FabricFabricHarness
Getting Started

Fabric Harness in 5 minutes

Create, validate, and run a minimal Fabric Harness agent with no Docker or cloud setup.

Fabric Harness supports a Flue-style start: write a TypeScript agent, call init(), open a session, and prompt it. The default path uses the lightweight virtual sandbox, so you do not need Docker, Temporal, Cloudflare, or a remote sandbox to start.

Create an agent

npx @fabric-harness/cli init my-agent --template minimal
cd my-agent
npm install

Validate readiness

npx fabric-harness doctor --getting-started --tools

This checks Node, ESM package setup, Fabric dependencies, agent discovery, session storage, model resolution, and built-in tool schemas.

Run it

npx fabric-harness agents
npx fabric-harness run hello name=Preetham

Or start the HTTP/SSE dev server:

npx fabric-harness dev
curl http://localhost:4317/agents/hello/demo \
  -H 'content-type: application/json' \
  -d '{"name":"Preetham"}'

Choose the next runtime

NeedUse
Fast no-container agentsandbox: 'virtual'
CI/repo automation with host toolssandbox: 'local' plus scoped defineCommand() commands
Untrusted code or data analysisDocker sandbox
Human approval delays or restart durabilityTemporal runtime
Edge/serverless endpointCloudflare target

Start with the minimal template, then add only the enterprise controls your use case needs: policy, approvals, audit, cost budgets, durable workflows, and deployment attestations.