BAM Changelog - Sept 11

ACTION REQUIRED: SIMD-0385 Transaction V1 Mainnet Activation

Transaction V1 is scheduled to activate on Mainnet at Epoch 1035 (September 15, 2026 at approximately 1:20 AM UTC).

Upgrade Requirements for TX V1 Support:

• FireBAM: Upgrade to v0.12.x (i.e., v0.1202.40302) or the v26.08.2+/ v26.09.x line.
• Jito Agave & Jito BAM: Upgrade to at least v4.2.2-jito.

Transaction V1’s larger payloads will be supported across all BAM paths except MPP (for now).

Note on Legacy Versions: Clients remaining on FireBAM v0.11 will still process V1 transactions in consensus and replay, but will not process V1 bundles or transactions sent to their own leader slots. Upgrading before the feature gate activates is required for full support.

Developer Impact: Compute Budgets

Transaction V1 sets compute budgets through a new transaction configuration field. Existing compute budget instructions remain effective for V0 transactions but are no-ops for V1 transactions. Application developers building on BAM should review the updated compute budget guidance and test their integrations on devnet now.

Critical Alpenglow Fix

Validator operators running recent beta/alpha builds must update promptly to prevent production environments from accidentally enabling dev-context-only-utils (DCOU), which activates test-only Alpenglow settings. Update paths:

• v4.3.0-beta.3-jito → v4.3.0-rc.0-jito (or at minimum v4.3.0-beta.3-jito.1)
• v4.4.0-alpha.3-jito → v4.4.0-alpha.3-jito.1

Releases & Upgrades

• FireBAM Mainnet (v26.08.4): Recommended release. Synced with upstream Firedancer for critical performance and reliability improvements. (Also shipped this week: v26.08.2, v26.08.3)
• FireBAM Testnet (v26.09.2): Recommended release. (Also shipped this week: v26.09.1, v0.1202.40302)
• Jito Agave & Jito BAM Mainnet (v4.2.2-jito): Recommended release.
• Jito Agave & Jito BAM Testnet (v4.3.0-rc.0-jito): Recommended release.

Performance & Reliability

• Authentication: BAM now caches authorization fingerprints, reducing HTTP auth time by 80.3% and QUIC auth time by 84.7%.
• FireBAM Hot-Path Optimizations: Rolled out reusable parsing buffers, reduced gRPC overhead, decreased redundant timestamp/tx-metadata operations, and simplified pack lookups.
• v26.08 Branch Improvements: Introduces smaller txn storage, indexed batch tracking, default TLS certificate verification, and graceful SSL-allocation retries/monitoring.
• Block Engine Cache: Signature caching extended across all BE sources alongside DAG, allocation reduction, and scheduler optimizations.
• Security: Production build safeguards now strictly prevent test-only configs from entering BAM or Jito-Solana binaries.

Protocol & Scheduling Alignment

• Market-Tick Transactions: BAM now schedules a market-tick transaction at the start of each batch auction, allowing market makers to measure sub-slot oracle timing and quote more precisely. Read more on GitHub.

Product Features

• BAM Preconfirmations: Live with initial distribution partners Helius and Triton. BAM validators will now earn 35% of all revenue generated by these preconfirmations. Read the announcement.

Network Adoption

Total BAM stake has surpassed 34% of the network

Team Updates

We recently welcomed two new engineers to the BAM team:

• Release Engineer (formerly at Figment)
• Performance Engineer (formerly at Meta and Citadel)