GthSqliteSaver

Defined in: packages/core/src/history/checkpointSaver.ts:328

A LangGraph BaseCheckpointSaver persisting to a node:sqlite database.

Obtain one through openCheckpointSaver, which is fail-soft; the constructor is private so there is no way to hold one whose tables were never created.

Extends

BaseCheckpointSaver

Properties

serde

serde: SerializerProtocol

Defined in: node_modules/.pnpm/@langchain+langgraph-checkpoint@1.1.5_@langchain+core@1.2.13_openai@7.20.0_undici@8.11.2_ws@8.21.3_zod@4.6.5__ws@8.21.3_/node_modules/@langchain/langgraph-checkpoint/dist/base.d.ts:58

Inherited from

BaseCheckpointSaver.serde

Methods

close()

close(): void

Defined in: packages/core/src/history/checkpointSaver.ts:447

Close every held connection (fail-soft), and drop the in-memory copy with them, so a closed saver answers no read from memory that it could not answer from disk.

Returns

void

deleteThread()

deleteThread(threadId): Promise<void>

Defined in: packages/core/src/history/checkpointSaver.ts:859

Delete a thread’s state from memory and from disk: its file, whole (see removeThreadState).

Parameters

threadId

string

Returns

Promise<void>

Overrides

BaseCheckpointSaver.deleteThread

get()

get(config): Promise<Checkpoint<string, string> | undefined>

Parameters

config

RunnableConfig

Returns

Promise<Checkpoint<string, string> | undefined>

Inherited from

BaseCheckpointSaver.get

getDeltaChannelHistory()

getDeltaChannelHistory(options): Promise<Record<string, DeltaChannelHistory>>

Walk the parent chain returning per-channel writes + seed, used to reconstruct DeltaChannel state from checkpoint_writes.

For each requested channel, walks ancestors of the checkpoint identified by config (following parentConfig) and accumulates the 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 getTuple + parentConfig once for all channels — each ancestor visited once, not once per channel. Savers with direct storage access (e.g. MemorySaver) override for performance; the return contract is fixed here.

Parameters

options

channels

string[]

Channel names to walk for. Empty → empty mapping.

config

RunnableConfig

Configuration identifying the target checkpoint.

Returns

Promise<Record<string, DeltaChannelHistory>>

Per-channel DeltaChannelHistory for every requested name.

Remarks

Beta. The signature, return shape, and interaction with DeltaSnapshot blobs may change. Override at your own risk; the default implementation will continue to work against the public BaseCheckpointSaver contract.

Inherited from

BaseCheckpointSaver.getDeltaChannelHistory

getNextVersion()

getNextVersion(current): number

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.

Parameters

current

number | undefined

Returns

number

Inherited from

BaseCheckpointSaver.getNextVersion

getTuple()

getTuple(config): Promise<CheckpointTuple | undefined>

Defined in: packages/core/src/history/checkpointSaver.ts:511

Parameters

config

RunnableConfig

Returns

Promise<CheckpointTuple | undefined>

Overrides

BaseCheckpointSaver.getTuple

list()

list(config, options?): AsyncGenerator<CheckpointTuple>

Defined in: packages/core/src/history/checkpointSaver.ts:588

History, read from SQLite only. Nothing in this repo lists a thread’s checkpoints (getStateHistory is never called), and memory holds only each thread’s latest checkpoint, so after a cut this omits what reached memory alone.

Parameters

config

RunnableConfig

options?

CheckpointListOptions

Returns

AsyncGenerator<CheckpointTuple>

Overrides

BaseCheckpointSaver.list

put()

put(config, checkpoint, metadata, _newVersions): Promise<RunnableConfig<Record<string, any>>>

Defined in: packages/core/src/history/checkpointSaver.ts:661

Parameters

config

RunnableConfig

checkpoint

Checkpoint

metadata

CheckpointMetadata

_newVersions

ChannelVersions

Returns

Promise<RunnableConfig<Record<string, any>>>

Overrides

BaseCheckpointSaver.put

putWrites()

putWrites(config, writes, taskId): Promise<void>

Defined in: packages/core/src/history/checkpointSaver.ts:742

Store intermediate writes linked to a checkpoint.

Parameters

config

RunnableConfig

writes

PendingWrite[]

taskId

string

Returns

Promise<void>

Overrides

BaseCheckpointSaver.putWrites

reclaimUnresumableThreads()

reclaimUnresumableThreads(options?): ReclaimSummary

Defined in: packages/core/src/history/checkpointSaver.ts:877

GS2-107 — remove the state of every thread no conversation row names, past the grace window. The retention module owns the policy and the reasoning; this runs it over this saver’s store, releasing any connection this saver holds to a thread before its file is touched.

Every thread this saver wrote is excluded, always, on top of whatever the caller names. A caller cannot supply that set: the runner rotates threads without telling anyone, so the only place that knows which thread the session ended on is the object the writes went through. The union is the contract — excludeThreadIds adds to the protection and can never subtract from it.

Parameters

options?

excludeThreadIds?

readonly string[]

graceMs?

number

now?

number

Returns

ReclaimSummary

storeStats()

storeStats(topN?): CheckpointStoreStats

Defined in: packages/core/src/history/checkpointSaver.ts:888

GS2-107 — what this saver’s store holds.

Parameters

topN?

number

Returns

CheckpointStoreStats

toJSON()

toJSON(): string

Prevent JSON.stringify from traversing backend clients (e.g. pg Pool timers) when a checkpointer is present in runnable configurable.

Returns

string

Inherited from

BaseCheckpointSaver.toJSON

open()

static open(storePath, options?): GthSqliteSaver | null

Defined in: packages/core/src/history/checkpointSaver.ts:434

Open the saver over the store at storePath, creating the store (and splitting a single-file store from an earlier release) as needed. Returns null on any failure — a store that cannot be created, a split another process is running, a path that is not a store — so the caller can fall back to a MemorySaver without a try/catch of its own. Thread files are opened lazily.

Parameters

storePath

string

options?

CheckpointSaverOptions = {}

Returns

GthSqliteSaver | null