Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (38,207)	$ (21,283)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	2,096	1,113
Gain on disposal of property and equipment	(9)	(5)
Stock-based compensation expense	2,187	348
Non-cash interest expense	111	210
Change in fair value of warrant liability	359	(1)
Amortization of deferred finance costs	224
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(6,259)	(1,554)
Accounts receivable	(5,000)
Accounts payable	(1,952)	(272)
Accrued expenses and other liabilities	(8,039)	434
Deferred rent	278	(3)
Deferred revenue	4,743	(23)
Other liabilities		(322)
Net cash used in operating activities	(49,468)	(21,358)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of property and equipment	37
Purchases of property and equipment	(287)	(4,688)
Net cash used in investing activities	(250)	(4,688)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from business combination, net of of transaction costs	80,491
Proceeds from issuance of convertible debt - PIPE Investors	21,750
Proceeds from stock option exercises	22	6
Principal payments on debt	(815)
Proceeds from equipment financing		2,842
Exercise of public warrants	1,209
Repayments of tenant improvement allowance	(43)	(39)
Principal payments on capital lease obligations	(160)	(175)
Net cash provided by financing activities	102,454	2,634
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	52,736	(23,412)
Cash, cash equivalents and restricted cash, beginning of period	31,808	95,148
Cash, cash equivalents and restricted cash, end of period	84,544	71,736
SUPPLEMENTAL DISCLOSURE OF CASH-FLOW INFORMATION
Cash paid for interest	620	85
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment included in accrued expenses and accounts payable	1,313	906
Conversion of convertible debt to equity	53,541
Legacy GreenLight cashless warrant exercises	1,643
Warrant liabilities assumed in the Business Combination	1,341
Deferred financing costs in accrued expenses and accounts payable	$ 1,948
Non-cash equipment financing issuance costs		$ 138