diff --git a/.changeset/slow-stingrays-kiss.md b/.changeset/slow-stingrays-kiss.md
new file mode 100644
index 00000000..a93126de
--- /dev/null
+++ b/.changeset/slow-stingrays-kiss.md
@@ -0,0 +1,5 @@
+---
+'@powersync/service-core': minor
+---
+
+Moved Write Checkpoint APIs to SyncBucketStorage
diff --git a/packages/service-core/src/routes/endpoints/checkpointing.ts b/packages/service-core/src/routes/endpoints/checkpointing.ts
index 0cfd2dc1..3ce913ad 100644
--- a/packages/service-core/src/routes/endpoints/checkpointing.ts
+++ b/packages/service-core/src/routes/endpoints/checkpointing.ts
@@ -1,6 +1,7 @@
 import { logger, router, schema } from '@powersync/lib-services-framework';
 import * as t from 'ts-codec';
 
+import * as framework from '@powersync/lib-services-framework';
 import * as util from '../../util/util-index.js';
 import { authUser } from '../auth.js';
 import { routeDefinition } from '../router.js';
@@ -63,7 +64,13 @@ export const writeCheckpoint2 = routeDefinition({
       storageEngine: { activeBucketStorage }
     } = service_context;
 
-    const writeCheckpoint = await activeBucketStorage.createManagedWriteCheckpoint({
+    const activeSyncRules = await activeBucketStorage.getActiveSyncRulesContent();
+    if (!activeSyncRules) {
+      throw new framework.errors.ValidationError(`Cannot create Write Checkpoint since no sync rules are active.`);
+    }
+
+    using syncBucketStorage = activeBucketStorage.getInstance(activeSyncRules);
+    const writeCheckpoint = await syncBucketStorage.createManagedWriteCheckpoint({
       user_id: full_user_id,
       heads: { '1': currentCheckpoint }
     });
diff --git a/packages/service-core/src/storage/BucketStorage.ts b/packages/service-core/src/storage/BucketStorage.ts
index 84165fb7..446362a5 100644
--- a/packages/service-core/src/storage/BucketStorage.ts
+++ b/packages/service-core/src/storage/BucketStorage.ts
@@ -12,16 +12,15 @@ import * as util from '../util/util-index.js';
 import { ReplicationEventPayload } from './ReplicationEventPayload.js';
 import { SourceEntityDescriptor } from './SourceEntity.js';
 import { SourceTable } from './SourceTable.js';
-import { BatchedCustomWriteCheckpointOptions, ReplicaId, WriteCheckpointAPI } from './storage-index.js';
+import { BatchedCustomWriteCheckpointOptions, ReplicaId } from './storage-index.js';
+import { SyncStorageWriteCheckpointAPI } from './WriteCheckpointAPI.js';
 
 export interface BucketStorageFactoryListener extends DisposableListener {
   syncStorageCreated: (storage: SyncRulesBucketStorage) => void;
   replicationEvent: (event: ReplicationEventPayload) => void;
 }
 
-export interface BucketStorageFactory
-  extends DisposableObserverClient<BucketStorageFactoryListener>,
-    WriteCheckpointAPI {
+export interface BucketStorageFactory extends DisposableObserverClient<BucketStorageFactoryListener> {
   /**
    * Update sync rules from configuration, if changed.
    */
@@ -206,7 +205,9 @@ export interface SyncRulesBucketStorageListener extends DisposableListener {
   batchStarted: (batch: BucketStorageBatch) => void;
 }
 
