Manhattan’s first bitcoin ATM launched Thursday in the historic West Village — prompting a few curious onlookers to open their digital wallets on the spot.

The Lamassu-made machine, which costs a cool $6,500, was installed at Flat 128, a luxury store on Christopher Street that sells UK-styled jewelry and home goods.

The machine allows people to insert cash to be transferred to their bitcoin wallets.

One caveat: The ATM (or BTM, bitcoin teller machine) is currently a one-way street that only allows cash in — not out.

That could change in the coming months, however, as Lamassu plans to release software that will let the machines exchange cyber currency for cash, said founder Zach Harvey.

The BTM’s one-way policy didn’t deter River Edge, NJ, resident Chuong Nguyen-Thanh from losing his bitcoin “virginity” to the machine during a lunch outing on Thursday.

The 26-year-old co-founder of Vaan Group, a marketing company in Brooklyn, bought $20 worth of the digital currency with the help of staff sent by the machine’s operator, PYC.

“It was very much an on- the-spot decision,” Nguyen-Thanh told The Post.

“I wanted to see how it worked and happened to have some cash on me. It was a relatively simple transaction,” he said.

Of course, $20 doesn’t buy a lot of bitcoin with one digital coin worth about $522 at the going rate, according to CoinDesk, which tracks prices for the digital currency.

Users of this particular machine also will have to wait until they use it to learn how much they will be charged for each transaction.

Matt Russell of PYC, the operator that bought and is now managing the machine, said the transaction fee will fluctuate, although he suggested that it was currently less than 10 percent of the transaction value.

By contrast, a BTM that opened earlier this month in Brooklyn promises a flat fee of 2.95 percent. That BTM is operated by bitcoin seller CoinCafe and was installed in an old phone booth in its Williamsburg offices on Nassau Avenue.

The benefit of using an BTM instead of a bank account is speed, according to Lamassu’s Harvey.

People who change cash to bitcoin through a bank may have to wait days for the transactions to clear, but with the Lamassu BTM it’s almost instant, Harvey said.