---
title: "Cairo and the Stwo prover"
description: "Cairo and the Stwo prover: Language + VM + prover. Kind: Language + VM + prover. Arithmetisation / backend: Circle STARK (Mersenne-31). Setup: None."
type: "option"
url: "https://zkpick.com/frameworks/cairo-stwo/"
section: "02 Choosing a framework"
authors:
  - "MarketComp"
publisher: "MarketComp"
version: "1.3"
updated: "2026-09-12"
license: "CC-BY-4.0"
json: "https://zkpick.com/data/frameworks/cairo-stwo.json"
---

*By MarketComp. Updated 2026-09-12. Version 1.3. CC BY 4.0.*

# Cairo and the Stwo prover — *Language + VM + prover*

> Cairo and the Stwo prover: Language + VM + prover. Kind: Language + VM + prover. Arithmetisation / backend: Circle STARK (Mersenne-31). Setup: None. Maintained by: StarkWare. Licence: Apache-2.0. Status: Production at scale. Choose it when: Applications native to its ecosystem, and any workload wanting a battle-tested, setup-free STARK stack with mature native recursion.

A language for provable programs executed by its own VM and proved by a Circle STARK prover over a small field. Verification is available both natively and as a verifier written in Cairo itself and run on the Cairo VM, which is what makes recursion native.

**Strengths**

- Among the longest-running production ZK stacks, proving blocks with settlement on Ethereum L1
- No trusted setup
- Recursive proving is native and well-exercised — the verifier runs on the VM it verifies
- Prover fully open-sourced under a permissive licence

**Tradeoffs**

- Strong gravitational pull toward its own ecosystem; general-purpose use is possible but not the main path
- Circle STARK proofs are large, so direct per-transaction L1 verification is impractical — the design intent is per-block aggregation
- A bespoke language with its own memory model, so no reuse of an existing toolchain ecosystem

**Choose it when:** Applications native to its ecosystem, and any workload wanting a battle-tested, setup-free STARK stack with mature native recursion.

Maintained by: StarkWare · Maturity: Production at scale · License: Apache-2.0 · Source: https://github.com/starkware-libs/cairo

**In the framework selection matrix** (https://zkpick.com/frameworks/#frameworks-matrix-cairo-stwo)

| Project | Kind | Arithmetisation / backend | Setup | Maintained by | Licence | Status |
| --- | --- | --- | --- | --- | --- | --- |
| Cairo + Stwo | Language + VM + prover | Circle STARK (Mersenne-31) | None | StarkWare | Apache-2.0 | Production at scale |