canonical · 1.5 capability schema

WebSocket

Score 31.4 / 100 219 providers 236 APIs Search apis.io →
Variants seen in the corpus: WebSocketWebsocketwebsocket

Providers using this tag (219)

Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.

Exemplar 7 Complete, well-documented, and agent-ready
Twelve DataMarket DataFinancial DataStocksForex6 APIs76.7PolygonFinanceFintechMarket DataStocks12 APIs71.5KrakenCryptocurrencyExchangeTradingMarket Data24 APIs70.6Heroic LabsGame BackendMultiplayerReal-Time4 APIs70.4falArtificial IntelligenceGenerative AIGenerative MediaImage-Generation12 APIs69.7BullishDigital AssetsCryptocurrencyExchangeTrading32 APIs67.38x8TelecommunicationsUnited StatesCPaaSUCaaS36 APIs67.1
Strong 20 Solid coverage with minor gaps
SiftingIOFinancial market dataStocks/equitiesForexCryptocurrency13 APIs66.1Amazon API GatewayAPI GatewayCloudRESTHTTP13 APIs65.8SolanaBlockchainCryptocurrencyWeb3DeFi12 APIs65.8ThetaDataFinancialMarket DataOptionsStocks14 APIs65.2S&P GlobalCapital IQCommodity InsightsCredit RatingsDocument Extraction9 APIs64.6PostmanAI Agent BuilderAI AgentsAPI CatalogAPI Client39 APIs64.5TradierFintechTradingStocksOptions4 APIs61.4LukkaCryptoDigital AssetsMarket DataReference Data22 APIs61.2Oracle HospitalityTravelUnited StatesHospitalityHotels135 APIs60.5CovalentBlockchainWeb3Multi-ChainData Infrastructure18 APIs60.4BuiltWithTechnology ProfilingLead GenerationWeb IntelligenceTechnology Detection31 APIs59.8Blockchain.comCryptocurrencyBitcoinBlockchainExchange18 APIs59.7AmberdataCryptoBlockchainMarket DataDigital Assets10 APIs55.3LiveblocksReal-TimeCollaborationMultiplayerPresence12 APIs55.3Binance.USCompanyCryptocurrencyDigital AssetsExchange3 APIs55.1AnacondaCompanyData ScienceMachine-LearningArtificial Intelligence24 APIs54.9BenzingaFinancialMarket DataStocksNews44 APIs54.9QfexCompanyTradingExchangePerpetual Futures5 APIs54.8Amazon API GatewayGatewayHTTP APIREST APIServerless18 APIs54.5Deutsche BörseFinancialMarket DataStocksDerivatives13 APIs54.4
Developing 79 Usable, with meaningful gaps to close
CryptoCompareCryptocurrencyMarket DataReference RatesNews18 APIs53.8TensorNFTMarketplaceSolanaBlockchain9 APIs53.2ApstalAnalyticsWeb AnalyticsPrivacySession Replay2 APIs52.8GladiaSpeech-to-TextTranscriptionAudio IntelligenceReal-Time9 APIs52.1GradiumCompanyAi MlVoice AIText-to-Speech6 APIs50.8OpenSeaNFTMarketplaceWeb3Blockchain17 APIs50.6Refinitiv EikonAnalyticsFinancial DataFinancial NewsMarket Data47 APIs50.6SpeechmaticsSpeech RecognitionSpeech-to-TextTranscriptionReal-Time Transcription7 APIs50.4ZenRowsWeb ScrapingData ExtractionAnti-BotProxies6 APIs50.4AxwayAPI ManagementEnterpriseIntegrationSecurity33 APIs50.0DeepLArtificial IntelligenceDeep LearningGlossaryLocalization7 APIs49.9NeonDatabasesServerlessPostgresInfrastructure13 APIs49.9DiscordChatCommunicationsGamingMessaging29 APIs49.4Triton OneSolanaRPCBlockchainWeb313 APIs49.4HiveMQMQTTIoTMessagingMessage Broker4 APIs48.2NeuphonicText-to-SpeechVoice AIAudioStreaming7 APIs47.8StepFunArtificial IntelligenceLLMMulti-ModalChat Completion12 APIs47.8Allo-MediaCompanyAi DataSpeech RecognitionSpeech-to-Text4 APIs47.2Infoway Real-time Market Data APIstock-apiforex-apicrypto-apicommodities-api5 APIs47.2FinnhubFinancialMarket DataStocksForex7 APIs47.1SenseEnergyHome Energy MonitoringIoTSmart Home6 APIs47.0HansoftCompanyProject ManagementAgilePlanning3 APIs46.8PredCompanyFintechPrediction MarketsSports7 APIs46.8TiingoFintechMarket DataStocksCrypto6 APIs46.8MEXCCryptocurrencyExchangeTradingFutures12 APIs46.7SanasCompanySpeech AIVoice AIAccent Translation2 APIs46.6FDC3Financial-ServicesFintechDesktop InteroperabilityOpen Standard6 APIs46.4Qlik