-export interface SyncRulesBucketStorage extends DisposableObserverClient<SyncRulesBucketStorageListener> {
+export interface SyncRulesBucketStorage
+  extends DisposableObserverClient<SyncRulesBucketStorageListener>,
+    SyncStorageWriteCheckpointAPI {
   readonly group_id: number;
   readonly slot_name: string;
 
diff --git a/packages/service-core/src/storage/MongoBucketStorage.ts b/packages/service-core/src/storage/MongoBucketStorage.ts
index 9da62758..f3175b91 100644
--- a/packages/service-core/src/storage/MongoBucketStorage.ts
+++ b/packages/service-core/src/storage/MongoBucketStorage.ts
@@ -25,16 +25,7 @@ import { PowerSyncMongo, PowerSyncMongoOptions } from './mongo/db.js';
 import { SyncRuleDocument, SyncRuleState } from './mongo/models.js';
 import { MongoPersistedSyncRulesContent } from './mongo/MongoPersistedSyncRulesContent.js';
 import { MongoSyncBucketStorage } from './mongo/MongoSyncBucketStorage.js';
-import { MongoWriteCheckpointAPI } from './mongo/MongoWriteCheckpointAPI.js';
 import { generateSlotName } from './mongo/util.js';
-import {
-  CustomWriteCheckpointOptions,
-  DEFAULT_WRITE_CHECKPOINT_MODE,
-  LastWriteCheckpointFilters,
-  ManagedWriteCheckpointOptions,
-  WriteCheckpointAPI,
-  WriteCheckpointMode
-} from './write-checkpoint.js';
 
 export interface MongoBucketStorageOptions extends PowerSyncMongoOptions {}
 
@@ -47,10 +38,6 @@ export class MongoBucketStorage
   // TODO: This is still Postgres specific and needs to be reworked
   public readonly slot_name_prefix: string;
 
-  readonly write_checkpoint_mode: WriteCheckpointMode;
-
-  protected readonly writeCheckpointAPI: WriteCheckpointAPI;
-
   private readonly storageCache = new LRUCache<number, MongoSyncBucketStorage>({
     max: 3,
     fetchMethod: async (id) => {
@@ -78,7 +65,6 @@ export class MongoBucketStorage
     db: PowerSyncMongo,
     options: {
       slot_name_prefix: string;
-      write_checkpoint_mode?: WriteCheckpointMode;
     }
   ) {
     super();
@@ -86,11 +72,6 @@ export class MongoBucketStorage
     this.db = db;
     this.session = this.client.startSession();
     this.slot_name_prefix = options.slot_name_prefix;
-    this.write_checkpoint_mode = options.write_checkpoint_mode ?? DEFAULT_WRITE_CHECKPOINT_MODE;
-    this.writeCheckpointAPI = new MongoWriteCheckpointAPI({
-      db,
-      mode: this.write_checkpoint_mode
-    });
   }
 
   getInstance(options: PersistedSyncRulesContent): MongoSyncBucketStorage {
@@ -299,22 +280,6 @@ export class MongoBucketStorage
     });
   }
 
-  async batchCreateCustomWriteCheckpoints(checkpoints: CustomWriteCheckpointOptions[]): Promise<void> {
-    return this.writeCheckpointAPI.batchCreateCustomWriteCheckpoints(checkpoints);
-  }
-
-  async createCustomWriteCheckpoint(options: CustomWriteCheckpointOptions): Promise<bigint> {
-    return this.writeCheckpointAPI.createCustomWriteCheckpoint(options);
-  }
-
-  async createManagedWriteCheckpoint(options: ManagedWriteCheckpointOptions): Promise<bigint> {
-    return this.writeCheckpointAPI.createManagedWriteCheckpoint(options);
-  }
-
-  async lastWriteCheckpoint(filters: LastWriteCheckpointFilters): Promise<bigint | null> {
-    return this.writeCheckpointAPI.lastWriteCheckpoint(filters);
-  }
-
   async getActiveCheckpoint(): Promise<ActiveCheckpoint> {
     const doc = await this.db.sync_rules.findOne(
       {
@@ -426,7 +391,7 @@ export class MongoBucketStorage
         }
         return (await this.storageCache.fetch(doc._id)) ?? null;
       }
-    };
+    } satisfies ActiveCheckpoint;
   }
 
