Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
OPERATING ACTIVITIES
Net loss	$ (71,169)	$ (32,775)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	25,927	7,348
Depreciation and amortization	2,558	1,606
Net amortization of premium on available-for-sale securities	1,197	261
Non-cash interest expense and other adjustments	0	10
Non-cash operating lease expense	1,005	0
Changes in operating assets and liabilities:
Accounts receivable, net	(2,495)	0
Related party receivables	(1,184)	0
Other receivables	(203)	64
Prepaid expenses and other current assets	(2,884)	8
Inventory	(3,594)	(551)
Other assets	(94)	(7)
Accounts payable	1,603	912
Deferred revenue	126	75
Deferred rent	0	242
Accrued expenses	2,277	2,036
Accrued research and development	627	(254)
Operating lease liabilities	91	0
Other noncurrent liabilities	(135)	197
Net cash used in operating activities	(46,347)	(20,828)
INVESTING ACTIVITIES
Purchases of property and equipment	(6,922)	(4,534)
Purchase of available-for-sale securities	(279,956)	(87,724)
Proceeds from maturities of available-for-sale securities	116,000	57,750
Investment in equity method investee	0	(50)
Net cash used in investing activities	(170,878)	(34,558)
FINANCING ACTIVITIES
Proceeds from issuance of common stock upon follow-on public offering, net of issuance costs	102,959	0
Proceeds from return of profit	11,403	0
Repurchase of Class A common stock	(35)	(13)
Proceeds from exercise of Class A common stock options including early exercised options	1,885	1,265
Proceeds from issuance of common stock in connection with employee stock purchase plan	422	0
Proceeds from issuance of Series D-1 convertible preferred stock, net of issuance costs	0	54,896
Proceeds from issuance of Class A common stock upon initial public offering, net of issuance costs	0	185,063
Proceeds of issuance of Class A common stock in private placement	0	130,275
Net cash provided by financing activities	116,634	371,486
Net increase (decrease) in cash, cash equivalents and restricted cash	(100,591)	316,100
Cash, cash equivalents and restricted cash, beginning of period	333,928	17,828
Cash, cash equivalents and restricted cash, end of period	233,337	333,928
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for income taxes	645	0
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Lease liability obtained in exchange for right-of-use assets	23,232	0
Conversion of convertible preferred stock into common stock upon initial public offering	0	162,848
Accounts Payable
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Property and equipment purchases	186	115
Offering costs	0	468
Accrued Liabilities
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Property and equipment purchases	269	58
Offering costs	$ 0	$ 729