[thread_id][checkpoint_ns].update(
+            {
+                checkpoint["id"]: (
+                    self.serde.dumps_typed(c),
+                    self.serde.dumps_typed(get_checkpoint_metadata(config, metadata)),
+                    config["configurable"].get("checkpoint_id"),  # parent
+                )
+            }
+        )
+        return {
+            "configurable": {
+                "thread_id": thread_id,
+                "checkpoint_ns": checkpoint_ns,
+                "checkpoint_id": checkpoint["id"],
+            }
+        }
+
+    def put_writes(
+        self,
+        config: RunnableConfig,
+        writes: Sequence[tuple[str, Any]],
+        task_id: str,
+        task_path: str = "",
+    ) -> None:
+        """Save a list of writes to the in-memory storage.
+
+        This method saves a list of writes to the in-memory storage. The writes are associated
+        with the provided config.
+
+        Args:
+            config: The config to associate with the writes.
+            writes: The writes to save.
+            task_id: Identifier for the task creating the writes.
+            task_path: Path of the task creating the writes.
+
+        Returns:
+            RunnableConfig: The updated config containing the saved writes' timestamp.
+        """
+        thread_id = config["configurable"]["thread_id"]
+        checkpoint_ns = config["configurable"].get("checkpoint_ns", "")
+        checkpoint_id = config["configurable"]["checkpoint_id"]
+        outer_key = (thread_id, checkpoint_ns, checkpoint_id)
+        outer_writes_ = self.writes.get(outer_key)
+        for idx, (c, v) in enumerate(writes):
+            inner_key = (task_id, WRITES_IDX_MAP.get(c, idx))
+            if inner_key[1] >= 0 and outer_writes_ and inner_key in outer_writes_:
+                continue
+
+            self.writes[outer_key][inner_key] = (
+                task_id,
+                c,
+                self.serde.dumps_typed(v),
+                task_path,
+            )
+
+    def delete_thread(self, thread_id: str) -> None:
+        """Delete all checkpoints and writes associated with a thread ID.
+
+        Args:
+            thread_id: The thread ID to delete.
+
+        Returns:
+            None
+        """
+        if thread_id in self.storage:
+            del self.storage[thread_id]
+        for k in list(self.writes.keys()):
+            if k[0] == thread_id:
+                del self.writes[k]
+        for k in list(self.blobs.keys()):
+            if k[0] == thread_id:
+                del self.blobs[k]
+
+    async def aget_tuple(self, config: RunnableConfig) -> CheckpointTuple | None:
+        """Asynchronous version of `get_tuple`.
+
+        This method is an asynchronous wrapper around `get_tuple` that runs the synchronous
+        method in a separate thread using asyncio.
+
+        Args:
+            config: The config to use for retrieving the checkpoint.
+
+        Returns:
+            The retrieved checkpoint tuple, or None if no matching checkpoint was found.
+        """
+        return self.get_tuple(config)
+
+    async def alist(
+        self,
+        config: RunnableConfig | None,
+        *,
+        filter: dict[str, Any] | None = None,
+        before: RunnableConfig | None = None,
+        limit: int | None = None,
+    ) -> AsyncIterator[CheckpointTuple]:
+        """Asynchronous version of `list`.
+
+        This method is an asynchronous wrapper around `list` that runs the synchronous
+        method in a separate thread using asyncio.
+
+        Args:
+            config: The config to use for listing the checkpoints.
+
+        Yields:
+            An asynchronous iterator of checkpoint tuples.
+        """
+        for item in self.list(config, filter=filter, before=before, limit=limit):
+            yield item
+
+    async def aput(
+        self,
+        config: RunnableConfig,
+        checkpoint: Checkpoint,
+        metadata: CheckpointMetadata,
+        new_versions: ChannelVersions,
+    ) -> RunnableConfig:
+        """Asynchronous version of `put`.
+
+        Args:
+            config: The config to associate with the checkpoint.
+            checkpoint: The checkpoint to save.
+            metadata: Additional metadata to save with the checkpoint.
