Schema

The schema is defined in code and generated to JSON Schema; those files are the authoritative field-level spec.

Three identifiers, because they name three different things. The cross-venue link is the question_id, never the event — every event is single-venue.

• market_id (CM-MKT-…) — one contract on one venue. The atomic unit.
• event_id (CM-EVT-…) — a venue's bundle of one or more markets under a canonical question. Single-venue; one event can hold many distinct questions (a price ladder, a basket).
• question_id — the venue-independent identity of the bet. Markets sharing a question_id are the same question across Kalshi and Polymarket, and across events within a venue.
• also_on — on each market, an array of { venue, market_id, price } for the same question priced on other venues, or null when it trades on only one. The only field that asserts a cross-venue twin.

The ids are deterministic and stable — they are the citation unit. Persist them and a claim stays traceable to its source. Full reasoning on the three grains is in methodology §5.

Every market carries a Resolution Clarity Grade (per market, not per event) and a source status. The full 7-factor model is on /methodology.

Resolution Clarity Grade

• A — objective trigger and a named, committed resolution source.
• B — minor ambiguity, or a source gestured at but not committed to.
• C — discretionary trigger, contested reality, or no committed source.

source_status

• platform_named — the venue names a concrete, resolvable authority.
• no_committed_source — a source is gestured at but not committed to (a placeholder or illustrative example).
• no_source_stated — no resolution-source language at all.

Controlled values on the records, each published as a versioned, citable DefinedTermSet with its own canonical URL:

• settlement_style — touch · terminal · relative · occurrence
• direction — above · below · reach · between · occurrence
• arbitration_model — uma_oracle · kalshi_staff · polymarket_staff · platform_auto · determinations_committee · other
• resolution_proposer — permissionless · managed_whitelist · platform_staff · gov_agency
• source_type — gov_stat_agency · central_bank · regulated_data_vendor · media_consensus · court_filing · issuer_announcement · scheduled_event · subjective · other
• field_provenance — platform_api · clearmarket_editorial · derived · imputed · null_by_venue_limitation
• category — economics · financials · crypto · companies · technology · health · politics · geopolitics · climate

Every public record ships in parallel formats: an HTML page (with embedded JSON-LD Dataset markup), a machine-readable .json twin, and a row in /llms.txt.

• REST — https://api.clearmarket.fyi (open, no key, 1,000 req/day per IP; free key lifts to 10,000).
• MCP — https://api.clearmarket.fyi/mcp (streamable HTTP, read-only). See API · MCP.
• Machine schema — /schema.json · per-table JSON Schema files above.
• Repository — github.com/JDSource/clearmarket.

Schema definitions and identifiers are licensed CC-BY-4.0; the populated dataset is open and free with attribution required (cite ClearMarket, clearmarket.fyi). Every API and MCP record carries a _provenance field.