Revenue information (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2022 CNY (¥)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 CNY (¥)	Dec. 31, 2020 CNY (¥)
Revenue information
Total revenue	¥ 245,948	$ 35,659	¥ 942,380	¥ 2,451,287
Base Commission From Transactions [Member]
Revenue information
Total revenue	201,907		821,899	2,223,685
Innovation initiatives and other value-added services
Revenue information
Total revenue	¥ 44,041		¥ 120,481	¥ 227,602

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details