Concepts

Five primitives

Asset Registry names every model, agent, prompt, tool, dataset, evaluation, and deployment with name@versionidentity. Promotion from development to production is gated by eval suites that pass or fail.

Run Capsule is a self-contained, schema-validated record of one AI run: the command, every model call, every tool call, the environment, the assets referenced. Stored as a directory under ~/.novafabric/capsules/<ulid>/.

Replay reconstructs a run under one of five modes with explicit guarantees. You always know what was real and what was reconstructed.

Lineage is the causation graph that links runs to the assets they consumed and the artifacts they produced — answers "what depended on what" without guesswork.

Evidence Bundle is the signed, portable proof of what happened: in-toto DSSE Statement v1, ed25519 signature, vendored schemas, a tamper-evident manifest hash.

Five replay modes

• exact — re-execute end-to-end. Available only for local models or fully containerized environments. Greyed out for remote LLMs because we will not pretend a remote API call is deterministic.
• mocked — re-execute the agent code, serve every model and tool call from the capsule's cache. Same control flow, same outputs, no network.
• semantic — re-execute, then a judge model compares meaning. Requires a judge model in real use. Useful for "did the meaning change?"
• forensic — no re-execution. Read-only inspection of what the capsule recorded. The audit mode.
• intervention (experimental) — substitute one captured model/tool event and replay downstream under mocked semantics for counterfactual root-cause analysis.

Why self-hosted

AI runs accumulate sensitive data: prompts, intermediate reasoning, internal documents pulled by tools. Shipping that to a hosted service means signing a DPA, picking a region, paying per GB, waiting for a backup window when audit asks. NovaFabric runs in your own infrastructure instead — on your machine for a single user, or in your own self-hosted server (server mode, with OIDC and RBAC) for teams. Your run data never leaves your environment unless you choose to move it.

Why CLI-first

The CLI remains the canonical automation surface and emits machine-readable output. NovaFabric also ships nova serve for browser/dashboard workflows; v0.102.0 added scoped authorization and tenancy safety checks to that surface.