+            new_versions: New versions as of this write
+
+        Returns:
+            RunnableConfig: The updated config containing the saved checkpoint's timestamp.
+        """
+        return self.put(config, checkpoint, metadata, new_versions)
+
+    async def aput_writes(
+        self,
+        config: RunnableConfig,
+        writes: Sequence[tuple[str, Any]],
+        task_id: str,
+        task_path: str = "",
+    ) -> None:
+        """Asynchronous version of `put_writes`.
+
+        This method is an asynchronous wrapper around `put_writes` that runs the synchronous
+        method in a separate thread using asyncio.
+
+        Args:
+            config: The config to associate with the writes.
+            writes: The writes to save, each as a (channel, value) pair.
+            task_id: Identifier for the task creating the writes.
+            task_path: Path of the task creating the writes.
+
+        Returns:
+            None
+        """
+        return self.put_writes(config, writes, task_id, task_path)
+
+    async def adelete_thread(self, thread_id: str) -> None:
+        """Delete all checkpoints and writes associated with a thread ID.
+
+        Args:
+            thread_id: The thread ID to delete.
+
+        Returns:
+            None
+        """
+        return self.delete_thread(thread_id)
+
+    def get_next_version(self, current: str | None, channel: None) -> str:
+        if current is None:
+            current_v = 0
+        elif isinstance(current, int):
+            current_v = current
+        else:
+            current_v = int(current.split(".")[0])
+        next_v = current_v + 1
+        next_h = random.random()
+        return f"{next_v:032}.{next_h:016}"
+
+
+MemorySaver = InMemorySaver  # Kept for backwards compatibility
+
+
+class PersistentDict(defaultdict):
+    """Persistent dictionary with an API compatible with shelve and anydbm.
+
+    The dict is kept in memory, so the dictionary operations run as fast as
+    a regular dictionary.
+
+    Write to disk is delayed until close or sync (similar to gdbm's fast mode).
+
+    Input file format is automatically discovered.
+    Output file format is selectable between pickle, json, and csv.
+    All three serialization formats are backed by fast C implementations.
+
+    Adapted from https://code.activestate.com/recipes/576642-persistent-dict-with-multiple-standard-file-format/
+
+    """
+
+    def __init__(self, *args: Any, filename: str, **kwds: Any) -> None:
+        self.flag = "c"  # r=readonly, c=create, or n=new
+        self.mode = None  # None or an octal triple like 0644
+        self.format = "pickle"  # 'csv', 'json', or 'pickle'
+        self.filename = filename
+        super().__init__(*args, **kwds)
+
+    def sync(self) -> None:
+        "Write dict to disk"
+        if self.flag == "r":
+            return
+        tempname = self.filename + ".tmp"
+        fileobj = open(tempname, "wb" if self.format == "pickle" else "w")
+        try:
+            self.dump(fileobj)
+        except Exception:
+            os.remove(tempname)
+            raise
+        finally:
+            fileobj.close()
+        shutil.move(tempname, self.filename)  # atomic commit
+        if self.mode is not None:
+            os.chmod(self.filename, self.mode)
+
+    def close(self) -> None:
+        self.sync()
+        self.clear()
+
+    def __enter__(self) -> PersistentDict:
+        return self
+
+    def __exit__(self, *exc_info: Any) -> None:
+        self.close()
+
+    def dump(self, fileobj: Any) -> None:
+        if self.format == "pickle":
+            pickle.dump(dict(self), fileobj, 2)
+        else:
+            raise NotImplementedError("Unknown format: " + repr(self.format))
+
+    def load(self) -> None:
+        # try formats from most restrictive to least restrictive
+        if self.flag == "n":
+            return
+        with open(self.filename, "rb" if self.format == "pickle" else "r") as fileobj:
+            for loader in (pickle.load,):
+                fileobj.seek(0)
+                try:
+                    return self.update(loader(fileobj))
+                except EOFError:
+                    return
+                except Exception:
+                    logger.error(f"Failed to load file: {fileobj.name}")
+                    raise
+            raise ValueError("File not in a supported format")