Build a complete logging suite with Shadow

Emit private logs off of mainnet to monitor, test, debug, and run analysis on how contracts are executing actual mainnet transactions.
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Powerful tools to analyze contract execution.

Whether you're a protocol developer, searcher, or a risk researcher, use shadow logs to understand the inner details and outputs of any deployed contract.
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Monitor and observe
Understand contract execution in detail by monitoring actual mainnet transactions.
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Log any contract
Shadow is not limited to your own contracts; you can log any mainnet contract of interest.
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Multichain support
Create logs for popular EVM chains: Ethereum, Polygon, Arbitrum, and OP Stack.
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Reduce gas fees
Shadow logs are gasless – keep costs low for users while increasing contract visibility.
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Reduce contract size
There are no contract size limits on Shadow, so you can add as many logs as you want.
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Risk simulations
Supercharge your risk and security simulations with detailed execution logs.
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No more tracing
Eliminate slow and complex tracing workflows by emitting rich shadow log data.
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Save on compute costs
Make `eth_call` data event-driven instead of hammering RPCs to reduce costs.
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Access peripheral contract data
Get anything you need from other contracts with simple view function or storage calls.

Emit private logs anywhere in any contract

Edit contracts in your Shadow fork to emit custom internal logs with full access to mainnet state data. Emit any message or data you want for internal analysis.
01 add logs

Add shadow logs to any contract

Use internal logs to understand step by step program execution for any contract.
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Create a comprehensive monitoring and testing logging suite
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Access to any state data on mainnet in log emits
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Shadow logs are completely gasless
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Shadow logs don't affect mainnet contract size
02 replay transactions

Instant transaction replay

Shadow automatically replays mainnet transactions on your own private fork.
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Visualize and understand internal function calls with actual transactions
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Get detailed step-by-step logs of contract execution
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Map out contract vulnerabilities to different types of attacks
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Instant frontfills, full backfills in less than 15 minutes
03 Sync

Ready-to-use indexed data

Shadow automatically decodes and indexes your custom events for export.
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Export shadow events to your data environment of choice
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Ready for instant use; no additional pipelines or data engineering
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Automatic event decoding and other data ergonomics

Shadow

Get custom onchain data for indexing and analytics in minutes.
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