Trading Engine contract v5

This directory is the authoritative v5 process and file contract shared by Trading Engine and its clients. Versions 4 and 3 remain readable during their client transitions.

• scenario.schema.json validates batch replay inputs.
• scenario-stream.schema.json validates each JSON Lines scenario-stream record.
• journal.schema.json validates each JSON Lines audit record.
• The files under fixtures/ form the canonical valid conformance corpus.
• fill-clipped.scenario.json and its journal exercise a leverage-limited partial fill.

Version 5 adds explicit immutable venue-calendar snapshots. Each calendar has stable venue and calendar identities, a calendar contract version, explicit instrument membership, and ordered date policies. A date is either a holiday or an open session named as regular or early-close. Open sessions contain absolute timestamp intervals for configured premarket, opening-auction, regular, closing-auction, and postmarket phases.

Calendar producers resolve local civil time, time-zone database versions, daylight-saving rules, and clock changes before creating a scenario. The reducer receives only absolute instants. Missing date policies are errors and must never be inferred from weekdays or adjacent sessions. Runtime validation also rejects duplicate calendar identities, overlapping instrument membership, missing instrument coverage, unordered or overlapping phases, holidays with phases, and open sessions without a regular phase.

Every v5 scenario, stream record, and journal record carries "contract_version": "5".

The v5 execution object also namespaces strict configuration beneath the stable model name. completed_bar_v1 configuration version "1" requires participation basis points, fixed fee, and fee basis points. Runtime capabilities describe its required fields, supported market and limit orders, completed-OHLCV data requirement, and numeric limits.