   /**
@@ -516,6 +481,7 @@ export class MongoBucketStorage
       if (doc == null) {
         continue;
       }
+
       const op = this.makeActiveCheckpoint(doc);
       // Check for LSN / checkpoint changes - ignore other metadata changes
       if (lastOp == null || op.lsn != lastOp.lsn || op.checkpoint != lastOp.checkpoint) {
@@ -546,12 +512,14 @@ export class MongoBucketStorage
       // 1. checkpoint (op_id) changes.
       // 2. write checkpoint changes for the specific user
       const bucketStorage = await cp.getBucketStorage();
+      if (!bucketStorage) {
+        continue;
+      }
 
       const lsnFilters: Record<string, string> = lsn ? { 1: lsn } : {};
 
-      const currentWriteCheckpoint = await this.lastWriteCheckpoint({
+      const currentWriteCheckpoint = await bucketStorage.lastWriteCheckpoint({
         user_id,
-        sync_rules_id: bucketStorage?.group_id,
         heads: {
           ...lsnFilters
         }
diff --git a/packages/service-core/src/storage/StorageEngine.ts b/packages/service-core/src/storage/StorageEngine.ts
index bdafeb24..a6639211 100644
--- a/packages/service-core/src/storage/StorageEngine.ts
+++ b/packages/service-core/src/storage/StorageEngine.ts
@@ -1,17 +1,12 @@
 import { DisposableListener, DisposableObserver, logger } from '@powersync/lib-services-framework';
 import { ResolvedPowerSyncConfig } from '../util/util-index.js';
 import { BucketStorageFactory } from './BucketStorage.js';
-import { ActiveStorage, BucketStorageProvider, StorageSettings } from './StorageProvider.js';
-import { DEFAULT_WRITE_CHECKPOINT_MODE } from './write-checkpoint.js';
+import { ActiveStorage, BucketStorageProvider } from './StorageProvider.js';
 
 export type StorageEngineOptions = {
   configuration: ResolvedPowerSyncConfig;
 };
 
-export const DEFAULT_STORAGE_SETTINGS: StorageSettings = {
-  writeCheckpointMode: DEFAULT_WRITE_CHECKPOINT_MODE
-};
-
 export interface StorageEngineListener extends DisposableListener {
   storageActivated: (storage: BucketStorageFactory) => void;
 }
@@ -20,11 +15,9 @@ export class StorageEngine extends DisposableObserver<StorageEngineListener> {
   // TODO: This will need to revisited when we actually support multiple storage providers.
   private storageProviders: Map<string, BucketStorageProvider> = new Map();
   private currentActiveStorage: ActiveStorage | null = null;
-  private _activeSettings: StorageSettings;
 
   constructor(private options: StorageEngineOptions) {
     super();
-    this._activeSettings = DEFAULT_STORAGE_SETTINGS;
   }
 
   get activeBucketStorage(): BucketStorageFactory {
@@ -39,20 +32,6 @@ export class StorageEngine extends DisposableObserver<StorageEngineListener> {
     return this.currentActiveStorage;
   }
 
-  get activeSettings(): StorageSettings {
-    return { ...this._activeSettings };
-  }
-
-  updateSettings(settings: Partial<StorageSettings>) {
-    if (this.currentActiveStorage) {
-      throw new Error(`Storage is already active, settings cannot be modified.`);
-    }
-    this._activeSettings = {
-      ...this._activeSettings,
-      ...settings
-    };
-  }
-
   /**
    * Register a provider which generates a {@link BucketStorageFactory}
    * given the matching config specified in the loaded {@link ResolvedPowerSyncConfig}
@@ -65,8 +44,7 @@ export class StorageEngine extends DisposableObserver<StorageEngineListener> {
     logger.info('Starting Storage Engine...');
     const { configuration } = this.options;
     this.currentActiveStorage = await this.storageProviders.get(configuration.storage.type)!.getStorage({
-      resolvedConfig: configuration,
-      ...this.activeSettings
+      resolvedConfig: configuration
     });
     this.iterateListeners((cb) => cb.storageActivated?.(this.activeBucketStorage));
     logger.info(`Successfully activated storage: ${configuration.storage.type}.`);
diff --git a/packages/service-core/src/storage/StorageProvider.ts b/packages/service-core/src/storage/StorageProvider.ts
index 7c730fb4..385a042f 100644
--- a/packages/service-core/src/storage/StorageProvider.ts
+++ b/packages/service-core/src/storage/StorageProvider.ts
@@ -1,6 +1,5 @@
 import * as util from '../util/util-index.js';
 import { BucketStorageFactory } from './BucketStorage.js';
-import { WriteCheckpointMode } from './write-checkpoint.js';
 
 export interface ActiveStorage {
   storage: BucketStorageFactory;
@@ -12,14 +11,7 @@ export interface ActiveStorage {
   tearDown(): Promise<boolean>;
 }
 
