contract
Identity and time
A record is not identified by timestamp alone; source, series, generation, correction lineage, and durability travel with it.
- Question
- How can retries, corrections, and aggregation remain deterministic?
- Binding decision
- Nautilus types carry market identity and event/init time; Anthera adds only source, durability, coverage, and entitlement metadata.
- Owner input
- Final provider record keys and correction guarantees require DBN fixture evidence.
- source
- provider · dataset · schema · instrument
- series
- aggregation · step · price source · generation
- time
- event · receive · commit watermark
- order
- record identity · sequence · correction lineage
- scope
- tenant · entitlement · query budget
- proof
- coverage · completeness · exhaustion · provenance
External SDK and infrastructure types terminate outside this boundary.
Canonical value plus service envelope
The payload is a Nautilus QuoteTick, TradeTick, Bar, order-book value, instrument, or adapter-specific supported type. Anthera's envelope adds provider dataset and DBN schema, raw-source identity, entitlement scope, generation, correction lineage, coverage, commit watermark, and provenance without redefining the payload.
- Event identity deduplicates provider retries without erasing valid corrections.
- Series identity includes aggregation, step, price source, schema version, and generation.
- QuestDB, Redis, and browser keys derive from stable Nautilus identity plus explicit service metadata.
EvidenceOfficial DBN mapping and timestamp docs plus the Nautilus model/data audit.
Watermarks state what is safe
A provisional live sequence tells the viewer what it has seen. A committed watermark tells readers what QuestDB has acknowledged. Coverage intervals describe which historical ranges are complete, while generation prevents a stale response from contaminating a newer symbol or timeframe.
- A cursor binds to a stable watermark and semantic series identity.
- Completeness and exhaustion are explicit response fields.
- Late events and corrections advance lineage rather than silently rewriting client state.
EvidencePrompt: durability and query contracts.
mise x -- task schema:testAcceptance target: Round trips, malformed inputs, and generation races are covered.