stem_sqlite

SQLite broker and result backend implementations for the Stem runtime. Use it to embed Stem into single-node or desktop deployments without external infrastructure.

Install

dart pub add stem_sqlite

Add the core runtime if you haven't already:

dart pub add stem

Usage

Direct enqueue

import 'dart:io';
import 'package:stem/stem.dart';
import 'package:stem_sqlite/stem_sqlite.dart';

Future<void> main() async {
  final registry = SimpleTaskRegistry()
    ..register(FunctionTaskHandler(name: 'demo.sqlite', handler: print));

  final dbFile = File('stem.db'); // or File(':memory:') for in-memory
  final broker = await SqliteBroker.open(dbFile);
  final backend = await SqliteResultBackend.open(dbFile);

  final stem = Stem(broker: broker, backend: backend, registry: registry);
  await stem.enqueue('demo.sqlite', args: {'name': 'Stem'});
}

Typed TaskDefinition

import 'dart:io';
import 'package:stem/stem.dart';
import 'package:stem_sqlite/stem_sqlite.dart';

final demoSqlite = TaskDefinition<SqliteArgs, void>(
  name: 'demo.sqlite',
  encodeArgs: (args) => {'name': args.name},
  metadata: TaskMetadata(description: 'SQLite-backed demo task'),
);

class SqliteArgs {
  const SqliteArgs({required this.name});
  final String name;
}

Future<void> main() async {
  final registry = SimpleTaskRegistry()
    ..register(
      FunctionTaskHandler<void>(
        name: demoSqlite.name,
        entrypoint: (context, args) async {
          print('Hello ${(args['name'] as String?) ?? 'world'}');
        },
        metadata: demoSqlite.metadata,
      ),
    );

  final dbFile = File('stem.db'); // or File(':memory:') for in-memory
  final broker = await SqliteBroker.open(dbFile);
  final backend = await SqliteResultBackend.open(dbFile);

  final stem = Stem(broker: broker, backend: backend, registry: registry);
  await stem.enqueueCall(demoSqlite(const SqliteArgs(name: 'Stem')));
}

CLI usage

The Stem CLI can target a SQLite result backend via a connection string. When you only need backend-backed commands, set a memory broker alongside the SQLite URL:

export STEM_BROKER_URL=memory://
export STEM_RESULT_BACKEND_URL=sqlite:///absolute/path/to/stem.db

stem observe tasks show --id <task-id>

Broker-required commands (enqueue, control, DLQ replay) still need a real broker URL.

Tests

The package bundles compliance tests from stem_adapter_tests. Running

dart test

executes the shared broker and backend contract suites against the SQLite adapters.

Support

Report issues or feature requests on the GitHub tracker. Commercial support is available via Buy Me A Coffee.