v3.26.1
Income taxes - Summary of Reconciliation Between Expenses of Income Taxes (Details)
¥ in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2023
CNY (¥)
Reconciliation, amount        
(Loss)/income before income taxes ¥ 2,647 $ 379 ¥ (6,659) ¥ (64,554)
Income tax expense computed at PRC statutory rate (25%)     (1,665) (16,139)
Statutory tax rate difference between Cayman and PRC     2,080 4,206
Changes in valuation allowance (7,316) (1,046) (44,340) 28,842
Nontaxable or Nondeductible Items        
Meals and entertainment 1,627 233    
Others 662 95    
Other Adjustments        
Out of period adjustment 5,176 740    
Research and development super-deduction (1,760) (252) (19,403) (26,393)
Preferential tax rate (1,230) (176) (16,830) 10,613
Deferred tax items tax rate differential     15,283 (6,502)
Non-deductible expenses     2,257 3,438
Deferred tax expenses     1,423 49
Non-taxable income     (3)  
Recognition of prior year tax loss     2,156  
Deemed income     59,152  
Adjustment for tax return amendments 824 118    
Income tax expense ¥ 73 $ 10 ¥ 110 ¥ (1,886)
Tax Jurisdiction of Domicile [Extensible Enumeration] China China China China
Reconciliation, percent        
Changes in Valuation Allowances (276.00%) (276.00%)    
Nontaxable or Nondeductible Items        
Meals and entertainment 61.50% 61.50%    
Others 25.00% 25.00%    
Other Adjustments        
Out of period adjustment 195.30% 195.30%    
Research and development super-deduction (66.50%) (66.50%)    
Preferential tax rate (46.40%) (46.40%)    
Adjustment for tax return amendments 31.10% 31.10%    
Effective tax rate 2.60% 2.60%    
China        
Reconciliation, amount        
Income tax expense computed at PRC statutory rate (25%) ¥ 662 $ 95    
Other Adjustments        
Others (384) (56)    
Income tax expense ¥ 394 $ 56    
Reconciliation, percent        
Income tax expense computed at PRC statutory rate (25%) 25.00% 25.00% 25.00% 25.00%
Statutory tax rate difference between Cayman and PRC 25.00% 25.00%    
Other Adjustments        
Others (14.70%) (14.70%)    
Foreign        
Other Adjustments        
Income tax expense ¥ 467 $ 66    
Cayman Islands        
Reconciliation, amount        
Statutory tax rate difference between Cayman and PRC ¥ 1,489 $ 213    
Reconciliation, percent        
Statutory tax rate difference between Cayman and PRC 56.20% 56.20%    
Other foreign country        
Other Adjustments        
Others ¥ 323 $ 46    
Other Adjustments        
Others 12.10% 12.10%