A Stacks smart contract audit is a security review of code deployed to Stacks, carried out against the Chain-specific execution environment execution model and written in Clarity — covering both the bug classes shared across Chain-specific runtime systems and the failure modes specific to Stacks.
Clarity is decidable and non-Turing-complete, and it is interpreted from published source rather than compiled — so there is no bytecode surprise. The risk moves to post-conditions, Bitcoin finality assumptions and trait usage.
Clarity removes reentrancy-by-default and makes control flow analysable, which eliminates several classic classes. What remains is authorisation logic, post-condition handling on asset transfers, and the assumptions Stacks contracts make about Bitcoin block finality and PoX cycles.
We review contract authorisation and trait usage, post-condition design, Bitcoin-anchored timing assumptions, and any bridge or sBTC integration.
Stacks runs on Chain-specific execution environment, so it inherits the bug classes below from every system in that family.
Stacks contracts are written in Clarity. See our Clarity audit methodology.
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.
It removes the classic pattern by design, which is a real advantage. Authorisation errors, trait misuse and post-condition assumptions remain, and those are where Clarity findings concentrate.
Yes — peg-in and peg-out flows, finality assumptions and the trust model of the signer set.
Confusing tx-sender with contract-caller in authorisation checks, which grants access through an intermediate contract.
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.