SenseAnalyticsBusiness IntelligenceCloudData Integration8 APIs46.4ConvexBackendDatabaseFunctionsReal-Time14 APIs46.2Nord PoolDay-Ahead PricesElectricityEnergy MarketsPower Exchange10 APIs46.2Jito LabsSolanaMEVBlock EngineBundles10 APIs46.1LMNTText-to-SpeechVoice SynthesisVoice CloningAudio Streaming4 APIs46.1GeminiAgentsArtificial IntelligenceAudio UnderstandingBatch Processing20 APIs46.0MorningstarFinancialMarket DataInvestingStocks18 APIs46.0LegendTradeCompanyDeFiTradingCryptocurrency5 APIs45.8AT ProtocolSocial NetworkingDecentralizedFederatedOpen-Source9 APIs45.3tastytradeFinanceBrokerageTradingOptions29 APIs45.1TwitchEntertainmentGamingLive VideoStreaming43 APIs44.9dxFeedFinancialMarket DataReal-TimeHistorical Data6 APIs44.7DeribitDerivativesCryptocurrencyBitcoinEthereum19 APIs44.6Juniper Mist AIArtificial IntelligenceAIOpsNetworkingWi-Fi211 APIs44.5LBankCryptocurrencyExchangeTradingMarket Data6 APIs44.4AiseraCompanyAgentic AIConversational AIITSM4 APIs44.3SfoxCompanyCryptocurrencyPrime BrokerageTrading3 APIs44.2PlivoCommunicationsCPaaSVoiceSMS24 APIs44.0NablaHealthcareAmbient AIClinical DocumentationMedical Transcription5 APIs43.5MudrexCompanyCryptocurrencyTradingFutures3 APIs43.4BinanceCryptocurrencyExchangeTradingBlockchain28 APIs43.2CartesiaArtificial IntelligenceVoice AIText-to-SpeechSpeech-to-Text21 APIs43.0CoinSwitchCompanyCryptocurrencyCrypto ExchangeTrading1 API42.9Refinitiv45 APIs42.9ForumCompanyTradingExchangePerpetual Futures9 APIs42.5PintuCompanyCryptocurrencyCrypto ExchangeTrading1 API42.5SupabaseBackend-as-a-ServicePostgreSQLOpen-SourceAuthentication21 APIs42.3StreamChatMessagingActivity FeedsVideo14 APIs42.2QuixStream ProcessingReal-TimeKafkaPython9 APIs42.1InstantDBDatabaseReal-TimeSyncBackend6 APIs42.0Trading EconomicsEconomic IndicatorsInterest RatesMacroeconomicsFinancial Data7 APIs41.9WellnessLivingFitnessWellnessSpaBusiness Management15 APIs41.9HibachiCompanyDeFiCryptocurrencyExchange3 APIs41.7TendermintCompanyInfrastructureBlockchainConsensus5 APIs41.6UpbitCryptocurrencyExchangeMarket DataOrder8 APIs41.6HighriseCompanyVirtual WorldMetaverseSocial7 APIs41.4VideoSDKVideoAudioWebRTCReal-Time Communication7 APIs41.4KorbitCompanyCryptoCryptocurrency ExchangeDigital Assets8 APIs41.1Jupyter NotebookData ScienceInteractive ComputingJupyterMachine-Learning14 APIs40.8OddpoolCompanyPrediction MarketsMarket DataFinancial Data2 APIs40.7PandaScoreEsportsOddsBettingLive Data14 APIs40.6PartyKitReal-TimeMultiplayerWebSocketsCloudflare4 APIs40.6SEC APISEC FilingsRegulatory FilingsEDGARFinancial Data7 APIs40.5BitnomialCompanyFintechCryptocurrencyDerivatives2 APIs40.4Rho ProtocolCompanyTradingDeFiDerivatives4 APIs40.3NakamaGamingGame BackendBackendReal-Time11 APIs40.2AT ProtocolAt-ProtocolatprotoBlueskyFederation12 APIs40.0CircleCommunityCreatorsCoursesMemberships8 APIs39.8FinlightFinancial NewsSentiment AnalysisMarket DataEquities2 APIs39.5PhemexCryptocurrencyDerivativesSpot TradingPerpetual Contracts9 APIs39.5CryptomusCryptocurrencyPaymentsInvoicesPayouts9 APIs39.4FortnoxAccountingERPInvoicingBookkeeping12 APIs39.3
Thin 77 Limited public surface area
KalshiPrediction MarketsEvent ContractsExchangeCFTC21 APIs39.1TezosTezosBlockchainTzKTBaking Bad34 APIs39.1Reclaim.aiArtificial IntelligenceSchedulingCalendarProductivity83 APIs39.0River MarketsCompanyPrediction MarketsTradingPrime Brokerage13 APIs38.8PapercupsCustomer MessagingLive ChatOpen-SourceSupport7 APIs38.5PolymarketPrediction MarketsDeFiPolygonOrder Book11 APIs38.2RailwayDeploymentPlatform-as-a-ServiceCloudInfrastructure13 APIs38.1CometChatChatMessagingVoiceVideo13 APIs38.0LayercodeArtificial IntelligenceVoiceVoice AgentsReal-Time5 