Rongchai Wang
Jan 16, 2026 15:38
Sei’s SIP-3 improve deprecates CosmWasm to change into EVM-only by mid-2026. USDC.n holders should migrate belongings by March or threat dropping entry.
Sei Community is gutting its Cosmos roots to chase 200,000 transactions per second. The SIP-3 improve, accredited by governance final Might, will rework Sei into an EVM-only chain by mid-2026—and customers holding legacy IBC belongings have to act now or lose entry to their funds.
The primary domino falls this month. Model 6.3, deploying to Pacific testnet in January, permits full staking performance by EVM interfaces. March brings v6.4, which provides the kill swap for inbound IBC transfers. As soon as that governance proposal passes, Cosmos-native tokens like ATOM and USDC.n can now not enter the community.
The Weight Discount Technique
Sei Labs frames this as automotive engineering: to make one thing quick, you both add energy or lower weight. SIP-3 does the latter, stripping “tons of of 1000’s of traces of code” from the protocol. The Giga improve coming afterward presumably handles the ability facet of that equation.
What’s getting eliminated? CosmWasm good contract help. Native Cosmos transaction dealing with. The chain’s built-in oracle resolution—changed by Chainlink, API3, and Pyth. IBC interoperability, each inbound and outbound transfers, will probably be disabled by separate governance votes.
By the point this wraps up, solely EVM addresses will be capable of provoke transactions on Sei. Full cease.
USDC.n Holders Face Deadline Stress
This is the pressing half: anybody holding USDC by way of Noble (USDC.n) must migrate to native USDC earlier than late March 2026. Sei Labs is not being refined about this—they have been warning customers since early January to swap or migrate instantly.
The excellence issues. Native USDC, which went stay on Sei with Circle’s CCTP v2, provides institutional-grade infrastructure and regulatory compliance. USDC.n, the bridged Cosmos model, turns into nugatory baggage as soon as IBC transfers shut down.
Sei Labs factors customers towards Skip:Go as one migration possibility, although they’re cautious to notice this is not an endorsement. Customers in DeFi protocols with USDC.n publicity ought to “wind down any reliance on these belongings,” in accordance with the announcement.
What Modifications for Builders
Infrastructure suppliers face the largest carry. Indexers and custodians have to replace their programs to trace staked steadiness modifications by EVM APIs. Any software constructed on CosmWasm wants an entire rewrite or abandonment.
The upside for builders who stick round: a cleaner, extra aggressive place inside the broader EVM ecosystem. Fewer edge circumstances. One execution atmosphere as an alternative of two. Whether or not that tradeoff appeals relies on how a lot Cosmos-specific performance a venture really used.
Timeline and Buying and selling Implications
The total transition completes by mid-2026, however the essential dates hit sooner. Q1 2026 brings the IBC inbound shutdown. Extra releases will disable outbound transfers and sundown the native oracle.
For merchants, watch the governance proposals. Every vote that passes removes one other Cosmos functionality and doubtlessly triggers migration flows. The USDC market, at the moment at $75.72 billion in market cap, will not discover Sei’s transition—however Sei’s inside liquidity dynamics may shift as legacy belongings exit.
Sei is betting that changing into a pure EVM chain at 200K TPS beats being a hybrid at decrease speeds. Customers have till March to resolve in the event that they’re coming alongside for the trip.
Picture supply: Shutterstock
