Examples catalog

The noir-examples/ directory contains circuits that exercise ProveKit’s compiler and proving pipeline. Some are minimal demos; others are real-world primitives used to benchmark and validate the system end-to-end.

Each example is a self-contained Noir package. To run any of them:

cd noir-examples/<name>
cargo run --release --bin provekit-cli -- prepare
cargo run --release --bin provekit-cli -- prove
cargo run --release --bin provekit-cli -- verify

Start with `basic`

If you’re new, the Quickstart walks through noir-examples/basic. Once you have that running, the examples below show how Noir scales to larger primitives.

Hash primitives

Circuits demonstrating the hash functions ProveKit can prove over.

Example	What it demonstrates
basic	Poseidon2 BN254 preimage proof, the canonical “hello world” circuit.
basic-2, basic-3, basic-4	Progressive Poseidon variations for compiler testing.
poseidon2	Direct Poseidon2 hashing primitive in isolation.
many_poseidons	Stress test with many Poseidon hash calls in one circuit.
poseidon-rounds	Single-round Poseidon decomposition, useful for understanding round structure.
sha256, noir_sha256, noir-native-sha256	SHA-256 variants compiled through Noir’s black-box and native paths.
partial_sha256	SHA-256 with a partial preimage, common for incremental hashing patterns.

Elliptic curves and signatures

Circuits exercising scalar multiplication, signature schemes, and curve arithmetic.

Example	What it demonstrates
babyjubjub	Baby Jubjub curve operations, the standard curve for in-circuit ECC over BN254.
eddsa_poseidon2	EdDSA signature verification using Poseidon2 for hashing.
embedded_curve_msm	Multi-scalar multiplication on the embedded curve via Noir’s intrinsic.
native_msm	MSM expressed without the embedded-curve intrinsic, heavier circuit, useful for comparisons.
msm_conditional	Conditional MSM, pick scalars or points at runtime inside the circuit.
msm_conditional_nested	Nested conditional MSM, demonstrating composition.
p256_std	P-256 (secp256r1) signature verification over the standard curve.
p256_bigcurve	P-256 with bigcurve representation, relevant when proving WebAuthn or hardware-attestation signatures.

Identity and credentials

Circuits demonstrating real-world identity workflows.

Example	What it demonstrates
noir-passport	Passport-style credential verification, the foundation for selective disclosure.
noir-passport-examples	Variations of the passport flow used for testing different selective-disclosure patterns.
noir-passport-monolithic	Single-circuit version of the passport workflow, useful for understanding the full constraint cost.
oprf	Oblivious Pseudorandom Function, a primitive used in private set intersection and de-anonymization defenses.

Arithmetic primitives

Small circuits that ProveKit uses internally for testing and benchmarking.

Example	What it demonstrates
power	Modular exponentiation inside a circuit.
rangechecks	Range constraints, the building block for bounded arithmetic.
noir-r1cs-test-programs	A suite of programs used by the R1CS compiler’s own test harness.

Applications

Larger circuits modeled after real applications.

Example	What it demonstrates
zkchase	A small game-like circuit demonstrating state transitions and rule enforcement.

Benchmarks

Example	What it demonstrates
csp-benchmarks	Constraint system performance benchmarks. Use these as a baseline when measuring circuit cost.

Reading an example

Every example follows the same layout:

noir-examples/basic/
├── Nargo.toml        # Noir package metadata + dependencies
├── Prover.toml       # Witness inputs (private + public)
└── src/
    └── main.nr       # Circuit definition

The Prover.toml is the only file you typically edit to change what’s being proven, the circuit is fixed; the inputs vary per proof. To inspect what a verified proof actually exposes:

cargo run --release --bin provekit-cli -- show-inputs --hex \
  <example>.pkv \
  proof.np

Contributing examples

Pull requests adding new example circuits are welcome. Keep them minimal, focused on one primitive, and accompanied by a Prover.toml that produces a verifiable proof out of the box.