The Sei community first approved SIP-3 through governance in May 2025. The change reached mainnet approximately twelve months later, on May 1, 2026. Any attempt to upload new CosmWasm code or launch a new contract now fails outright. Contracts already deployed continue to run, but their practical reach has been shrinking for months as the chain stripped away the Cosmos transaction layer underneath them.

What Changed and What Comes Next

SIP-03 did not arrive in isolation. Sei has been systematically dismantling its dual-VM architecture since early 2026 through a series of software updates, beginning with v6.3 in January 2026, which enabled EVM staking and launched balance-change tracking via EVM APIs.

Version 6.4, released in February and March, cut inbound IBC transfers, severing direct liquidity connections to Cosmos chains like Osmosis, Injective, and dYdX. Version 6.5 followed with the removal of Sei's native oracle, which was replaced by Chainlink, API3, and Pyth Network. SIP-03 is the capstone of that sequence.

Following v6.4's removal of inbound IBC, outbound transfers remained temporarily available, and Sei urged users, exchanges, and custodians to complete all address migrations before June 15, 2026.

That deadline has now passed. Users who held IBC-bridged stablecoins such as USDC.n from Noble or USDT.kava on Sei needed to move those assets via DragonSwap, Symphony, or Circle's CCTP v2 before that window closed. According to on-chain analysis by BlockEden.xyz, approximately $1.4 million in USDC.n was flagged as at risk in the weeks leading up to the cutoff.

The end goal is the "Sei Giga" upgrade, which introduces a consensus mechanism called Autobahn that allows multiple validators to propose blocks simultaneously and decouples transaction processing from consensus. Sei currently handles roughly 12,500 transactions per second. The team has stated a post-Giga target of more than 200,000 TPS with finality under 400 milliseconds.

Jay Jog, co-founder of Sei Labs, framed the deprecation as a performance trade-off: "To make something a lot faster, you do both [add power and reduce weight]. The code changes for implementing SIP-3...are enormous." Philip Su, Sei Labs' Engineering Lead, described the former dual-architecture as introducing "significant complexity and friction for both users and developers."

A Sharp Drop in Chain Activity

The on-chain numbers tell a complicated story. SEI trades at approximately $0.042 as of late July 2026, with a market cap around $307 million, placing it near rank 95 on CoinMarketCap. Active addresses peaked at more than 28 million in June 2025, a figure that helps illustrate how far ecosystem activity has since contracted. Total value locked on Sei sits at roughly $41 to $47 million, down from a peak of $626 million to $1 billion recorded in mid-2025. That decline of about 93 percent reflects both the deliberate unwinding of IBC-based liquidity and broader crypto market conditions. DEX trading volume across Sei runs about $88 million per week. Roughly 33 percent of Sei's 10 billion token supply remains locked, with 112 to 132 million tokens unlocking per month through mid-2027.

Not everyone welcomed the direction. One developer, posting under the handle Bernd-BHB in a public comment thread on the SIP repository, argued: "Moving from SEI's high-performance, Cosmos-native L1 to an Ethereum execution model is not progress. It's regression."

Barry Plunkett, Co-CEO of Interchain Labs, the primary development organisation behind the Cosmos SDK, took a more measured position, noting that "even if Sei cuts Cosmos support, it is still a Cosmos-based blockchain" with access to staking and governance infrastructure.

Regional Impact: South Asia and Africa

The shift carries distinct implications outside the United States. In India, where Rust developers have contributed meaningfully to Cosmos-based projects, the CosmWasm deprecation forces a real decision: rewrite existing contracts in Solidity for Sei's EVM layer, or move to a Cosmos chain that still supports CosmWasm, such as Neutron or Osmosis.

That is a non-trivial engineering cost, particularly for solo builders or small teams working with limited resources.

The deprecation may also affect users who held IBC-bridged stablecoins for savings or remittance purposes on Sei, a genuine use case in markets with limited forex access. Those users needed on-chain literacy and timely awareness to migrate before the June 15 deadline.

On the other side of the ledger, Sei's December 2025 partnership with Xiaomi to pre-install a crypto wallet on new Xiaomi smartphones has particular relevance for South Asia and sub-Saharan Africa. Xiaomi holds roughly 24 percent smartphone market share in India and has significant presence across African markets. The pivot to EVM puts Sei in closer alignment with those users' existing tools: MetaMask and EVM-compatible wallets carry far more recognition and community support in those regions than Cosmos-native alternatives like Keplr. The reach of Sei's broader mobile strategy extends into Southeast Asia as well, a distinct region from South Asia but one facing similar dynamics. Sei's $5 million Global Mobile Innovation Program targets mobile-first developers specifically in Africa and Southeast Asia.

What to Watch

As of July 30, 2026, the June 15 migration deadline has closed. The definitive post-deadline status of IBC on Sei, including whether the protocol was formally disabled and whether any assets were stranded at the cutoff, could not be confirmed at time of publication. How many CosmWasm developers chose to stay on Sei versus migrate to other Cosmos chains will shape assessments of what this restructuring actually cost the ecosystem. Sei Giga's performance results, once live, will determine whether the trade-off was worth it.