Installation

Fabric Harness lives in a pnpm monorepo. There is no published npm package yet — you install the framework by cloning the repo, building the workspace, and running the CLI from packages/cli/dist/.

Prerequisites

• Node.js 22+
• pnpm 10+ (the repo pins pnpm@10.10.0)
• Git
• (optional) Docker for the Docker sandbox
• (optional) Temporal (local dev server) for the Temporal worker target
• An LLM provider API key (e.g. OPENAI_API_KEY) when you want real model calls. The repo ships a mock/test-model provider for local development.

Clone and build

git clone <fabric-harness-repo-url>
cd fabric-harness
pnpm install
pnpm build

pnpm build compiles every workspace package, including the CLI at packages/cli/dist/bin/fabric-harness.js.

Run the CLI

The CLI is invoked through node against the built JavaScript:

node packages/cli/dist/bin/fabric-harness.js --help

For convenience the root package.json exposes both binaries as scripts:

pnpm fabric-harness --help
pnpm fh --help

If you want a global shim, the CLI package installs a fh and fabric-harness bin once it's published. Until then, an alias works fine:

alias fh="node $(pwd)/packages/cli/dist/bin/fabric-harness.js"

Verify your environment

Run the doctor command from any workspace (e.g. examples/hello-world):

cd examples/hello-world
fh doctor --tools

To verify a real model end-to-end:

cp .env.example .env.local
# edit .env.local and set OPENAI_API_KEY=...
fh doctor --live --model openai/gpt-5.5

Run the hello-world example

cd examples/hello-world
fh agents
fh describe ask
fh run ask --question "What is Temporal?"

If the configured model responds, you're ready for your first agent. For a credential-free smoke test, add --model mock/test-model.