The appointment sees Smith link up with two former colleagues, having worked with both Lee Picton and Graham Fenton in the past.
Smith was team-mates with Picton at Whitley Bay and Ashington and a key member of Fenton's coaching staff during his time in charge of North Shields.
He later went on to manage the Robins himself before departing his role with the club in February 2018.
He will assist Picton and Fenton at training and games, and will also help in a scouting capacity.
Smith - who has won the FA Vase as a player and a coach - said: "This has been ticking over for three or four weeks with Graham and Lee, and I'm really looking forward to getting involved in the project here.
"Everything about the club is looking good at the moment and to be part of that is exciting.
"I know Graham and Lee well and to get the chance to work alongside them is brilliant.
"I'll assist them with whatever they need and look forward to working with what is a fantastic squad."
Fenton said: "At this stage we feel we need some extra eyes to help us, and another opinion around the place.
"Brian is the ideal person to provide that.
"His experience and expertise should compliment what myself and Lee do very well and give us a bit of breathing space, because we feel like we're stretched to get all of the responsibilities carried out between us.
"He'll be in and around the first-team to assist us but also go to different games which we feel we need to be viewed, or to watch players we are tracking.
"It's an ideal appointment and we're very much looking forward to having Brian around the place."
Keep up-to-date with our exclusive email newsletters.
Subscribe