Cash and cash equivalents and financial assets - Cash and cash equivalents (Details) SFr in Thousands	Jun. 30, 2025 CHF (SFr) SFr / $	Dec. 31, 2024 CHF (SFr) SFr / $	Jun. 30, 2024 CHF (SFr) SFr / $	Dec. 31, 2023 CHF (SFr)
Cash and cash equivalents [Abstract]
Cash and cash equivalents \| SFr	SFr 25,722	SFr 36,275	SFr 51,564	SFr 78,494
Translation rate into CHF \| SFr / $	0.807	0.912	0.909

The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2024-01-01
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-Subparagraph a
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant