Re: List of Bitcoin blockchain APIs

what exactly do these limits at BlockTrail mean?

Code:

1 request per second
86,400 requests per day
Burst Capabilities
2 per second
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Does it mean, that my application is only allowed to check for one transaction in one second?

Assumed i have an online shop, and 4 customers send 4 payments at the same time, then i will be able to check only for the confirmation of one payment out of 4 at once?

What are the costs for the "Pro" package?

No. You can only make one request per second. Please check their page for knowing the rates.

well but thats the point, what is meant by "request"?

A request is a http request, that means, a single call to their API per second. Your example might still work if they allow to check multiple addresses etc in a single request. But yes, most likely you'll need the pro package.