-/**
- * Settings which can be modified by various modules in their initialization.
- */
-export interface StorageSettings {
-  writeCheckpointMode: WriteCheckpointMode;
-}
-
-export interface GetStorageOptions extends StorageSettings {
+export interface GetStorageOptions {
   // TODO: This should just be the storage config. Update once the slot name prefix coupling has been removed from the storage
   resolvedConfig: util.ResolvedPowerSyncConfig;
 }
diff --git a/packages/service-core/src/storage/write-checkpoint.ts b/packages/service-core/src/storage/WriteCheckpointAPI.ts
similarity index 55%
rename from packages/service-core/src/storage/write-checkpoint.ts
rename to packages/service-core/src/storage/WriteCheckpointAPI.ts
index 0b61fe0c..d38ac397 100644
--- a/packages/service-core/src/storage/write-checkpoint.ts
+++ b/packages/service-core/src/storage/WriteCheckpointAPI.ts
@@ -3,7 +3,7 @@ export enum WriteCheckpointMode {
    * Raw mappings of `user_id` to `write_checkpoint`s should
    * be supplied for each set of sync rules.
    */
-  CUSTOM = 'manual',
+  CUSTOM = 'custom',
   /**
    * Write checkpoints are stored as a mapping of `user_id` plus
    * replication HEAD (lsn in Postgres) to an automatically generated
@@ -26,19 +26,19 @@ export interface CustomWriteCheckpointFilters extends BaseWriteCheckpointIdentif
   sync_rules_id: number;
 }
 
-export interface CustomWriteCheckpointOptions extends CustomWriteCheckpointFilters {
+export interface BatchedCustomWriteCheckpointOptions extends BaseWriteCheckpointIdentifier {
   /**
    * A supplied incrementing Write Checkpoint number
    */
   checkpoint: bigint;
 }
 
-/**
- * Options for creating a custom Write Checkpoint in a batch.
- * A {@link BucketStorageBatch} is already associated with a Sync Rules instance.
- * The `sync_rules_id` is not required here.
- */
-export type BatchedCustomWriteCheckpointOptions = Omit<CustomWriteCheckpointOptions, 'sync_rules_id'>;
+export interface CustomWriteCheckpointOptions extends BatchedCustomWriteCheckpointOptions {
+  /**
+   * Sync rules which were active when this checkpoint was created.
+   */
+  sync_rules_id: number;
+}
 
 /**
  * Managed Write Checkpoints are a mapping of User ID to replication HEAD
@@ -52,15 +52,33 @@ export interface ManagedWriteCheckpointFilters extends BaseWriteCheckpointIdenti
 
 export type ManagedWriteCheckpointOptions = ManagedWriteCheckpointFilters;
 
+export type SyncStorageLastWriteCheckpointFilters = BaseWriteCheckpointIdentifier | ManagedWriteCheckpointFilters;
 export type LastWriteCheckpointFilters = CustomWriteCheckpointFilters | ManagedWriteCheckpointFilters;
 
