+
+
+
+## Browing the example
+
+The core chatbot logic is in [chat.ts](./src/chat.ts). This uses Restate's Virtual Objects to
+have a chat session per user, with history and active tasks easily maintained in the object state.
+
+The workflow-as-code execution of handlers ensures strict consistency and the single-writer semantics
+eforce a consistent message history even under concurrent messages or task notifications.
+
+The tasks are simple Restate workflows. See the [flight watch task](./src/tasks/flight_prices.ts) as an example.
+
+Finally, the [slack integration](./src/slackbot.ts) handles slack webhooks, API calls,
+verification, deduplication, tracking message timestamps, etc.
+
+
+## Running the ChatBot
+
+You need an [OpenAI]() access key to access GPT-4o. Export it as an environment variable like `export OPENAI_API_KEY=sk-proj-...`
+
+Start the Restate Server (see ["Get Restate"](https://restate.dev/get-restate/) if you don't have it downloaded, yet.)
+
+Make sure you install the dependencies via `npm install`.
+
+Start the *reminder* and *flight-watch* tasks via `npm run reminder-task` and `npm run flights-task` respectively
+(e.g., in different shells). In this example, we run them as separate endpoints. Since they are mostly suspending,
+they would be prime candidates to be deployed on a FaaS platform.
+
+Let Restate know about your task services via
+```shell
+restate dep add -y localhost:9081
+restate dep add -y localhost:9082
+```
+
+### Option (1) Without Slack
+
+Start the main chatbot service via `npm run app` and register it at Restate Server `restate dep add -y localhost:9080`.
+
+To chat with the bot, make calls to the chatbot service, like
+```
+curl localhost:8080/chatSession/ = {
+
+ run: (ctx: restate.WorkflowContext, params: P) => Promise = {
+ taskTypeName: string,
+ taskWorkflow: restate.WorkflowDefinition (task: TaskSpec ) {
+ availableTaskTypes.set(task.taskTypeName, task);
+}
+
+const availableTaskTypes: Map (
+ ctx: restate.Context,
+ channelForResult: string,
+ taskOps: TaskOpts): Promise | undefined;
+ if (!task) {
+ throw new Error("Unknown task type: " + taskOps.workflowName);
+ }
+
+ const workflowParams = task.paramsParser(taskOps.name, taskOps.params)
+ const workflowId = ctx.rand.uuidv4();
+
+ ctx.serviceSendClient(workflowInvoker).invoke({
+ taskName: taskOps.name,
+ workflowServiceName: task.taskWorkflow.name,
+ workflowParams,
+ workflowId,
+ channelForResult
+ });
+
+ return workflowId;
+}
+
+export async function cancelTask(
+ ctx: restate.Context,
+ workflowName: string,
+ workflowId: string): Promise