Testnet Only Version, don't deploy to mainnet environment

Release Notes

Changes compared with the latest mainnet release v2.7.1.

🚀 Highlights

Main Features enable after 83,600,000 on testnet

• Reward Automation (Reward 2.0)
• Dynamic Gas Limit Change
• Consensus Penalty V2
• Gas2500x tiered gas price

Other highlights

• Support Fast Sync (10x faster)
• New p2p discovery stack: discv4 with ENR (EIP-868), discv5, and DNS discovery (EIP-1459)
• New eth sub-protocols: xdc/164 handshake with fork ID (EIP-2364) and xdc/165 transaction fetcher (EIP-2464)
• Prague / Osaka EIPs implemented, including EIP-7702 set code transactions. They are not scheduled on testnet in this release (PragueBlock / OsakaBlock are unset).

✨ New Features

Blockchain & Consensus

• Reward 2.0: reward automation, fixed reward per node (per capita), float reward parameters and updated reward parameters.
• Reward files are saved during Seal for the block miner.
• Consensus Penalty V2 (consecutive penalty upgrade).
• Dynamic gas limit, with a configurable miner gas limit.
• Gas2500x fork:
  • Underpriced transactions are dropped from the pool when a gas tier fork activates.
  • Raised the gas tip ceiling, the default max gas price oracle price and RPCTxFeeCap.
  • The default max fee cap is worked out at the next block.
• Total minted rewards are recorded on-chain (smart contract), with an API.
• Added the SyncInfo pool.
• TIPEpochHalving switch (not scheduled).
• Chain config is now centralized, with stricter genesis startup checks and a CLI flag to handle config mismatches.

EVM & Protocol (EIPs)

• EIP-7702 set code transactions (Prague), including txpool protection.
• EIP-2935 (historical block hashes), EIP-7623 (higher calldata cost).
• EIP-7825 (tx gas limit cap), EIP-7823 / EIP-7883 (MODEXP bounds and gas cost), EIP-7939 (CLZ opcode), EIP-7934 (RLP block size limit), EIP-8024, EIP-7954 (larger max contract size).
• EIP-7910 eth_config / XDPoS_getConfig.
• Osaka fork groundwork.

JSON-RPC Enhancements

• Added new RPC APIs:
  • XDPoS_getRewardByAccount
  • XDPoS_getConfig
  • An endpoint that returns the signing tx count for an epoch
  • eth_simulateV1 (with MaxUsedGas)
  • eth_getStorageValues
  • debug_accountRange, debug_intermediateRoots
  • getHeaderBy* APIs
• XDPoS_getMasternodesByNumber takes an epoch number and supports TipUpgradeReward.
• Block and state overrides for eth_call, eth_estimateGas, eth_createAccessList and debug_traceCall.
• Block timestamp in eth_getTransactionByHash.
• Added support for:
  • finalized block tag
  • Decimal block numbers
  • JWT authentication
  • Custom AuthRPC endpoints (--authrpc-*)
  • Configurable HTTP/WebSocket request limits, batch limits and eth_call timeout
  • Configurable WebSocket message size
  • eth_getLogs block range and address limits (rpc.rangelimit)
• ethclient improvements: eth_simulateV1, tracing methods, BlobBaseFee, EstimateGasAt*, PeerCount and more.

Tracing

• Live chain tracing with hooks, and tx-level tracer hooks.
• Native tracers: callTracer, prestateTracer (with diffMode), flatCallTracer (parity style), 4byte and multiplexing tracer.
• The goja JS tracer replaces duktape.
• debug_traceCall and tracing now support XDC special (non-EVM) transactions.

Networking (P2P)

• New p2p node representation (enode / ENR), with better IPv6 support and DNS names in enode URLs.
• Discovery v4 with ENR (EIP-868), discovery v5 (v5.1 wire protocol) and DNS discovery (EIP-1459).
• New dial scheduler, server-side connection retry limit, and peer whitelist/blacklist.
• Fork ID is announced over ENR, and eth/62 and eth/63 are removed.
• xdc/164 handshake with fork ID (EIP-2364) and xdc/165 transaction fetcher (EIP-2464).
• Sanity checks for unbounded and malformed propagated blocks.
• Metrics for bandwidth, throughput and discv5 traffic.
• Brought cmd/devp2p in line with upstream (crawler, discv4 UDP reachability check, protocol test suite).

Node & Tooling

• Sync status logger and structured V2 consensus config log at startup.
• delete-all-bad-blocks flag; start.sh accepts SYNC_MODE and GC_MODE.
• Grafana Pyroscope integration; configurable influxdb interval.
• Ledger Nano Gen5 / Ledger Flex, and full 32-bit chain ID support for Trezor.
• abigen v2.
• puppeth supports the v3 private chain generator.

⚡ Performance Improvements

• Big optimizations to Trie storage and synchronization:
  • Snap sync changes ported, with faster snapshot generation
  • Read caching layer
  • More memory for holding state trie
  • Fewer memory allocations
  • Better range proof generation
  • Faster iterators and trie commits
• State now uses uint256, plus a state journal wrapper and a global hasher pool.
• Faster EVM interpreter loop and PUSH opcodes; configurable jumpdest analysis cache.
• Transaction pool: read locks, fewer allocations, faster pending tx ordering.
• Faster blockchain import and downloader.
• Better RPC subscription and notification throughput; logs are fetched asynchronously.
• Shorter test runs across the project.

🛠 Stability & Bug Fixes

Consensus & Rewards

• Reward standby nodes are taken from the historical epoch snapshot.
• Candidate status uses the consensus stake ordering.
• Missing V2 gap snapshots are repaired at startup; XDPoS snapshots are cleaned up on SetHead.
• Fixed staking loss for an epoch when a checkpoint lands during sync.
• Fixed the signingTX mempool flood; signer txs use the pending nonce.
• Timeouts are verified from epochInfo.
• SyncInfo is no longer rejected when the sender has no TC yet.
• Fixed several reward distribution edge cases, including a zero value in recorded minted tokens.

Networking & Sync

• Fixed downloader race conditions, sync falling behind, and lagging heads being treated as stalling peers.
• Imports are split at gaps; the common ancestor search is capped at the local head.
• Fixed the peer unregister flood and the broadcaster stopping after send errors.
• Removed the per-peer dual-connection mechanism.
• Fixed goroutine leaks and deadlocks across p2p and discovery.
• Better HTTP/WebSocket timeout handling.

Transaction Pool & Miner

• Fixed a Sync deadlock, a journal data race and head-event subscription leaks.
• Added DoS defenses and EIP-2681 checks.
• Fixed the global MinGasPrice override and the gasPrice override at checkpoints.
• Fixed a timer handshake deadlock in the miner worker.

RPC

• Fixed many JSON-RPC edge cases and compatibility issues (Prague encoding, legacy chain ID, yParity).
• Clearer error reporting.
• More stable WebSocket connections.
• Fixed batch request handling.
• Better client shutdown synchronization.

Core & Tracing

• Fixed --set-head rewinding too far; dangling/orphan blocks are cleaned up on SetHead.
• Fixed chain indexer reorg issues and delivery of removed reorg logs.
• Fixed invalid Merkle root generation and genesis configuration problems.
• Fixed nonce errors, null entries and dropped frames in block traces.
• Stopped negative fees during RPC calls.

🔒 Security

• JWT authentication for authenticated RPC endpoints; the engine API is not exposed on unauthenticated endpoints.
• Deprecated and insecure APIs are off by default.
• Removed the legacy personal namespace.
• Removed the deprecated shh and swarm APIs.
• Removed the public XDCx / XDCxlending APIs.
• Configurable request and method-name limits to reduce abuse.
• Non-EIP-155 replay-protected transactions are rejected by default.

🧹 Maintenance

• Updated cryptography libraries (gnark-crypto v0.18.1, bn256 synced from geth).
• Updated bootnodes and configs for Mainnet, Testnet and Devnet.
• Refactored many internal packages.
• Removed deprecated components:
  • LES/light client support
  • Faucet
  • Legacy database components and XDCx mongodb support
  • Ethash PoW remnants
  • Slave mode and static/trusted node list files
• Better CLI usability and shell auto-completion.
• Added make quick-test and more developer tooling.
• Build upgraded to Go 1.25.12, golangci-lint v2.12.2 and execution-spec-tests v5.1.0.
• Updated CI/CD pipelines and deployment workflows.

📚 Documentation

• Added documentation for:
  • JSON-RPC APIs
  • XDCValidator contract
  • Tiered gas price in Solidity
• Improved developer documentation.
• Updated outdated links and examples.

🔄 Upstream Synchronization

This release brings in a large set of upstream Ethereum changes across:

• RPC
• Trie
• State database
• Downloader
• P2P networking and discovery
• Transaction pool
• EVM
• Tracing
• EthClient
• Accounts & ABI
• Cryptography
• Node networking
• Performance optimizations
• Code quality and linting

📈 Overall

This release focuses on:

• Reward automation, penalty V2, dynamic gas limit and the Gas2500x tier
• Better node stability
• Better RPC compatibility
• Faster sync
• Lower memory use
• Better tracing and debugging
• A modern p2p discovery and networking stack
• Better security defaults
• Up-to-date developer tooling
• Continued alignment with upstream Ethereum

Full Changelog: v2.7.1...v2.9.0-testnet