Release Notes - v0.209.1

v0.209.1

Title: Improve ledger validation, Plutus support, and dependency consistency

Version: v0.209.1

This release strengthens Dijkstra transaction and certificate validation, enforces MIR transfer rules, expands Plutus V4 support, improves native script handling, and aligns example dependency management with the root module.

Bug Fixes

• Fixed Dijkstra block decoding so each transaction reads the trailing is_valid value, reports invalid transactions, and rejects missing or non-boolean values.
• Corrected MIR certificate data to use the two-element source and target array format, validate source pots and targets, reject malformed reward maps and duplicate credential keys, and handle credential discriminants safely.
• Enforced MIR pending reward and transfer rules by rejecting pre-Alonzo pot transfers and negative deltas, then bounding post-Alonzo negative deltas against pending rewards from prior, in-transaction, and in-block changes.
• Refined native script validation by skipping unneeded witness native scripts during evaluation and routing them to witness validation; Byron output indexes now remain within 0 through 65,535 during construction and CBOR decoding.

Additional Changes

• Expanded Dijkstra regression coverage to verify Plutus V3 regular and reference input overlap across rewarding, spending, guarding, protocol versions, and subtransaction levels.
• Updated mock ledger fixtures and the protocol modeling dependency to version 0.20.4.
• Introduced the Plutus V4 script context builder updates from version 0.8.0 and a complete Plutus V4 CEK cost table.
• Unified example builds with the root module so dependency updates apply automatically and the root build, test, and lint workflows cover the examples.

Recommended Network Compatibility ⚠️

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

Release: v0.209.1

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Docs authored by Doc Holiday