USDT0 is the infrastructure bringing Tether assets to every network, extending the world's largest stablecoin across leading EVM and non-EVM blockchain ecosystems. With more than $95 billion transferred cross-chain and millions of users served, USDT0 is one of the most systemically important pieces of stablecoin infrastructure in onchain finance.

The Challenge

Scaling the world's largest stablecoin across every major network is a different security problem than auditing a single protocol. The asset itself is systemically important, and the trust model behind it is the product. Three pressures defined what kind of security partnership USDT0 needed:

  • The cost of a single failure is asymmetric: trusted by exchanges, institutional integrators, and retail users alike, security is foundational to the product itself at a project of USDT0's scale. Counterparty trust and the resilience of the broader stablecoin market depend on getting every deployment right, which is why USDT0 treats security as a continuous program rather than a periodic review.
  • Velocity is non-negotiable: USDT0's mandate is to be present wherever institutions and users transact, which means a continuous sequence of new network rollouts, integrations, migrations, and governance changes all moving in parallel. A traditional audit cadence with multi-month wait times is structurally incompatible with that roadmap, so USDT0 built security directly into it.
  • Coverage had to span environments no single team builds for natively: extending USDT0 across EVM networks alongside non-EVM ecosystems like TON and Hedera required a partner who could deliver the same depth of coverage across every environment rather than fragmenting across boutique firms specialized in each chain.

USDT0 needed a security partner with the scale, multi-environment depth, and continuous engagement model to keep pace with a stablecoin roadmap operating at institutional scale.

OpenZeppelin's Solution

A Continuous Security Program Built Into the Roadmap

OpenZeppelin delivers the Continuous Security Program to USDT0 as an ongoing partnership rather than a sequence of point-in-time audits. A dedicated team of senior researchers, project managers, and technical leads carries context across every engagement, so each review compounds on the last rather than starting from scratch.

Coverage spans architecture, security evaluation, and deployment. New networks, new integrations, and new governance changes ship on the cadence the market demands, with the security signal in place from design through production.

Multi-Chain Coverage Under One Engagement

Across more than 23 engagements, OpenZeppelin has secured the full surface area of the USDT0 system: the core token contracts, the chain-specific extensions, the bridges and integrations routing real settlement volume, and the deployments and governance changes behind every launch.

Coverage spans EVM ecosystems and non-EVM networks including TON and Hedera, delivered by senior researchers who cover each environment to the same standard. The same engagement model that handles a Polygon integration handles a non-EVM rollout.

Engagements include the foundational integration audit, the Polygon bridging pathway review securing one of USDT0's highest-volume liquidity corridors, the child-token migration onto the unified omnichain model, and the ERC-7802 upgrade aligning USDT0 with the emerging Crosschain Token Interface Standard ahead of broader industry adoption.

Deployment Verification That Catches Issues Before Users Do

A meaningful share of the engagement is deployment-time work: verifying that on-chain bytecode, peer configurations, fee settings, and admin roles match the audited intent before users transact. This pre-deployment assurance layer is where the program's only high-severity finding was identified and remediated, caught at review time, before user funds were exposed. Deployment Verification is exactly the kind of continuous control institutional counterparties increasingly require as evidence that what was audited is what was deployed.

“Scaling USDT0 across more than 20 networks means a continuous sequence of deployments, migrations, and governance changes all moving in parallel. Security has to be built into that cadence from the start. OpenZeppelin's continuous coverage model is what makes that possible. Their team carries context across every environment we ship on, and the result is a clean track record since launch and a technical roadmap that has been able to match the pace of demand.”

Keno Budde
CTO, Everdawn

The Results

A Clean Security Record at Stablecoin Scale

USDT0 has surfaced more than 110 issues across 23+ security engagements with OpenZeppelin, all contained, and maintained zero critical findings and zero exploits since launch. For an asset of USDT's systemic weight, this is the result that matters: continuous coverage produces the evidence base that lets users, counterparties, and integrators rely on USDT0 the way they rely on USDT itself.

Roadmap Velocity at Institutional Scale

The Continuous Security Program kept pace with one of the most aggressive expansion roadmaps in onchain finance. The business outcomes followed:

  • $95B+ in cross-chain value transferred
  • $63B in cumulative transfers within the first year of launch
  • 799,000+ transactions across 20+ supported networks

Security operating as a continuous program rather than a gated checkpoint is what made that cadence possible.

One Program, Every Chain USDT0 Ships On

A single security partner carrying context across every environment closed the seams that fragmenting across several firms would have created. Institutional integrators receive the same assurance signal regardless of which network they support, and USDT0's team works with one engagement model rather than coordinating across multiple.