HTND v2.16.0 Release Notes

Release date: 2026-09-01

This release includes 365 commits with ~7856 lines added and ~1606 lines deleted across 173 files. Major focus areas include IBD reliability improvements, UTXO diff corruption fixes, coinbase handling with block versions 8 and 9 activation, virtual block management, and performance optimizations.

Consensus & Block Processing

Block Version 8 & 9 Activation

• Block version 8 activated at DAA score 217,137,983 (POWScores[6])
• Block version 9 activated at DAA score 218,735,007 (POWScores[7])
• Added per-block coinbase entropy (version 8+) based on merge set + DAA score to prevent transaction ID collisions between sibling blocks
• Added timestamp-based coinbase entropy (version 9+) that additionally folds the block's own header timestamp into entropy for stronger collision resistance
• All version-indexed parameter arrays extended to 9 entries to support versions 8 and 9

Coinbase & UTXO

• Fixed coinbase manager to use each block's own version (not ambient GetBlockVersion()) when building expected coinbase transactions
• Fixed UTXO diff corruption in reorg merges caused by coinbase ID collisions
• Fixed AddTransaction in mutable UTXO diff to properly handle outpoint collisions (only treat same-valued collisions as no-op)
• Restored previously-disabled pruning-point-import UTXO commitment validation
• Fixed updateSelectedTipUTXODiff to reconcile full absolute virtual diff with selected tip's relative diff instead of silently staging wrong diff

Reorg & Diff Handling

• Added reconcile_reorg_utxo.go with reconciliation logic for reorg UTXO sets
• Fixed resolve_block_status.go to properly handle disqualified blocks and their UTXO diffs
• Added tolerance for inherited pruning-point offsets in UTXO commitment validation
• Made verifyUTXO uniformly permissive on inherited pruning-point offsets
• Added repair of imported pruning-point UTXO multisets at import time
• Fixed the fourth unprotected conflict shape in diffFrom
• Fixed missing-input block transaction handling on inherited pruning-point offsets
• Added robust, marker-free UTXO commitment toleration

Virtual Blocks

• Comprehensive fixes for virtual genesis and virtual block handling
• Fixed virtual block staging and retrieval in consensus state manager
• Added guards for virtual genesis blocks in blue anticone calculations
• Fixed pick_virtual_parents.go to not select disqualified blocks
• Ensured virtual genesis/blocks are not added as last valid blocks in tip calculations
• Added filtering of virtual genesis hashes from merge sets
• Fixed child iterators to properly handle nil high/low values against virtual blocks
• Added mutex to block retrieval to prevent race conditions

Pruning

• Added pruning store with 2-entry cache (new file)
• Added pruning point validation: ensure pruning point is in selected parent chain of locator hash
• Fixed pruning point diff calculation and messages
• Added CheckMergeSetBluesAndIfBlockExistsInThem to validate pruning points
• Don't create pruning point with any other than UTXO valid blocks
• Increased UTXODiff LRU cache size from 1000 to 250,000

IBD (Initial Block Download)

Core IBD Fixes

• Replaced selected child iterator with BFS (Breadth-First Search) in antiPastHashesBetween for improved parent-closure completeness
• Fixed antiPastHashesBetween parent-closure completeness bug causing IBD missing parents
• Fixed missing parent errors in antiPastHashesBetween by ensuring actualHighHash progress
• Fixed integer overflow on IBD zooming
• Added configurable past median time tolerance (2 seconds) to accommodate clock drift between nodes

Zoom & Stall Handling

• Root-cause fix: conclude IBD negotiation when the zoom window is all header-only
• Don't ban peers for IBD zoom stalls caused by all-header-only windows
• Abandon (don't ban) peers on any prolonged IBD zoom stall
• Stop banning peers for IBD zoom-in stalls caused by local disqualification
• Log IBD zoom steps at debug level on healthy path, warn only when stuck
• Dump full locator window when IBD zoom stalls for non-disqualification reasons
• Fixed premature NO-OP exit from ResolveVirtual during IBD

Header-Only Blocks

• Send blocks in IBD even if header-only, but mark their PoW hash as header-only and don't process them
• Don't send header-only blocks in normal operation
• Don't use header-only blocks as lowest unknown syncer chain hash
• Fixed resolve virtual failure with header-only blocks in IBD
• Fixed pruning point error during IBD with headers proof
• Fixed IBD with headers proof when pruning point is unchanged
• Fall back to shared ancestor when pruning point isn't on syncer tip's chain
• Never fail IBD in missingBlockBodyHashes on a diverged local chain

Performance

• Added per-block stage timing to identify ~400ms/block IBD processing cost
• Separated IBD network-wait time from local-processing time per batch
• Instrumented restorePastUTXO and DiffFrom to find IBD slowness sources

GHOSTDAG & DAGKnight

DAGKnight

• DAGKnight consensus algorithm is present in codebase (dagknight.go)
• Fixed DAGKnight selected-parent attribution and error propagation
• Added filtering of disqualified blocks in GHOSTDAG/DAGKnight merge sets
• Added check in findSelectedParent to skip disqualified blocks
• Added MaxDAGKnightTips constant (24)
• Added DAGKnight faithfulness analysis document

GHOSTDAG Manager

• Fixed nil pointer dereference in ghostdag manager that propagated to get anticone
• Fixed getChainPath to handle nil blocks and nil selected parents
• Removed excessive logging from partitionByLCAFuture
• Fixed agrees function to handle nil B or C parameters
• Added sorting of antipast by blue score
• Fixed child iterator to respect not going beyond high hash and include low hash support