APIs37.9BitsoCryptocurrencyExchangeTradingStablecoins5 APIs37.8TD AmeritradeBrokerageTradingFinanceEquities15 APIs37.6VocodeVoice AIVoice AgentsTelephonyConversational AI9 APIs37.6HyperliquidDeFiPerpetualsDEXLayer 17 APIs37.2Clockwork LabsCompanyDatabaseReal-Time1 API36.9BitstampCryptocurrencyExchangeTradingBitcoin2 APIs36.8PipecatArtificial IntelligenceVoiceMulti-ModalAgents7 APIs36.8Qlik Sense EnterpriseAnalyticsBusiness IntelligenceData VisualizationEnterprise32 APIs36.7Qlik69 APIs36.6Gate.ioCryptocurrencyExchangeTradingSpot Trading5 APIs36.5Blockchain.comCryptocurrencyBitcoinBlockchain DataExchange12 APIs36.4RestreamBroadcastChatContent DeliveryLive Streaming7 APIs36.4MattermostMessagingCollaborationTeam ChatOpen-Source6 APIs36.1One TradingCompanyCryptocurrencyCrypto ExchangeTrading5 APIs36.11ForgeCurrency ExchangeForexCryptocurrencyMarket Data6 APIs35.6SuiBlockchainMoveWeb3Cryptocurrency11 APIs35.5ptc-thingworx8 APIs35.4BithumbCryptocurrencyExchangeTradingSouth Korea6 APIs34.9Photon EngineGamingMultiplayerReal-TimeNetcode9 APIs34.9PowerTradeCompanyCryptoCryptocurrencyDerivatives3 APIs34.6WazoTelephonyVoIPUnified CommunicationsUCaaS14 APIs34.6AISStreamVessel TrackingAISMaritimeShip Tracking1 API34.4WazirXCryptocurrencyExchangeTradingINR8 APIs34.4ArgmaxCompanyEnterpriseArtificial IntelligenceMachine-Learning1 API34.3Capital.com Public APICFDCommoditiesCryptocurrencyFinancial8 APIs34.3Ribbon FinanceDeFiFinanceOptionsStructured Products10 APIs34.1zkSyncLayer 2EthereumzkEVMZK-Rollup10 APIs33.9Urban SkyCompanyAerospaceStratospheric BalloonsRemote Sensing1 API33.8LiteLLMGateways33 APIs33.7AlpacaMarket DataTradingBrokerageStocks16 APIs33.5eToroSocial TradingCopy TradingInvestingMarket Data29 APIs33.4LiveChatLive ChatCustomer ServiceCustomer-SupportMessaging12 APIs33.4RespeecherVoice AIVoice CloningSpeech to SpeechText-to-Speech17 APIs33.0MatrixportCompanyCrypto FinanceCryptocurrency ExchangeTrading7 APIs32.9PerpCompanyCrypto Web3DeFiDerivatives2 APIs32.9HTXCompanyTechnologyCryptocurrencyCrypto Exchange2 APIs32.7LiveKitReal-TimeWebRTCAudioVideo6 APIs32.4QuickNodeWeb3BlockchainRPCStreams12 APIs32.4Spring WebFluxJavaMicroservicesNon-Blocking IOReactive Programming8 APIs32.4Mantle NetworkLayer 2EthereumRollupEigenDA8 APIs32.2BitqueryBlockchain DataGraphQLStreamingIndexer10 APIs32.1HeliusWeb3BlockchainSolanaRPC20 APIs31.7SyndicaSolanaBlockchainWeb3RPC4 APIs31.7CourierNotificationEmailSMSPush22 APIs31.6LightpandaHeadless BrowserBrowser AutomationCDP3 APIs31.4PushoverNotificationPush NotificationsMessagingAlerts6 APIs31.4Vert.xEvent-DrivenFrameworksJavaJVM7 APIs31.4Blue Square Group LimitedCompanyCryptocurrencyDerivatives ExchangeTrading2 APIs31.3InfuraWeb3BlockchainRPCInfrastructure6 APIs31.3WhopMembershipsPaymentsCreator EconomyMarketplace12 APIs31.3SynthetixDeFiDerivativesPerpetualsSynthetic Assets11 APIs31.2PortainerContainer ManagementContainersDockerKubernetes32 APIs31.1ReownWeb3WalletsWalletConnectAppKit7 APIs31.1PulsoidHeart RateHealthWearablesReal-Time8 APIs31.0AlchemyWeb3BlockchainRPCNFT12 APIs30.9NostrNostrDecentralized SocialOpen ProtocolRelays4 APIs30.6Rev AISpeech RecognitionSpeech-to-TextTranscriptionAudio7 APIs30.5Qlik CloudAnalyticsBusiness IntelligenceCloudData Integration13 APIs30.4ExotelCloud TelephonyVoiceSMSIndia6 APIs29.9Options TechnologyFinancialMarket DataReal-TimeStreaming1 API29.5Morgan StanleyFinancialInvestment BankingWealth ManagementBrokerage6 APIs29.3HulyProject ManagementCollaborationOpen-SourceProductivity4 APIs28.6RimeArtificial IntelligenceVoiceTTSReal-Time2 APIs28.1BitMartCryptocurrencyExchangeTradingBlockchain6 APIs28.0LitecoinCryptocurrencyBlockchainLitecoinLTC10 APIs28.0OWASP ZAPSecurity TestingApplication SecurityVulnerability ScanningTesting49 APIs27.7AVEVASCADAMESIndustrial AutomationManufacturing2 APIs26.8CoinExCryptocurrencyExchangeSpot TradingFutures3 APIs26.4
