> For the complete documentation index, see [llms.txt](https://cctp-express.gitbook.io/cctp-express/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cctp-express.gitbook.io/cctp-express/concept/how-is-cctp-express-different-from-across.md).

# How is CCTP Express different from Across

1. ## CCTP**-Specific**

The primary distinction between CCTP Express and Across lies in our positioning. While both protocols are intent-based bridges powered by fillers/relayers, CCTP Express is positioned to be a booster tool to use CCTP.\
\
Given this focus, CCTP Express is closely integrated with CCTP and evolves in tandem with it. For instance, if CCTP supports EURC, CCTP Express will promptly support it as well. \
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And this alignment also applies to the choice of picking which chain CCTP Express supports.  CCTP Express aims to cover all EVM and non-EVM chains CCTP operates. And like [CCTP](https://developers.circle.com/stablecoins/docs/message-format#message-header), CCTP Express adopts the `bytes32`address format, instead of the 20 byte address used in EVM, to handle 32 byte addresses in many non-EVM chains. \
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In contrast, Across is limited to EVM chains only, as it has a [hard requirement](https://docs.across.to/resources/new-chain-requests) to support EVM- chains only. 

2. ## Settlement Mechanism

In CCTP Express, the Hub Pool smart contract utilizes the Iris attestation service used in CCTP to relay and verify messages. `Deposit` and `Filled` messages from various Spoke Pools are sent to Iris for attestation and then collected in the Hub Pool, which processes repayments on-chain. \
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In contrast, Across uses canonical bridges to relay messages and utilizes [UMA](https://docs.across.to/use-cases/settle-cross-chain-intents) to optimistically verify fill events off-chain. Since UMA works off-chain, an interval is needed as a dispute window.

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