This is a project for demonstrating Temporal with the Rust SDK.

It implements a money transfer workflow that orchestrates withdrawing from a source account and depositing into a target account, with configurable retry policies and non-retryable error handling.

Based on the Go money transfer template.

src/
├── shared.rs           # PaymentDetails struct and task queue constant
├── workflow.rs         # MoneyTransferWorkflow definition with retry policy
├── activity.rs         # Withdraw, deposit, and refund activities
├── banking_client.rs   # Mock banking service with in-memory accounts
├── worker/main.rs      # Worker binary — registers workflows and activities
└── start/main.rs       # Starter binary — kicks off a workflow execution

temporal-test-harness/  # Testing utility for running workflows without a server
tests/
├── activity_tests.rs           # Unit tests for banking activities
└── workflow_replay_tests.rs    # Workflow integration tests using mock history

• Rust (edition 2024)
• A running Temporal Server

Make sure Temporal Server is running first. The quickest way is with the Temporal CLI:

temporal server start-dev

Or with Docker Compose:

git clone https://github.com/temporalio/docker-compose.git
cd docker-compose
docker-compose up

In another terminal instance, clone this repo:

git clone <repo-url>
cd temporal-rs-tutorial

cargo run --bin start

Observe that Temporal Web (http://localhost:8233) reflects the workflow, but it is still in "Running" status. This is because there is no Worker yet listening to the TRANSFER_MONEY_TASK_QUEUE task queue to process this work.

In another terminal instance, run the worker. This worker hosts both the Workflow and Activity implementations.

cargo run --bin worker

Now you can see the workflow run to completion.

The project includes unit tests for activities and workflow replay tests that run without a Temporal Server. This is a bit of a prototype on my part as I couldn't see any obvious way to do this with the current rust sdk alpha:

cargo test

Run specific test suites:

cargo test --test activity_tests
cargo test --test workflow_replay_tests

The MoneyTransferWorkflow executes two activities in sequence:

1. Withdraw — pulls funds from the source account
2. Deposit — deposits funds into the target account

Each activity is configured with a retry policy:

• Initial interval: 1 second
• Backoff coefficient: 2x
• Maximum interval: 5 seconds
• Maximum attempts: 5
• Non-retryable errors: InvalidAccountError, InsufficientFundsError

The workflow uses rust_decimal::Decimal for precise monetary calculations.