Emerging 34 Early or largely undocumented
Arkham IntelligenceOnchain IntelligenceEntity ResolutionCrypto ExchangeTrading6 APIs26.1Leap MotionCompanyHand TrackingComputer-VisionSpatial Computing2 APIs25.9Phidata / AgnoAI AgentsAgnoPhidataPython3 APIs25.8SeiBlockchainLayer 1EVMDeFi10 APIs25.1XRP LedgerBlockchainXRPCryptocurrencyDeFi4 APIs24.8CoinAPIBlockchainCrypto IndexesCrypto MetricsCryptocurrency3 APIs24.7Pendle FinanceDeFiYield TradingYield StrippingPrincipal Tokens9 APIs24.6Apache TinkerPopGraph ComputingGraph DatabaseGremlinOLAP2 APIs23.5ACTIV Financial SystemsCompanyFintechMarket DataFinancial Data1 API23.0WhistleDebugging ProxyProxyNetwork DebuggingHTTP1 API22.9TalosCompanyDigital AssetsCryptocurrencyTrading22.7Qlik Sense APIsAnalyticsBusiness IntelligenceCloudData Visualization13 APIs22.6LyraOptionsAMMDeFiDerivatives3 APIs22.4BitgetCryptocurrencyExchangeSpot TradingFutures7 APIs22.0QuoteMediaFinancialMarket DataStocksOptions4 APIs22.0Mock Service WorkerAPI MockingGraphQLHTTPMock Server1 API21.9RestfoxAPI TestingHTTP ClientBrowserDesktop1 API20.3Abios (Sportradar)EsportsSports DataOddsWidgets3 APIs19.2MercuriusGraphQLFastifyNode.jsFederation1 API19.2CoinDCXCryptocurrencyPublic APIs2 APIs19.1DashCryptocurrencyBlockchainDASHInstantSend2 APIs19.1PicFinderCompanyArtificial IntelligenceMachine-LearningImage-Generation1 API18.9FirecampAPI ClientClientsGraphQLGUI1 API17.9RealtimeReal-TimeWebRTCServer-Sent Events26 APIs17.0Netflix ZuulAPI GatewayEdge ServiceNetflixOpen-Source3 APIs16.9FlowdeskCompanyFintechCryptoDigital Assets1 API16.6SoketiReal-TimeWebSocketsOpen-SourcePusher Protocol1 API15.7Jakarta EEEnterpriseJakarta EEJavaStandards6 APIs15.0Mango MarketsCryptocurrencyDeFiDecentralized ExchangePerpetual Futures2 APIs15.0StreamingStreamingReal-TimeEvent StreamingChange Data Capture21 APIs14.8MilkmanAPI ClientCassandraDesktop ApplicationGraphQL1 API14.4Qlik MashupsAnalyticsBusiness IntelligenceEmbedded AnalyticsMashup5 APIs14.2tldrawWhiteboardSDKCanvasReact2 APIs14.0TrackManSportsSports TechnologyGolfBaseball11.9
Minimal 2 Almost no public developer surface
Parallel FinanceCompanyDeFiBlockchainPolkadot1 API8.6MayStreetFinancialMarket DataReal-TimeTrading2 APIs7.8

APIs with this tag (235)

Ranked by the provider's API Evangelist rating — the Kin Score is scored per provider, not per API, so every API of a provider shares its band. How the rating works →

Exemplar 16 Complete, well-documented, and agent-ready
Twelve Data WebSocket Streaming APIReal-time price streaming over a persistent, bidirectional WebSocket at wss://ws.twelvedata.com/v1/quotes/p...76.7Polygon WebSocket APIReal-time streaming WebSocket clusters per asset class (stocks/options/indices/forex/crypto). Subscribers a...71.5Kraken Futures WebSocket APIReal-time market data and private user feeds for Kraken Futures over WebSocket. Public feeds include trade,...70.6Kraken Prime REST + WebSocket + FIX APIPrime brokerage API surface (REST, WebSocket, FIX) for institutional clients consolidating execution, custo...70.6Kraken Spot WebSocket API v1 (Legacy)Legacy Kraken Spot WebSocket API. Continues to operate alongside v2 but v2 is the recommended path for new ...70.6Kraken Spot WebSocket API v2Real-time market data and private user data over WebSocket v2 using subscribe/unsubscribe semantics. Public...70.6Kraken WebSocket APIEndpoints that mint tokens for private WebSocket subscriptions70.6Nakama APIThe Nakama API is the core REST and WebSocket API for Heroic Labs' open-source