California regulators granted Tesla a permit on Tuesday to operate a ride service in the state, an early step toward the electric car maker’s ambitions of having its own robot taxi fleet.

The permit, issued by the California Public Utilities Commission, allows Elon Musk’s company to “transport Tesla employees on a prearranged basis and in Tesla-owned vehicles,” the agency said in a statement. The approval is the first of many that Tesla will need to test self-driving vehicles on California roads.

While Waymo, the robot taxi company owned by Google’s parent company, Alphabet, is the only company that offers autonomous-vehicle rides to the public in California, Tesla has long been expected to become a major player in the growing sector. Mr. Musk, the chief executive, has said robot taxis will add trillions of dollars to the market cap of Tesla, whose stock is slumping.

Tesla debuted a prototype of its robot taxi, which Mr. Musk calls a “cybercab,” in October. A month later, Tesla applied for the ride service permit in California, the agency said, and has yet to apply for ones necessary to run a robot taxi service.

Mr. Musk has said Tesla plans to deploy robot taxis in Texas as early as June, though the company has a history of delaying its robot taxi plans. Regulations in Texas covering robot taxis are much looser than in California, and Waymo debuted its robot taxis to the public in Austin this month.

In order for Tesla to offer autonomous taxis on public roads in California, it needs a series of approvals from the California Public Utilities Commission and the Department of Motor Vehicles.

While the utilities commission regulates vehicles-for-hire, including Uber and Lyft, the Department of Motor Vehicles regulates safety, which is the loftier regulatory hurdle for aspiring robot taxis.

“What they really need to do is convince the California D.M.V. that their technology is safe,” said Matt Wansley, a law professor at the Cardozo School of Law in New York. “Once the California D.M.V. says your technology is safe, then the C.P.U.C. can make a decision about whether to carry passengers” in a public service.

Tesla also wants to give its current line of electric vehicles, including the Models 3 and Y, robot taxi capabilities using currently available software called Supervised Full Self-Driving. But that goal presents its own set of safety and regulatory challenges that have yet to be tested, or approved, by the State Department of Motor Vehicles.

“While Tesla has approval to test autonomous vehicles with a safety driver in California, it doesn’t have, nor has applied for, a driverless testing or deployment permit from the D.M.V.,” the department said.

Tesla did not respond to a request for comment.