AI research startup Exa has taken over the approximately 40,000-square-foot Pioneer Building in San Francisco’s Mission District under a minimum seven-year lease, moving into a property previously occupied by Stripe, OpenAI and xAI.
Key Takeaways
- Exa has signed a minimum seven-year lease for the Pioneer Building at 3180 18th St.
- The approximately 40,000-square-foot property is located in San Francisco’s Mission District.
- Exa previously operated from 430 Shotwell St. in the Mission.
- The Pioneer Building has previously housed Stripe, OpenAI and xAI.
- The property dates to 1902 and was originally an automobile trunk factory.
The transaction places Exa in a building with an established technology history. Stripe previously occupied the property before OpenAI moved in, followed by xAI. Exa is now taking over the space as xAI’s lease reaches its end this month.
Real estate firm CBRE represented Exa in the lease transaction. Charlie Hannafin of JLL represented the building’s landlord, Artemis Real Estate Partners.
The Pioneer Building is one of the Mission District properties zoned specifically for office use rather than light industrial activity. That designation distinguishes it from other commercial properties in the neighborhood.
The lease adds another example of a technology company maintaining a physical San Francisco presence. Earlier this year, another AI company expanded its office footprint in SoMa through a new commercial lease.
San Francisco AI Ecosystem Gains Another Mission District Tenant
Exa’s new headquarters adds another AI company to a San Francisco property that has housed several technology businesses. The building’s recent tenants include companies that have operated in different areas of the technology sector, with OpenAI and xAI both using the property for AI-related work.
Exa describes itself as an AI research company and has developed search infrastructure for artificial intelligence applications. According to the company’s own account, its technology powers search for more than 400,000 developers and customers including Cursor.
The company’s move also keeps its headquarters within the Mission District. Its previous address at 430 Shotwell St. was located a short distance from the new Pioneer Building site.
The seven-year minimum lease gives Exa a long-term tenancy at a property that has already served as a home for multiple technology companies. The arrangement also places the company in a building with a distinct connection to San Francisco’s technology sector.
San Francisco has continued to attract companies working on artificial intelligence and related technologies. Recent local coverage has also included developments involving Bay Area AI technology companies and their operations in the region.
Pioneer Building Previously Housed Stripe, OpenAI and xAI
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The Pioneer Building’s technology use began after its earlier industrial history. The 1902 structure was originally an automobile trunk factory before being converted into creative office space in the 1980s.
The property changed hands in 2013 when it was acquired by real estate investment firms. Stripe subsequently leased the building and used it as its San Francisco workplace before moving to larger offices in nearby SoMa.
OpenAI became the building’s next major technology tenant in 2016. Elon Musk arranged a long-term lease through Musk Industries, and the property served as a headquarters for the AI nonprofit that Musk had helped fund.
Musk later left OpenAI, but his connection to the property continued because he remained the leaseholder after his departure from the organization. OpenAI continued operating from the building for several years before leaving in 2024 for a larger lease in Mission Bay.
Musk then moved xAI into the Pioneer Building in 2024. The company is not renewing its lease, which expires this month, as xAI has expanded its footprint in Palo Alto.
The sequence of tenants gives the building a specific place in the recent history of San Francisco technology companies. The city’s technology sector has occupied a range of commercial properties as companies have expanded, consolidated or shifted their office footprints.
Exa Expands From Its Former Shotwell Street Headquarters
Exa’s relocation moves the company from 430 Shotwell St. to the larger Pioneer Building. The company has grown from its original operations into an AI research business focused on search infrastructure.
The founders have also connected the new headquarters with the building’s previous technology tenants. Will Bryk said in a post on X that the property had housed work associated with Elon Musk, OpenAI co-founder and researcher Alec Radford, and Stripe co-founders Patrick and John Collison.
Those comments described the building’s previous technology activity rather than announcing a change to Exa’s business operations. Exa’s new lease instead establishes the Pioneer Building as its latest San Francisco workplace.
The property gives Exa access to approximately 40,000 square feet of office space. The minimum seven-year term also distinguishes the arrangement from a short-term occupancy.
Exa’s previous address and its new headquarters are both in the Mission District, keeping the company in the same San Francisco neighborhood while moving into a substantially larger historic property.
The company’s move also places its office strategy within San Francisco’s commercial real estate market, where technology tenants have occupied and vacated large office properties at different points in the city’s recent business cycle.
Historic Mission District Property Continues Its Technology Use
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The Pioneer Building’s latest lease maintains its use as office space after more than a century of changing uses. Its original function as an automobile trunk factory predates its conversion to creative offices and later occupation by technology companies.
The building’s office zoning is also relevant to its continued use by technology businesses. It is among Mission District properties designated as true office space rather than light industrial space.
Exa’s arrival follows a sequence that began with Stripe’s tenancy and continued through OpenAI and xAI. Each company occupied the property at different stages of its business development, while the building retained its location at 3180 18th St.
The current lease gives Exa a minimum seven-year term at the property. Its move therefore establishes a new long-term technology tenancy in the Mission District.
Frequently Asked Questions
What is Exa and what does the San Francisco AI startup do?
Exa is an AI research company founded by Will Bryk and Jeff Wang. The company provides search infrastructure for artificial intelligence applications and says its technology powers search for more than 400,000 developers and customers including Cursor.
Where is Exa’s new San Francisco headquarters located?
Exa’s new headquarters is in the Pioneer Building at 3180 18th St. in San Francisco’s Mission District. The building covers approximately 40,000 square feet.
How long is Exa’s lease for the Pioneer Building?
Exa’s lease has a minimum term of seven years. Real estate firm CBRE represented Exa in the transaction.
Which technology companies previously occupied the Pioneer Building?
Stripe previously occupied the building, followed by OpenAI and xAI. xAI’s lease expires this month, before Exa takes over the property.
How large is San Francisco’s Pioneer Building?
The Pioneer Building contains approximately 40,000 square feet. The 1902 property was originally built as an automobile trunk factory and was later converted into creative office space.