game backend server. It prov...70.4fal Realtime APIWebSocket-based realtime inference for ultra-low latency interactive generative experiences such as LCM/SDX...69.7Bullish WebSocket Anonymous Ticks APIAsyncAPI 3.0.0 document for simultaneous tick subscriptions across multiple Bullish markets over WebSocket.67.3Bullish WebSocket Anonymous Trades APIAsyncAPI 3.0.0 document for batched anonymous trade subscriptions across multiple Bullish markets over WebS...67.3Bullish WebSocket Auction Feed APIAsyncAPI 3.0.0 document for the real-time auction feed, delivering phase and order-imbalance data for Bulli...67.3Bullish WebSocket Index Data APIAsyncAPI 3.0.0 document for streaming Bullish index prices, with the subscribed asset set controlled by sub...67.3Bullish WebSocket Multi-Order Book APIAsyncAPI 3.0.0 document for simultaneous subscriptions to multiple L1 and L2 order books across different B...67.3Bullish WebSocket Private Data APIAsyncAPI 3.0.0 document for the authenticated private stream — real-time orders, trades, asset accounts, tr...67.38x8 Event Streaming APIReal-time contact center event stream delivered over the Apache Pulsar WebSocket interface. Clients connect...67.1
Strong 23 Solid coverage with minor gaps
SiftingIO Live StreamWebSocket streaming API for live market data, described by an AsyncAPI 3.0 contract. Also offers a document...66.1SiftingIO MCP ServerLOCALLY-RUN MCP server, not a hosted endpoint. The client launches it (`npx -y siftingio-mcp`, or the Pytho...66.1Solana RPC WebSocket Subscriptions APIReal-time WebSocket subscription API for the Solana blockchain. Provides event-driven notifications for acc...65.8ThetaData Streaming WebSocket APIJSON WebSocket streaming of US stock trade/quote, options trade/quote, and index price streams, served loca...65.2Kensho Scribe Real Time APIReal-time streaming transcription over a WebSocket at wss://scribe.kensho.com/ws. Clients send an Authentic...64.6Tradier Streaming APIThe Tradier Streaming API delivers real-time market and account events over HTTP and WebSocket. Quote, trad...61.4Lukka Market Data Streaming APIWebSocket streaming for executed trades, Level-1 order-book quotes, Lukka Prime pricing, Lukka Index valuat...61.2OPERA Cloud Business Events Streaming APIPush delivery of OPERA Cloud Business Events as a GraphQL subscription over WebSocket. Each event carries t...60.5GoldRush Hyperliquid WebSocket APIWebSocket channels for Hyperliquid markets including l2Book (wire-equal to the public feed), l2BookDiff (Go...60.4BuiltWith Live Feed APIReal-time WebSocket feed of technology detections as they happen across the web.59.8Blockchain.com Exchange WebSocket APIReal-time WebSocket gateway for the Blockchain.com Exchange. Anonymous channels stream heartbeat, L2/L3 ord...59.7Blockchain.com Explorer WebSocket APILow-latency streaming socket channel providing notifications on new bitcoin blocks, unconfirmed transaction...59.7Amberdata WebSocket Streaming APILow-latency real-time WebSocket streaming over a JSON-RPC 2.0 subscribe interface for spot trades and price...55.3Liveblocks Realtime Client APIWebSocket-based client API exposed through Liveblocks client SDKs for React, JavaScript, Redux, Zustand, Vu...55.3Binance.US WebSocket APIThe Binance.US WebSocket API is a request/response API delivered over a persistent WebSocket connection at ...55.1Binance.US WebSocket StreamsBinance.US WebSocket Streams deliver real-time market data and account events over persistent WebSocket con...55.1Anaconda Websocket APIThe websocket API from Anaconda — 3 operation(s) for websocket.54.9Benzinga WebSocket Streaming APIReal-time WebSocket streams over