Install
NovaFabric needs Python 3.12+. Install it with pip, add it to a uv project, or install the CLI as an isolated tool so nothing leaks into a project's environment.
Then check the CLI is on your path:
nova and novafabric are the same command. The base install covers everything on this page; optional extras exist for the dashboard, server mode and other integrations, and nova doctor --check-extras lists which you have.
Capture your first run
Wrap any command with nova capture. Wrapping needs no code changes: for Python workloads, model calls are captured automatically; other clients can send their model traffic through nova api-proxy.
The command runs as usual and keeps its own exit code. NovaFabric prints a run id and writes a Run Capsule to ~/.novafabric/capsules/<run-id>/: the manifest, execution spans, the model and tool calls capture could see, an environment snapshot and a secret-scan record. Prompts and responses are stored in the capsule, on your machine.
Validate, replay, compare
validate, replay and diff take the run id that capture printed.
Forensic replay is read-only: it inspects the capsule and runs nothing. Mocked replay re-runs the command and serves the recorded replies of supported model calls from the capsule (OpenAI Chat Completions and Responses API calls and Anthropic messages, sync or async, streamed or not, plus recorded MCP tool results, since v0.105.0), but other tool calls still run live. Use nova replay --dry-run <run-id> to see what would execute first. The five replay modes are described in the docs; intervention is experimental. Every flag of nova replay and nova diff is in the replay and diff command reference.
Optional set-up
nova init creates ~/.novafabric/ up front and generates a local Ed25519 key pair. It is optional: capture creates what it needs on first use. nova doctor checks the installation.
A default capture is not sealed. To seal capsules with your own key and verify them offline later, configure novaseal.yaml, or run nova seal init (experimental, since v0.105.0); see verify a sealed run for an auditor.
Other ways to run it
- No internet access: air-gapped installation. The core workflow (capture, validate, replay, diff, lineage) needs no network.
- Container image for server mode:
docker pull ghcr.io/mskazemi/novafabric:0.108.0, with server deployment covering Compose, Helm and signature verification. - Non-Python clients: how capture works, including
nova api-proxy.
Next
The getting-started guide walks the whole loop in 10–15 minutes: capture, validate, a real LLM call, replay, diff, lineage and a signed Evidence Bundle. Prefer to look first? The demo runs in your browser, no install needed.
NovaFabric is pre-1.0 (v0.108.0): the Run Capsule format is documented but not frozen, and several surfaces are labelled experimental. Something above does not work as written? That is a bug; please report it.