CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS EQUITY (DEFICIT) - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulate Other Comprehensive Income (Loss)	Accumulated Deficit	Series C redeemable convertible preferred stock	Total
Redeemable Convertible Preferred Stock, Beginning balance at Dec. 31, 2023						$ 375,370
Redeemable Convertible Preferred Stock, Beginning balance (in shares) at Dec. 31, 2023						85,960,088
Redeemable convertible preferred stock
Issuance of redeemable convertible preferred stock for cash, net of derivative liability and offering cost					$ 120,205
Issuance of redeemable convertible preferred stock for cash, net of derivative liability and offering cost (in shares)					41,264,891
Redeemable Convertible Preferred Stock, Ending balance at Mar. 31, 2024						$ 495,575
Redeemable Convertible Preferred Stock, Ending balance (in shares) at Mar. 31, 2024						127,224,979
Beginning balance at Dec. 31, 2023	$ 1	$ 25,055	$ 2	$ (364,318)		$ (339,260)
Beginning balance (in shares) at Dec. 31, 2023	2,675,979
Stockholders' deficit
Issuance of common stock upon exercise of stock options and early exercised stock options		29				29
Issuance of common stock upon exercise of stock options and early exercised stock options (in shares)	3,186
Vesting of early exercised stock options		494				494
Vesting of restricted shares of common stock		6				6
Stock-based compensation expense		2,657				2,657
Other comprehensive income (loss), net			(3)			(3)
Net loss				(49,849)		(49,849)
Ending balance at Mar. 31, 2024	$ 1	28,241	(1)	(414,167)		(385,926)
Ending balance (in shares) at Mar. 31, 2024	2,679,165
Beginning balance at Dec. 31, 2024	$ 5	918,610	40	(658,551)		260,104
Beginning balance (in shares) at Dec. 31, 2024	54,407,327
Stockholders' deficit
Vesting of early exercised stock options		224				224
Vesting of restricted shares of common stock		2				2
Stock-based compensation expense		6,995				6,995
Other comprehensive income (loss), net			(48)			(48)
Net loss				(98,963)		(98,963)
Ending balance at Mar. 31, 2025	$ 5	$ 925,831	$ (8)	$ (757,514)		$ 168,314
Ending balance (in shares) at Mar. 31, 2025	54,407,327