Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Accumulated other comprehensive (loss) income	Accumulated deficit	Total
Balance at Beginning of period at Dec. 31, 2019	$ 11	$ 198,829	$ (19)	$ (167,859)	$ 30,962
Balance at Beginning of period (in shares) at Dec. 31, 2019	11,406,221
Vesting of common stock previously subject to repurchase		2			2
Vesting of common stock previously subject to repurchase (in shares)	163
Exercise of stock options		44			44
Exercise of stock options (in shares)	6,306
Foreign currency translation adjustment			31		31
Stock-based compensation expense		943			943
Issuance of common stock	$ 3	44,719			44,722
Issuance of common stock (in shares)	3,000,000
Net loss				(13,301)	(13,301)
Balance at Ending period at Jun. 30, 2020	$ 14	244,537	12	(181,160)	63,403
Balance at Ending period (in shares) at Jun. 30, 2020	14,412,690
Balance at Beginning of period at Mar. 31, 2020	$ 11	199,287	8	(175,079)	24,227
Balance at Beginning of period (in shares) at Mar. 31, 2020	11,407,600
Vesting of common stock previously subject to repurchase		1			1
Vesting of common stock previously subject to repurchase (in shares)	73
Exercise of stock options		36			36
Exercise of stock options (in shares)	5,017
Foreign currency translation adjustment			4		4
Stock-based compensation expense		494			494
Issuance of common stock	$ 3	44,719			44,722
Issuance of common stock (in shares)	3,000,000
Net loss				(6,081)	(6,081)
Balance at Ending period at Jun. 30, 2020	$ 14	244,537	12	(181,160)	63,403
Balance at Ending period (in shares) at Jun. 30, 2020	14,412,690
Balance at Beginning of period at Dec. 31, 2020	$ 14	245,736	(71)	(196,653)	49,026
Balance at Beginning of period (in shares) at Dec. 31, 2020	14,437,107
Vesting of common stock previously subject to repurchase (in shares)	82
Exercise of stock options		152			$ 152
Exercise of stock options (in shares)	22,585				22,585
Foreign currency translation adjustment			(10)		$ (10)
Stock-based compensation expense		2,106			2,106
Stock-based compensation expense (in shares)	12,000
Reclassification of liability-classified stock-based compensation awards		82			82
Net loss				(16,391)	(16,391)
Balance at Ending period at Jun. 30, 2021	$ 14	248,076	(81)	(213,044)	34,965
Balance at Ending period (in shares) at Jun. 30, 2021	14,471,774
Balance at Beginning of period at Mar. 31, 2021	$ 14	246,548	(82)	(204,789)	41,691
Balance at Beginning of period (in shares) at Mar. 31, 2021	14,440,275
Vesting of common stock previously subject to repurchase (in shares)	36
Exercise of stock options		116			116
Exercise of stock options (in shares)	19,463
Foreign currency translation adjustment			1		1
Stock-based compensation expense		1,412			1,412
Stock-based compensation expense (in shares)	12,000
Net loss				(8,255)	(8,255)
Balance at Ending period at Jun. 30, 2021	$ 14	$ 248,076	$ (81)	$ (213,044)	$ 34,965
Balance at Ending period (in shares) at Jun. 30, 2021	14,471,774