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  "title": "Kern Sandbox",
  "description": "Kern Sandbox is a rootless, daemonless container runtime that runs LLM-generated code and agent tool calls in kernel-enforced isolation, callable from a CLI or Python/Node SDKs with MCP support. Open source: yes (Apache-2.0); self-hostable; pricing free. Single static binary; 427 stars; active.",
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  "one_liner": "Kern Sandbox runs LLM-generated code and agent tool calls rootless and daemonless, in kernel-enforced isolation, from a CLI or Python/Node SDKs.",
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  "who_its_for": "An engineer running untrusted, LLM-generated code or agent tool calls who wants a fast, rootless, daemonless sandbox — no Docker daemon to run or privilege to grant — driven from a CLI or embedded via Python/Node SDKs, with MCP support to hand it to an agent directly.",
  "who_its_not_for": "Teams that need a managed, hosted execution service with an SLA rather than a self-run binary, or workloads that require full VM-level isolation beyond kernel-enforced containment.",
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    "note": "Apache-2.0 per repo; 427 stars; ships as a single static binary plus Python and Node SDKs, no daemon; rootless, kernel-enforced isolation; MCP support. Vendor-reported performance: ~1/20th the per-tool-call cost of `docker run`, 21x faster via a prewarm pool, and 7x faster than Docker on library imports (getkern.dev guide + repo, verified 2026-09-28)."
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  "caveats": "Verified from the primary repo and getkern.dev docs (2026-09-28); no independent testing here. The cost/speed figures (~1/20th `docker run` cost per call, 21x prewarm speedup, 7x faster imports) are the vendor's own benchmarks (vendor-claim), not independently reproduced — measure against your own workload. Kernel-enforced isolation is a container boundary, not a VM; threat-model accordingly for fully hostile code.",
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      "text": "Kern Sandbox is a rootless, daemonless container runtime that runs LLM-generated code and agent tool calls in kernel-enforced isolation, callable from a CLI or Python/Node SDKs with MCP support. Open source: yes (Apache-2.0); self-hostable; pricing free. It ships as a single static binary and has 427 stars."
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      "text": "Kern Sandbox is a rootless, daemonless container runtime that runs LLM-generated code and agent tool calls in kernel-enforced isolation, callable from a CLI or Python/Node SDKs with MCP support. Open source: yes (Apache-2.0); self-hostable; pricing free. It ships as a single static binary and has 427 stars.\n\nKern Sandbox gives an agent somewhere safe and fast to run code. It executes LLM-generated code and tool calls inside a container isolated by the kernel, but without a root requirement and without a background daemon — the whole thing is a single static binary you drop in and call. You reach it from a CLI, embed it through the Python or Node SDK, or expose it to an agent over MCP. The design target is throughput at agent scale: a prewarm pool keeps ready sandboxes on hand so a tool call does not pay full container-startup cost each time. Open source: yes (Apache-2.0); self-hostable; pricing free."
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      "text": "it through the Python or Node SDK, or expose it to an agent over MCP. The design target is throughput at agent scale: a prewarm pool keeps ready sandboxes on hand so a tool call does not pay full container-startup cost each time. Open source: yes (Apache-2.0); self-hostable; pricing free.\n\n- Apache-2.0 per repo; 427 stars; single static binary, no daemon; Python + Node SDKs; CLI; MCP support; rootless, kernel-enforced isolation (github.com/getkern/kern + getkern.dev/guide/sandbox.html, verified 2026-09-28).\n- Vendor-reported benchmarks: ~1/20th the cost of `docker run` per tool call, 21x faster via the prewarm pool, and 7x faster than Docker on library imports — stated here as the vendor's own numbers (vendor-claim), not independently reproduced.\n- Curated from the GTM Stacker signal registry (2026-09-28 pass); license/facts independently verified 2026-09-28."
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      "text": "benchmarks: ~1/20th the cost of `docker run` per tool call, 21x faster via the prewarm pool, and 7x faster than Docker on library imports — stated here as the vendor's own numbers (vendor-claim), not independently reproduced. - Curated from the GTM Stacker signal registry (2026-09-28 pass); license/facts independently verified 2026-09-28.\n\nThe moment a GTM agent starts running code — parsing a scraped page, transforming an enrichment payload, executing a generated SQL or Python snippet — you need that code contained, and you need it cheap enough to do thousands of times a day. Kern Sandbox targets exactly that: rootless, daemonless isolation you can self-host, addressable over MCP so an agent can call it as a tool, with a prewarm pool aimed at keeping per-call cost low. Open source: yes (Apache-2.0); self-hostable; pricing free. The honest read: the isolation is a container boundary rather than a VM, and the eye-catching cost and speed multiples are the vendor's own benchmarks — pilot it against your real tool-call mix and confirm both the containment guarantees and the numbers before it fronts untrusted execution at scale."
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