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// EFFECT DAYS 2026

SqlEventJournal unstable

SQL-backed event journal with per-remote upload checkpoints.

2 exports Since v4.0.0 Source

Constructors

make

unstable
Since v4.0.0

Creates an EventJournal backed by a SQL database.

Details

Maintains entryTable, ${entryTable}_sequence, ${entryTable}_sources, ${remotesTable}_checkpoints and remoteCursorsTable (default ${remotesTable}_cursors) using the configured SqlClient.

Gotchas

Creating or migrating the schema requires a writable connection. Migrated databases can be reopened read-only.

Journals from earlier releases keep one remotesTable row per entry per remote. Opening one replaces those rows with entry sources and drops the table; an entry known to several remotes keeps one of them as its source.

Upload acknowledgements do not advance past unseen entries.

Signature

declare function make(options?: {
  readonly entryTable?: string;
  readonly remoteCursorsTable?: string;
  readonly remotesTable?: string;
}): Effect<{
  readonly changes: Effect<Subscription<Entry>, never, Scope>;
  readonly destroy: Effect<void, EventJournalError>;
  readonly entries: Effect<readonly Array<Entry>, EventJournalError>;
  readonly entriesById: (ids: readonly Array<EntryId>) => Effect<readonly Array<Entry | undefined>, EventJournalError>;
  readonly nextRemoteSequence: (remoteId: RemoteId) => Effect<number, EventJournalError>;
  readonly withLock: (storeId: StoreId) => <A, E, R>(effect: Effect<A, E, R>) => Effect<A, E, R>;
  readonly withRemoteUncommited: <A, E, R>(remoteId: RemoteId, f: (entries: readonly [Entry, Entry]) => Effect<A, E, R>) => Effect<Option<A>, EventJournalError | E, R>;
  readonly write: <A, E, R>(options: {
    readonly effect: (entry: Entry) => Effect<A, E, R>;
    readonly event: string;
    readonly payload: Uint8Array;
    readonly primaryKey: string;
  }) => Effect<A, EventJournalError | E, R>;
  readonly writeFromRemote: (options: {
    readonly compact?: (uncommitted: readonly Array<RemoteEntry>) => Effect<readonly Array<Entry>, EventJournalError>;
    readonly effect: (entries: readonly Array<{
      readonly conflicts: readonly Array<Entry>;
      readonly entry: Entry;
    }>) => Effect<void, EventJournalError>;
    readonly entries: readonly Array<RemoteEntry>;
    readonly remoteId: RemoteId;
  }) => Effect<{
    readonly duplicateEntries: readonly Array<Entry>;
  }, EventJournalError>;
  readonly writeMany: <A, E, R>(options: {
    readonly effect: (entries: readonly [Entry, Entry]) => Effect<A, E, R>;
    readonly entries: readonly [{
      readonly event: string;
      readonly payload: Uint8Array;
      readonly primaryKey: string;
    }, {
      readonly event: string;
      readonly payload: Uint8Array;
      readonly primaryKey: string;
    }];
  }) => Effect<A, EventJournalError | E, R>;
  readonly writeRemoteAcks: (options: {
    readonly acks: readonly Array<RemoteAck>;
    readonly firstSequence?: number;
    readonly remoteId: RemoteId;
  }) => Effect<void, EventJournalError>;
}, SqlError, SqlClient>

Layers

layer

unstable
Since v4.0.0

Provides a SQL-backed EventJournal from an existing SqlClient service.

Gotchas

Creating or migrating the schema requires a writable connection.

See

Signature

declare function layer(options?: {
  readonly entryTable?: string;
  readonly remoteCursorsTable?: string;
  readonly remotesTable?: string;
}): Layer<EventJournal, SqlError, SqlClient>