Stockholder's equity (deficit) - Warrants Associated with Loan Agreement (Details) - USD ($)				3 Months Ended		6 Months Ended
	Feb. 28, 2024	Mar. 10, 2023	Jun. 15, 2022	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Class of Stock [Line Items]
Additional warrants to purchase shares	$ 431,000	$ 330,000		$ 431,000	$ 330,000
Proceeds from term loan						$ 10,000,000	$ 15,000,000
Loan Agreement
Class of Stock [Line Items]
Issued warrants to purchase shares of common stock						36,718
Hercules Capital Inc and Hercules Private Global Venture Growth Fund I L.P.
Class of Stock [Line Items]
Maximum percentage of warrants purchased						1.50%
Issued warrants to purchase shares of common stock	18,359	9,180	36,718
Hercules Capital, Inc
Class of Stock [Line Items]
Issued warrants to purchase shares of common stock	18,359	9,180
Hercules Capital, Inc | Loan Agreement
Class of Stock [Line Items]
Proceeds from term loan	$ 10,000,000	$ 15,000,000
Hercules Capital, Inc | Term Loan | Loan Agreement
Class of Stock [Line Items]
Issued warrants to purchase shares of common stock						211,137
Proceeds from term loan			$ 10,000,000