How can I view mtsupermouseeth's crypto portfolio?

You can view the full portfolio of mtsupermouseeth (0x9800f669f13c4957c4e11f9c4ee2678dedf7929b) on Zerion at https://app.zerion.io/0x9800f669f13c4957c4e11f9c4ee2678dedf7929b/overview — including token balances, DeFi positions, NFTs, and transaction history across 20+ chains.

How can I access wallet portfolio data programmatically?

Use the Zerion API at https://developers.zerion.io to query any wallet's portfolio, token positions, DeFi positions, NFTs, and transaction history programmatically.