Summary of significant accounting policies and basis of presentation - Early exercised options (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
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	$ 1,831	$ 3,000
Total shares legally outstanding	58,997,659	56,633,898
Less: unvested early exercised shares	(565,224)	(946,586)
Less: unvested restricted stock	(247,780)	(681,789)
Total shares issued and outstanding	58,184,655	55,005,523