wss://api.benzinga.com for news, earnings, analyst ratings, consensus rati...54.9QFEX Market Data WebSocket (MDS)Multiplexed WebSocket gateway for all QFEX real-time market data streams: order book, trades, candles, BBO,...54.8QFEX Trade WebSocketMultiplexed WebSocket gateway for QFEX order entry and account streams: add / modify / cancel orders, stop ...54.8Amazon API Gateway Management APIAPI for directly managing runtime aspects of deployed APIs, including sending data to connected WebSocket c...54.5Amazon API Gateway WebSocket APIBuild real-time two-way communication applications with WebSocket APIs.54.5Deutsche Börse Cloud Stream Market Data APICloud-delivered real-time market data streaming over WebSocket (host md.deutsche-boerse.com) with Protocol ...54.4
Developing 76 Usable, with meaningful gaps to close
CryptoCompare Streaming WebSocketSingle secure WebSocket endpoint multiplexing every subscription via tilde-delimited subscription strings (...53.8Tensor WebSocket APISubscription-based realtime stream of Tensor marketplace events. Channels include `newTransaction` (every c...53.2Apstal Analytics APIDocumented REST surface for programmatic access to Apstal analytics: POST /api/v1/m for batched event inges...52.8Gladia Live (Real-time) APIWebSocket API for real-time live audio transcription with sub-second latency, supporting multi-language det...52.1LSEG WebSocket APIStandards-based WebSocket API for real-time pricing streaming using JSON message formats. Connects to Real-...50.6OpenSea Stream APIReal-time WebSocket event streaming for NFT marketplace activity per collection, including item listed, ite...50.6Speechmatics Realtime Transcription APIWebSocket API for low-latency real-time streaming transcription supporting live audio input, speaker diariz...50.4ZenRows Scraping BrowserCloud headless browser exposed over WebSocket at wss://browser.zenrows.com?apikey=KEY, compatible with Play...50.4Axway Amplify StreamsAxway Amplify Streams provides a real-time event streaming API platform enabling publishers to push data up...50.0DeepL Voice APIThe DeepL Voice API provides real-time speech transcription and translation. A POST to /v3/voice/realtime i...49.9Neon Serverless DriverThe Neon Serverless Driver is a low-latency JavaScript and TypeScript driver that enables querying Neon Pos...49.9Discord Gateway APIThe Gateway API from Discord — 2 operation(s) for gateway.49.4Discord Voice APIThe Voice API from Discord — 1 operation(s) for voice.49.4Triton One Whirligig WebSocketsWhirligig — Triton's enhanced WebSocket layer over Solana RPC. Adds the missing transactionSubscribe stream...49.4HiveMQ MQTT over WebSocketMQTT 3.x and MQTT 5 messaging endpoints exposed over WebSocket for browser and edge clients to publish and ...48.2Neuphonic TTS WebSocket APIWebSocket endpoint for continuous, low-latency text-to-speech streaming. Enables real-time voice synthesis ...47.8StepFun Realtime APIBidirectional realtime voice over WebSocket (wss://api.stepfun.com/v1/realtime) with OpenAI Realtime-style ...47.8Infoway WebSocket Streaming APIPersistent WebSocket connection for real-time trades, order-book depth, candlesticks and multilingual news....47.2Sense Realtime APIThe Sense Realtime API delivers live electricity usage data via a WebSocket connection, streaming second-by...47.0P4 Plan (Hansoft) Web APIWeb service exposing a limited set of data and tasks over the DDP protocol via a WebSocket connection.46.8Pred WebSocket APIPRED uses [Ably](https://ably.com/) for real-time WebSocket data. Use Ably's token auth with `POST /api/v1/...46.8Tiingo Crypto APICrypto top-of-book and trade data aggregated from major exchanges over REST