Summary of significant accounting policies - Assets and liabilities measured at fair value (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Summary of significant accounting policies
Total	$ 136,444
Money market funds
Summary of significant accounting policies
Cash and cash equivalents	73,988	$ 20,013
U.S. Treasury securities
Summary of significant accounting policies
Cash and cash equivalents	22,993
Marketable securities	39,463
Level 1
Summary of significant accounting policies
Total	73,988
Level 1 | Money market funds
Summary of significant accounting policies
Cash and cash equivalents	73,988	$ 20,013
Level 2
Summary of significant accounting policies
Total	62,456
Level 2 | U.S. Treasury securities
Summary of significant accounting policies
Cash and cash equivalents	22,993
Marketable securities	$ 39,463