Practical overview
When it fits
Use Sandbase Harness when you need a runtime layer for persistent AI agent sessions and want control over sandboxing, tool access, runtime state and operational records.
Who it is for
- Developers and teams operating AI agents on their own machines or infrastructure.
- Operators who need to inspect, resume, replay or debug persistent agent sessions.
- Teams that want to govern agent tool access through MCP toolsets, permissions and approvals.
Documented uses
- Run agent sessions within local, Docker, Kubernetes or self-hosted worker sandboxes.
- Connect agents to MCP-compatible tools and manage access with policies and approvals.
- Keep session memory and credentials alongside agent runtime operations.
- Inspect and replay agent activity through resumable event streams and the console.
Requirements & limits
The project is open source under the Apache-2.0 license. The documented local setup requires Node.js 22+, npm 10+ and a model-provider API key; Docker is optional and only required for Docker-backed sandboxes.
- The project runs on local or self-managed infrastructure and does not require a hosted control plane.
- Metadata uses SQLite by default; local file and skill data is stored in the workspace state directory.
- Provider configuration changes require a runtime restart, and model IDs must match the selected provider.
- The documented interfaces include a local console, a /v1 API and a TypeScript SDK.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Set up the runtime and configure a model
Build and start a local Sandbase Harness workspace, then configure a provider and model in the console.
Before you start
- Node.js 22 or later
- npm 10 or later
- An API key for OpenAI, Anthropic, MiniMax, or an OpenAI-compatible endpoint
- Docker only if using Docker-backed sandboxes
Steps
Clone the v0.3.8 repository release, enter the project directory, install dependencies with npm ci, and build with npm run build.
Create a workspace directory, run the built CLI's init command there, then start the runtime.
In Settings > Setup, enter and save the provider API key; restart the runtime for the saved setting to take effect.
In Agent models, set a model ID served by the selected provider.
Expected outcome
A workspace is initialized and the runtime serves its API and local console at 127.0.0.1:3000, with provider and model settings configured.
Guide limitations
- A provider setting saved in the console does not become active until the runtime restarts.
- The model ID must be one served by the selected provider; an unsupported ID causes a model_not_found error.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 13 October 2026
- Original website title
- sandbaseai/sandbase-harness · Official homepage title · retained in its source language

