diff --git a/core/sdk.go b/core/sdk.go
index 223634e..abee330 100644
--- a/core/sdk.go
+++ b/core/sdk.go
@@ -25,6 +25,11 @@ type AtlasSdk struct {
 
 	userLastNonSequentialNonce map[uint64]map[common.Address]*big.Int
 	noncesMu                   sync.Mutex
+
+	atlasAddress             map[uint64]common.Address
+	atlasVerificationAddress map[uint64]common.Address
+	simulatorAddress         map[uint64]common.Address
+	sorterAddress            map[uint64]common.Address
 }
 
 func NewAtlasSdk(ethClient []*ethclient.Client, chainOverrides map[uint64]*config.ChainConfig) (*AtlasSdk, error) {
@@ -42,6 +47,10 @@ func NewAtlasSdk(ethClient []*ethclient.Client, chainOverrides map[uint64]*confi
 		simulatorContract:          make(map[uint64]*simulator.Simulator),
 		sorterContract:             make(map[uint64]*sorter.Sorter),
 		userLastNonSequentialNonce: make(map[uint64]map[common.Address]*big.Int),
+		atlasAddress:               make(map[uint64]common.Address),
+		atlasVerificationAddress:   make(map[uint64]common.Address),
+		simulatorAddress:           make(map[uint64]common.Address),
+		sorterAddress:              make(map[uint64]common.Address),
 	}
 
 	for _, client := range ethClient {
@@ -82,6 +91,10 @@ func NewAtlasSdk(ethClient []*ethclient.Client, chainOverrides map[uint64]*confi
 		sdk.simulatorContract[chainIdUint64] = simulatorContract
 		sdk.sorterContract[chainIdUint64] = sorterContract
 		sdk.userLastNonSequentialNonce[chainIdUint64] = make(map[common.Address]*big.Int)
+		sdk.atlasAddress[chainIdUint64] = chainConf.Contract.Atlas
+		sdk.atlasVerificationAddress[chainIdUint64] = chainConf.Contract.AtlasVerification
+		sdk.simulatorAddress[chainIdUint64] = chainConf.Contract.Simulator
+		sdk.sorterAddress[chainIdUint64] = chainConf.Contract.Sorter
 	}
 
