Flue to Fabric Harness

Fabric Harness keeps the simple agent/session/skill/task model familiar from Flue, then adds enterprise controls: durable Temporal workflows, policy, approvals, audit, cost controls, multi-tenancy, and deployment hardening.

Concept mapping

Minimal Fabric Harness agent

import { agent, schema } from '@fabric-harness/sdk';

export default agent({
  name: 'hello',
  input: schema.object({ name: schema.string().default('World') }),
  output: schema.string(),
  triggers: { webhook: true },
  async run({ init, input }) {
    const fabric = await init();
    const session = await fabric.session();
    return session.prompt(`Say hello to ${input.name}.`);
  },
});

CLI migration

# Flue
flue dev --target node
flue run hello --target node --id test-1 --payload '{"name":"Alice"}'
flue build --target cloudflare
flue add daytona | claude

# Fabric Harness
fh dev --target node
fh run hello --target node --id test-1 --payload '{"name":"Alice"}'
fh build --target cloudflare
fh add daytona | claude

Fabric Harness also adds fh doctor, fh describe, fh export-audit, SBOM/provenance build flags, fh temporal-worker, authenticated admin/OpenAPI routes, Workers AI Gateway request metadata, and Cloudflare Shell Workspace mode.

Migration order

1. Move .flue/agents to .fabricharness/agents and convert exports to agent({ ... }).
2. Keep init(), session.prompt(), session.skill(), and session.task() calls as-is where possible.
3. Replace flue commands with fh equivalents.
4. Start on sandbox: 'virtual' or sandbox: 'local'.
5. Add policies, approvals, audit, and Temporal after the basic agent works.