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Capital.com Public API

Capital.com WebSocket API

The Capital.com WebSocket API streams real-time market data, supporting up to 40 concurrent instruments and OHLC candlestick subscriptions for low-latency trading applications.

Documentation Provider Profile APIs.io AsyncAPI GitHub

Capital.com WebSocket API is one of 8 APIs that Capital.com Public API publishes on the APIs.io network, described by an AsyncAPI event-driven specification.

Tagged areas include Market Data, Streaming, Trading, and WebSocket. The published artifact set on APIs.io includes API documentation and an AsyncAPI specification.

This event API exposes 2 operations across 1 channel, and defines 18 schemas. It is described by AsyncAPI 2.6.0, at version 1.0.0.

The API connects through 2 servers: api-streaming-capital.backend-capital.com/connect (wss), demo-api-streaming-capital.backend-capital.com/connect (wss).

2 operations 1 channels 18 schemas

Metadata

The identity and technical contract details declared by the specification.

Specification
AsyncAPI 2.6.0
API Version
1.0.0
Servers
api-streaming-capital.backend-capital.com/connect (wss)
demo-api-streaming-capital.backend-capital.com/connect (wss)
Contact
Capital.com API Support
License
Capital.com Terms of Service
Resource Areas
1

Channels & Operations 2

Across 1 channel, the API surfaces 2 operations. Each is listed below with its action, channel, parameters, and response codes.

Channels 2
SUB
/
Frames received from Capital.com.
receiveServerFrame body
PUB
/
Frames sent from the client to Capital.com.
sendClientFrame body

Messages & Schemas 18

The contract defines 18 schemas that model the data carried by its messages. The most detailed are MarketDataUnsubscribeFrame (5 properties), OHLCMarketDataUnsubscribeFrame (5 properties), OHLCMarketDataSubscribeFrame (5 properties), MarketDataSubscribeFrame (5 properties). Each schema is shown below with its type and property counts.

MarketDataSubscribe
message
Subscribe to live bid/offer price updates for a set of instrument epics.
MarketDataUnsubscribe
message
Remove real-time price subscriptions for one or more epics.
OHLCMarketDataSubscribe
message
Subscribe to OHLC candle updates for a set of epics, resolutions, and bar type.
OHLCMarketDataUnsubscribe
message
Remove OHLC subscriptions for the given epics, with optional resolution and type filters.
Ping
message
Keep the WebSocket session alive (must be sent at least every 10 minutes).
SubscriptionStatus
message
Confirms processing status of a subscribe or unsubscribe request per epic.
MarketDataUpdate
message
Streaming bid/offer quote update for a subscribed instrument.
OHLCMarketDataUpdate
message
Streaming OHLC bar update for a subscribed instrument and resolution.
PingResponse
message
Server acknowledgement of a client ping.
MarketDataSubscribeFrame
object
5 properties 5 required
MarketDataUnsubscribeFrame
object
5 properties 5 required
OHLCMarketDataSubscribeFrame
object
5 properties 5 required
OHLCMarketDataUnsubscribeFrame
object
5 properties 5 required
PingFrame
object
4 properties 4 required
SubscriptionStatusFrame
object
Frame returned in response to marketData.subscribe, marketData.unsubscribe, OHLCMarketData.subscribe, or OHLCMarketData.unsubscribe.
4 properties
MarketDataUpdateFrame
object
Streaming market data quote frame.
3 properties
OHLCMarketDataUpdateFrame
object
Streaming OHLC candle update frame.
3 properties
PingResponseFrame
object
4 properties

Specification

The full machine-readable AsyncAPI contract behind this narrative.

Source

capital-com-public-api-asyncapi.yml Raw ↑

Other APIs Capital.com Public API publishes across the network.

Capital.com Public API Accounts API
AE Profile APIs.io
Capital.com Public API General API
AE Profile APIs.io
Capital.com Public API History API
AE Profile APIs.io
Capital.com Public API Markets API
AE Profile APIs.io
Capital.com Public API Positions API
AE Profile APIs.io
Capital.com Public API Session API
AE Profile APIs.io
Capital.com Public API Working Orders API
AE Profile APIs.io
#Market Data#Streaming#Trading#WebSocket
← Back to C APIs
API Details
ID
capital-com-public-api:capital-com-websocket-api
Server
api-streaming-capital.backend-capital.com/connect (wss)
Docs
https://open-api.capital.com
Provider
Capital.com Public API
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