How to configure Rabby Wallet for gas simulation? (Zero Failed Tx)

Gas Simulation Fundamentals in Rabby Wallet

1. Rabby Wallet embeds a real-time gas estimation engine directly into its transaction signing layer, leveraging on-chain mempool analytics and historical fee density models across EVM-compatible networks.

2. The simulation does not rely solely on eth_gasPrice RPC calls but instead aggregates data from multiple block producers, priority fee auctions, and recent block inclusion patterns to project optimal gas parameters.

3. Every transaction draft undergoes pre-execution bytecode analysis to detect potential revert conditions—such as insufficient balance, invalid calldata length, or unauthorized contract access—before any network broadcast occurs.

4. Gas simulation results are rendered with three distinct tiers: Safe Low, Recommended, and Aggressive, each mapped to empirical confirmation latency percentiles observed over the past 60 minutes.

5. Users can toggle between legacy EIP-1559 and legacy gas price mode via the advanced settings panel, with automatic fallback logic activated when network congestion triggers base fee volatility beyond ±35% of median.

Enabling Pre-Transaction Validation

1. Navigate to Settings > Advanced > Transaction Safety and activate “Simulate Before Sign” — this forces Rabby to execute a full eth_call with identical calldata, sender, value, and gas limit prior to signature generation.

2. Enable “Contract Risk Scanning” to trigger static analysis of target contract opcodes; Rabby cross-references deployed bytecode against its local threat signature database maintained at src/background/service/securityEngine.ts.

3. Toggle on “Balance Sufficiency Check” which validates not only native token balance but also ERC-20 allowance status for any token transfer operation involving third-party contracts.

4. Activate “Slippage-Aware Simulation” for Swap and Bridge actions — this injects dynamic slippage buffers into the simulation loop, adjusting gas estimates based on expected price impact derived from pool reserves and route depth.

5. Set custom gas cap thresholds per chain under Network Configuration; Rabby rejects simulations returning gasUsed values exceeding these caps, preventing accidental overestimation on high-fee chains like Ethereum Mainnet during peak load.

Customizing Gas Parameters Manually

1. Within any transaction flow (Send, Swap, Bridge), click the gear icon beside the gas display to expose manual override fields for maxFeePerGas, maxPriorityFeePerGas, and gasLimit.

2. Input precise hex-encoded values or decimal integers — Rabby validates syntax and enforces chain-specific bounds before accepting modifications.

3. Use the “Estimate From Block” slider to select reference block height for fee calculation; selecting blocks older than 12 confirms improves stability but may reduce speed accuracy.

4. Paste raw transaction hex into the “Import Raw Tx” field in Advanced Tools to simulate unsigned RLP payloads, enabling forensic validation of externally constructed transactions.

5. Export simulation logs via Developer Mode (enabled by clicking Rabby logo seven times) to generate JSON traces containing gasUsed, effectiveGasPrice, revert reason, and opcode-level execution steps.

Debugging Failed Simulation Traces

1. When simulation returns “Reverted” status, Rabby displays decoded revert strings if contract source is verified on Etherscan or Blockscout; otherwise, it renders raw error bytes alongside ABI fragment matching.

2. Click “View Trace” to open an interactive call tree showing nested internal calls, storage slot reads/writes, and memory allocation events leading up to the failure point.

3. Filter trace entries by opcode class (e.g., SLOAD, CALL, REVERT) using the search bar inside the trace viewer to isolate problematic state interactions.

4. Compare simulation trace against live transaction receipt using the “Compare With Onchain” button — discrepancies highlight timing-dependent failures such as frontrunning or nonce mismatches.

5. Export failed simulation context as .rabbytrace file for offline analysis or submission to Rabby’s diagnostics portal hosted at diagnostics.rabby.io.

Frequently Asked Questions

Q: Does Rabby Wallet simulate gas usage for non-EVM chains like Solana or Cosmos?No. Gas simulation is exclusively available for EVM-compatible networks including Ethereum, Polygon, BSC, Arbitrum, Optimism, Base, and all other chains implementing the Ethereum JSON-RPC specification.

Q: Can I disable gas simulation entirely to speed up transaction signing?Yes. Under Settings > Advanced > Transaction Safety, toggling off “Simulate Before Sign” removes pre-execution validation. This increases risk of failed transactions and is not recommended for production use.

Q: Why does the same transaction show different gasUsed values across repeated simulations?Gas consumption varies due to dynamic factors including contract storage layout changes, timestamp-dependent logic, and external oracle feed updates — all of which alter execution paths between simulation attempts.

Q: Is simulated gasUsed guaranteed to match onchain gasUsed?No. Simulation assumes identical state at time of call; however, race conditions, reorgs, or concurrent state mutations may cause divergence. Rabby flags simulations with >5% variance from historical median as “Unstable Estimate”.