-export interface WriteCheckpointAPI {
-  batchCreateCustomWriteCheckpoints(checkpoints: CustomWriteCheckpointOptions[]): Promise<void>;
-
-  createCustomWriteCheckpoint(checkpoint: CustomWriteCheckpointOptions): Promise<bigint>;
-
+export interface BaseWriteCheckpointAPI {
+  readonly writeCheckpointMode: WriteCheckpointMode;
+  setWriteCheckpointMode(mode: WriteCheckpointMode): void;
   createManagedWriteCheckpoint(checkpoint: ManagedWriteCheckpointOptions): Promise<bigint>;
+}
+
+/**
+ * Write Checkpoint API to be used in conjunction with a {@link SyncRulesBucketStorage}.
+ * This storage corresponds with a set of sync rules. These APIs don't require specifying a
+ * sync rules id.
+ */
+export interface SyncStorageWriteCheckpointAPI extends BaseWriteCheckpointAPI {
+  batchCreateCustomWriteCheckpoints(checkpoints: BatchedCustomWriteCheckpointOptions[]): Promise<void>;
+  createCustomWriteCheckpoint(checkpoint: BatchedCustomWriteCheckpointOptions): Promise<bigint>;
+  lastWriteCheckpoint(filters: SyncStorageLastWriteCheckpointFilters): Promise<bigint | null>;
+}
 
+/**
+ * Write Checkpoint API which is interfaced directly with the storage layer. This requires
+ * sync rules identifiers for custom write checkpoints.
+ */
+export interface WriteCheckpointAPI extends BaseWriteCheckpointAPI {
+  batchCreateCustomWriteCheckpoints(checkpoints: CustomWriteCheckpointOptions[]): Promise<void>;
+  createCustomWriteCheckpoint(checkpoint: CustomWriteCheckpointOptions): Promise<bigint>;
   lastWriteCheckpoint(filters: LastWriteCheckpointFilters): Promise<bigint | null>;
 }
 
diff --git a/packages/service-core/src/storage/mongo/MongoBucketBatch.ts b/packages/service-core/src/storage/mongo/MongoBucketBatch.ts
index f0f95cd4..c24a0499 100644
--- a/packages/service-core/src/storage/mongo/MongoBucketBatch.ts
+++ b/packages/service-core/src/storage/mongo/MongoBucketBatch.ts
@@ -12,7 +12,7 @@ import {
   SaveOptions
 } from '../BucketStorage.js';
 import { SourceTable } from '../SourceTable.js';
-import { CustomWriteCheckpointOptions } from '../write-checkpoint.js';
+import { BatchedCustomWriteCheckpointOptions, CustomWriteCheckpointOptions } from '../WriteCheckpointAPI.js';
 import { PowerSyncMongo } from './db.js';
 import { CurrentBucket, CurrentDataDocument, SourceKey, SyncRuleDocument } from './models.js';
 import { MongoIdSequence } from './MongoIdSequence.js';
@@ -83,7 +83,7 @@ export class MongoBucketBatch extends DisposableObserver<BucketBatchStorageListe
     this.sync_rules = sync_rules;
   }
 
-  addCustomWriteCheckpoint(checkpoint: CustomWriteCheckpointOptions): void {
+  addCustomWriteCheckpoint(checkpoint: BatchedCustomWriteCheckpointOptions): void {
     this.write_checkpoint_batch.push({
       ...checkpoint,
       sync_rules_id: this.group_id
diff --git a/packages/service-core/src/storage/mongo/MongoStorageProvider.ts b/packages/service-core/src/storage/mongo/MongoStorageProvider.ts
index ef16900e..b4e84f20 100644
--- a/packages/service-core/src/storage/mongo/MongoStorageProvider.ts
+++ b/packages/service-core/src/storage/mongo/MongoStorageProvider.ts
@@ -19,8 +19,7 @@ export class MongoStorageProvider implements BucketStorageProvider {
     return {
       storage: new MongoBucketStorage(database, {
         // TODO currently need the entire resolved config due to this
-        slot_name_prefix: resolvedConfig.slot_name_prefix,
-        write_checkpoint_mode: options.writeCheckpointMode
+        slot_name_prefix: resolvedConfig.slot_name_prefix
       }),
       shutDown: () => client.close(),
       tearDown: () => {
diff --git a/packages/service-core/src/storage/mongo/MongoSyncBucketStorage.ts b/packages/service-core/src/storage/mongo/MongoSyncBucketStorage.ts
index e4b57788..9243c010 100644
--- a/packages/service-core/src/storage/mongo/MongoSyncBucketStorage.ts
+++ b/packages/service-core/src/storage/mongo/MongoSyncBucketStorage.ts
@@ -2,7 +2,8 @@ import { SqliteJsonRow, SqliteJsonValue, SqlSyncRules } from '@powersync/service
 import * as bson from 'bson';
 import * as mongo from 'mongodb';
 
