Introducing Enso Quote Simulator
A swap says one thing; execution delivers another. Liquidity changes, and markets move between quote and signature.
Over the last month, we publicly exposed this problem through the Enso Shield Dashboard, analyzing thousands of simulations across aggregators. The takeaway was simple:
Execution is not always as predictable as it looks.
That is why we built our Enso Quote Simulator, our proprietary pre-trade simulation and verification infrastructure enabling transaction validation, operational safeguards, and deterministic execution controls.
Simulate swaps, deposits, bridges, and balance changes.
For more than two years, every transaction routed through Enso has been simulated before execution. It has quietly powered the infrastructure behind billions in settled volume, helping ensure transactions behave as expected before users ever sign.
Enso Quote Simulator is a blazing-fast API that simulates the outcome of any transaction in under 50 milliseconds.
- Swaps
- Vault deposits
- Bridges
- LP zaps
- Complex DeFi flows
And because simulation only matters if people can understand the result, it focuses on the thing users actually care about:
Balance changes.
Instead of showing vague estimates, the API returns the expected outcome of a transaction in a format users instantly recognize.
This is the same mental model users already trust in wallets like Rabby, now available as infrastructure for any application to integrate. Instead of asking users to trust an output number, products can show what a transaction is actually expected to do before execution.
The Architecture
The Quote Simulator API functions as a two-layer transaction-trust API.
First, it simulates any transaction, returning the expected balance changes, amountOut, and gas fast enough for live routing without degrading UX. It works across any transaction source, including DEX aggregators, DeFi protocols, custom contracts, or Enso’s own routing infrastructure.
Second, it validates unsigned transactions before signing, confirming that critical fields such as calldata, recipient address, contract target, value, and chain ID still match the original. Under the hood, it runs on isolated RPC infrastructure, separate from Enso’s core production systems, with API key authentication, rate limiting, and full OpenAPI documentation available from launch.
What Enso Quote Simulator supports
- Trade simulation: simulate swaps, deposits, bridges, LP zaps, and complex DeFi flows before execution.
- Balance change previews: return the expected balance changes from a transaction, so applications can show users what will happen before they sign.
- Blazing-fast responses: return simulations in under 50ms, fast enough for live routing, trading interfaces, and wallet UX.
- Batch simulations: simulate hundreds of trades, routes, or transactions in parallel, making it easier to compare execution paths at scale.
- Automatic slot overrides and top-ups: handle the low-level simulation requirements needed for accurate results across complex DeFi transactions.
- Transaction validation: verify that unsigned transactions still match the original simulation before signing, including calldata, recipient address, contract target, value, and chain ID.
Speed matters.
The Quote Simulator is built for real-time applications.
It returns simulations in under 50ms, fast enough for live routing, trading interfaces, wallets, and user-facing product experiences without degrading UX.
It also supports batch simulations, allowing developers to simulate hundreds of trades, routes, or transactions in parallel. This makes it useful for aggregators, trading products, and protocols that need to compare many possible execution paths before showing a result to the user.
Under the hood, it automatically performs the correct slot overrides and top-ups required to accurately simulate complex DeFi transactions. That means applications can preview swaps, deposits, bridges, LP zaps, and balance changes without producing misleading results or unnecessary failures.
Wallets, meta aggregators, and trading interfaces can use it to show users real balance changes before signing.
- Aggregators can simulate routes before returning them to users.
- Protocols can preview deposits and more complex flows directly inside their applications.
- Auditors and security teams can inspect transaction outcomes at scale.
It can also validate unsigned transactions, helping applications confirm that what the user is about to sign still matches what was originally simulated. That creates stronger integrity between generation and execution, especially for products that care about trust, security, and reliability.
Our Quote Simulator is now live.
→ API docs: https://docs.enso.build/pages/quoter