The open schema for African and emerging-market company and asset data.
One LinkML file is the source of truth. Pydantic models, SQL DDL, JSON Schema, a JSON-LD context and this site are all generated from it — nothing is hand-maintained, and CI fails on drift.
pip install certvas-ontology
Every Fundamentals row carries an effective date and an availability date, and they answer different questions:
| column | question it answers |
|---|---|
period_end | What period does this number describe? |
available_at | From when could someone have acted on it? |
A backtest must filter on both. Filtering on period_end alone
hands you months of information nobody had. available_at is
coalesce(announcement_date, observed_at) and is never null; the fallback is always
later than true publication, so it can only ever exclude a row from an as-of window, never
admit one early. Poor announcement-date coverage costs recall, never correctness.
announcement_date is sourced as a fact and left null where
unevidenced — never inferred. announcement_source records which
evidence tier it came from, so you can weight or
exclude the weaker ones yourself.
A metric computed from fundamentals rather than extracted from a filing.
A legal entity — the spine every other table joins to.
An external identifier for an entity — ticker, ISIN, FIGI, CIK or registry number.
A directed ownership link between two entities, sourced from GLEIF Level 2 data or derived.
One extracted financial-statement line item, as filed, for one entity and period — and for one OBSERVATION of that value.
One macroeconomic observation for a country and period.
A public procurement process, shaped by the Open Contracting Data Standard.
An award made under a tender, to a supplier that may or may not resolve to the spine.
A party participating in a tender, with the entity-resolution confidence that linked it to the spine.
Dated membership of a market universe, INCLUDING delisted and suspended issuers, which are retained permanently.
certvas-ontology.yaml — the LinkML sourcecertvas.schema.json · certvas.context.jsonld · certvas.sqlThis schema is CC0 — public domain. Model against it, map to it, implement it.
That is not a licence to Certvas data: the datasets it describes carry their own
per-source terms, recorded in license_class on every row.