{"data":{"slug":"substrate","name":"Agent Substrate","tagline":"High-density secure sandbox runtime for idle-heavy agent workloads","category":"agents","categoryName":"AI Agents","url":"https://github.com/agent-substrate/substrate","github":"https://github.com/agent-substrate/substrate","pricing":"open-source","hook":"Agent Substrate runs many agent sandboxes densely by multiplexing idle actors onto fewer workers with fast suspend/resume and kernel/network isolation.","whatsGood":"Apache-2.0 (agent-substrate/substrate). Purpose-built execution runtime for agent-like workloads: microVM and gVisor sandboxes, sub-500ms resume claims, zero-trust isolation, and Kubernetes-based worker lifecycle with agent-aware scheduling. It is infrastructure for running agents at scale, not another agent SDK.","theCatch":"Vs AgentBox and Flue: Substrate is the dense sandbox/runtime control plane on Kubernetes, not a developer ADE and not a TypeScript harness framework. Ops cost is real — you need cluster competence. README notes it is not an officially supported Google product.","verdict":"Apache-2.0 agent sandbox runtime. Reach for dense suspend/resume isolation on K8s; bring cluster ops.","addedAt":"2026-09-20","featured":false,"domain":"AI Agents","subSpecialty":"Orchestration","subcategory":"Orchestration","tags":["self-host","permissive","sandbox","active","young-repo"],"capabilities":["sandbox","kubernetes","runtime"],"surfaces":["Self-host"],"ecosystem":["Go","Multi-platform"],"licenseModel":"Apache-2.0","githubStars":5530,"starsPerWeek":243,"access":"free","archived":false,"repo":{"createdAt":"2026-05-13","pushedAt":"2026-10-19","license":"Apache-2.0","archived":false,"checkedAt":"2026-10-19"}},"related":[{"slug":"claude-code","name":"Claude Code","tagline":"Terminal-first coding agent with deep repository context"},{"slug":"cursor","name":"Cursor","tagline":"The AI-first code editor that understands your codebase"},{"slug":"devin","name":"Devin","tagline":"Autonomous AI engineer for defined engineering tasks"},{"slug":"stagehand","name":"Stagehand","tagline":"AI-native browser automation that mixes code and natural language"},{"slug":"browser-use","name":"Browser Use","tagline":"Open-source framework for LLM-driven browser agents"}],"links":{"self":"/api/gems/substrate","html":"/gems/substrate","markdown":"/gems/substrate.md","category":"/api/gems?category=agents","categoryPage":"/stacks/agents"}}