pubsub.ts

export type Subscriber = {
  service: string;
  handler: string;
  key?: string;
};

export const pubsub = restate.object({
  name: "pubsub",
  handlers: {
    /**
     * Add a subscriber to the list of subscribers
     */
    subscribe: async (ctx: restate.ObjectContext, subscriber: Subscriber) => {
      const current = (await ctx.get<Subscriber[]>("sub")) ?? [];
      current.push(subscriber);
      ctx.set("sub", current);
    },

    /**
     * Remove a subscriber
     *
     */
    unsubscribe: async (ctx: restate.ObjectContext, subscriber: Subscriber) => {
      const current = (await ctx.get<Subscriber[]>("sub")) ?? [];
      const filtered = current.filter((s) => s !== subscriber);
      ctx.set("sub", filtered);
    },

    /**
     * publish a message
     */
    publish: async (ctx: restate.ObjectContext, data: any) => {
      const current = (await ctx.get<Subscriber[]>("sub")) ?? [];
      for (const subscriber of current) {
        ctx.genericSend({
          service: subscriber.service,
          method: subscriber.handler,
          key: subscriber.key,
          parameter: data,
          inputSerde: restate.serde.json,
        });
      }
    },
  },
});

you can even publish an event externally like this:

curl ${INGRESS_URL}/pubsub/emails/publish --json '{ "foo" : "bar" }'

Awesome 😍