Summary of significant accounting policies and basis of presentation - Early exercised options (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Summary of significant accounting policies and basis of presentation
Amount of deposit liability related to shares held by employees and nonemployees that were subject to repurchase	$ 1,314	$ 1,584
Total shares legally outstanding	59,541,904	59,137,491
Less: unvested early exercised shares	(385,655)	(470,800)
Less: unvested restricted stock awards (Note 16)	(49,465)	(193,031)
Total shares issued and outstanding	59,106,784	58,473,660