Organization	6 Months Ended
Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Description of the Business RAPT Therapeutics, Inc. (“RAPT” or the “Company”) is a clinical-stage, immunology-based biopharmaceutical company focused on discovering, developing and commercializing oral small molecule therapies for patients with significant unmet needs in inflammatory diseases and oncology. Utilizing its proprietary drug discovery and development engine, the Company develops highly selective small molecules that are designed to modulate the critical immune responses underlying these diseases. The Company is located in South San Francisco, California. Equity Financing In May 2022, the Company completed the sale of pre-funded warrants to purchase 4,000,000 shares of its common stock at a price of $12.4999 per pre-funded warrant, which sale was done as a private investment in public equity ("PIPE") financing. Net proceeds received from the PIPE financing were approximately $49.8 million, after deducting $0.2 million of offering expenses. As of June 30, 2022, all of the pre-funded warrants issued in the PIPE financing were outstanding (see Note 8).

The entire disclosure for the nature of an entity's business, major products or services, principal markets including location, and the relative importance of its operations in each business and the basis for the determination, including but not limited to, assets, revenues, or earnings. For an entity that has not commenced principal operations, disclosures about the risks and uncertainties related to the activities in which the entity is currently engaged and an understanding of what those activities are being directed toward.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-URI https://asc.fasb.org/topic&trid=2134479

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