> ## Documentation Index > Fetch the complete documentation index at: https://docs.kairos.trade/llms.txt > Use this file to discover all available pages before exploring further. # The cross-venue link holding each venue market > Batched reverse lookup from venue markets to the catalog row that holds them. A market is matched by its executor market id, its stream key (the numeric Gamma id for Polymarket), or — for a Kalshi two-ticker game — the ticker that books the link's NO side. References without a published link are omitted from the response rather than returned empty. Cached with `Cache-Control: public, max-age=15, s-maxage=30`. ## OpenAPI ````yaml /openapi/data-api.yaml get /market-links/lookup openapi: 3.1.0 info: title: Kairos Data API version: 1.0.0 summary: >- The full Kairos data plane — markets, candles, trades, search, discover, sports, trader analytics, and PnL. description: | The Kairos Data API at `data.kairos.trade` is the platform's primary data plane: market metadata and prices, OHLCV candles, live venue trade proxies, normalized trade history, full-text search, discovery feeds, the sports catalog, public trader analytics, and account PnL. ## Authentication Most endpoints accept a Kairos **API key** (`X-Client-Id` + `X-Api-Key` + `X-Api-Secret`, all three) or a first-party session JWT. Endpoints tagged `public` (trader analytics, provider configs, several sports feeds) need no credentials at all. Some endpoints additionally require an API-key **scope** (`trade:read`, `position:read`) — stated per operation. For high-volume market-data consumption (candles/trades/metadata at scale), prefer the dedicated **Market Data API** at `md.kairos.trade` — it has higher budgets, ETag caching, and a binary candle format. ## Rate limits Rate limits use a sliding window keyed on the authenticated user (JWT `sub`) or, for anonymous callers, the trusted client IP. Routes belong to a named **bucket** (`x-kairos-bucket`) whose per-minute budget is shared by every route in it; routes with no bucket run under the service default of 100/minute. `x-kairos-rate-limit` states the bucket's compile-time default — operators can raise or lower a bucket at runtime, so treat the documented number as the baseline, not a contract. 429 responses carry `Retry-After` and `X-RateLimit-*`. ## Conventions - Prices are on the **0–100 cents scale** unless a field says otherwise (trader-analytics position/trade prices use the 0–1 scale; each field's description states its scale). - Errors: `{"detail": ""}` for handler errors; FastAPI's standard validation envelope for 422s. Errors surfaced from a venue adapter instead use `{"error", "provider", "operation", "message"}` — see `DataProviderError`. Unhandled failures always return the generic 500 body; internal details are logged, never returned. - Every request body is capped at 8 MiB service-wide (413). contact: name: Kairos url: https://app.kairos.trade/docs/api-reference termsOfService: https://kairos.trade/terms servers: - url: https://data.kairos.trade description: Production - url: https://staging-data.kairos.trade description: Staging security: - apiKeyClientId: [] apiKeyKey: [] apiKeySecret: [] paths: /market-links/lookup: get: tags: - Markets summary: The cross-venue link holding each venue market description: > Batched reverse lookup from venue markets to the catalog row that holds them. A market is matched by its executor market id, its stream key (the numeric Gamma id for Polymarket), or — for a Kalshi two-ticker game — the ticker that books the link's NO side. References without a published link are omitted from the response rather than returned empty. Cached with `Cache-Control: public, max-age=15, s-maxage=30`. operationId: lookupMarketLinks parameters: - name: markets in: query required: true description: >- Comma-separated `:` references, max 100 distinct. Only the first colon separates the two parts, so market ids may contain colons; the provider is case-insensitive. schema: type: string minLength: 1 maxLength: 8192 example: >- polymarket:0x8a9f8be5bef9bc8d36c7895707a4f2561d49de9f5467b6675ba206196e8bd2e2,kalshi:KXNFLGAME-26OCT01PITCLE-CLE responses: '200': description: >- The link for each referenced market that has one, keyed by the reference as given (provider lower-cased). headers: Cache-Control: schema: type: string example: public, max-age=15, s-maxage=30 content: application/json: schema: $ref: '#/components/schemas/MarketLinksLookupResponse' '400': description: >- No parseable `:` reference, or more than 100 of them. content: application/json: schema: $ref: '#/components/schemas/DataError' '422': $ref: '#/components/responses/DataValidationError' '429': $ref: '#/components/responses/DataRateLimited' '503': description: The catalog store could not be read. content: