To enable v1 execution, set maxSupportedTransactionVersion to 1 for all reads, ensure indexers read transactionConfig when present and fall back to instruction scanning, and normalize fee and compute unit measurements before aggregation; explicitly specify compute/unit limits and use base64 encoding for large v1 transactions.

End-to-end runnable examples and verification were performed against the Agave 4.2 validator, and activation on mainnet/testnet/devnet remains inactive as of late August 2026, with rollout continuing.

Upgrade all relevant SDKs and libraries to the listed versions, enable v1, audit ComputeBudget instruction scans, and verify behavior with local validators before any mainnet activation.

V1 transactions require explicit compute unit limits because defaults are zero unless explicitly set.

Legacy and v0 transactions remain valid, but readers not upgraded will fail when parsing v1 transactions in a block.

V1 wire format introduces a fixed-position transactionConfig, inline accounts (no Address Lookup Tables), fixed-width instruction headers, and signatures moved to the end of the message.

Anticipate reading-related breaks after activation, including -32015 errors without maxSupportedTransactionVersion: 1, misreporting of priority fees and CU limits by indexers, and potential downgrades on older gRPC/protobuf stacks unless updated.

Solana is increasing max transaction size from 1,232 to 4,096 bytes via two proposals, SIMD-0296 and SIMD-0385 (the latter introducing a new v1 format).

In v1, priority fees are an absolute total in lamports, not micro-lamports per compute unit, so normalization is required for cross-version fee calculations.

Gating and rollout expect minimum versions for understanding v1, including Solana kits, solana crates, and Yellowstone-grpc-proto, with mainnet activation anticipated within weeks of August 2026 and local testing available via Solana CLI 4.2+ or Surfpool 1.5+.