Transaction Simulation

The new standard

Transact with confidence. Preview how transactions will behave on-chain, and keep your assets safe.


Empower your users to transact with confidence

Actionable simulations

In 2022, more than $5B was lost in crypto scams. With transparent previews, Transaction Simulation ensures transactions will behave as users expect.

Save gas

Simulate a transaction and know if it will revert on chain ahead of time. No more wasting unnecessary gas.

Control your data

With three products, Asset Changes, Execution Simulation and Bundle Simulation, choose the type of transaction to simulate, and the format and granularity of the preview data.

Ergonomic access

Simulate any transaction with a single method. Compatible with the Alchemy SDK and available on Ethereum, Polygon, Arbitrum, Optimism and Base.

Educate your users

Malicious transactions are predicated on opaque smart contracts that most users don't understand. Users deserve predictability and clear previews, 100% of the time.

Complex inputs, simple outputs

Other simulation methods, e.g., debug_traceCall, have limited functionality with hard-to-parse outputs. Now, simulate complex transactions and get simple results, such as why transactions will fail and revert.

What you can do

Asset Changes

Receive simulation data that is sanitized and simplified, to quickly find out the asset deltas of a transaction, before it's executed.

Execution Simulation

Receive an end-to-end simulation of the EVM execution, inclusive of ABI decoded results and comprehensive logs, events and traces data.

Bundle Simulation

Pass in an array of transactions to accurately simulate and preview sequential transactions. Example use cases may be (1) simulating the end-to-end flow of approving before swapping a token or (2) deploying a contract then calling a function on that contract.

“Alchemy handled the heavy lifting for us and saved us hundreds of hours of development time. Transaction Simulation allowed us to go-to-market 4 weeks faster!”

Ohm Shah, CEO and Co-Founder of Wallet Guard

tools for the transaction lifecycle

The Smart Transaction Platform

use with

UserOp Simulation

UserOp Simulation APIs enable you to know how a UserOp will behave before it's executed.

Use with Transaction Simulation so users can preview both Externally Owned Accounts (EOA) and Smart Contract Account (SCA) transactions.

Read the docs

Reinforced Transactions

Reinforced transactions send transactions 7.9x faster and 100% reliably, no matter what.

Use with Transaction Simulation so users can preview transactions then send them fast and reliably.

Read the docs

Private Transactions

Use Flashbots' private relay to prevent frontrunning.

Use with Transaction Simulation so your users understand asset changes ahead of time, and then can protect their txn from malicious MEV until it's included on chain.

Read the docs

Alchemy Notify

Through advanced webhooks, get notified as transactions move through the mempool and land on chain.

Use with Transaction Simulation to understand how a transaction will behave ahead of time and get notified as soon as its mined.

Read the docs

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