Simulator

Know the outcome
before it's final

Model every transaction, cross-chain deployment, or financial strategy against the live state of 100+ chains.

Book a demoExplorer
TENDERLY · SIMULATOR
FORKING
MODEForked state
NETWORKEthereum · 1
BUNDLE3 steps
SIMULATION BUNDLE · DEPENDENT STEPS
@ BLOCK 19,842,140
1USDC.mint()+2,500,000 USDC supply46,210 gas
2USDC.approve()allowance → 2,500,00024,388 gas
3TreasuryVault.transferFrom()2,500,000 USDC moved51,902 gas
STEPS SIMULATED0 / 3
GAS · TOTAL0
OUTCOME—
SIMULATING AGAINST LIVE STATEETHEREUM · 100+ NETWORKS

Blockchain outcomes are irreversible.
Simulations make them predictable.

On a blockchain, you commit deployments, transfers, and protocol changes directly to a live, open environment that cannot be reversed. Tenderly's pioneering simulations predict outcomes so you can avoid irreversible damage.

Model every decision against your live operating conditions before it reaches production.

Without simulation
Signer
→
Mainnet
Finalized · irreversible
setReserveFactor(USDC)0.15 → 0.45
Submitted blind · no pre-check
Oracle deviation during block+0.8%
42 positions crossed liq. threshold−$8.2M
Keeper MEV extraction−$340k
LP withdrawals cascade−$3.1M TVL
Final outcome
Irreversible loss · post-mortem begins
−$11.6M
With simulation as pre-check
Signer
→
Sim gate
Virtual Environment
⏸
Mainnet
Not yet sent
setReserveFactor(USDC)0.15 → 0.45
Dry-run against live state · 847ms
!
Simulation warning
This decision would liquidate 42 positions and extract ~$11.6M from users. 4 invariant breaks detected. Review or adjust parameters before signing.
Positions at risk42
Projected user loss$11.6M
Invariants broken4
Safe alternativereserveFactor = 0.22
Decision gated
Tx held. Adjust, re-simulate, then sign.

Model every decision against
your actual operating environment

Test every action against a production-synced copy of your entire operating environment, with every contract, balance, oracle, liquidity pool, and external dependency across chains.

Full-fidelity conditions for reduced production risks

Run simulations against real state, with live oracle prices, current liquidity, and actual protocol positions to identify risks that would otherwise surface in production.

Multichain Virtual Environments ↗State Sync ↗

Entire simulated networks for cross-chain operations

Configure one environment with every network your system touches to validate complete cross-chain flows, including failures that only appear when chains interact.

Cross-chain environments ↗Simulation API ↗

Any scenario reproducible
on demand

Simulate any scenario, from single transactions to complete cross-chain workflows, with complete control over all parameters and reproducible audit trails.

Environment controls ↗Quickstart ↗

One multichain environment for every scenario

Simulate transactions, cascading analysis, or entire cross-chain workflows on a full-fidelity simulation infrastructure. Every type runs on Virtual Environments — production-synced forks with real contracts, balances, and oracle prices.

Single transactions

Preview the outcome of any individual action before it executes. Simulate transactions to predict gas costs, asset movements, and state changes to surface potential risks before signing.

Simulation bundles

Validate multi-step treasury operations, complex DeFi workflows, and governance actions. Sequence multiple transactions and simulate them as a single unit, each dependent on the state produced by the previous one, with cumulative gas and net position changes.

Historical replays

Test your strategies and run what-if analysis against the historical state. Mirror a chain from any past block, adjust network parameters, and test strategy effectiveness against real market conditions.

Mirror mode

Model financial strategies and enable paper trading against the current mainnet state. Rewind or fast-forward time at will and test against real mempool, gas, and block execution. Detect divergences from production to uncover unexpected behavior before production.

Multichain environments with bridging

Validate cross-chain workflows end-to-end in a single simulated environment for every chain you operate on. Test multichain deployments, preview cross-chain message passing, and validate bridge integrations to surface issues before production.

All run on
The Foundation
Simulations technology
A live fork of real chain state. One environment, shared by every simulation above. Same contracts, same balances, same oracle prices.
Real contracts
Real balances
Real oracle prices
State sync
Multichain
Update every block
Tenderly Simulator returning a successful simulation result for a UniswapV4 transaction

Control every aspect of your simulated environment

01 / 07
Verify contracts privately — visible only to your team
Decode and verify contracts inside your environment without making them visible to the public. Decoded events and state changes look identical to mainnet, only your team sees them.

How leading teams operate on Tenderly

Aave$27B TVL · DeFi lending

Aave relies on Tenderly to validate V4 upgrades and cross-chain workflows before they reach mainnet

Aave, the underlying protocol behind decentralized finance, transformed V4 development on Tenderly's simulation infrastructure. Aave used Tenderly to spin custom partner demos against live protocol state, run Aave Pro and Developer Preview on a simulated environment, and test cross-chain workflows with built-in CCIP bridge integration.

Cross-chain CCIP testingShared team environmentsZero mock contractsProduction-fidelity stateExternal demo environments
Read the full case study →
"
With the Aave app, this is the first time we're building this multichain vision where actions need to go between chains. That's where we started using the CCIP integration on Virtual Environments. It really streamlined our development environment and allowed us to test things we couldn't before.
"
Josh Stevens
ex-SVP of Engineering, Aave
500+
E2E tests per environment
2K+
Tests across 4M+ instances
30 min
Partner demo setup

Single simulation layer for every operational challenge

Pioneering simulation technology for DeFi, financial institutions, and network teams, ensuring you know the outcomes before they're final.

DeFi

Model cascade risk before governance votes. Test protocol integrations against full-fidelity chain replicas with Aave, Morpho, Uniswap, and any other live protocol. Validate cross-chain deployments with native LayerZero, CCIP, and Across bridging.

Explore DeFi solutions →
Financial Institutions

Validate large transfers, treasury operations, and tokenized product flows against live state before committing capital. Meet the operational standards and regulatory requirements with fully documented records, private verification and deployments, and on-premise solutions.

Explore institutional solutions →
Networks

Give internal, partner, and ecosystem teams a production-fidelity environment to integrate and test against your chain, with an unlimited faucet, custom precompile support, and instant bridging for cross-chain logic validation.

Explore network solutions →