For buying bitcoin:
For observing current fee rates of transactions:
It displays estimated delays (in blocks and in minutes) for ranges of fee rates (in satoshis / byte).
For searching the Bitcoin blockchain:
Inputs: address, transaction hash (txid), block hash, block number.
Note: On a transaction page e.g.
it's possible to click Advanced Details / API Call, which produces a raw text dump of the transaction, e.g.
Note: You have to read through the transaction raw text dump in order to find the index of a particular unspent output. A service that allowed someone to look up the index of an unspent output would be useful.
For tracking the status of a transaction (i.e. whether it has been mined or not), you can search for its txid using the search field on
If the transaction has been received by the service but has not yet been mined, it will be displayed with "Confirmations: 0/6".
If the service has not seen the transaction, you will get a search result similar to this:
"No transaction found with the hash bf7a16ef4bf8763b7bf7f02b03155c9a2f9b997d19e64a770bf3f7d3f24cc480"
For decoding a signed transaction:
If the service can successfully decode a transaction, this indicates that the transaction is formatted correctly.
For broadcasting a signed transaction to the Bitcoin network:
Author: Mircea Popescu
- GPG contracts
- The V Manual Genesis
- The woes of Altcoin, or why there is no such thing as "cryptocurrencies"
- The necessary prerequisite for any change to the Bitcoin protocol
Author: Stanislav Datskovskiy
- Bitcoin, or How to Hammer in Nails with a Microscope.
- Seven Laws of Sane Personal Computing
- No Formats, no Format Wars.
- You have made your bedrock, now lie in it.
Author: Ken Shirriff
- Bitcoins the hard way: Using the raw Bitcoin protocol
- Bitcoin mining the hard way: the algorithms, protocols, and bytes