Release Notes - v0.209.0

v0.209.0

Title: Improve protocol safety, transaction validation, and timing visibility

Version: v0.209.0

This release strengthens protocol input handling, validates transactions against earlier block effects, exposes stage timing data, and corrects Plutus, cost model, and Byron transaction behavior.

Breaking Changes

• Added aggregate timing data for successful decode, validate, and apply stages through PipelineStats and StageTimings; code that creates PipelineStats with unkeyed literals must add the new fields or switch to keyed literals.

Bug Fixes

• Corrected Plutus V4 Dijkstra TxInfo direct deposit and account balance interval maps so they follow AccountAddress order.
• Strengthened protocol boundary checks by rejecting unsolicited handshake query replies, bounding block body input, count, and CBOR shapes, and enforcing leiosnotify MaxPendingBytes and announcement size limits.
• Rejected explicit witnesses that duplicate reference scripts, preventing the same script from serving through both witness paths.
• Preserved independent CostModels state by deep copying it during parameter updates, era upgrades, and genesis initialization.
• Applied per-state transaction submission pending message limits of 65,535 bytes in Init, Idle, and Done, and 2,500,000 bytes in TxIds and Txs; MaxPendingMessageBytes continues to govern mux ingress. Clients that depend on larger pending messages in the smaller states must account for the reduced 65,535 byte limit.
• Validated block transactions sequentially against preceding effects, supporting chained spends and partial withdrawals while rejecting same-block double spends and applying Dijkstra effect levels and pool re-registration semantics consistently.
• Limited Byron Produced() UTxOs to output indexes 0 through 65,535; later outputs remain in the transaction and continue to affect its ID.

Additional Changes

• Replaced muxer test sleeps with bounded synchronization so test execution waits for the expected state without relying on fixed delays.
• Made a blockfetch test tolerate the expected connection error race while still checking the intended result.
• Corrected the Leios Fetch README CDDL tag coverage so it defines tags 0 through 3 and 9, comments tags 6 through 8, omits tags 4 and 5, and keeps votes separate.

Recommended Network Compatibility ⚠️

Network	Compatible
mainnet	⛔
preprod-testnet	✅
preview-testnet	✅
musashi	✅

Release: v0.209.0

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Docs authored by Doc Holiday