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OpenAPI Specification

openapi: 3.2.0
info:
  title: ClearMarket Marks API
  version: 0.2.1
  description: 'Reference data layer for prediction markets: cross-venue event linking, Resolution Clarity Grades (A/B/C), committed resolution sources with provenance, jurisdiction eligibility screens, live marks, and CM Signal wires across Kalshi and Polymarket. Open access, no key required (optional free key raises rate limits). Attribution required: clearmarket.fyi. Same data via MCP (https://api.clearmarket.fyi/mcp) and A2A (https://api.clearmarket.fyi/a2a).'
  contact:
    name: ClearMarket
    url: https://clearmarket.fyi/for-data/
servers:
- url: https://api.clearmarket.fyi
tags:
- name: Marks
paths:
  /v1/marks:
    get:
      operationId: listMarks
      summary: Bulk + incremental pull of every market's price, volume, status and freshness…
      description: 'Baseline: call without since= and page with next_cursor (1,000/page). Incremental: since= returns only markets whose price/volume or status changed after that instant. Each row carries price_as_of (last price change), last_checked_at (last seen in a live venue feed; null = not since the last reload) and reconciled_at (last venue status check). Timestamps UTC.'
      parameters:
      - name: since
        in: query
        description: ISO-8601 UTC instant; return rows changed after it
        schema:
          type: string
          format: date-time
      - name: cursor
        in: query
        description: Opaque next_cursor from the previous page
        schema:
          type: string
      - name: status
        in: query
        schema:
          type: string
          enum:
          - open
          - resolved
          - closed
      - name: platform
        in: query
        schema:
          type: string
          enum:
          - kalshi
          - polymarket
      - name: limit
        in: query
        schema:
          type: integer
          maximum: 1000
          default: 500
      responses:
        '200':
          description: as_of, schema_version, count, next_cursor, marks[]
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Bad since/cursor/status/platform
      tags:
      - Marks
externalDocs:
  description: Human docs, schema tour, and grading methodology
  url: https://clearmarket.fyi/for-data/