FAQ
What is a Kristal, in one sentence?
A Kristal is a verifiable, deterministic, offline-executable knowledge bundle you can publish, activate, and query reliably.
Is Kristal a database?
Not exactly. Kristal produces portable artifacts (Exchange + Runtime Pack(s)) that can be queried like a local database, but it’s primarily a build/verify/distribute framework.
Why do “determinism” and “content-addressed IDs” matter?
They make results reproducible and auditable: - the same inputs/policies yield the same identity - you can verify that what you received is exactly what was built
What’s the difference between Exchange and Runtime Pack?
- Exchange: canonical published bundle (what was compiled, under what policies, with what evidence)
- Runtime Pack: optimized local format for fast queries
What are “profiles”?
Profiles are named configurations for: - validation rules (shape, integrity, domain checks) - projections/exports - query behaviors (pagination, capabilities)
They let deployments standardize behavior without rewriting the core.
What is a Validation Report?
A Validation Report is evidence that declared checks ran and passed (or failed). Deployments can gate activation on required reports.
What does “fail-closed” mean here?
If an artifact declares hashes/signatures/evidence, and verification fails or is missing, the consumer should treat it as invalid (not “best effort”).
What are Shards and why use them?
A shard is a domain-scoped published unit that can be updated independently. Use shards when: - you have multiple publishers/domains - you want independent update cadence - you need explicit authority boundaries
What is a Federation Manifest?
It’s the “composition root” that declares: - which shards are included - deterministic merge rules - optional trust requirements and references
It gives clients a single entrypoint to a multi-shard world.
Do I need an Authority Registry?
Not always. If your deployment needs explicit trust policy (“which authorities are recognized for this scope”), an Authority Registry makes that policy pinned and auditable.
Can I rollback or downgrade safely?
Yes, if you treat activation as atomic and follow explicit compatibility rules: - rollback returns to the previously active version - downgrade is policy-gated and avoids mixing incompatible artifacts
Where are the technical details?
This wiki focuses on overview and usage. For exact formats/schemas/specs, use the referenced docs:
- Core/specs: kristal-docs-v3/01-core-spec/...
- Schemas: kristal-docs-v3/02-schemas/...
- Examples: kristal-docs-v3/10-examples/...