Revenue - Schedule of total revenue disaggregated by geographic region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue by country of domicile:
Revenue	$ 13,056	$ 7,426
% of Revenue	100.00%	100.00%
Japan
Revenue by country of domicile:
Revenue	$ 7,020	$ 3,948
% of Revenue	54.00%	53.00%
United States
Revenue by country of domicile:
Revenue	$ 5,459	$ 2,400
% of Revenue	42.00%	32.00%
China
Revenue by country of domicile:
Revenue	$ 386	$ 880
% of Revenue	3.00%	12.00%
Other
Revenue by country of domicile:
Revenue	$ 191	$ 198
% of Revenue	1.00%	3.00%