> For the complete documentation index, see [llms.txt](https://gitbook-docs.coinmetrics.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gitbook-docs.coinmetrics.io/cm-api-spec/timeseries/timeseries-stream/market-contract-prices.md).
# Market contract prices
Returns a WebSocket stream of contract prices for specified markets.\
This includes index price and mark price that are used by the exchange for settlement and risk management purposes.\
If you are falling behind (slow client) you will get `warning` message first, then `error` message and disconnection will happen.
```json
{"openapi":"3.0.2","info":{"title":"Coin Metrics API v4","version":"4.0.0"},"tags":[{"name":"Timeseries stream","description":"WebSocket endpoints for getting a real-time stream of metrics, market data, indexes and other time series data.\n\n**Endpoints on this page:**\n- `GET /timeseries-stream/asset-metrics` — Asset metrics\n- `GET /timeseries-stream/asset-quotes` — Asset quotes\n- `GET /timeseries-stream/index-levels` — Index levels\n- `GET /timeseries-stream/market-candles` — Market candles\n- `GET /timeseries-stream/market-contract-prices` — Market contract prices\n- `GET /timeseries-stream/market-liquidations` — Market liquidations\n- `GET /timeseries-stream/market-openinterest` — Market open interest\n- `GET /timeseries-stream/market-orderbooks` — Market orderbooks\n- `GET /timeseries-stream/market-quotes` — Market quotes\n- `GET /timeseries-stream/market-trades` — Market trades\n- `GET /timeseries-stream/pair-quotes` — Pair quotes"}],"servers":[{"url":"wss://api.coinmetrics.io/v4"}],"security":[{"api_key":[]}],"components":{"securitySchemes":{"api_key":{"description":"Coin Metrics API key can be specified as `?api_key=` query parameter.","in":"query","name":"api_key","type":"apiKey"}},"parameters":{"MarketId":{"description":"Comma separated list of markets or market patterns like `exchange-*` or `exchange-*-spot` or `*USDT-future`.
Use a corresponding `/catalog-all-v2/market-{dataType}` endpoint for the full list of supported markets for a given data type.","in":"query","name":"markets","required":true,"schema":{"type":"array","items":{"type":"string"}},"explode":false},"Backfill":{"description":"What data should be sent upon a connection.
By default the latest values are sent just before real-time data.","in":"query","name":"backfill","schema":{"type":"string","default":"latest","enum":["latest","none"]}},"Pretty":{"description":"Human-readable formatting of JSON responses.","in":"query","name":"pretty","schema":{"type":"boolean","default":false}}},"responses":{"Unauthorized":{"description":"Requested resource requires authorization.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"}}}},"Forbidden":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"}}},"description":"Requested resource is not available with supplied credentials."},"UriTooLong":{"description":"Provided URI is too long. It must not be greater than 10000 symbols."},"StreamingMarketContractPrices":{"description":"Contract prices WebSocket message.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/StreamingMarketContractPrice"}}}}},"schemas":{"ErrorResponse":{"properties":{"error":{"$ref":"#/components/schemas/ErrorObject"}},"required":["error"],"type":"object"},"ErrorObject":{"properties":{"type":{"description":"Error type string. Can be used for error identification.","type":"string"},"message":{"description":"Human-friendly error description. Can be amended without prior notification. Do not use for error identification in your code.","type":"string"}},"required":["type","description"],"type":"object"},"StreamingMarketContractPrice":{"description":"Market contract price WebSocket message.","properties":{"market":{"$ref":"#/components/schemas/MarketId"},"time":{"$ref":"#/components/schemas/Time"},"mark_price":{"$ref":"#/components/schemas/MarkPrice"},"index_price":{"$ref":"#/components/schemas/IndexPrice"},"settlement_price_estimated":{"$ref":"#/components/schemas/SettlementPriceEstimated"},"exchange_time":{"$ref":"#/components/schemas/OptionTickerExchangeTime"},"cm_sequence_id":{"$ref":"#/components/schemas/cmSequenceId"}},"required":["market","time","cm_sequence_id"],"type":"object"},"MarketId":{"description":"Unique name of the market.","type":"string"},"Time":{"description":"The time in ISO 8601 date-time format. Always with nanoseconds precision.","type":"string","format":"date-time"},"MarkPrice":{"description":"The price representing the futures' or option's price calculated by the exchange for risk management purposes.","type":"string","format":"decimal"},"IndexPrice":{"description":"The price index is an aggregate price derived from the major exchanges to be representative of the underlying asset's market consensus price.","type":"string","format":"decimal"},"SettlementPriceEstimated":{"description":"The estimated price of the underlying asset.","type":"string","format":"decimal"},"OptionTickerExchangeTime":{"description":"Time corresponding to option ticker data point, according to the exchange. Can be NULL, if exchange doesn't support it.","type":"string","format":"date-time"},"cmSequenceId":{"description":"The monotonically increasing message number, resets on disconnection.","type":"string"}}},"paths":{"/timeseries-stream/market-contract-prices":{"get":{"summary":"Market contract prices","description":"Returns a WebSocket stream of contract prices for specified markets.
This includes index price and mark price that are used by the exchange for settlement and risk management purposes.
If you are falling behind (slow client) you will get `warning` message first, then `error` message and disconnection will happen.","operationId":"getTimeseriesStreamMarketContractPrices","tags":["Timeseries stream"],"parameters":[{"$ref":"#/components/parameters/MarketId"},{"$ref":"#/components/parameters/Backfill"},{"$ref":"#/components/parameters/Pretty"}],"responses":{"401":{"$ref":"#/components/responses/Unauthorized"},"403":{"$ref":"#/components/responses/Forbidden"},"414":{"$ref":"#/components/responses/UriTooLong"},"default":{"$ref":"#/components/responses/StreamingMarketContractPrices"}}}}}}
```
---
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