Blockchain & Smart
Contract Security
We examine contracts, protocol logic, bridges and off-chain dependencies to find exploitable flaws before assets are at risk.
We find exploitable flaws in contracts, protocols and bridges before they put assets at risk.
Security beyond the source code.
Protocol-level thinking
We trace how contracts, permissions, external dependencies, and protocol rules interact to identify risks that isolated code reviews can miss.
Adversarial validation
We investigate realistic attack paths using manual analysis and targeted testing, validating findings with reproducible evidence where appropriate.
Findings that drive fixes
Every confirmed finding is documented with its impact, technical details, severity, and recommended remediation. Fix verification is available within the agreed engagement scope.
Security reviews built around your system.
01
Design Assessment
Find architectural weaknesses before implementation.
Review trust assumptions, privileged roles, upgrade mechanisms, oracle dependencies, and protocol interactions before design decisions become expensive to change.
- 01Architecture and threat-model review
- 02Access-control and trust-boundary analysis
- 03Integration and dependency risks
- 04Security recommendations for implementation
Outcome: A clearer understanding of architectural risks before deployment.
02 · Flagship engagement
Comprehensive Audit
Find exploitable flaws in contracts and protocol logic.
Combine manual code review with appropriate automated analysis and adversarial testing to investigate implementation flaws, business logic errors, and protocol-level attack paths.
- 01Manual review of in-scope code
- 02Automated analysis and targeted testing
- 03DeFi economic and integration risk assessment
- 04Severity-ranked findings with technical evidence
- 05Remediation guidance and agreed fix verification
Outcome: A detailed security report with actionable findings and a documented remediation status.
03
Protocol & Node Review
Assess the infrastructure behind the protocol.
Examine protocol implementations, node configurations, consensus assumptions, governance mechanisms, and cross-chain dependencies where relevant.
- 01Protocol and node implementation review
- 02Consensus and trust-assumption analysis
- 03Governance and privileged-operation risks
- 04Bridge and cross-chain integration review
Outcome: Documented risks across the reviewed protocol and infrastructure components.
04
Continuous Security
Keep security aligned with protocol changes.
Establish recurring reviews for upgrades, new features, and changing dependencies under an agreed security plan.
- 01Upgrade and release reviews
- 02Targeted regression testing
- 03Reassessment of previously identified risks
- 04Ongoing security recommendations
Outcome: A repeatable security review process that evolves with your protocol.
From threat model to verified findings.
A structured review that combines manual research, targeted testing, and clear reporting.
Scope & Threat Model. Define the assets, trust boundaries, dependencies, and assumptions in scope.
Understand how the system can fail.
Smart contracts
Reentrancy, authorization flaws, unsafe external calls, and state inconsistencies.
DeFi protocols
Price manipulation, accounting errors, liquidation logic, and economic attack paths.
Bridges
Message validation, replay protection, signature verification, and cross-chain trust assumptions.
Oracles
Stale data, manipulation, incorrect assumptions, and integration failures.
Governance & upgrades
Privileged roles, upgrade authorization, initialization risks, and governance attacks.
Protocol infrastructure
Node configuration, external services, and off-chain components within the engagement scope.
Testing coverage depends on the architecture, agreed scope, and applicable threat model.
Featured security reports.
Start with the right level of review.
Every engagement is scoped with you first. Models can be combined.
Why clients trust us.
“Vaultline (formerly 0xTeam) provided us with a comprehensive audit that uncovered critical and hidden vulnerabilities. Their turnaround was fast, and communication was seamless. The team was highly professional and technically sound. We felt secure launching post-audit.”
Playarts Ai@playartsdotai“The audit experience with Vaultline (formerly 0xTeam) was exceptional. Their findings were detailed, accurate, and easy to follow. They identified logic bugs others missed. Our smart contracts are now more robust thanks to their efforts.”
DZap@dzap_io“Working with Vaultline (formerly 0xTeam) was smooth from start to finish. Their security insights helped us fix serious issues early. Their report was thorough, and the post-audit call added great clarity. Definitely our go-to team for future audits.”
Funtoken@funtoken_io“We needed a reliable audit before launch, and Vaultline (formerly 0xTeam) delivered. Their approach blended automation and manual review perfectly. The team was responsive, skilled, and security-focused. We gained major trust from users post-audit.”
AMGI Studios@amgistudios“We loved how hands-on Vaultline (formerly 0xTeam) was during our audit. They didn't just find issues, they educated us too. The report was actionable, clear, and helped our developers level up. Our product is now safer and play-ready.”
Elevate Finance
Press & news.
Vaultline backs Colosseum builders with up to $4,000 in audit services per Solana project before launch.View post 
Meet the Vaultline team at Devcon in Mumbai, India, to talk audits, exploits and shipping secure Web3.View post 
Web3 Security Breach Analysis, H1 2026 is live: the biggest exploits, attack trends and lessons so far.Read report Smart contract audit questions.
01What is a smart contract audit?
A smart contract audit is a security review of a protocol's contracts before or after launch. Vaultline engineers read the code by hand, run static analysis, fuzzing and invariant tests, and try realistic attack paths to find flaws in logic, permissions and protocol design.
02How much does a smart contract audit cost?
Cost depends on code size, complexity and timeline. Share your repository or contract addresses through the contact form and we send an estimated quote within 24 hours, after a free scoping call.
03How long does a smart contract audit take?
It depends on the size and complexity of the codebase. The timeline is agreed on the scoping call before the review starts, and every engagement ends with a full report and a review of your fixes.
04Which chains and languages do you audit?
We audit Solidity and Vyper contracts on Ethereum and EVM chains such as Polygon and BNB Chain, Rust programs on Solana, Move on Sui, plus Cairo and Go codebases.
05What is included in the audit report?
Each confirmed finding comes with its severity, impact, affected code, technical evidence and recommended fix. After you fix the issues, we review the changes and issue a final report with the remediation status of every finding.
06Can the audit report be public?
Yes. You choose whether the report is public or private. Public reports are published on our reports page and GitHub, and NDAs are available for private engagements.
Build with fewer unknowns.
Tell us what you're building, what needs reviewing, and when you plan to deploy. We'll discuss the scope and recommend an appropriate security engagement.