application/json: schema: $ref: '#/components/schemas/DataError' security: [] components: schemas: MarketLinksLookupResponse: type: object required: - links properties: links: type: object description: >- Keyed by `:` as requested; markets without a link are omitted. additionalProperties: $ref: '#/components/schemas/MarketLinkRow' DataError: type: object description: Handler error envelope (FastAPI HTTPException). required: - detail properties: detail: type: string description: Human-readable error message. example: Invalid provider MarketLinkRow: type: object description: One cross-venue link as the catalog publishes it. required: - id - title - image - league - sport - startTime - venues - syntheticIdYes - syntheticIdNo - executableVenues - rank - sideLabels - primary properties: id: type: string format: uuid description: The `MarketLink` id. title: type: string description: >- The event title from Discover's row for the primary venue, else the link's own title. image: type: string nullable: true league: type: string nullable: true description: >- League named by Discover's sports chip (e.g. `NFL`); null where the chip is the sport itself or the link is not sports. sport: type: string nullable: true description: Sport family (e.g. `Football`, `Soccer`). startTime: type: string format: date-time nullable: true description: >- Earliest leg expiration; venues close a game market at its scheduled start. slug: type: string description: The venue's game slug when Discover carries one; absent otherwise. venues: type: array minItems: 2 maxItems: 4 items: $ref: '#/components/schemas/MarketLinkVenue' syntheticIdYes: type: string description: >- Id of the union book for the link's YES side (`synthetic:` on the stream). syntheticIdNo: type: string executableVenues: type: array items: type: string description: Providers whose legs are `executable`, in leg order. rank: type: number description: >- The largest Discover hourly-volume score across legs; the featured ordering key, never a displayed volume. sideLabels: type: object required: - 'yes' - 'no' properties: 'yes': type: string 'no': type: string primary: type: object required: - provider - marketId properties: provider: type: string marketId: type: string description: >- The leg whose Discover row supplied the title, else the first executable leg. MarketLinkVenue: type: object description: One venue's listing of a linked contract, in that venue's own keys. required: - provider - marketId - streamKey - tokenIdYes - tokenIdNo - executable properties: provider: type: string enum: - polymarket - predictfun - kalshi - hyperliquid marketId: type: string description: >- Executor-convention market id (Polymarket condition id, Predict.fun numeric id, Kalshi ticker, Hyperliquid outcome id). streamKey: type: string description: >- Stream-side id (Polymarket's numeric Gamma id; the market id elsewhere). marketIdNo: type: string description: >- The venue market that books the link's NO side where it is not `marketId` (Kalshi lists a game as one ticker per team). Present only on such legs. streamKeyNo: type: string tokenIdYes: type: string nullable: true description: >- The token the union book reads for the link's YES side on this venue. tokenIdNo: type: string nullable: true executable: type: boolean description: >- Whether `GET /orders/route-fees` reports this venue routable for the link; false for a display-only leg. responses: DataValidationError: description: Request failed FastAPI parameter validation. content: application/json: schema: type: object required: - detail properties: detail: type: array description: >- One entry per failed field, with location, message, and error type. items: type: object additionalProperties: true DataRateLimited: description: > Rate limit exceeded for this route's sliding window, keyed on the session `sub` when authenticated and on the trusted client IP otherwise. Honor `Retry-After`. A per-API-key data ceiling (set per credential) rejects with `{"detail": "API key data rate limit exceeded"}` instead of the `error` envelope below. headers: Retry-After: schema: type: integer X-RateLimit-Limit: schema: type: integer X-RateLimit-Remaining: schema: type: integer X-RateLimit-Reset: schema: type: integer content: application/json: schema: type: object properties: error: type: string example: 'Rate limit exceeded: 100 per 1 minute' securitySchemes: apiKeyClientId: type: apiKey in: header name: X-Client-Id description: >- Credential client id (`kairos_ck_...`). Must be sent together with X-Api-Key and X-Api-Secret. apiKeyKey: type: apiKey in: header name: X-Api-Key description: 64-char hex API key. apiKeySecret: type: apiKey in: header name: X-Api-Secret description: 64-char hex API secret. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.