v3.26.1
Income taxes - Effective Tax Rate Reconciliation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Amount      
Tax calculated at the statutory tax rate: $ (16,924)    
Research and development expenses additional deduction (2,954)    
Effect of preferential tax rate 2,720    
Prior year return-to-provision true up 405    
Income tax benefit (expense) $ 1,244 $ 210 [1] $ (525) [1]
Percent      
Tax calculated at the statutory tax rate: 25.00% 25.00% 25.00%
Non-deductible expenses and non-taxable income   (1.00%) (4.00%)
Research and development expenses additional deduction 4.00% 5.00% 6.00%
Effect of preferential tax rate (0.04)    
Change in valuation allowance   (14.00%) (5.00%)
Prior year return-to-provision true up (0.01)    
Effect of different tax jurisdiction 1.00% (4.00%) (2.00%)
Actual income tax expense (2.00%) 0.00% 0.00%
United Kingdom      
Amount      
Non-deductible expenses and non-taxable income $ 296    
Change in valuation allowance 2,979    
Tax rate differential $ 1,038    
Percent      
Non-deductible expenses and non-taxable income 0.00%    
Change in valuation allowance (4.00%)    
Effect of different tax jurisdiction (2.00%)    
Cayman Islands      
Amount      
Tax rate differential $ 3,425    
Percent      
Effect of different tax jurisdiction (5.00%)    
Singapore      
Amount      
Non-deductible expenses and non-taxable income $ (669)    
Change in valuation allowance 1,881    
Tax rate differential $ 875    
Percent      
Non-deductible expenses and non-taxable income 1.00%    
Change in valuation allowance (3.00%)    
Effect of different tax jurisdiction (1.00%)    
Hong Kong      
Amount      
Non-deductible expenses and non-taxable income $ 408    
Change in valuation allowance 877    
Tax rate differential $ 614    
Percent      
Non-deductible expenses and non-taxable income (1.00%)    
Change in valuation allowance (1.00%)    
Effect of different tax jurisdiction (1.00%)    
Others      
Amount      
Tax rate differential $ (572)    
United States      
Amount      
Non-deductible expenses and non-taxable income 1,333    
Change in valuation allowance $ 5,512    
Percent      
Non-deductible expenses and non-taxable income (2.00%)    
Change in valuation allowance (8.00%)    
[1] Restated (refer to Note 2(c))