| Document And Entity Information - USD ($) | 12 Months Ended | ||
| Dec. 31, 2023 | Mar. 15, 2024 | Jun. 30, 2023 | |
| Document Information Line Items | |||
| Entity Registrant Name | ONYX ACQUISITION CO. I | ||
| Document Type | 10-K/A | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Public Float | $ 45,510,403 | ||
| Amendment Flag | true | ||
| Amendment Description | This Form 10-K/A Amendment No. 1 (the “Amendment”) to the Annual Report on Form 10-K for the year ended December 31, 2023 (the “Original 10-K”) is being filed solely for the purpose of furnishing revised certifications by our principal executive officer and principal financial officer as Exhibits 32.1 and 32.2, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (the “906 Certifications”). As a result of a typographical error, the Section 906 Certifications attached as Exhibits 32.1 and 32.2 to the Original 10-K referenced the incorrect fiscal year. Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, this Amendment also contains new certifications by our principal executive officer and principal financial officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (the “302 Certifications”).This Amendment contains only the Cover Page, the Explanatory Note, paragraph (a)(3) of Item 15, the Signature Page, the corrected 906 Certifications and the 302 Certifications. Except as described above, no other changes have been made to the Original 10-K.Other than as expressly set forth herein, this Amendment does not, and does not purport to, amend, update or restate the information in the Original 10-K or reflect any events that have occurred after the Original 10-K was filed. Information not affected by this Amendment remains unchanged and reflects the disclosures made at the time as of which the Original 10-K was filed. This Amendment should be read together with the Original 10-K and our other filings with the Securities and Exchange Commission. | ||
| Entity Central Index Key | 0001849548 | ||
| Entity Current Reporting Status | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Filer Category | Non-accelerated Filer | ||
| Entity Well-known Seasoned Issuer | No | ||
| Document Period End Date | Dec. 31, 2023 | ||
| Document Fiscal Year Focus | 2023 | ||
| Document Fiscal Period Focus | FY | ||
| Entity Small Business | true | ||
| Entity Emerging Growth Company | true | ||
| Entity Shell Company | true | ||
| Entity Ex Transition Period | false | ||
| ICFR Auditor Attestation Flag | false | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Entity Incorporation, State or Country Code | E9 | ||
| Entity File Number | 001-41003 | ||
| Entity Tax Identification Number | 95-1584432 | ||
| Entity Address, Address Line One | 104 5th Avenue | ||
| Entity Address, State or Province | NY | ||
| Entity Address, City or Town | New York | ||
| Entity Address, Postal Zip Code | 10011 | ||
| City Area Code | (212) | ||
| Local Phone Number | 974-2844 | ||
| Entity Interactive Data Current | Yes | ||
| Document Financial Statement Error Correction [Flag] | false | ||
| Documents Incorporated by Reference [Text Block] | None | ||
| Auditor Name | Marcum LLP | ||
| Auditor Location | Hartford, CT | ||
| Auditor Firm ID | 688 | ||
| Units, each consisting of one Class A Ordinary Share, $0.0001 par value per share, and one-half of one redeemable warrant | |||
| Document Information Line Items | |||
| Trading Symbol | ONYXU | ||
| Title of 12(b) Security | Units, each consisting of one Class A Ordinary Share, $0.0001 par value per share, and one-half of one redeemable warrant | ||
| Security Exchange Name | NASDAQ | ||
| Class A Ordinary Shares included as part of the Units | |||
| Document Information Line Items | |||
| Trading Symbol | ONYX | ||
| Title of 12(b) Security | Class A Ordinary Shares included as part of the Units | ||
| Security Exchange Name | NASDAQ | ||
| Redeemable warrants included as part of the Units, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share | |||
| Document Information Line Items | |||
| Trading Symbol | ONYXW | ||
| Title of 12(b) Security | Redeemable warrants included as part of the Units, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 | ||
| Security Exchange Name | NASDAQ | ||
| Class A Ordinary Shares | |||
| Document Information Line Items | |||
| Entity Common Stock, Shares Outstanding | 7,945,461 | ||
| Class B Ordinary Shares | |||
| Document Information Line Items | |||
| Entity Common Stock, Shares Outstanding | 0 |