Network & Peer Management

• Added force-same-version peer filtering to prevent protocol mismatches
• Don't get stuck talking to very slow senders (tar pit mitigation)
• Handle ErrUnexpectedParents gracefully in block relay
• Added checks to prevent relaying blocks with disqualified parents
• Don't ban for sending disqualified blocks when node already has them
• Disabled indirect parent check (temporarily)
• Fixed nil pointer dereferences in sendLoop, receiveLoop, and fromAppMessage
• Added mutex to get block operations
• Ignore inv for virtual hashes
• Added proper error handling for missing blocks

Performance & Database

PebbleDB

• Applied PebbleDB settings from v2.10.1
• Better Pebble value separation (1KB was too small)
• Increased value separation for better performance
• Better PebbleDB settings based on community feedback (Claude, Gemini, Grok)

Caching

• Increased UTXODiff LRU cache size from 1000 to 250,000
• Disabled LRU cache mutexes (were slowing down the node)
• Removed redundant calls from restorePastUTXO
• Added cache for RestorePastUTXO (later disabled due to inconsistencies)

Blue Anticone

• Added max walk limits to blueAnticoneSize to prevent excessive traversal
• Increased max traversal by 5x where needed
• Fixed nil pointer dereference in blueAnticoneSize
• Fixed blueAnticoneSize to not fetch ghostdag data for virtual block hashes
• Small optimization: cut one iteration of loop when candidateBluesAnticoneSizes exceeds max

Security & Stability

• 20+ nil pointer dereference fixes across: ghostdag manager, dagTraversalManager, blueAnticoneSize, sendLoop, receiveLoop, fromAppMessage, ghostdag data store, block validator, etc.
• Fixed races to pass CI tests
• Fixed double-close panic in RPC stats Stop()
• Fixed panic in ghostdag data store when block hash is nil
• Added validation that block hash cannot be nil from ghostdag datastore
• Reverted unsafe byteslice operations in serialization code for memory safety
• Removed hardcoded GitHub personal access token from source code
• Added proper mutex locking for thread-safe operations
• Don't propagate ErrMissingTxOut error
• If transaction is missing outpoints, don't error - just don't accept the transaction

Auto-Updater

• Changed auto-updater to opt-in (was opt-out) per NonKYC request
• Auto-updater now self-updates HTND and its binaries from GitHub releases
• Added automatic GitHub issue reporting on panics (opt-in)
• Added random delay before installing updates to prevent mass simultaneous updates
• Fixed race condition in updater with updateInProgress flag
• Fixed GitHub release API issues
• Updated Dockerfile to disable auto-updating by default
• Removed application options from auto-updater
• Fixed auto-enable logic

Build & Infrastructure

• Upgraded to Go 1.26.0 (recommended minimum)
• Added Go 1.27 support
• Cross-platform rlimit support with Windows-safe implementation
• Dockerfile updated to Go 1.27
• Better build system for Docker images
• Removed genalphabet reference
• Updated module dependencies
• Added lefthook for pre-commit git hooks
• Added sample lefthook.yml and letfhook.yml files

Code Quality & Testing

• Added skip to long-running tests
• Fixed numerous test golden data comparisons
• Improved debug logging across consensus, UTXO, and network components
• Moved excessive logging from INFO/WRN to DBG level
• Fixed format string errors (%d to %s) throughout
• Removed code coverage requirements where not needed
• Fixed test failures and build errors
• Added detailed script comparison logging for coinbase validation
• Added targeted IBD/virtual-resolution diagnostic logging
• Fixed TestReverseUTXODiffs

RPC & API

• Fixed nil pointer dereference in RPC routerInitializer
• Fixed format string errors in various RPC handlers
• Removed ASCII art from output
• Added info of block status to received blocks
• Return error if header DAA score does not exist, use daaBlockStore
• Use headers DAA score, not daaBlockStore DAA score for consistency

Wallet

• Added fee estimation to wallet (cherrypick from Kaspa kaspanet#2291)
• Wallet compounder improvements to prevent mempool orphans and selfish mining

Mining

• Fixed block template builder to use correct blue scores
• Reconciled reorg UTXOs for proper mining
• Don't stage disqualified block UTXOs
• Added backup validation for coinbase red block outputs
• Added detailed debug logging to coinbase manager
• Stopped bucketing red block merge rewards

Configuration

• Added PastMedianTimeValidationTolerance config option (default: 2000ms = 2 seconds)
• Added EnableUTXODebugDiagnostics config option for expensive startup self-consistency checks
• Added EnableSanityCheckPruningUTXOSet config option
• Updated sample-htnd.conf with new options

Mainnet Parameters (Activated)

• Block version 8: Activated at DAA score 217,137,983 (POWScores[6])
• Block version 9: Activated at DAA score 218,735,007 (POWScores[7])
• K values: Extended to 9 entries (versions 1-9), versions 8-9 use K=40
• TargetTimePerBlock: Extended to 9 entries, versions 8-9 use 200ms
• FinalityDuration: Extended to 9 entries, versions 8-9 use 10800 seconds
• DifficultyAdjustmentWindowSize: Extended to 9 entries, versions 8-9 use 2640
• PruningMultiplier: Extended to 9 entries, versions 8-9 use 1
• MaxBlockMass: Extended to 9 entries, versions 8-9 use 1,000,000

Known Issues

• Some finality tests are currently disabled (not yet compatible with DAGKnight consensus)
• Pruning point validation is temporarily disabled in some scenarios

Breaking Changes

None. This is a backward-compatible release.

Files Changed

• 173 files changed
• 7856 insertions(+)
• 1606 deletions(-)
• New files: pruningstore/pruning_store.go, child_iterator.go, reconcile_reorg_utxo.go, antipast_test.go, antipast_order_test.go, rlimit files, lefthook configs, etc.

Full Changelog: v2.15.0...v2.16.0