and WebSocket.46.8Tiingo Forex APIReal-time and historical FX rates for major and emerging-market currency pairs.46.8Tiingo IEX Intraday APIIEX-sourced intraday quotes and trades over REST and WebSocket - real-time during US market hours.46.8MEXC Futures WebSocket APIThe MEXC Futures WebSocket API streams real-time derivatives market data and account events over persistent...46.7MEXC Spot WebSocket StreamsThe MEXC Spot WebSocket Streams deliver real-time market data and user account updates via persistent WebSo...46.7Sanas Stream APIReal-time speech-to-speech translation over a single persistent WebSocket connection, supporting consecutiv...46.6FDC3 Desktop Agent BridgingFDC3 Desktop Agent Bridging (DAB) is a wire protocol that enables multiple Desktop Agent implementations to...46.4Qlik Sense Engine APIWebSocket-based API for interacting with the Qlik Associative Engine, including data modeling, selections, ...46.4Convex Sync ProtocolThe Convex Sync Protocol is the bidirectional WebSocket protocol spoken between Convex client SDKs and the ...46.2Nord Pool Intraday Trading APIWebSocket API for continuous intraday power trading - clients speak STOMP over secure WebSocket (port 443) ...46.2Jito Streaming SurfacesReal-time streaming surfaces from Jito infrastructure — the wss tip_stream for continuous bundle-tip percen...46.1LMNT Speech Sessions APIWebSocket-based real-time speech generation API for streaming LLM text output to synthesized audio with res...46.1Gemini Live APILow-latency bidirectional streaming API enabling real-time voice and video interactions with Gemini models ...46.0Morningstar Streaming APIWebSocket-based real-time market data streaming with Level 1 quote and Level 2 market-by-price subscription...46.0Legend WebSocket APILegend's Hyperliquid-compatible WebSocket at wss://api.legend.trade/ws, using subscription-based messaging....45.8AT Protocol Firehose (Event Stream)Public WebSocket event stream providing real-time access to all public activity on the AT Protocol network,...45.3tastytrade Account Streamer APIWebSocket-based account streaming that delivers real-time notifications for order fills, position changes, ...45.1tastytrade DXLink Market Data Streaming APIReal-time market data streaming via DXLink, a WebSocket-based protocol backed by dxFeed. Clients fetch a qu...45.1Twitch Chat APIManage chat settings, emotes, badges, and announcements44.9dxFeed dxLink WebSocket APIdxLink is dxFeed's WebSocket protocol for real-time market data streaming with multiplexed virtual channels...44.7Deribit WebSocket APIJSON-RPC over WebSocket interface for real-time bidirectional communication with the Deribit exchange. Reco...44.6Juniper Mist WebSocket Streaming APIMist exposes a WebSocket channel for real-time event subscriptions including device events, location update...44.5LBank WebSocket Account and Order APIAuthenticated WebSocket API for receiving real-time account balance and order status updates from LBank. Cl...44.4LBank WebSocket Market Data APIReal-time WebSocket API for streaming live market data from LBank. Clients can subscribe to K-line (candles...44.4Aisera Conversation & Workflows API and WebSocketBuild custom conversational interfaces for AiseraGPT applications — decoration, NLP/NLU processing, slot fi...44.3Plivo Audio Stream APIThe Plivo Audio Stream API attaches a real-time WebSocket audio stream to a live call, enabling AI voice ag...44.0Nabla Copilot User APIThe User API enables client-side applications to act on behalf of an individual user by exchanging server-i...43.5Nabla Core APIThe Nabla Core API transcribes medical encounters, generates structured clinical notes (for example