Demos various aspects of Temporal using the Typescript SDK.

https://transfer.tmprl-demo.cloud/

A Java SDK version of this example is also available.

(optional if using local Temporal dev server)

• server/ contains .env_example. Copy it to .env.development and change settings to match your temporal installation.
• STRIPE_SECRET_KEY is optional (use if you want to run simulated charges against the Stripe API)
• ui/ contains .env_example. Copy it to .env.development and change settings to point to your API (server) location (default is / which should be fine)
• The server respects .env.production if NODE_ENV is "production" (and the Svelte app is built using npm run build such as in the Dockerfile)

Run a Temporal Server (Guide)

• brew install temporal
• temporal server start-dev (Temporal Server web UI: localhost:8233)

Install Node dependencies:

• cd server/

• npm install

• cd ui/

• npm install

Run workers

• Run a workflow worker:
  • cd server
  • npm run worker

Run API and Web UI (localhost:3000)

• nodemon /server/index.ts (from the project root directory)

A dropdown menu simulates the following scenarios

• The transfer will run to completion

The transfer will pause and wait for approval. If the user doesn't approve the transfer within a set time, the workflow will fail.

Approve a transfer using Signals

You can also do this through the temporal cli:

temporal workflow signal \
--query 'ExecutionStatus="Running" and WorkflowType="moneyTransferWorkflow"' \
--name approveTransfer \
--reason 'approving transfer'

Approve a transfer using Updates (COMING SOON)

You can do this through the temporal cli:

temporal workflow update \
 --env prod \
 --workflow-id TRANSFER-XXX-XXX \
 --name approveTransferUpdate

The workflow's Update function has a validator. It will reject an Update if:

• The transfer isn't waiting for approval
• The transfer has already been approved

In ./server/temporal/workflows.ts, uncomment the line // throw new Error('Workflow bug!');. Re-comment it and restart the worker for the workflow to recover.

Will introduce artifical delays in the withdraw activity's API calls. This will cause activity retries. After 5 retries, the delay will be removed and the workflow will proceed.

Introduces an unrecoverable failure in the deposit activity (invalid account). The workflow will fail after running compensation activities (undoWithdraw).

Creates a Schedule that will run a set of workflows on a cadence.

Produces a schedule ID, which you can inspect in the Temporal UI's "Schedules" menu.

Set ENCRYPT_PAYLOADS to "true" in the configuration file (see Configuration section above).

You can decrypt these payloads in Temporal Cloud's UI/cli using the codec server: https://codec.tmprl-demo.cloud (source). Ensure you switch on "Pass the user access token with your endpoint" setting in the Codec Configuration in Temporal Cloud. Note: The codec server is only compatible with workflows running in Temporal Cloud.

temporal workflow list --env prod -q 'ExecutionStatus="Failed" OR ExecutionStatus="Terminated"'

• Open /server as a VSCode project
• Run the replayer on a downloaded workflow JSON file