-import { DisposableObserver } from '@powersync/lib-services-framework';
+import { DisposableObserver, logger } from '@powersync/lib-services-framework';
+import * as timers from 'timers/promises';
 import * as db from '../../db/db-index.js';
 import * as util from '../../util/util-index.js';
 import {
@@ -26,13 +27,19 @@ import {
 import { ChecksumCache, FetchPartialBucketChecksum, PartialChecksum, PartialChecksumMap } from '../ChecksumCache.js';
 import { MongoBucketStorage } from '../MongoBucketStorage.js';
 import { SourceTable } from '../SourceTable.js';
+import {
+  BatchedCustomWriteCheckpointOptions,
+  ManagedWriteCheckpointOptions,
+  SyncStorageLastWriteCheckpointFilters,
+  WriteCheckpointAPI,
+  WriteCheckpointMode
+} from '../WriteCheckpointAPI.js';
 import { PowerSyncMongo } from './db.js';
 import { BucketDataDocument, BucketDataKey, SourceKey, SyncRuleState } from './models.js';
 import { MongoBucketBatch } from './MongoBucketBatch.js';
 import { MongoCompactor } from './MongoCompactor.js';
+import { MongoWriteCheckpointAPI } from './MongoWriteCheckpointAPI.js';
 import { BSON_DESERIALIZE_OPTIONS, idPrefixFilter, mapOpEntry, readSingleBatch, serializeLookup } from './util.js';
-import { logger } from '@powersync/lib-services-framework';
-import * as timers from 'timers/promises';
 
 export class MongoSyncBucketStorage
   extends DisposableObserver<SyncRulesBucketStorageListener>
@@ -46,15 +53,53 @@ export class MongoSyncBucketStorage
   });
 
   private parsedSyncRulesCache: SqlSyncRules | undefined;
+  private writeCheckpointAPI: WriteCheckpointAPI;
 
   constructor(
     public readonly factory: MongoBucketStorage,
     public readonly group_id: number,
     private readonly sync_rules: PersistedSyncRulesContent,
-    public readonly slot_name: string
+    public readonly slot_name: string,
+    writeCheckpointMode: WriteCheckpointMode = WriteCheckpointMode.MANAGED
   ) {
     super();
     this.db = factory.db;
+    this.writeCheckpointAPI = new MongoWriteCheckpointAPI({
+      db: this.db,
+      mode: writeCheckpointMode
+    });
+  }
+
+  get writeCheckpointMode() {
+    return this.writeCheckpointAPI.writeCheckpointMode;
+  }
+
+  setWriteCheckpointMode(mode: WriteCheckpointMode): void {
+    this.writeCheckpointAPI.setWriteCheckpointMode(mode);
+  }
+
+  batchCreateCustomWriteCheckpoints(checkpoints: BatchedCustomWriteCheckpointOptions[]): Promise<void> {
+    return this.writeCheckpointAPI.batchCreateCustomWriteCheckpoints(
+      checkpoints.map((checkpoint) => ({ ...checkpoint, sync_rules_id: this.group_id }))
+    );
+  }
+
+  createCustomWriteCheckpoint(checkpoint: BatchedCustomWriteCheckpointOptions): Promise<bigint> {
+    return this.writeCheckpointAPI.createCustomWriteCheckpoint({
+      ...checkpoint,
+      sync_rules_id: this.group_id
+    });
+  }
+
+  createManagedWriteCheckpoint(checkpoint: ManagedWriteCheckpointOptions): Promise<bigint> {
+    return this.writeCheckpointAPI.createManagedWriteCheckpoint(checkpoint);
+  }
+
+  lastWriteCheckpoint(filters: SyncStorageLastWriteCheckpointFilters): Promise<bigint | null> {
+    return this.writeCheckpointAPI.lastWriteCheckpoint({
+      ...filters,
+      sync_rules_id: this.group_id
+    });
   }
 
