Conflux (CFX) CFX Releases v3.0.3 Testnet with CIP-166 Opcode and Critical Bug Fixes

Conflux (CFX) Network released its v3.0.3 testnet upgrade on February 28, addressing seven bug fixes and introducing CIP-166, a new Count Leading Zeros opcode that expands smart contract capabilities on the EVM-compatible chain.

The upgrade comes as CFX trades at $0.0458, down 9.31% over 24 hours, with the token consolidating around key support levels following its February listing on Kraken.

What’s Actually in This Release

The most consequential fix addresses CIP-78 sponsor flags—specifically, incorrect gasCoveredBySponsor and storageCoveredBySponsor receipt fields that were appearing on reverted transactions during testnet replay. For developers building on Conflux’s sponsorship mechanism (a core feature that lets dApps pay gas for users), this was causing headaches with transaction tracking.

Other notable fixes include:

• A deadlock issue in fee_history that could freeze RPC responses
• A panic-inducing overflow bug when Proof-of-Stake force-retire events triggered early
• Incorrect gas limit maintenance in the transaction packing pool
• CPU mining timing irregularities

The new CIP-166 opcode adds Count Leading Zeros functionality—a low-level operation useful for bit manipulation in smart contracts. While technical, these opcodes matter for developers optimizing gas-intensive computations.

RPC Improvements for Developers

The release packs several quality-of-life improvements for builders. The eth_blockByNumber call now supports the pending tag, bringing it closer to standard Ethereum RPC behavior. Transaction receipts gain an accumulatedGasUsed field, and Core Space logs now include timestamps—small additions that streamline debugging.

A new dump subcommand lets operators export all eSpace accounts to JSON, useful for state analysis and migration scenarios.

Infrastructure Modernization

Behind the scenes, the team bumped Rust to version 1.90 and updated core dependencies including revm and c-kzg. New GitHub Actions workflows now automate builds across Linux, macOS, and Windows—a sign of maturing development infrastructure following the major 3.0 “Tree-Graph” upgrade that shipped in August 2025.

Should Node Operators Upgrade?

Conflux explicitly states this upgrade is optional. The fixes target stability rather than consensus changes, so nodes running older versions won’t fork off the network. That said, operators experiencing RPC deadlocks or transaction pool issues should consider upgrading.

The straightforward process: stop your node, swap the executable, restart. New operators can grab v3.0.3-testnet directly from the GitHub release page.

For a network positioning itself as China’s regulatory-compliant blockchain gateway—complete with Tether’s CNH-pegged stablecoin launched in November—maintaining infrastructure stability matters. Whether this testnet release signals an imminent mainnet update remains unclear, but the development cadence suggests active protocol maintenance ahead of potential enterprise adoption cycles.

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