# Build on STRK20 — Add privacy to your stack

> STRK20 brings shielded balances, private transfers, and private app flows to ERC-20 assets on Starknet. Build on existing liquidity and existing wallets, with a built-in compliance path.

## Pick your integration route

- [Build a private dapp](https://strk20-by-example.org/helpers/privacy-invoke) — private DeFi, private consumer apps, private games. Anonymizer contracts + the Starknet Wallet API.
- [Build a privacy wallet](https://strk20-by-example.org/sdk/getting-started) — or an advanced backend that needs direct control. The Privacy SDK.
- [Run your own prover](https://strk20-by-example.org/sdk/proving-config) — operate proof generation infrastructure yourself.
- **Hide the wallet link** — break the public link between a main wallet and app activity. Private sub-accounts, coming soon.

## Core pieces

- [STRK20 Pool](https://strk20-by-example.org/what-is-strk20) — the live Starknet mainnet pool that holds ERC-20s as encrypted notes and enables shielded balances, private transfers, and private DeFi.
- [Starknet Wallet API](https://strk20-by-example.org/starknet-wallet-api/overview) — the application-layer route, and the one most apps should use — integrate through starknet.js and ask the wallet to perform the private action, so the dapp never touches the user's viewing key or the SDK.
- [Anonymizer contracts](https://strk20-by-example.org/helpers/privacy-invoke) — app-specific privacy_invoke adapters for DeFi; the pool calls the anonymizer atomically, then credits the result back into private notes.
- [Privacy SDK](https://strk20-by-example.org/sdk/getting-started) — the low-level route for wallets and advanced integrations that need direct control over registration, channels, note discovery, and proving.
- **Private sub-accounts** — an advanced account-privacy route for hiding the public link between a user's main wallet and app activity (coming soon).
- [Prover backend](https://strk20-by-example.org/sdk/proving-config) — infrastructure for teams that need to operate their own proof generation.

## Why build on STRK20

- **Protocol-level privacy** — built into the protocol, not bolted on at the app layer. Every shielded asset shares one unified privacy pool, so the anonymity set grows with total system usage.
- **Anonymous DeFi on existing liquidity** — anonymous swaps run on existing AMMs (Ekubo, AVNU). No unshield-swap-reshield, no fragmented liquidity.
- **Multi-call composability** — unshield, swap across AMMs, flash-loan, repay, and reshield inside one private transaction.
- **No new wallets** — existing Starknet wallets via native account abstraction: multisig, hardware, social recovery.
- **Compliance-first** — deposit screening is mandatory and enforced onchain: FPI screens the addresses that shield tokens and signs every deposit, and the pool verifies that signature. Running your own prover doesn't bypass it. Private by default, disclosable when required.
- **Built on Cairo** — both the smart contract and the proving language, which is what makes atomic, composable privacy possible.

## Get involved

- [Proof of Privacy Incubator](https://proof.starknet.io) — eight weeks of mentorship, milestone-based support, and a demo day for teams building with STRK20.
- [Request for Startups](https://strk20.starknet.io/rfp) — defined problem statements for specific builds: private payroll, lending, identity, and more.
- [Book a call](https://cal.com/adithyadinesh) — a direct line to the team to validate your idea.

## Resources

- [STRK20 by Example](https://strk20-by-example.org/) — learn Starknet Privacy with runnable examples: the Starknet Wallet API, Cairo anonymizer contracts, and wallet-builder SDK flows. Agent-readable: https://strk20-by-example.org/llms-full.txt
- [Starknet Privacy SDK](https://github.com/starkware-libs/starknet-privacy) — the open-source monorepo (Apache-2.0): TypeScript SDK, pool contracts, and anonymizer reference packages.
- [Awesome STRK20](https://github.com/Akashneelesh/awesome-strk20) — a collection of Starknet privacy libraries, resources, and PoCs.
- [Brand & UI kit](https://strk20.starknet.io/brand) — colors, fonts, logos, and components with machine-readable design tokens (/brand/tokens.json) and guidelines (/brand.md) — build interfaces that look like STRK20.

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_Machine-readable: [https://strk20.starknet.io/llms.txt](https://strk20.starknet.io/llms.txt) · [https://strk20.starknet.io/llms-full.txt](https://strk20.starknet.io/llms-full.txt)_