The upgrade, version 2.2.0, went live on July 2, 2026, alongside the activation of Sonic's Brio hard-fork on mainnet. Its headline feature is native transaction bundling: a set of four new RPC methods. Three of them, sonic_prepareBundle, sonic_submitBundle, and sonic_getBundleInfo, allow developers to prepare, submit, and query grouped transactions entirely through the protocol layer. A fourth method, sonic_estimateGasForTransactions, serves a distinct purpose: it lets developers calculate gas costs across a sequence of dependent transactions before submitting anything. None of these methods require relying on external bundler services, smart account deployments, or wallet-level standard support.

The Problem It Targets

Most EVM-compatible chains process multi-step operations as a sequence of independent transactions with no shared outcome guarantee. The textbook example is a token approval followed by a swap. If a user approves spending but the subsequent swap reverts due to price slippage or a gas spike, the approval remains on-chain. The user has paid gas fees for an incomplete outcome and holds an open allowance they may not have intended to leave active.

Sonic Labs described the issue in the "Bundled By Default" blog post published today: "The action is one thing. The execution path underneath it is usually several things, stitched together and exposed one step at a time. That gap between intent and execution is where onchain products break down."

This problem has attracted multiple proposed fixes at different layers. ERC-4337 account abstraction introduces smart accounts that can batch operations, but requires deploying and maintaining new account infrastructure. EIP-5792, a wallet communication standard that supports grouped transaction calls, has seen limited uptake. As of mid-2026, only Safe wallet supports it via WalletConnect. EIP-7702, introduced in the Ethereum Pectra upgrade of May 2025, provides another path: it enables externally owned accounts to temporarily execute smart contract code, offering account-level batching without a full smart account deployment, but it still requires wallet implementation. Sonic's approach routes around these dependencies by placing bundling at the protocol itself.

How It Works

The new RPC interface centers on three methods: sonic_prepareBundle, sonic_submitBundle, and sonic_getBundleInfo. A fourth method, sonic_estimateGasForTransactions, lets developers calculate gas costs across a sequence of dependent transactions before submitting anything.

Two properties define how bundles behave once submitted, according to Sonic Labs. First, fate-sharing: if any transaction in the bundle fails, the entire bundle rolls back. No partial execution occurs, and no orphaned approvals are left behind. Second, non-interleaving: the protocol guarantees that no external transactions are inserted between the bundled transactions during processing, which preserves the execution order developers intend. No independent developer testing or third-party verification of either property has been published.

The Brio hard-fork that shipped alongside V2.2 brought additional EVM changes. Contract size limits increased to 48 KiB. A maximum RLP block size of 10 MiB was set under EIP-7934. Other additions include a per-transaction gas upper bound (EIP-7825), the CLZ virtual machine instruction (EIP-7939), native support for the secp256r1 elliptic curve (EIP-7951), and revised gas pricing for the ModExp precompile under EIP-7883 and EIP-7823. A follow-up stability patch, V2.2.1, shipped on August 5, 2026, correcting trace format alignment with the Parity and OpenEthereum specification and enforcing request timeouts on metric endpoints.

Market Context

Sonic launched as the successor to Fantom Opera in September 2025, carrying the rebrand from FTM to the S token and a DAG-based consensus engine capable of over 10,000 transactions per second with sub-second finality. The transition brought reported improvements including node sync times roughly ten times faster than Fantom, a 66% reduction in validator operating costs, and a total value locked milestone of approximately $260 million representing roughly 20-fold growth over a single month. As of August 25, 2026, the S token trades at approximately $0.028, giving the network a circulating market cap of around $109 million. The token is down significantly from its all-time high of $1.03, though it has gained roughly 22.9% over the past seven days. Sonic's Fee Monetization program has distributed more than 2.6 million S tokens, worth over $2 million at time of launch, to application developers since mainnet went live.

Regional Significance

The upgrade has practical relevance in markets where DeFi participation is growing fastest but user margins are thinnest. India ranked first in the Chainalysis 2025 Global Crypto Adoption Index with approximately $338 billion in crypto value received in the preceding twelve months. Pakistan ranked third. Sub-Saharan Africa received more than $205 billion in on-chain crypto value over the same period, a 52% year-on-year increase, with stablecoin usage growing over 180%.

In these markets, individual transaction sizes are often small. Mobile users in Sub-Saharan African cities such as Lagos face real exposure to the timing failures that bundling is designed to prevent. Users in South Asian markets, including Karachi and Dhaka, encounter the same risks. Sonic's approach also matters for local developers: because the bundling interface uses standard RPC methods rather than requiring new wallet integrations or smart contract infrastructure, teams building on the network can implement grouped transaction flows without rebuilding significant portions of their stack.

What Comes Next

The V2.2 release is the second installment in a technical blog series. The first post, titled "Fast was the Floor" and published August 18, introduced sponsored transactions and pre-execution checks as part of a broader UX framework. Sonic Labs has characterized speed as a baseline requirement rather than a competitive advantage, and is now directing development attention toward infrastructure quality and selective vertical integration.

The practical impact of V2.2 will depend on how quickly application developers integrate the new RPC methods into production code. No independent technical audits of the bundling implementation have been published. On the ecosystem side, Sonic Labs has discontinued the Meme Season incentive program and is transitioning the Fee Monetization rebate model from a flat 90% return to a tiered structure tied to value contribution and S token burn, changes that will shape the developer incentive landscape in the months ahead. The team is also navigating a leadership transition following the departure of CEO Mitchell Demeter, with a successor search ongoing.