 	return sdk, nil
diff --git a/core/simulate.go b/core/simulate.go
new file mode 100644
index 0000000..14bda05
--- /dev/null
+++ b/core/simulate.go
@@ -0,0 +1,140 @@
+package core
+
+import (
+	"context"
+	"encoding/hex"
+	"fmt"
+	"math/big"
+
+	"github.com/FastLane-Labs/atlas-sdk-go/contract"
+	"github.com/FastLane-Labs/atlas-sdk-go/types"
+	"github.com/FastLane-Labs/atlas-sdk-go/utils"
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func (sdk *AtlasSdk) SimulateUserOperation(chainId uint64, userOp *types.UserOperation) error {
+	pData, err := contract.SimulatorAbi.Pack("simUserOperation", *userOp)
+	if err != nil {
+		return fmt.Errorf("failed to pack simUserOperation: %w", err)
+	}
+
+	if _, ok := sdk.ethClient[chainId]; !ok {
+		return fmt.Errorf("no ethClient for chainId %d", chainId)
+	}
+
+	simulatorAddr, ok := sdk.simulatorAddress[chainId]
+	if !ok {
+		return fmt.Errorf("no simulator Address for chainId %d", chainId)
+	}
+
+	bData, err := sdk.ethClient[chainId].CallContract(
+		context.Background(),
+		ethereum.CallMsg{
+			To:        &simulatorAddr,
+			Gas:       userOp.Gas.Uint64() + 1500000, // Add gas for validateCalls and others
+			GasFeeCap: new(big.Int).Set(userOp.MaxFeePerGas),
+			Value:     new(big.Int).Set(userOp.Value),
+			Data:      pData,
+		},
+		nil)
+	if err != nil {
+		return fmt.Errorf("failed to call simUserOperation: %w", err)
+	}
+
+	validOp, err := contract.SimulatorAbi.Unpack("simUserOperation", bData)
+	if err != nil {
+		return fmt.Errorf("failed to unpack simUserOperation: %w", err)
+	}
+
+	if !validOp[0].(bool) {
+		result := validOp[1].(uint8)
+		validCallResult := validOp[2].(*big.Int)
+		return fmt.Errorf(
+			"simUserOperation failed with result %d and outcome %s and pData %s",
+			result,
+			hex.EncodeToString(validCallResult.Bytes()),
+			hex.EncodeToString(pData),
+		)
+	}
+
+	return nil
+}
+
+func (sdk *AtlasSdk) SimulateSolverOperation(chainId uint64, userOp *types.UserOperation, solverOp *types.SolverOperation) error {
+	userOpHash, err := userOp.Hash(utils.FlagTrustedOpHash(userOp.CallConfig), chainId)
+	if err != nil {
+		return fmt.Errorf("failed to hash userOp: %w", err)
+	}
+	dAppOp := &types.DAppOperation{
+		From:          common.Address{},
+		To:            userOp.To,
+		Nonce:         big.NewInt(0),
+		Deadline:      userOp.Deadline,
+		Control:       userOp.Control,
+		Bundler:       common.Address{},
+		UserOpHash:    userOpHash,
+		CallChainHash: common.Hash{},
+		Signature:     []byte(""),
+	}
+
+	if utils.FlagVerifyCallChainHash(userOp.CallConfig) {
+		callChainHash, err := CallChainHash(userOp, []*types.SolverOperation{solverOp})
+		if err != nil {
+			return fmt.Errorf("failed to calculate callChainHash: %w", err)
+		}
+		dAppOp.CallChainHash = callChainHash
+	}
+
+	pData, err := contract.SimulatorAbi.Pack("simSolverCall", *userOp, *solverOp, *dAppOp)
+	if err != nil {
+		return fmt.Errorf("failed to pack simSolverCall: %w", err)
+	}
+
+	gasPrice := new(big.Int).Set(userOp.MaxFeePerGas)
+	if solverOp.MaxFeePerGas.Cmp(userOp.MaxFeePerGas) > 0 {
+		gasPrice.Set(solverOp.MaxFeePerGas)
+	}
+
+	if _, ok := sdk.ethClient[chainId]; !ok {
+		return fmt.Errorf("no ethClient for chainId %d", chainId)
+	}
+
+	simulatorAddr, ok := sdk.simulatorAddress[chainId]
+	if !ok {
+		return fmt.Errorf("no simulator Address for chainId %d", chainId)
+	}
+
+	bData, err := sdk.ethClient[chainId].CallContract(
+		context.Background(),
+		ethereum.CallMsg{
+			To:        &simulatorAddr,
+			Gas:       userOp.Gas.Uint64() + solverOp.Gas.Uint64() + 1500000, // Add gas for validateCalls and others
+			GasFeeCap: gasPrice,
+			Value:     new(big.Int).Set(userOp.Value),
+			Data:      pData,
+		},
+		nil,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to call simSolverCall: %w", err)
+	}
+
+	validOp, err := contract.SimulatorAbi.Unpack("simSolverCall", bData)
+	if err != nil {
+		return fmt.Errorf("failed to unpack simSolverCall: %w pData %s", err, hex.EncodeToString(pData))
+	}
+
+	if !validOp[0].(bool) {
+		result := validOp[1].(uint8)
+		solverOutcomeResult := validOp[2].(*big.Int)
+		return fmt.Errorf(
+			"simSolverCall failed with result %d and outcome %s and pData %s",
+			result,
+			hex.EncodeToString(solverOutcomeResult.Bytes()),
+			hex.EncodeToString(pData),
+		)
+	}
+
+	return nil
+}