   getParsedSyncRules(options: ParseSyncRulesOptions): SqlSyncRules {
diff --git a/packages/service-core/src/storage/mongo/MongoWriteCheckpointAPI.ts b/packages/service-core/src/storage/mongo/MongoWriteCheckpointAPI.ts
index 230db315..bbcebb0d 100644
--- a/packages/service-core/src/storage/mongo/MongoWriteCheckpointAPI.ts
+++ b/packages/service-core/src/storage/mongo/MongoWriteCheckpointAPI.ts
@@ -7,7 +7,7 @@ import {
   ManagedWriteCheckpointOptions,
   WriteCheckpointAPI,
   WriteCheckpointMode
-} from '../write-checkpoint.js';
+} from '../WriteCheckpointAPI.js';
 import { PowerSyncMongo } from './db.js';
 
 export type MongoCheckpointAPIOptions = {
@@ -17,11 +17,19 @@ export type MongoCheckpointAPIOptions = {
 
 export class MongoWriteCheckpointAPI implements WriteCheckpointAPI {
   readonly db: PowerSyncMongo;
-  readonly mode: WriteCheckpointMode;
+  private _mode: WriteCheckpointMode;
 
   constructor(options: MongoCheckpointAPIOptions) {
     this.db = options.db;
-    this.mode = options.mode;
+    this._mode = options.mode;
+  }
+
+  get writeCheckpointMode() {
+    return this._mode;
+  }
+
+  setWriteCheckpointMode(mode: WriteCheckpointMode): void {
+    this._mode = mode;
   }
 
   async batchCreateCustomWriteCheckpoints(checkpoints: CustomWriteCheckpointOptions[]): Promise<void> {
@@ -29,9 +37,9 @@ export class MongoWriteCheckpointAPI implements WriteCheckpointAPI {
   }
 
   async createCustomWriteCheckpoint(options: CustomWriteCheckpointOptions): Promise<bigint> {
-    if (this.mode !== WriteCheckpointMode.CUSTOM) {
+    if (this.writeCheckpointMode !== WriteCheckpointMode.CUSTOM) {
       throw new framework.errors.ValidationError(
-        `Creating a custom Write Checkpoint when the current Write Checkpoint mode is set to "${this.mode}"`
+        `Creating a custom Write Checkpoint when the current Write Checkpoint mode is set to "${this.writeCheckpointMode}"`
       );
     }
 
@@ -52,9 +60,9 @@ export class MongoWriteCheckpointAPI implements WriteCheckpointAPI {
   }
 
   async createManagedWriteCheckpoint(checkpoint: ManagedWriteCheckpointOptions): Promise<bigint> {
-    if (this.mode !== WriteCheckpointMode.MANAGED) {
+    if (this.writeCheckpointMode !== WriteCheckpointMode.MANAGED) {
       throw new framework.errors.ValidationError(
-        `Creating a managed Write Checkpoint when the current Write Checkpoint mode is set to "${this.mode}"`
+        `Attempting to create a managed Write Checkpoint when the current Write Checkpoint mode is set to "${this.writeCheckpointMode}"`
       );
     }
 
@@ -77,7 +85,7 @@ export class MongoWriteCheckpointAPI implements WriteCheckpointAPI {
   }
 
   async lastWriteCheckpoint(filters: LastWriteCheckpointFilters): Promise<bigint | null> {
-    switch (this.mode) {
+    switch (this.writeCheckpointMode) {
       case WriteCheckpointMode.CUSTOM:
         if (false == 'sync_rules_id' in filters) {
           throw new framework.errors.ValidationError(`Sync rules ID is required for custom Write Checkpoint filtering`);
diff --git a/packages/service-core/src/storage/storage-index.ts b/packages/service-core/src/storage/storage-index.ts
index b5857663..231bb384 100644
--- a/packages/service-core/src/storage/storage-index.ts
+++ b/packages/service-core/src/storage/storage-index.ts
@@ -5,6 +5,7 @@ export * from './SourceEntity.js';
 export * from './SourceTable.js';
 export * from './StorageEngine.js';
 
