A Flow smart contract audit is a security review of code deployed to Flow, carried out against the Chain-specific execution environment execution model and written in Cadence — covering both the bug classes shared across Chain-specific runtime systems and the failure modes specific to Flow.
Cadence stores resources in user accounts, not in a contract's mapping. That eliminates some EVM bug classes entirely and creates its own: capabilities that grant more access than intended, and storage paths that can be linked incorrectly.
In Cadence the security question is who holds which capability and what it authorises. A capability published to a public path with an over-broad type, or a private capability that can be re-linked, hands an attacker exactly the access the type allows — no exploit required.
We review resource and capability design, storage and public path linking, entitlements and access modifiers, and transaction-level authorisation, including how Cadence 1.0 changes affect existing contracts.
Flow runs on Chain-specific execution environment, so it inherits the bug classes below from every system in that family.
Flow contracts are written in Cadence. See our Cadence 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.
Assets live in user accounts as resources, and access is granted through capabilities. Most findings are capability scope and storage path linking rather than the arithmetic and reentrancy classes that dominate EVM audits.
Yes. The entitlements model changed how access is expressed, and migrated contracts frequently end up granting more than the original intended.
Yes — these are the most common Flow engagements, and capability design is where the risk concentrates.
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.