Mike Hale Cloak is live on Solana mainnet, and private USDC, USDT, and SOL payments are open to anyone. Shielding funds is free and leaving the shielded pool costs 0.3%.
Cloak is a privacy layer that keeps balances, amounts, and counterparties hidden, then lets you prove any of it to a specific person on demand. The company calls that private by default, auditable when required. It came out of Colosseum Accelerator Cohort 4, and a third-place finish in the Cypherpunk hackathon's Stablecoin track.
What Cloak hides and what it still shows
Cloak hides the link between sender and recipient. The transaction itself stays visible. A deposit moves funds into a shielded pool, where transfers and swaps run against encrypted notes instead of public balances, so an observer sees that something happened without seeing the amount, the parties, or the running balance. When money leaves, the chain records a withdrawal from the pool to an address. It does not record who funded it.
Cloak's privacy scales with the number of people using it. Every deposit and every withdrawal adds another plausible origin for every other withdrawal, so a shielded pool with four users protects nobody and one with forty thousand protects everybody in it. A pool on its first day of mainnet gives you weaker privacy than the same pool will give you in six months.
Auditability runs on viewing keys. You generate one from your wallet and hand it to whoever needs to see your activity, an auditor, a regulator, a counterparty who wants proof you paid them. They can verify every transaction the key covers and nothing beyond it. A finance team that cannot produce records for an auditor cannot use a privacy tool at all, however good the cryptography is, which is why this matters more to a company than to an individual.
Cloak also screens addresses on the way in. It uses Range's Risk API to check an address against OFAC, UN, EU, and UK sanctions lists, PEP lists, and stablecoin issuer blacklists before funds reach the shield pool, and sends submitted through its relay get checked as well. Range returns the assessment and the evidence behind it, and Cloak decides what happens to a flagged address. The check has to happen on the way in, because once a transfer is private the public record no longer ties a depositor to a recipient.
Cloak integrated that before its program went to audit, so the screening path was part of the code the auditors reviewed.
What it costs and what a developer has to do
Cloak charges nothing to shield and 0.3% to withdraw, and it covers gas for everything in between so a shielded transfer does not need SOL sitting in the sending wallet.
For a team building on top of Cloak, the documentation describes three surfaces:
SDK. Proof generation, transaction building, and scanning your own history.
Shield Pool program. The onchain verification, running as a Solana program.
Circuit package. Generating the proving artifacts.
A payments company can put shielded transfers behind its own interface without its users ever seeing the word Cloak, and a treasury tool can scan a client's history through a registered viewing key instead of scraping a public address. You do not have to be a cryptographer to wire it up, and you do not have to run any of it yourself.
The minimum to try it is 0.01 SOL, with no KYC and no account. Cloak aims this at enterprises, and the use cases it leads with are B2B payments, treasury operations, cross-border transfers, and payroll. Payroll is the clearest one. A company paying 30 people from one address publishes every salary to anyone who looks, and no amount of address rotation fixes that.
From a Cypherpunk track win to mainnet
Cloak's design changed after the hackathon. The hackathon submission described a privacy pool maintained by miners who would generate transaction traffic to keep the anonymity set growing even when real users were idle. What shipped is a shielded UTXO model with zero-knowledge proofs, two-in two-out transactions, nullifiers to prevent double spends, and viewing keys for compliance export. Most of a year separates the hackathon submission from the mainnet launch, and the team spent it rebuilding rather than polishing what placed.
Here is how the project got here:
September 25 to October 30, 2025: Cloak competes in the Solana Cypherpunk hackathon, which drew 1,576 submitted projects
December 13, 2025: Cloak takes third in the Stablecoin track, behind MCPay and Credible
December 22, 2025: Colosseum names Cloak to accelerator cohort 4, sourced from Cypherpunk and the Eternal program
September 2026: Mainnet goes live with USDC, USDT, and SOL, after more than $500,000 in payment volume during private beta
The team is based in Sao Paulo and lists four founders, Arthur Bretas, Marcelo Feitoza, Matheus Macedo Santos, and Victor Carvalho.
Viewing keys are a real answer to the problem that has kept compliant businesses off privacy tools, and handing an auditor a key that reveals your transactions and nothing else is a better deal than the all-or-nothing choice those businesses have had. Cloak's privacy is still a function of how many people use it, and on day one of mainnet that number starts small. Check the pool size before you move anything that matters through it.