saving

ts/packages/base/src/spec/consumer-spec.ts

@@ -0,0 +1,32 @@
+/**
+ * Consumer specification — declares a message consumer for a flow.
+ *
+ * Python reference: trustgraph-base/trustgraph/base/consumer_spec.py
+ */
+
+import type { Spec } from "./types.js";
+import type { PubSubBackend } from "../backend/types.js";
+import type { Flow, FlowDefinition } from "../processor/flow.js";
+import { Consumer, type MessageHandler } from "../messaging/consumer.js";
+
+export class ConsumerSpec<T> implements Spec {
+  constructor(
+    public readonly name: string,
+    private readonly handler: MessageHandler<T>,
+    private readonly concurrency = 1,
+  ) {}
+
+  async add(flow: Flow, pubsub: PubSubBackend, definition: FlowDefinition): Promise<void> {
+    const topic = definition.topics?.[this.name] ?? this.name;
+
+    const consumer = new Consumer<T>({
+      pubsub,
+      topic,
+      subscription: `${flow.processorId}-${flow.name}-${this.name}`,
+      handler: this.handler,
+      concurrency: this.concurrency,
+    });
+
+    flow.registerConsumer(this.name, consumer as Consumer<unknown>);
+  }
+}

ts/packages/base/src/spec/index.ts

@@ -0,0 +1,4 @@
+export type { Spec } from "./types.js";
+export { ConsumerSpec } from "./consumer-spec.js";
+export { ProducerSpec } from "./producer-spec.js";
+export { ParameterSpec } from "./parameter-spec.js";

ts/packages/base/src/spec/parameter-spec.ts

@@ -0,0 +1,18 @@
+/**
+ * Parameter specification — declares a configuration parameter for a flow.
+ *
+ * Python reference: trustgraph-base/trustgraph/base/parameter_spec.py
+ */
+
+import type { Spec } from "./types.js";
+import type { PubSubBackend } from "../backend/types.js";
+import type { Flow, FlowDefinition } from "../processor/flow.js";
+
+export class ParameterSpec implements Spec {
+  constructor(public readonly name: string) {}
+
+  async add(flow: Flow, _pubsub: PubSubBackend, definition: FlowDefinition): Promise<void> {
+    const value = definition.parameters?.[this.name];
+    flow.setParameter(this.name, value);
+  }
+}

ts/packages/base/src/spec/producer-spec.ts

@@ -0,0 +1,21 @@
+/**
+ * Producer specification — declares a message producer for a flow.
+ *
+ * Python reference: trustgraph-base/trustgraph/base/producer_spec.py
+ */
+
+import type { Spec } from "./types.js";
+import type { PubSubBackend } from "../backend/types.js";
+import type { Flow, FlowDefinition } from "../processor/flow.js";
+import { Producer } from "../messaging/producer.js";
+
+export class ProducerSpec<T> implements Spec {
+  constructor(public readonly name: string) {}
+
+  async add(flow: Flow, pubsub: PubSubBackend, definition: FlowDefinition): Promise<void> {
+    const topic = definition.topics?.[this.name] ?? this.name;
+    const producer = new Producer<T>(pubsub, topic);
+    await producer.start();
+    flow.registerProducer(this.name, producer as Producer<unknown>);
+  }
+}

ts/packages/base/src/spec/types.ts

@@ -0,0 +1,13 @@
+/**
+ * Specification types for declarative flow configuration.
+ *
+ * Python reference: trustgraph-base/trustgraph/base/spec.py and siblings
+ */
+
+import type { PubSubBackend } from "../backend/types.js";
+import type { Flow, FlowDefinition } from "../processor/flow.js";
+
+export interface Spec {
+  name: string;
+  add(flow: Flow, pubsub: PubSubBackend, definition: FlowDefinition): Promise<void>;
+}