Baseten acquires Blaxel, a startup building sandboxes for AI agents; terms undisclosed
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What happened
AI inference company Baseten announced on 10 September 2026 that it had acquired Blaxel, a San Francisco startup that builds sandboxes, or secure execution environments, for AI agents. Axios Pro reported the deal first, with Baseten co-founder and chief technology officer Amir Haghighat discussing it, and Baseten followed with a Business Wire release and a blog post. Terms were not disclosed. Wilson Sonsini advised Blaxel on the transaction.
Blaxel builds microVM-based sandboxes that Baseten said suspend and resume in 25 milliseconds, up to five times faster than other sandbox products, along with a distributed filesystem called Agent Drive and a networking layer that connects agents to tools, MCP servers and APIs. Baseten said Blaxel would continue to operate, its product would not change, and Baseten would add new products on Blaxel's technology, starting with sandboxes. In the near term the technology expanded Baseten's support for code execution, tool use and session persistence; over time Baseten planned to integrate it with its inference, storage, observability and enterprise infrastructure. The Next Web noted that Baseten raised $1.5 billion at up to $13 billion in June and had acquired Parsed in December 2025.
Key points
- Baseten announced on 10 September 2026 that it had acquired Blaxel; terms were not disclosed.24
- Blaxel builds microVM sandboxes that Baseten says spin up and resume up to 5x faster than other sandbox products.24
- Blaxel continues to operate, and its product does not change.24
- Baseten has raised more than $2 billion, including $1.5 billion at up to $13 billion in June.4
- Axios Pro reported the deal first; Wilson Sonsini advised Blaxel.345
Why it matters
Baseten said Blaxel extends its support for code execution, tool use and session persistence, and that it plans to integrate the technology with its inference, storage and observability infrastructure. That widens what customers can run on one platform, as the company describes it.
Terms were not disclosed, so the deal gives no purchase price to set against the $13 billion valuation of Baseten's Series F.
Baseten's blog names Sapiom and Webflow as Blaxel customers and says Sapiom runs hundreds of millions of agent loops on Blaxel. These are company statements.
In context
| Round | Date | Post-money valuation | Raised | Led by |
|---|---|---|---|---|
| Series C | Feb 19, 2025 | $825M | $75M | IVP and Spark |
| Series D | Sep 5, 2025 | $2.1B | $150M | BOND |
| Series E | Jan 23, 2026 | $5.0B | $300M | CapitalG and IVP |
| Series F | Jun 22, 2026 | $13B | $1.5B | Altimeter Capital, Conviction Partners, Sands Capital, Spark Capital, and Wellington Management |
Updated
Fact-check
- Baseten announced on 10 September 2026 that it acquired Blaxel, a San Francisco startup building sandboxes for AI agents.Confirmed by [2] Baseten's blog (dated 10 September 2026) and [4] The Next Web (10 September 2026; calls Blaxel a San Francisco startup). [1] Business Wire and [5] Wilson Sonsini returned 403 to the checker.Verified
- The financial terms of the deal were not disclosed.Confirmed by [4] The Next Web: 'Terms were not disclosed.' [2] gives no terms.Verified
- Blaxel's microVM sandboxes suspend and resume in 25 milliseconds, up to five times faster than other sandbox products.Confirmed by [2] Baseten's blog and [4] The Next Web. These are company figures.Verified
- Blaxel continues to operate, its product does not change, and Baseten will add products starting with sandboxes and integrate the technology with its infrastructure.Confirmed by [2] Baseten's blog and [4] The Next Web, which also gives the near-term and long-term integration plans, Agent Drive and the networking layer.Verified
- Baseten raised $1.5 billion at up to $13 billion in June, has raised more than $2 billion in total, and acquired Parsed in December 2025.Confirmed by [4] The Next Web, which says the release puts the Series F valuation at $13 billion.Verified
- Axios Pro reported the deal first, via Baseten co-founder and CTO Amir Haghighat.Confirmed by [4] The Next Web; [3] Axios Pro returned 403 to the checker.Verified
- Wilson Sonsini advised Blaxel on the acquisition.Stated in the title of [5] Wilson Sonsini's notice per the writer's read; the page returned 403 to the checker.Partly verified
- Baseten's blog names Sapiom and Webflow as Blaxel customers; Sapiom runs hundreds of millions of agent loops on Blaxel.Confirmed by [2] Baseten's blog, which quotes Webflow's CTO and states the Sapiom figure.Verified
Sources
- [1]Business Wire (opens in a new tab)Baseten Acquires Blaxel to Build the Infrastructure for AI Agents in ProductionAgents need models, but they also need a secure environment to run in
- [2]Baseten (opens in a new tab)Blaxel is joining Baseten to build the future of agentic infrastructure
- [3]Axios Pro (opens in a new tab)Exclusive: Baseten buys agentic infrastructure startup Blaxel
- [4]The Next Web (opens in a new tab)Baseten buys Blaxel, a startup that builds sandboxes for AI agentsFinancial terms of the transaction were not disclosed.
- [5]Wilson Sonsini (opens in a new tab)Wilson Sonsini Advises Blaxel on its Acquisition by Baseten
