StartupSan Francisco, CA · Est. 2024 · Acquired (Baseten)
Blaxel
Perpetual-standby microVM sandboxes for production agents, now part of Baseten.
Blaxel (YC Spring 2025) provides compute, storage and networking for autonomous agents. Each sandbox is an isolated microVM that resumes in about 25ms with memory state intact and can stay on standby indefinitely when idle; it also offers batch jobs across sandboxes, MCP servers as first-class workloads, persistent volumes, egress controls and a model gateway. Founded in 2024 in San Francisco by Paul Sinai, Christophe Ploujoux and others, it was acquired by AI inference company Baseten in 2026 (terms undisclosed); YC lists it as acquired.
Neighbours in the directory
Prague, Czechia · Est. 2023
Open-source sandboxes for running AI-generated code.
E2B gives agents secure, isolated cloud micro-VMs to execute code and commands — the execution runtime layer of the harness, used by many coding and data-analysis agents.
Est. 2023
Elastic sandboxes for running AI-generated code.
Daytona provides secure, OCI-compatible sandbox 'computers' that spin up in under 90ms — with snapshots for persistent agent state. In 2026 it moved core development to a private codebase while continuing to run as a commercial platform.
New York, NY · Est. 2021
Serverless cloud built for AI and agentic compute.
Modal lets teams run inference, fine-tuning and arbitrary agent workloads as serverless Python without managing infrastructure — a common substrate for harness backends at scale.
Connections
Relations from the Harness Hub knowledge graph, as charted in the State of Harness reports.
Built on · 1
- Model Context ProtocolProject
Sources
Verified Oct 29, 2026