+export * from './mongo/config.js';
 export * from './mongo/db.js';
 export * from './mongo/models.js';
 export * from './mongo/MongoBucketBatch.js';
@@ -17,5 +18,4 @@ export * from './mongo/MongoSyncRulesLock.js';
 export * from './mongo/OperationBatch.js';
 export * from './mongo/PersistedBatch.js';
 export * from './mongo/util.js';
-export * from './mongo/config.js';
-export * from './write-checkpoint.js';
+export * from './WriteCheckpointAPI.js';
diff --git a/packages/service-core/src/util/config/compound-config-collector.ts b/packages/service-core/src/util/config/compound-config-collector.ts
index 78e8500c..7c2b70c8 100644
--- a/packages/service-core/src/util/config/compound-config-collector.ts
+++ b/packages/service-core/src/util/config/compound-config-collector.ts
@@ -122,7 +122,8 @@ export class CompoundConfigCollector {
       },
       // TODO maybe move this out of the connection or something
       // slot_name_prefix: connections[0]?.slot_name_prefix ?? 'powersync_'
-      slot_name_prefix: 'powersync_'
+      slot_name_prefix: 'powersync_',
+      parameters: baseConfig.parameters ?? {}
     };
 
     return config;
diff --git a/packages/service-core/src/util/config/types.ts b/packages/service-core/src/util/config/types.ts
index e5f461e4..99829526 100644
--- a/packages/service-core/src/util/config/types.ts
+++ b/packages/service-core/src/util/config/types.ts
@@ -64,4 +64,5 @@ export type ResolvedPowerSyncConfig = {
 
   /** Prefix for postgres replication slot names. May eventually be connection-specific. */
   slot_name_prefix: string;
+  parameters: Record<string, number | string | boolean | null>;
 };
diff --git a/packages/sync-rules/package.json b/packages/sync-rules/package.json
index bb942b1e..727188bb 100644
--- a/packages/sync-rules/package.json
+++ b/packages/sync-rules/package.json
@@ -15,10 +15,9 @@
   "type": "module",
   "scripts": {
     "clean": "rm -r ./dist && tsc -b --clean",
-    "build": "tsc -b",
+    "build:tsc": "tsc -b",
+    "build": "pnpm build:tsc && node scripts/compile-schema.js",
     "build:tests": "tsc -b test/tsconfig.json",
-    "compile:schema": "pnpm build && node scripts/compile-schema.js",
-    "postversion": "pnpm compile:schema",
     "test": "vitest"
   },
   "dependencies": {
diff --git a/packages/types/src/config/PowerSyncConfig.ts b/packages/types/src/config/PowerSyncConfig.ts
index e9dff54f..dbd33e1a 100644
--- a/packages/types/src/config/PowerSyncConfig.ts
+++ b/packages/types/src/config/PowerSyncConfig.ts
@@ -135,7 +135,9 @@ export const powerSyncConfig = t.object({
       disable_telemetry_sharing: t.boolean,
       internal_service_endpoint: t.string.optional()
     })
-    .optional()
+    .optional(),
+
+  parameters: t.record(t.number.or(t.string).or(t.boolean).or(t.Null)).optional()
 });
 
 export type PowerSyncConfig = t.Decoded<typeof powerSyncConfig>;
diff --git a/service/Dockerfile b/service/Dockerfile
index 715931b1..d6641555 100644
--- a/service/Dockerfile
+++ b/service/Dockerfile
@@ -29,6 +29,7 @@ COPY packages/jpgwire/src packages/jpgwire/src/
 COPY packages/jpgwire/ca packages/jpgwire/ca/
 COPY packages/jsonbig/src packages/jsonbig/src/
 COPY packages/sync-rules/src packages/sync-rules/src/
+COPY packages/sync-rules/scripts packages/sync-rules/scripts/
 COPY packages/rsocket-router/src packages/rsocket-router/src/
 COPY packages/types/src packages/types/src/