1930: The Black Star Passes, a novella by John W. Campbell, Jr. in his Arcot, Morey and Wade series, first published in Amazing Stories Quarterly, Fall 1930, available at the Internet Archive. (The Project Gutenberg etext of The Black Star Passes is useless for our purposes, as it was transcribed from the 1965 Ace edition, which is not identical with the original 1930 magazine story.)
The Terrestrial scientists are preparing to do battle with the invaders from the Black Star:
"The ships must be capable of about six or seven thousand miles a second, and that implies all the acceleration a human being can endure. Since I expect to make long trips in them, I think we will do best if we make several types of ships. Three should suffice: a small single man cruiser, with no bunk or living quarters, just a little power plant and weapon. One that can jump out of the way of a ray so quickly that it will be very hard to hit, and at the same time, because of its ray, be very dangerous. There will have to
be some place for the operator of this ship to sleep and eat. I think the easiest way to solve that is to have a large fleet of mother ships — ships with a twenty-man crew, but still very active, and very deadly. These should have bunks and living quarters for the crew. Some men would be sleeping in the bunks all the time. The men could take turns running the one-man ships
and sleeping. There will also be some ten-man scout cruisers. These will be used in the same way, but will have a smaller fleet of ships dependent on them.
[. . . .]
Each of the little ships, the one-man machines, was equipped with a small machine-gun shooting luminous paint bullets. One of these bullets, landing on a machine, made it visible for at least two hours, and as they would cover an area of perhaps thirty square feet, they were decidedly effective.
The aliens have their own mother-ships and fighters:
And thus that great courtyard had been filled with Giants of Space! And in each of these thousand great warships there nestled three thousand tiny one-man ships. A thousand five hundred miles the great metal bulks alone would stretch, and with them would go a great swarm of tiny stinging ships, like some horde of stinging wasps swarming about their nest.