Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2017	$ (26,948)			$ 5,262	$ (32,210)
Balance, temporary equity, shares at Dec. 31, 2017		31,074,017
Balance, temporary equity at Dec. 31, 2017		$ 26,341
Balance, shares at Dec. 31, 2017			2,016,838
Issuance of Series A redeemable convertible preferred stock		$ 10,825
Issuance of Series A redeemable convertible preferred stock, shares		9,020,833
Exercise of the redeemable convertible preferred stock tranche liability		$ 902
Issuance of common stock upon exercise of stock options	$ 221			221
Issuance of common stock upon exercise of stock options, shares	123,949		123,949
Vesting of early exercised stock options	$ 44			44
Stock-based compensation expense	2,479			2,479
Net loss	(9,299)				(9,299)
Unrealized gain (loss) on marketable debt securities, net of tax	(13)					$ (13)
Balance at Dec. 31, 2018	(33,516)			8,006	(41,509)	(13)
Balance, temporary equity, shares at Dec. 31, 2018		40,094,850
Balance, temporary equity at Dec. 31, 2018		$ 38,068
Balance, shares at Dec. 31, 2018			2,140,787
Issuance of Series A redeemable convertible preferred stock		$ 88
Issuance of Series A redeemable convertible preferred stock, shares		67,656
Issuance of Series B redeemable convertible preferred stock, net of issuance cost of $5,216		$ 74,784
Issuance of Series B redeemable convertible preferred stock, shares		57,004,415
Termination of redeemable convertible preferred stock tranche liability		$ 1,143
Issuance of common stock upon exercise of stock options	$ 30			30
Issuance of common stock upon exercise of stock options, shares	14,791		14,791
Vesting of early exercised stock options	$ 47			47
Stock-based compensation expense	1,175			1,175
Net loss	(28,138)				(28,138)
Unrealized gain (loss) on marketable debt securities, net of tax	36					36
Balance at Dec. 31, 2019	(60,366)			9,258	(69,647)	23
Balance, temporary equity, shares at Dec. 31, 2019		97,166,921
Balance, temporary equity at Dec. 31, 2019	114,083	$ 114,083
Balance, shares at Dec. 31, 2019			2,155,578
Issuance of common stock upon exercise of stock options	$ 460		$ 1	459
Issuance of common stock upon exercise of stock options, shares	210,752		210,752
Stock-based compensation expense	$ 5,263			5,263
Conversion of shares of redeemable convertible preferred stock to shares of common stock in connection with the Merger	114,083		$ 1	114,082
Conversion of shares of redeemable convertible preferred stock to shares of common stock in connection with the Merger, shares		(97,166,921)
Conversion of shares of redeemable convertible preferred stock to shares of common stock in connection with the Merger		$ (114,083)
Conversion of shares of redeemable convertible preferred stock to shares of common stock in connection with the Merger, shares			12,048,671
Exchange of common stock in connection with the Merger	83,516			83,516
Exchange of common stock in connection with the Merger, shares			5,207,695
Issuance of common stock upon accelerated vesting ofrestricted stock units in connection with the Merger	626			626
Issuance of common stock upon accelerated vesting of restricted stock units in connection with the Merger (Shares)			54,553
Conversion of redeemable convertible preferred stock warrants to common stock warrants	2,922			2,922
Net loss	(36,678)				(36,678)
Unrealized gain (loss) on marketable debt securities, net of tax	1					1
Balance at Dec. 31, 2020	$ 109,827		$ 2	$ 216,126	$ (106,325)	$ 24
Balance, temporary equity, shares at Dec. 31, 2020		0
Balance, shares at Dec. 31, 2020			19,677,249