The campaign has no fixed limit on the number of companions you can have in total, but you have to keep their approval up, so having too many might waste too much time and effort.
There is also no limit on the number of companions that can go on Shadowruns with you, but bringing more than 2 might start impacting the challenge and thus reduce XP gain. Bringing more than 3 companions will definitely reduce XP gain, but that could be OK in certain situations.
COMPANIONS
No companions recruited thus far.
PROSPECTS
Tag: Ork rigger, gym rat and Redmond local
Vanya: Elf combat mage, recently came up from Portland, eager to get into battle (and will usually leave a trail of corpses)
Eclipse: Human decker, fancies herself an urban crusader, something of a loose cannon