Uber Technologies has agreed to invest up to $1.25 billion in electric vehicle maker Rivian Automotive to deploy as many as 50,000 autonomous robotaxis across 25 cities through 2031.

Under the terms announced Thursday, Uber — or its fleet partners — will initially purchase 10,000 autonomous versions of Rivian's upcoming R2 SUV, with options for up to 40,000 more vehicles beginning in 2030. An initial $300 million tranche will transfer to Rivian after the deal closes, pending regulatory approval.

The robotaxis will operate exclusively on Uber's platform, launching in San Francisco and Miami in 2028 before expanding across the US, Canada, and Europe.

Rivian's autonomous stack centers on RAP1, its in-house Rivian Autonomy Processor — an AI inference platform backed by data from its growing consumer vehicle fleet. CEO RJ Scaringe has cited recent advances in AI and semiconductors as making viable large-scale robotaxi businesses possible for the first time.

"We're big believers in Rivian's approach — designing the vehicle, compute platform, and software stack together, while maintaining end-to-end control of scaled manufacturing and supply in the US," said Uber CEO Dara Khosrowshahi.

The deal extends Uber's growing roster of autonomous partners, which already includes Waymo, Zoox, Lucid, Stellantis, and Nvidia. For Rivian, it follows the automaker's $5.8 billion software partnership with Volkswagen in 2024 and arrives just as the company prepares to launch R2 consumer sales this spring — the data flywheel that will feed its autonomy program.

Shares of Rivian rose roughly 10% in premarket trading before settling 3% higher on the day.