Sei Network has set a timeline to complete the transition to an EVM-only blockchain by mid-2026, meaning it will cease the Cosmos ecosystem and require users to act early to avoid losing access to their assets.

The roadmap revolves around the upgrade 'Sei Giga' as proposed in SIP-3, with direct changes to Cosmos-native assets on Sei, particularly USDC via Noble (USDC.n). Holders need to prepare for the transition, withdraw DeFi positions, and monitor upgrade milestones to mitigate operational risks.

MAIN CONTENT

• Sei Network aims to complete the transition to EVM-only by mid-2026 according to SIP-3.

• Cosmos-native assets on Sei, especially USDC.n, need to convert to USDC native before the end of March 2026 to avoid the risk of losing access.

• The 'Sei Giga' upgrade is implemented in 3 versions: 6.3 (staking through EVM), 6.4 (disable IBC inbound), 6.5 (replace oracle native with Chainlink, API3, Pyth).

Sei Network transitions to EVM-only to simplify architecture and enhance performance.

Sei transitions to EVM-only because SIP-3 has been approved by the community, aiming to eliminate CosmWasm and native Cosmos transactions to reduce codebase complexity, thereby paving the way for optimal performance for the network.

The direct motivation comes from the SIP-3 proposal approved in May, under which Sei will stop supporting CosmWasm smart contracts and native Cosmos transactions. This means that the 'dual' architecture of EVM + Cosmos will be unified in one direction: only running EVM.

Sei Labs stated that streamlining helps eliminate 'hundreds of thousands of lines of code', reduces operational risk surface, and creates technical space for performance improvements. The goal set by Sei Labs is the ability to process over 200,000 transactions per second, based on changes at the execution layer and supporting infrastructure when no longer needing to maintain multiple compatibility layers simultaneously.

'To make something faster, you either have to increase power or reduce weight. To be much faster, you do both.'
– Jay Jog, co-founder of Sei Labs, post on X

Sei Network sets a phased roadmap to cut support for Cosmos until mid-2026.

Sei implements the transition through 3 upgrades (6.3, 6.4, 6.5) and requires users with Cosmos-native assets, particularly USDC.n, to switch to USDC native before the end of March 2026 to avoid risk.

The immediate impact focuses on those holding Cosmos-native assets on Sei, prominently USDC through Noble (USDC.n). The volume of USDC.n is reported to be around 1.4 million USD circulating on Sei Network, making holders need to plan for conversion before the IBC infrastructure tightens.

The conversion plan is announced in 3 version milestones. Version 6.3 is expected to launch in January and will activate staking functionality through EVM, allowing the staking mechanism to operate in an 'EVM-first' manner instead of relying on the Cosmos flow.

Version 6.4, expected in February, will disable IBC inbound, meaning users will no longer be able to bridge Cosmos-specific tokens like ATOM and USDC.n into Sei Network when the inbound flow is turned off. IBC is the native inter-chain interaction protocol of Cosmos, so this change marks an important 'closure' step for the flow of Cosmos assets into Sei.

Version 6.5 is expected to eliminate oracle native from the codebase in March and replace it with popular providers including Chainlink, API3, and Pyth. This approach shifts the focus of price data and on-chain feeds to specialized oracles, rather than maintaining Sei's own oracle component.

How to handle USDC.n and DeFi positions to avoid losing access?

Holders of USDC.n need to convert to USDC native; small volumes can swap through DEX, while large volumes should use migration tools routing through Noble, Polygon, and back to Sei using Circle's CCTP v2, while also closing related DeFi positions early.

Sei Labs requires holders of USDC.n to convert to USDC native before the end of March 2026. For small amounts, users can swap through decentralized exchanges like DragonSwap or Symphony, but slippage may vary according to market conditions.

For large conversion amounts, the described migration tool will route USDC.n from Noble, through Polygon, and back to Sei using Circle's Cross-Chain Transfer Protocol (CCTP) version 2. This approach aims for a more controlled flow of conversion compared to limited liquidity swaps on DEX.

In cases where USDC.n is being sent through DeFi protocols, the recommendation is to quickly unwind positions to avoid liquidity risk, cross-bridge dependence risk, or disruption when IBC inbound is turned off and the ecosystem gradually transitions to EVM-only.

Ecosystem context: mainnet 2023, market capitalization around 800 million USD and attention from the traditional market.

Sei launched the mainnet in 2023, with a market capitalization of around 800 million USD; the SEI token was listed by Robinhood in October 2025 and previously filed for a Crypto ETF spot for Sei in the US but has not yet been approved by the SEC.

Sei Labs launched the mainnet in 2023. The information presented shows that the market capitalization of the network is currently around 800 million USD, placing Sei in the group of medium-scale projects in the blockchain infrastructure sector.

In terms of access to individual investors, Robinhood listed the SEI token in October 2025, thereby expanding the trading channel for the retail segment. Additionally, Canary Capital previously submitted an application for a Crypto ETF spot related to Sei in the US, but it has not yet been approved by the U.S. Securities and Exchange Commission (SEC), amid the agency emphasizing the necessity for due diligence with cryptocurrency investment products.

Frequently Asked Questions

When will Sei Network complete the transition to EVM-only?

Sei Network aims to complete the transition to a blockchain that only supports EVM by mid-2026, according to the upgrade roadmap related to SIP-3 and the 'Sei Giga' upgrade package.

What changes in Sei with SIP-3?

SIP-3 will gradually stop CosmWasm smart contracts and native Cosmos transactions on Sei, aiming to dissolve the 'dual' architecture of EVM + Cosmos for Sei to become EVM-only.

What is USDC.n on Sei and why does it need to be converted?

USDC.n is USDC issued via Noble according to the Cosmos standard, circulating on Sei as a Cosmos-native asset. As Sei decreases and moves towards stopping support for Cosmos, holders are required to convert to USDC native before the end of March 2026 to avoid the risk of losing access.

What are the significant upgrade milestones of 'Sei Giga'?

The roadmap described includes: v6.3 (January) allowing staking through EVM, v6.4 (February) disabling IBC inbound, v6.5 (March) eliminating oracle native and replacing it with Chainlink, API3, Pyth.

How can USDC.n be converted to USDC native?

Small amounts can swap on DEX like DragonSwap or Symphony (note slippage). Large amounts can use the migration tool routing USDC.n from Noble through Polygon and back to Sei using Circle CCTP v2; those with DeFi positions in USDC.n are advised to close positions early.