Starting 2026-09-29 (UTC), we are upgrading our Solana Mainnet fleet to Agave v4.3.0, the release Anza recommends for Mainnet-beta, together with the matching Yellowstone gRPC (v16) and Blazar builds. RPC, WebSocket and gRPC endpoints stay available throughout. Our staked validators are already on v4.3.0.
What changes for Mainnet clients:
- getBlock, getTransaction and blockSubscribe now reject requests that combine encoding: "base58" (or "binary") with maxSupportedTransactionVersion >= 1, returning JSON-RPC error -32602 "base58 encoding is not supported with maxSupportedTransactionVersion>= 1". Use json, jsonParsed or base64 encoding for Transaction V1 requests.
- getInflationReward now accepts at most 32 addresses per request; larger lists return JSON-RPC error -32602 "Too many inputs provided; max 32". Split larger requests into batches of 32.
- Yellowstone gRPC moves to the v16 line. Existing subscriptions keep working unchanged, including clients built from the v15 proto. The v16 additions (a bank_id field on updates, a block_footer subscription) are optional and inert on Mainnet until Alpenglow activates; regenerate your app from the v16 proto only if you want them.