Anthropic launched self-hosted sandboxes in public beta at Code with Claude London on March 4, 2026. The company also introduced MCP tunnels as a research preview, per @bcherny and @claudeai.
Key facts
- Announced March 4, 2026 at Code with Claude London
- Self-hosted sandboxes in public beta
- MCP tunnels in research preview
- Per @bcherny and @claudeai
- No pricing or region details disclosed
Anthropic launched self-hosted sandboxes in public beta at Code with Claude London on March 4, 2026. The company also introduced MCP tunnels as a research preview, per @bcherny and @claudeai.
What the Products Do
Self-hosted sandboxes let developers run code execution environments on their own infrastructure, rather than on Anthropic's cloud. This addresses data residency and compliance requirements that have blocked enterprise adoption of Claude's code execution features. MCP tunnels provide secure connections between AI agents and local or private resources, extending the Model Context Protocol to allow Claude to access databases, APIs, and files behind corporate firewalls.
The unique take: Anthropic is betting that enterprise data gravity will drive Claude adoption more than raw model capability. By letting enterprises keep code execution and data access on-premises, the company removes the top objection cited by large financial and healthcare customers — but sacrifices the monitoring, billing, and optimization that cloud-only execution provides.
Competitive Context
OpenAI's Code Interpreter runs entirely on OpenAI's servers; Google's Gemini code execution similarly relies on Google Cloud. Anthropic's self-hosted approach mirrors the strategy of smaller players like StackBlitz's WebContainers (client-side execution) and GitHub's Codespaces (self-hosted runners). The MCP tunnels research preview suggests Anthropic is building toward a multi-agent architecture where Claude instances communicate with each other and with external services through a standardized protocol — a long bet that could differentiate Claude in enterprise workflows.
Missing Details
Anthropic did not disclose pricing, availability timelines beyond the beta and preview labels, or which regions or clouds support the self-hosted sandboxes. The company has not published documentation or a GitHub repository for either product as of the announcement.
What to watch
Watch for Anthropic to publish documentation and a GitHub repo for self-hosted sandboxes within 30 days. If MCP tunnels graduate to GA by Q2 2026, expect enterprise customer announcements from financial services and healthcare verticals. The key metric: whether self-hosted sandbox adoption exceeds cloud-based code execution within six months.
