Extending Reqon

Reqon's extension model is dependency injection, not a plugin registry. You implement an interface and pass the instance to the executor through ExecutorConfig. There's no global register* API and no hook system.

Custom store adapters

The most common extension point. Implement the StoreAdapter interface and pass your instances in the stores config, keyed by store name:

import { execute, type StoreAdapter, type StoreFilter } from 'reqon-dsl';

class MyStoreAdapter implements StoreAdapter {
  async get(key: string) { /* ... */ return null; }
  async set(key: string, value: Record<string, unknown>) { /* ... */ }
  async update(key: string, value: Partial<Record<string, unknown>>) { /* ... */ }
  async delete(key: string) { /* ... */ }
  async list(filter?: StoreFilter) { return []; }
  async count(filter?: StoreFilter) { return 0; }
  async clear() { /* ... */ }
}

await execute(source, {
  stores: {
    customers: new MyStoreAdapter(),
  },
});

When a store name in the config matches a store declared in the mission, your adapter is used instead of the built-in one. Optional bulkSet and bulkUpsert methods are called when present for batched writes. See custom adapters for the full interface.

Custom durability stores

The execution store, sync store, trace store, and pause store are all injectable the same way:

import { execute, MemoryExecutionStore, MemorySyncStore, MemoryTraceStore, MemoryPauseStore } from 'reqon-dsl';

await execute(source, {
  executionStore: new MemoryExecutionStore(),
  syncStore: new MemorySyncStore(),
  traceStore: new MemoryTraceStore(),
  pauseStore: new MemoryPauseStore(),
});

Each has a File* and a Memory* implementation out of the box, and a corresponding interface you can implement yourself.

Observability outputs and handlers

Hook into execution by subscribing to the event emitter or by adding a custom log output. See observability for the full event catalog.

import { execute, ObservabilityEmitter, type LogOutput, type LogEntry } from 'reqon-dsl';

// Custom log output
class MyOutput implements LogOutput {
  write(entry: LogEntry) {
    // forward to your logging system
  }
}

Vague plugin integration

Reqon extends Vague (the underlying DSL layer) through its plugin system. The plugin teaches Vague's lexer about Reqon's keywords.

Registering the plugin

Reqon registers its plugin automatically when you import the package. You can also register it explicitly:

import { registerReqonPlugin } from 'reqon-dsl';

registerReqonPlugin();

Inspecting the plugin

import { reqonPlugin } from 'reqon-dsl';

console.log(reqonPlugin.name);  // 'reqon'

Programmatic API

For full control, parse and execute directly with MissionExecutor:

import { parse, MissionExecutor } from 'reqon-dsl';

const program = parse(source);

const executor = new MissionExecutor({
  dryRun: false,
  verbose: true,
  progress: {
    onStageComplete: (event) => console.log(`Stage done: ${event.stageName}`),
  },
});

const result = await executor.execute(program);

The convenience functions execute, fromFile, and fromPath wrap this for the common cases.

Not currently supported

These extension points don't exist. Avoid building against them:

• Custom expression functions — there's no registerFunction. Expression functions come from Vague's evaluator.
• Custom step handlers — there's no registerStepHandler; step types are fixed.
• Custom auth providers — there's no registerAuthProvider. The built-in providers are bearer and OAuth2 (see authentication).
• Custom pagination strategies — there's no registerPaginationStrategy; the strategies are offset, page, and cursor.
• A plugin/hook system — there's no Reqon class, reqon.use(...), or reqon.hooks.*. Use store/observability injection instead.