Now in public beta

The ultimate simulation engine
for web3 companies.

Send any calldata. Get back token changes, NFT positions, and gas costs.
One API call. Any EVM chain. ERC20s, ERC721s, ERC1155s. No wallet required.

Get API Key Read the Docs
Ethereum
312ms
Uniswap V4 · Mint CLP position
Balance injected Approval added
0x88316456000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48000000000000000000000000c02aaa39b223fe8d0a0e5c4f27ead9083c756cc200000000000000000000000000000000000000000000000000000000000001f4
Simulation successful
Block #21,847,293
You send
USDC
USD Coin USDC ERC20
0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48
−4,217.39
$4,217.39
WETH
Wrapped Ether WETH ERC20
0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2
−1.5000
$4,192.50
You receive
UNI
Uniswap v4 Positions NFT ERC721
#1,207,888
0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e
+1
~$8,409.89
Gas used 461,218
Gas cost ~$1.05
Standard ERC721
Events 9 logs
Trusted by teams building
DEX Aggregators
Wallets
Yield Protocols
AI Agents
Protocol Frontends
Security Tools
How It Works
From calldata to clarity.

You bring the calldata. We execute it against live chain state and return structured results your UI can render directly.

01
Send your calldata
POST your transaction — from, to, data, value — and the target chain. That's it.
02
We simulate it
Executed on a fresh fork of live state. Balance injected, approval prepended, gas computed.
03
Get structured results
Token amounts, NFT positions, directions, standard types, names, symbols, decimals, gas cost, and human-readable errors.
Why Simulate
Real execution.
Zero requirements.

Your transaction runs on an isolated fork of live chain state — exactly as it would execute on-chain. No setup needed.

✓No wallet connection needed
✓No token balance needed
✓No approval transaction needed
✓No gas funding needed
✓Executes exactly like the real transaction
✓Isolated forked state per request
Use Cases
Know the exact impact before
it hits the chain.

From swap previews to security screening — simulation is the foundation for every DeFi product that takes user experience seriously.

DEX Aggregators & Routers
Show accurate output amounts, gas costs, and token metadata directly in your swap UI. Simulate against live chain state with automatic balance injection — no whale accounts or forked environments required.
Wallets & Portfolio Apps
Give users a clear preview of every transaction before they sign. Display human-readable asset changes for ERC20s, NFTs, and multi-tokens — with token names, amounts, and standard types. Building trust at sign time.
Lending, Yield & CLP Positions
Preview vault deposits, borrow positions, CLP mints, and leverage loops before committing capital. Batch simulation lets you chain supply→borrow→swap in a single call with shared state. Works with Uniswap V3, Aave, Morpho, Pendle, and any EVM protocol.
AI Agents & Automation
Verify transaction outcomes programmatically before execution. Chain multi-step flows with batch simulation — one API call returns structured results for every step.
Smart Contract Development
Test contract interactions against live mainnet state without deploying to a testnet. Validate user flows end-to-end with real token balances, prices, and protocol state.
Transaction Security
Screen transactions for unexpected asset transfers before users approve them. Surface clear warnings with decoded token names and amounts — catch reverts and malicious behavior before they cost gas.
Protocol Coverage
Every DeFi primitive.
Every token standard.

Simulate any transaction across the DeFi stack — from simple token swaps to CLP position mints, leverage loops with flash loans, and multi-step vault strategies.

Token Swaps
Lending & Borrowing
Liquid Staking
Yield Vaults
Restaking
CLP Positions
Flash Loans
Leverage Loops
Batch Simulations
ERC721 NFTs
ERC1155 Multi-Token
Yield Tokenization
RWAs
Governance
Real-time
Simulation results
1
API call — that's it
Sub-second
Cached lookups
Uniswap Morpho Aave V3 Pendle Compound Lido Rocket Pool EigenLayer Ethena Euler Yearn V3 Convex Curve Spark Maker Frax ether.fi Silo Beefy Usual Protocol

ERC20s, ERC721 NFTs, ERC1155 multi-tokens, proxy tokens, rebasing tokens, vault shares, LP tokens, PT/YT tokens — every standard works.
CLP positions tracked by tokenId. Leverage loops with flash loan netting. Batch simulations chain multi-step flows (supply→borrow→swap) in a single call. If it's an EVM transaction, we can simulate it.

What You Get
Everything in one response.

No chaining APIs, no post-processing, no separate metadata calls.

Automatic balance injection auto
Sender doesn't have tokens? We detect the right approach and inject the balance for the simulation. Works for every ERC20 we've tested — thousands of tokens across 31 chains.
Automatic token approval auto
The approve transaction is prepended automatically. You send the swap calldata, we handle the approval. One less thing to worry about.
Token metadata included included
Every response includes name, symbol, and decimals for all tokens involved. Display "1,234.56 USDC" instead of "1234560000 0xa0b8...".
Multi-standard asset tracking new
ERC20 tokens, ERC721 NFTs, and ERC1155 multi-tokens — all tracked with net direction, tokenId, and standard type. CLP positions, game items, and NFT mints all show up as structured asset changes.
Batch simulations pro
Chain multiple transactions in a single call — supply, borrow, swap, re-supply — all executed in one simulated block with shared state. Get per-step success/failure and aggregated net asset changes.
Human-readable reverts
When a transaction would fail, you get the actual error message — not a hex blob. "Insufficient liquidity" instead of "0x08c379a0000...".
31 chains, one endpoint
Ethereum, Base, Arbitrum, Polygon, Optimism, and 26 more networks. Same API, same response format, every chain.
Gas estimation accurate
Every simulation returns the exact gas used. No more guessing gas limits — get precise costs before sending a single transaction on-chain.
Ethereum
Base
Arbitrum
Polygon
Optimism
BNB Chain
Avalanche
Sonic
HyperEVM
Fraxtal
Mode
Gnosis
Unichain
zkSync
Worldchain
Metis
Lisk
Moonbeam
Sei
Soneium
Ronin
Mantle
Arb Nova
Celo
Ink
Linea
BOB
Berachain
Blast
Taiko
Scroll
Pricing
Simple pricing. No compute units.

No Compute Units. Just simulations. Every plan includes all chains, balance injection, and structured results.

Free
$0
forever
  • 1,000 simulations / month
  • 1 request / second
  • All chains
  • 1 API key
Start Free
Starter
$49/mo
then $0.002 per extra sim
  • 25,000 simulations / month
  • 5 requests / second
  • All chains
  • 2 API keys
Get Started
Pro
$149/mo
then $0.001 per extra sim
  • 100,000 simulations / month
  • 20 requests / second
  • Batch simulations (multi-step)
  • All chains
  • 5 API keys
  • Email support (24h)
Get Started
Business
$449/mo
then $0.0007 per extra sim
  • 500,000 simulations / month
  • 50 requests / second
  • Batch simulations (multi-step)
  • All chains
  • Unlimited API keys
  • Email support (24h)
Get Started
Enterprise
Custom
for high volume
  • Unlimited simulations
  • Custom rate limits
  • Batch simulations (multi-step)
  • Email support (24h)
  • Volume discounts
Contact Us
x402
$0.001 / sim · USDC on Base
No API key No subscription Any wallet AI agents
Learn more →
Start simulating in 30 seconds.
Get an API key, paste the code snippet, see your first result.
Get Your API Key Read the Docs