v3.26.1
Cover
Apr. 29, 2026
Document Type 8-K
Amendment Flag false
Document Period End Date Apr. 29, 2026
Entity File Number 001-42046
Entity Registrant Name GP-Act III Acquisition Corp.
Entity Central Index Key 0001834526
Entity Tax Identification Number 00-0000000
Entity Incorporation, State or Country Code E9
Entity Address, Address Line One 300 Park Avenue
Entity Address, Address Line Two 2nd Floor
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10022
City Area Code 212
Local Phone Number 430-4340
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false
Units, each consisting of one Class A ordinary share and one-half of one redeemable warrant  
Title of 12(b) Security Units, each consisting of one Class A ordinary share and one-half of one redeemable warrant
Trading Symbol GPATU
Security Exchange Name NASDAQ
Class A ordinary shares, par value $0.0001 per share  
Title of 12(b) Security Class A ordinary shares, par value $0.0001 per share
Trading Symbol GPAT
Security Exchange Name NASDAQ
Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50  
Title of 12(b) Security Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50
Trading Symbol GPATW
Security Exchange Name NASDAQ