Archive data is data on the blockchain that is older than 128 blocks.
Archive data is accessible from archive nodes.
Ethereum full nodes participate in block validation and verification. They maintain the current state of the blockchain and are responsible for providing data on request and executing smart contract transactions.
Full nodes store enough data to recalculate the chain in the event of a chain reorg. Beyond that, full nodes prune their data; only storing the data required for verifying transactions older than 128 blocks.
Pruning conserves disk space and helps with node sync time, thus reducing storage and computation costs. However, a pruned node cannot serve API requests for certain RPC methods older than 128 blocks.
Data older than 128 blocks is stored on archive nodes on the blockchain. These are full nodes running in archive mode.
Only an archive node can serve API requests for certain RPC methods older than 128 blocks. The Ethereum JSON-RPC and Websocket APIs include several methods which could require access to an archive node.
Methods requiring archive data
Requests for data older than the most recent 128 blocks require access to archive data.
The following methods include a parameter for specifying a block number for the request.
Enable archive data in Infura
To enable archive data go to your project settings and click ADD-ONS in the left menu.