Summary of significant accounting policies - Potentially dilutive securities (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Potentially dilutive securities
Total shares of common stock equivalents	634,623	621,660
Convertible preferred stock (as converted)
Potentially dilutive securities
Total shares of common stock equivalents	28,112	128,597
Options to purchase common stock
Potentially dilutive securities
Total shares of common stock equivalents	582,641	480,325
Unvested restricted stock units
Potentially dilutive securities
Total shares of common stock equivalents	23,870	12,738