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Sandbase Harness
Local-first, self-hosted AI agent runtime and MCP bridge with sandboxed sessions, memory, credentials, audit/replay, and a local Console.
Install
git clone https://github.com/sandbaseai/sandbase-harnessInstall command taken from the project's README or registry entry. Always review code before running it.
README excerpt
Read full README on GitHub →SandBase Harness
AI-readable project metadata: llms.txt · installation guide
A local-first runtime for AI agents. Sessions, sandboxed tools, memory, credentials, audit trails, and a built-in Console — all running on your machine or in your own infrastructure.
Why
Agent SDKs handle the model loop. Production agents need more: persistent
sessions, tool governance, sandbox boundaries, credential handling, memory,
auditability, and a UI for humans to inspect what happened. managed-agents
is that runtime layer — not a visual workflow builder and not another model SDK.
| Need | What Harness provides |
|---|---|
| Run generated code safely | Local, Docker, Kubernetes, and self-hosted worker sandboxes |
| Inspect long-running agents | Persistent sessions, resumable event streams, audit, and replay |
| Control tool access | MCP toolsets, credential vaults, permission policies, and approvals |
| Operate any model | OpenAI, Anthropic, MiniMax, and OpenAI-compatible providers, including DeepSeek V4 |
| Keep infrastructure yours | Local-first SQLite and file storage with no required hosted control plane |
Features
- Claude Managed Agents-style
/v1API and local Console - SQLite metadata by default for agents, sessions, environments, credential vaults, memory stores, files, skills, and API keys — local file/skill bytes in the workspace state directory
- Resumable Server-Sent Events for session replay and debugging
- One active model provider boundary configured through Settings V2
- Sandbox backends: local process, Docker (per-session containers), Kubernetes (kubectl exec/cp), self-hosted worker queue
- MCP toolsets, permission policies, built-in tools, and skill packages
- TypeScript SDK at
managed-agents/sdk - Release gate:
npm run release:check
Quick Start
Requirements: Node.js 22+, npm 10+, and a model provider API key (OpenAI, Anthropic, MiniMax, or any OpenAI-compatible endpoint). Docker is optional and only needed for Docker-backed sandboxes.
git clone --branch v0.3.8 --depth 1 https://github.com/sandbaseai/sandbase-harness.git
cd sandbase-harness
npm ci
npm run build
mkdir ../my-agents && cd ../my-agents
node ../sandbase-harness/dist/index.js init
node ../sandbase-harness/dist/index.js start
init writes a workspace into the directory you run it from: an agent, a skills
folder, and config.yaml, whose provider reference is the ${OPENAI_API_KEY}
environment variable. start serves the API and the Console on
http://127.0.0.1:3000.
Two steps finish the setup, both on Settings > Setup at http://127.0.0.1:3000/dashboard:
- The provider. Paste your API key into the provider form and save. The page
then reports that the saved configuration is not active yet, so restart the
runtime — stop it with Ctrl+C and run the
startcommand again, or use the restart button. A saved setting only takes effect at startup. If your provider is not in the list, choose the OpenAI-compatible vendor and set its base URL. - The model. In the Agent models panel, set the model ID your provider
actually serves —
deepseek-chatfor DeepSeek, for example. An agent carries its own model ID, so thegpt-4othatinitwrites is not valid for every provider, and a wrong ID fails the turn withmodel_not_found.
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