Green’s Dictionary of Slang

a general excl. of agreement.

1858		Taunton Courier 8 Dec. 4/5: Round you go [...] Right you are!
1864		Derby Day 42: ‘Right you are,’ replied the jockey.
1875		F.H. Sheppard Love Afloat 104: ‘I don’t care to be anybody’s fool for nothing.’ ‘Right you are.’.
1880		D.W. Barrett Life and Work among Navvies 35: The phrase by which you generally give assent to a proposition [...] ‘Right you are!’.
1887		H. Frederic Seth’s Brother’s Wife 274: ‘Right you air, tew!’ Milton responded.
1892		J. Newman Scamping Tricks 93: ‘On that you can bet the family plate.’ ‘Right you are.’.
1902		J.D. Corrothers Black Cat Club 47: ‘Right you is, Doc’, cried Saskatchewan Jones, ‘we’ll sho’ be dah!’.
1908		K. Grahame Wind in the Willows (1995) 119: ‘Right you are!’ cried the Rat, starting up. ‘We’ll rescue the poor unhappy animal!’.
1914		E. Pugh Cockney At Home 74: ‘Right y’are!’ he said.
1920		Marvel 10 Apr. 18: Right you are, then! Shell ’em.
1930		J. Lait Put on the Spot 111: ‘Right you got, boss,’ affirmed the bartender.
1941		K. Tennant Battlers 313: ‘Right y’are,’ the man said. ‘I’ve got my jinker here.’.
1956		J. Osborne Look Back in Anger Act I: Right you are.
1983		C. Heath A-Team 2 (1984) 37: ‘Right you are,’ Face told her.
1997		P. Theroux Kowloon Tong 155: ‘Right you are,’ he said to the sudden hum of the dial tone, for Mei-ping had rung off.