Deprecation Warning Injector for Old Functions

WHAT IT DOES

This tool identifies functions that are candidates for deprecation by analyzing on-chain usage patterns across a configurable block range. It scans historical transaction logs for a specified contract, extracts function signatures from transaction calldata, and counts how many times each function has been called. Functions that fall below a user-defined usage threshold are flagged as deprecation candidates, with priority levels assigned based on call frequency (unused functions get highest priority). The tool generates a detailed report showing each candidate function, its signature, call count, last call timestamp, and a clear deprecation recommendation. This is essential for developers maintaining active contracts, teams cleaning up technical debt, and projects migrating to newer contract versions.

HOW TO USE

Connect your wallet (read-only, no transaction required) and select the target network. Enter the contract name and address, set the lookback blocks for the usage scan, and define a usage threshold (e.g., functions with ≤10 calls). Click "identify deprecation candidates" and the tool will fetch the contract's ABI and scan historical logs to count function calls. Results display a summary with candidate counts, detailed cards for each candidate showing priority level and a deprecation warning, and a table of all candidates. Use the report to prioritize deprecation efforts, plan migration strategies, and inform users about upcoming changes.

TECHNICAL MECHANISM

The analyzer uses ethers.js v5.7.2 to perform a multi-stage deprecation analysis. First, it calls eth_getCode to verify the contract is deployed and uses block explorer APIs to fetch the contract's ABI. The engine then scans historical transaction logs using eth_getLogs across the specified block range, applying a chunk-and-halve strategy to handle RPC limits. For each log found, it fetches the associated transaction and extracts the method ID (first 4 bytes of calldata). These method IDs are mapped to function names using the contract's ABI, and call counts are aggregated per function. The tool also tracks the last call timestamp for each function by examining the block timestamp of the most recent transaction. Functions are then filtered by the user-defined threshold, and each candidate is assigned a priority: functions with zero calls are marked "high" (unused), functions with 1-5 calls are marked "high" (very low usage), functions with 6-50% of threshold are marked "medium", and functions at or near the threshold are marked "low". The implementation includes deduplication of transaction hashes to avoid double-counting and processes logs in batches to optimize performance while respecting RPC concurrency limits.

WHAT IT CANNOT SEE

This tool cannot modify contract behavior or emit on-chain events—it performs analysis only. It cannot determine whether a function should be deprecated without developer-defined criteria or usage metrics—the tool provides data and recommendations, but the final decision rests with the developer. It is limited by the RPC provider's rate limits and block range availability for historical log queries; very old blocks may be inaccessible. It cannot detect functions that are called through proxy patterns or delegate calls if the call origin is not captured in logs, as these interactions may not emit logs at the proxy address. The tool relies on the accuracy and completeness of source code verification and ABI data; unverified contracts or incomplete ABIs will produce incomplete results. It cannot analyze contracts that are not verified or have opaque implementation details where method IDs cannot be resolved to function names. It cannot inject warnings into the actual contract code—only identifies candidates for deprecation and produces a report. The tool cannot detect off-chain or private usage of functions, and it cannot predict future usage patterns.

PLEASE NOTE

This is a read‑only analytics tool—it never submits transactions or signs anything. It is designed for EVM‑compatible chains and works best with verified contracts. The deprecation recommendations are based on usage patterns and should be considered one of many inputs in your deprecation decision process. Always combine the generated report with manual code review, team discussion, and community communication before deprecating any function. The threshold and priority levels are configurable to fit your specific project needs.