Common Stock - Reserved for Future Issuance (Details)	Sep. 30, 2025 shares
Class of Stock [Line Items]
Total common stock reserved (in shares)	38,976,643
Series A-1 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	1,349,650
Series A-2 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	1,137,210
Series A-3 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	899,730
Series A-4 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	25,761
Series A-5 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	114,613
Series A-6 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	5,796,201
Series B-1 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	5,182,287
Series B-2 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	2,566,902
Series C Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	5,628,825
Series C-1 Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	1,726,823
Series D Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	4,656,233
Redeemable Convertible Preferred stock warrants
Class of Stock [Line Items]
Total common stock reserved (in shares)	9,660
Common stock warrants
Class of Stock [Line Items]
Total common stock reserved (in shares)	121,566
Options to purchase common stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	9,041,854
Stock options available for future grants
Class of Stock [Line Items]
Total common stock reserved (in shares)	719,328