Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ Equity (Deficit) - USD ($) $ in Thousands	Series A Redeemable convertible preferred stock	Series B Redeemable convertible preferred stock	Common stock	Additional paid-in capital	Accumulated other comprehensive income	Accumulated deficit	Total
Balance at Beginning of period at Dec. 31, 2017	$ 30,940	$ 80,409
Balance at Beginning of period (in shares) at Dec. 31, 2017	22,501,174	59,425,431
Increase (Decrease) in Temporary Equity [Roll Forward]
Sale of Series B redeemable convertible preferred stock, net of stock issue costs		3,607,069
Sale of Series B redeemable convertible preferred stock, net of stock issue costs		$ 3,978
Accretion of redeemable convertible preferred stock to redemption value	$ 2,172	6,651
Balance at Ending period at Dec. 31, 2018	$ 33,112	$ 91,038
Balance at Ending period (in shares) at Dec. 31, 2018	22,501,174	63,032,500
Balance at Beginning of period at Dec. 31, 2017						$ (108,171)	$ (108,171)
Balance at Beginning of period (in shares) at Dec. 31, 2017			293,791
Increase (Decrease) in Temporary Equity [Roll Forward]
Vesting of common stock previously subject to repurchase (in shares)			549
Vesting of common stock previously subject to repurchase				$ 5			$ 5
Exercise of stock options (in shares)			1,377				1,377
Exercise of stock options				5			$ 5
Stock-based compensation expense				216			216
Accretion of redeemable convertible preferred stock to redemption value				(226)		(8,597)	(8,823)
Net loss						(21,092)	(21,092)
Balance at Ending period at Dec. 31, 2018						(137,860)	(137,860)
Balance at Ending period (in shares) at Dec. 31, 2018			295,717
Increase (Decrease) in Temporary Equity [Roll Forward]
Sale of Series B redeemable convertible preferred stock, net of stock issue costs		12,527,956
Sale of Series B redeemable convertible preferred stock, net of stock issue costs		$ 14,367
Accretion of redeemable convertible preferred stock to redemption value	$ 1,563	$ 6,220
Vesting of common stock previously subject to repurchase (in shares)			628
Vesting of common stock previously subject to repurchase				4			$ 4
Exercise of stock options (in shares)			2,527				2,527
Exercise of stock options				14			$ 14
Foreign currency translation adjustment					$ (15)		(15)
Stock-based compensation expense				457			457
Issuance/Conversion of convertible preferred stock (in shares)	(22,501,174)	(75,560,456)	6,708,649
Issuance/Conversion of convertible preferred stock	$ (34,675)	$ (111,625)	$ 7	146,293			146,300
Issuance of common stock			$ 4	50,625			50,629
Issuance of common stock (in shares)			4,398,700
Unrealized loss on short-term investments					(4)		(4)
Accretion of redeemable convertible preferred stock to redemption value				(209)		(7,574)	(7,783)
Conversion of preferred stock warrants to redemption value				1,645			1,645
Net loss						(22,425)	(22,425)
Balance at Ending period at Dec. 31, 2019			$ 11	198,829	(19)	(167,859)	30,962
Balance at Ending period (in shares) at Dec. 31, 2019			11,406,221
Increase (Decrease) in Temporary Equity [Roll Forward]
Vesting of common stock previously subject to repurchase (in shares)			306
Vesting of common stock previously subject to repurchase				3			$ 3
Exercise of stock options (in shares)			27,783				27,783
Exercise of stock options				175			$ 175
Issuance of common stock under the employee stock purchase plan				34			34
Issuance of common stock under the employee stock purchase plan (in shares)			2,797
Foreign currency translation adjustment					(52)		(52)
Stock-based compensation expense				1,976			1,976
Issuance of common stock			$ 3	44,719			44,722
Issuance of common stock (in shares)			3,000,000
Net loss						(28,794)	(28,794)
Balance at Ending period at Dec. 31, 2020			$ 14	$ 245,736	$ (71)	$ (196,653)	$ 49,026
Balance at Ending period (in shares) at Dec. 31, 2020			14,437,107