A Clarity audit is a security review of Stacks contracts written in Clarity, focused on post-conditions, trait and contract-call trust boundaries, Bitcoin-anchored finality assumptions, and the logic errors that remain despite Clarity's decidable, non-Turing-complete design.
Clarity is interpreted, decidable and has no reentrancy in the EVM sense — the language deliberately removes several classic bug classes. What remains is everything about intent: whether your post-conditions actually constrain the transfer they are supposed to constrain, whether a dynamic contract-call trusts a trait implementation supplied by the caller, and whether your logic is correct about Bitcoin block ordering and reorg behaviour.
We review Clarity against the Stacks execution model, not a generalised smart-contract model. That means the post-condition mode of every transaction path, the trust placed in every trait, tx-sender versus contract-caller in every authorisation check, and how the contract behaves across Stacks blocks anchored to a Bitcoin chain that can reorganise.
We fix a commit hash, agree the in-scope contracts and read your architecture docs, then build a threat model: who the actors are, what the trust boundaries are, and which invariants must never break. Nothing is reviewed against assumptions we have not written down.
Line-by-line review by at least two auditors working independently, focused on authorisation, accounting, upgrade paths, external integrations and the gap between what the code does and what the documentation claims it does. Most critical findings come from this phase, not from tooling.
Static analysers appropriate to the language, plus property-based fuzzing and invariant testing to push the system into states no unit test covers. Tooling is used to widen coverage, never to replace the manual pass.
Candidate findings are proven on a forked network with a working proof of concept. We report what an attacker can actually do and what it costs them, not a theoretical severity label.
Every finding gets a severity rating, reproduction steps, the affected code, the impact in concrete terms and a specific remediation. You get a draft for discussion before anything is finalised.
We re-test every remediation against the original proof of concept and check that the fix has not opened a new path. The final report is yours to publish.
The design. Post-conditions that do not cover the assets they should, authorisation using tx-sender where contract-caller was meant, trait implementations trusted from the caller, and reward or fee arithmetic that is simply wrong. Clarity removes a bug class; it does not remove judgment.
Yes, and it is one of the highest-value parts of a Stacks review. Post-conditions are the user's last defence, and allow-mode paths regularly leave that defence disabled.
Anything that treats a recent Stacks block as final needs to be reviewed against the anchoring model. We test the reorg path explicitly rather than assuming it will not happen.
Yes. Integrations assume standard behaviour, and a token that deviates from the trait breaks every protocol that lists it.
A repository or contract address, a commit hash to freeze the scope, whatever architecture or spec documentation exists, and a point of contact who can answer design questions. If documentation is thin we will write our understanding of the system back to you and ask you to confirm it — that step alone catches design-level bugs.
A single token contract is 24–48 hours. A typical dApp or mid-sized protocol runs one to two weeks. Large DeFi systems, L2s, bridges and ZK circuits are scoped per project after we have seen the code. We will give you a fixed timeline with the quote, not an estimate that moves.
Yes. Fix review is part of the engagement, not an upsell. We re-run the original proof of concept against your patched code and confirm the fix has not introduced a new path.
Send the repository and a commit hash through the contact form, message @bugtester25 on Telegram, or book a 30-minute scoping call. 200+ protocols audited · $4B+ secured · 0 hacks post-audit. Prefer email? info@safeedges.in.