Release v1.9.0

Update Priority

Nodes that are not updated will fall out of sync at the T6 activation timestamp.

Activation Times

TIPs included with T6

The T6 network upgrade includes:

1. TIP-1028 Address-Level Receive Policies: Lets receivers define which TIP-20 tokens and senders they accept, redirecting blocked transfers or mints to ReceivePolicyGuard for later recovery instead of reverting.
2. TIP-1049 Admin Access Keys: Adds admin access keys for account key management and extends SignatureVerifier with stateful keychain/admin signature verification helpers.

Operators

What's Changed

• Certified Follow Mode (#2551): Followers run a lightweight consensus engine that validates consensus certificates as a prerequisite to progressing execution state. Mainnet & Testnet nodes behind the public RPC will be switched over by setting --follow.experimental.certify and serving consensus_ rpcs. The flag is available and will become the default in the next release.
• Consensus finalized block storage pruning (#3870, #5234): The consensus layer now stores blocks as a persisted cache, pruning it as execution layer finalization watermark rises. This will be automatically pruned for new nodes, for operators running existing nodes may delete the legacy archive at <consensus_storage>/engine-finalized_blocks-{freezer*,metadata,ordinal}. Make sure to retain <consensus_storage>/engine-finalized-blocks-prunable-{key,value}!
• Embedded Network Identities (#4004): The network keys for Mainnet and Tesnet are embedded in the binaries. Certified followers can jump past several epochs when verifying a certificate against this key instead of progressing boundary to boundary.
• Improved snapshot bootstrapping (#4482): Tempo snapshots now include finalization data in the manifest and dump the finalization certificate for startup recovery when the finalizations archive is empty.
• Consensus execution actor no longer blocks on every EL interaction (#5312): Queues forkchoice/new-payload work through the executor actor to improve consensus responsiveness.
• Consensus signing key CLI fix (#5276): Adds --secret support for signing consensus smart contract arguments.

Developers

Compatible Tooling Versions

T6 Protocol Changes

• Address-level receive policies (#3800, #5476): TIP-1028 extends TIP-403/TIP-20 so receivers can configure accepted tokens and senders. Blocked TIP-20 transfers and mints succeed by redirecting funds to ReceivePolicyGuard, where they can later be claimed by the originator or configured recovery authority. Recovery addresses may not be precompile addresses.
• Admin access keys (#4265): TIP-1049 adds authorizeAdminKey(...), isAdminKey(...), admin key authorization events, and account-bound admin key permissions. Admin keys can manage other keys but must not carry spending limits, call scopes, or expiry.
• Keychain signature verification (#4302): SignatureVerifier now exposes stateful keychain verification helpers, including verifyKeychain(account, hash, signature) and verifyKeychainAdmin(account, hash, signature), for contracts that need to validate active access-key or root/admin signatures against AccountKeychain state.

EVM, Transaction, and Fee Semantics

• Per-transaction fee accounting fix (#5506): Resets collected-fee state for each transaction so stale fee collection cannot affect same-transaction key authorization/use paths.
• Transaction validation caching (#5522, #5518, #5513): Validation now reuses state reads across EVM validation, AMM liquidity planning, and ETH account/code checks, while avoiding unnecessary transaction/env clones and eager batch allocation.
• Signature encoding optimization (#5553): Signature RLP length calculation now avoids materializing an intermediate Bytes buffer.
• Dynamic base fee support in txpool ordering (#5243): Transaction priority is no longer cached under a fixed-base-fee assumption; ordering indices are recomputed or reindexed when the base fee changes.

Performance

• Builder budget pacing (#5211): Payload building now reserves proposal-return time using recent local validation latency feedback instead of always mirroring projected builder work.
• Parallelize builder computations (#4473): Refactors block building to offload transaction cloning and computation of transaction/receipt roots to a separate spawned task
• Redundant builder precache disabled (#5419): Tempo nodes skip Reth’s basic parent-state pre-cache because the Tempo payload builder already uses the execution cache.
• Execution/storage hot-path work (#3626, #4455, #5038, #5239, #4480): precomputes TIP-20 keccak slots, improves storage handler caching, removes useless TIP-403 SLOADs, and caches AA replay hash.
• Transaction pool iteration and eviction improvements (#5432, #5546, #5585, #5590): Adds best-transaction size hints, moves AA allocation out of write locks, removes eviction entries with lightweight order keys, and defers dropping removed transactions until after block update windows.

Full Changelog: v1.5.2...v1.9.0