WASHINGTON — On the website for Jim Fulner’s U.S. Senate campaign, 34 letters and numbers appear in a string above the “Donate Now!” button.

They are the code for his campaign’s bitcoin wallet, where holders of the so-called digital currency can send it to the Libertarian from Michigan — without a bank acting as an intermediary.

“It’s an exciting new technology,” said Jeff Wood, the campaign treasurer and a self-described early adopter of bitcoin.

But as with any budding technology, federal agencies must examine how its use fits in with the law, including rules for campaign donations. The Federal Election Commission discussed the technology last week, while federal regulators and experts testified about it before two Senate committees.

The FEC plans to revisit the topic in the next year and may issue a set of rules. But the technology, embraced by some high-profile entrepreneurs who have invested in it, is already being accepted by the national Libertarian Party and some local chapters and candidates.

Wood said the Fulner camp has received just two bitcoin donations so far — one from Wood. Both were less than the $200 threshold over which donations must be reported to the FEC. The Libertarian National Committee has received several thousand dollars in bitcoins from dozens of donors, Executive Director Wes Benedict said. The FEC and other federal agencies have recognized that bitcoins hold value but continue to debate whether campaigns can treat them as currency.

“What they need to know is how to handle them, and how to account for them, and how we want to see them reflected on their public reports,” Lee E. Goodman, the FEC’s vice chairman, said at last week’s meeting