Fair value measurements (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Apr. 30, 2024	Jan. 31, 2024
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Money market mutual funds	$ 59,518	$ 58,942
Total assets	59,518	58,942
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Money market mutual funds	59,518	58,942
Total assets	59,518	58,942
Significant Other Observable Inputs (Level 2)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Money market mutual funds	0	0
Total assets	0	0
Significant Unobservable Inputs (Level 3)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Money market mutual funds	0	0
Total assets	$ 0	$ 0