Rust SDK Quickstart

Use this quickstart when you want the smallest runnable Rust app before the larger tutorial apps. It is shaped like a stoffel init project with normal Rust application code around the Stoffel program. The example is a private approval tally for a feature launch. The app owns the proposal, requester, public voter roster, approval threshold, and persistence. Each voter contributes one private yes/no bit through ClientStore. Stoffel opens only the aggregate yes-vote count, and the Rust app maps that opened count into a launch decision. Runnable source:

What this teaches

This is the minimal app-shaped SDK path:

public proposal + public voter roster
+ private voter bits
-> opened yes-vote count
-> Rust launch decision

Use it to see the SDK handoff without the extra domain logic in matchmaking, lottery, or Battleship.

Privacy boundary

Fact	Boundary decision
Proposal, requester, voter roster, approval threshold	Public app data. The app can store and display it.
One approval bit per voter	Private input owned by that voter. Do not store it as ordinary backend data.
Aggregate yes-vote count	Authorized output. Open it so the app can apply the public approval threshold.
Final launch decision	Ordinary app result derived from the opened count and public threshold.

The app learns the count it needs to decide whether the threshold passed. It does not need every voter’s ballot in the repository, logs, support tools, or analytics jobs.

Code map

tutorials/00-rust-sdk-quickstart/
  Stoffel.toml
  Cargo.toml
  build.rs                         generated binding setup
  src/main.stfl                    private approval tally
  src/domain.rs                    public product types
  src/client.rs                    voter-owned private payload
  src/repository.rs                public round metadata and opened decisions
  src/app.rs                       Rust SDK service boundary
  src/main.rs                      runnable sample app
  src/bin/voter_client.rs
  src/plaintext.rs                 trusted-server baseline for tests
  tests/quickstart.rs

Read the files in this order:

src/domain.rs: see the ordinary proposal, round, voter roster, and decision types.
src/client.rs: see how each voter owns a client slot and private approval bit.
src/main.stfl: see the private tally and single reveal point.
src/app.rs: see the Rust SDK boundary that validates input shape, attaches client inputs, runs local MPC, and persists the opened decision.
tests/quickstart.rs: see app-layer behavior and the trusted-server baseline.

Run it

From the tutorial repository root:

cargo test -p rust-sdk-quickstart
cargo run -p rust-sdk-quickstart --bin voter_client -- alice product 0 yes
cargo run -p rust-sdk-quickstart
cargo run -p rust-sdk-quickstart -- alice:product:0:yes bob:security:1:no cara:infra:2:yes

Expected app output:

proposal feature-flag-private-beta (Enable private beta launch for three design partners) requested by devrel: 2/2 approvals across 3 private voter clients => passed

Then run the Stoffel project directly:

cd tutorials/00-rust-sdk-quickstart
stoffel status --verbose
stoffel check
stoffel build
stoffel run --client-input 0=1 --client-input 1=0 --client-input 2=1 --timeout-secs 180

Expected CLI output: 2 or a result list containing 2, depending on the installed CLI display format.

Try a different cohort

The Stoffel program uses ClientStore.get_number_input_clients(), so the local run can use any contiguous client slots starting at 0:

cargo run -p rust-sdk-quickstart -- alice:product:0:yes bob:security:1:no cara:infra:2:no dan:eng:3:yes
stoffel run --client-input 0=1 --client-input 1=0 --client-input 2=0 --client-input 3=1 --timeout-secs 180

Keep the slots contiguous. The tutorial source loads slots 0..n; a missing slot means the app cannot know which private input belongs to which public voter.

Next steps

After this quickstart, use Build a private matchmaking service to see the same SDK boundary inside a richer app-shaped tutorial. Use Rust SDK App Integration when you want the reusable pattern without a tutorial domain.

Introduction

Getting Started

Tutorials

The Stoffel CLI

MPC Backends

Deployment

StoffelLang

Stoffel VM

Architecture

What this teaches

Privacy boundary

Code map

Run it

Try a different cohort

Next steps

​What this teaches

​Privacy boundary

​Code map

​Run it

​Try a different cohort

​Next steps

What this teaches

Privacy boundary

Code map

Run it

Try a different cohort

Next steps