The Compound v2 REST API (api.compound.finance) for reading structured data is being permanently shut down on April 15th, 2023.
All of the data returned from this API is publicly available as read-only data from the Ethereum blockchain.
To access the source of the data, you can do so using a node provider with history enabled, from a firm like alchemy.com or infura.io. These third-party providers have a free usage tier for users with minimal API usage.
The Compound v2 protocol will continue to run on the Ethereum blockchain unless otherwise changed through community governance. Users are encouraged to migrate from Compound v2 to v3 however no action is required in relation to the REST API shut down.
The v2 Dapp at v2-app.compound.finance no longer needs the API as a dependency. The Dapp is open source, community maintained, and will continue to be available after the API shut down.