# OpenDome

> OpenDome is an open-core data platform. A self-hoster runs a "cell" — a self-contained, per-tenant Kubernetes namespace — and consumes everything through OSL (the OpenDome Semantic Layer): a single open spec (Apache-2.0) that spans structured tables (Iceberg, via Trino) and unstructured collections (Lance, vector + full-text) under one fail-closed policy enforcement point and one audit chain. OSL is a superset of dbt MetricFlow (no lock-in: the structured plane stays valid in dbt-sl). These docs cover the open-source surface; Enterprise-only capabilities are marked inline.

## Get started

- [What is OpenDome?](https://docs.opendome.eu/en/getting-started/what-is-opendome/): The platform in one page — the cell, OSL as the sole consumption layer, the two planes, and what ships under Apache-2.0.
- [Quickstart (self-hosted)](https://docs.opendome.eu/en/getting-started/quickstart/): Bring up a cell on kind/Kubernetes with no control-plane, mint a local HS256 token, and make a governed `/osl/*` call.
- [OSS vs Enterprise](https://docs.opendome.eu/en/getting-started/editions/): Feature comparison and how the open core relates to the managed/Enterprise tier.

## Concepts

- [OSL — the consumption layer](https://docs.opendome.eu/en/concepts/overview/): Two physical planes (Iceberg + Lance), four families of primitives, "everything is an Entity", FQNs, and the compile → serve loop.
- [Access & capabilities](https://docs.opendome.eu/en/concepts/access-model/): The capability model that limits what a query can see — a subject's delegation chain composed by MEET, per-node grants (cleartext/mask/deny), named redaction versions (exact-or-deny), the ⟦redacted⟧ sentinel, and fail-closed enforcement.
- [Governance & the cell](https://docs.opendome.eu/en/concepts/governance/): How access limits plug into the cell — policy as facts, fail-closed enforcement, server-side redaction, and the single audit chain.

## OSL API reference

- [Overview](https://docs.opendome.eu/en/reference/osl-api/overview/): The four surfaces (REST, MCP tools, CLI, OpenLineage) and the single consumption endpoint /osl/query (the former /osl/retrieve, /osl/joint/resolve, /osl/traverse are removed — now forms of /osl/query).
- [Authentication](https://docs.opendome.eu/en/reference/osl-api/authentication/): The attested delegation chain (HS256, chain inside the signed payload — omission defense), scopes, roles, rate limits, audit.
- [Queries — OSL-SQL (POST /osl/query)](https://docs.opendome.eu/en/reference/osl-api/query/): The single consumption endpoint. OSL-SQL is a semantic SQL dialect (osql | sql | MetricFlow, mutually exclusive E0513) that lowers to a bounded operator IR — the lowering is the security boundary. Five forms: structured, RETRIEVE, TRAVERSE, Joint record, cross-modal join. R3 (relation×relation semantic join) is structurally inexpressible (E0514); cross-modal join key must be cleartext (fail-closed E0515). Projection operators: deterministic encoder + LLM-gated decoder.
- [Retrieval (RETRIEVE)](https://docs.opendome.eu/en/reference/osl-api/retrieve/): Governed hybrid retrieval as the RETRIEVE(...) table function inside OSL-SQL, served at the subject's required redaction version.
- [Entities (Joint record)](https://docs.opendome.eu/en/reference/osl-api/joint-resolve/): Entity-first resolution as a SELECT over osl.entities.<Joint> — structured columns + Lance evidence + derived attributes in one governed call.
- [Domain map & traversal](https://docs.opendome.eu/en/reference/osl-api/domain-map/): GET /osl/domain-map (unified graph), the TRAVERSE(...) form (L2 hop-by-hop), POST /osl/sample (governed preview).
- [Errors & status codes](https://docs.opendome.eu/en/reference/osl-api/errors/): The error envelope and the E-code bands (incl. E0513/E0514/E0515/E0521/E0522).

## CLI & clients

- [osl CLI](https://docs.opendome.eu/en/reference/cli/): validate, compile, plan, publish, migrate to/from MetricFlow; pyosl + osl-client reference libraries.

## Spec & governance

- [OSL specification](https://docs.opendome.eu/en/spec/specification/): The normative RFC 2119 contract — nine primitives, binding design principles, versioning guarantee.
- [Conformance levels](https://docs.opendome.eu/en/spec/conformance/): Core (mandatory), Lance, Lineage, Governance — declared independently per engine.
- [RFC process](https://docs.opendome.eu/en/spec/rfc-process/): Paper-style RFCs with pre-registered hypotheses and downstream-adopter sign-off.

## Contributing

- [Overview](https://docs.opendome.eu/en/contributing/overview/): Where things live, ground rules (additive/versioned, pin versions, OSS never references private domains), spec changes, security disclosure.