Is there an API to get data for multiple blockchains? Most blockchain explorers already offer an API but I'd like to be able to get information for different blockchains through the same API.
Found it: https://chainz.cryptoid.info/api.dws
You can see a list of all their supported block explorers through http://chainz.cryptoid.info/explorer/api.dws?q=summary
Depends on the data you're looking for. If you're looking for all historical transactions for a particular chain, chainz.cryptoid wouldn't cut it as they only store the 10 most recent transactions.
lasttxs: returns the last ten transactions (with at least one confirmation), excluding coinbase and stake transactions
https://bullpay.com/docs#Development has a unified API. Same calls for all their supported chains, Bitcoin, Ethereum, Litecoin, Dash, Dogecoin. They hold and allow retrieval of every transaction back to Block 0.
I'd also list Blockcypher but you said "the same API calls" and i can't tell based on their documentation if each chain has "the same API".