SOAP), ...43.5Mudrex Market Data APIPublic, unauthenticated market-data surface for Mudrex linear perpetual futures. Over REST it returns bulk ...43.4Binance Spot WebSocket APIThe Binance Spot WebSocket API provides an alternative way to access spot trading functionality through per...43.2Binance Spot WebSocket StreamsBinance Spot WebSocket Streams deliver real-time market data updates via persistent WebSocket connections. ...43.2Cartesia STT WebSocket APIRealtime transcription over WebSocket at wss://api.cartesia.ai/stt/websocket. Clients stream raw binary aud...43.0Cartesia TTS WebSocket APIBidirectional, multiplexed WebSocket at wss://api.cartesia.ai/tts/websocket for realtime speech generation....43.0Refinitiv Real-Time WebSocket APILow-latency streaming API for real-time market data using WebSocket connections. It supports the Open Messa...42.9Pintu Pro Partner APIPintu Pro's institutional/partner trading API. A unified message format is used over both an HTTP endpoint ...42.5Supabase Realtime APIThe Supabase Realtime API provides WebSocket-based subscriptions for real-time data changes from PostgreSQL...42.3Quix Streaming Reader API (Real-time)Subscribe to live parameter data, events, definitions, active streams, topic metrics, and raw packages from...42.1InstantDB Realtime Sync APIThe realtime sync transport - a persistent WebSocket at wss://api.instantdb.com/runtime/session over which ...42.0Trading Economics Streaming APIPersistent WebSocket connection at wss://stream.tradingeconomics.com delivering live market quote ticks by ...41.9WellnessLiving WebSocket APIThe WebSocket API from WellnessLiving — 1 operation(s) for websocket.41.9Tendermint Websocket APISubscribe/unsubscribe are reserved for websocket events.41.6Upbit WebSocket APIThe Upbit WebSocket API delivers real-time streaming data for market and account events. Public streams inc...41.6Highrise Bot APIWebSocket API for building and running programmable bots inside Highrise rooms. Bots receive a stream of ro...41.4Korbit Open API v2 WebSocketWebSocket streaming API for the Korbit exchange. Public channels stream ticker, orderbook and trade market ...41.1Jupyter Kernel Messaging ProtocolWebSocket-based messaging protocol for communication between Jupyter clients and computational kernels. Sup...40.8Oddpool WebSocket FeedsSingle-connection WebSocket streaming real-time, normalized cross-venue prediction market data (dist, book,...40.7PandaScore Live Data APIReal-time in-game state, frames, and event timelines streamed over WebSocket for supported esports titles. ...40.6PartyKit Deployed Party (HTTP / WebSocket)Public HTTP and WebSocket interface for a deployed PartyKit project at project.user.partykit.dev. Each part...40.6SEC API Filing Stream APIReal-time, push-based WebSocket feed of newly published SEC EDGAR filings. Connect to wss://stream.sec-api....40.5Bitnomial Market Data WebSocket APIReal-time WebSocket market-data feed delivering trade, order book, block trade, and market status messages ...40.4Nakama Realtime Socket APIPersistent WebSocket connection carrying realtime features - status presence, realtime chat channels, relay...40.2AT Protocol Relay & FirehoseThe Relay aggregates the com.atproto.sync.subscribeRepos firehose across PDS hosts and re-broadcasts the co...40.0Circle Realtime WebSocket APIBeta ActionCable (Rails) WebSocket surface for realtime chat and notifications, connected at wss://app.circ...39.8Cryptomus Exchange and Market Data APIREST and WebSocket API for accessing real-time cryptocurrency exchange rates, order books, tickers, trade h...39.4Fortnox Topics WebSocket APIDuplex WebSocket stream at wss://ws.fortnox.se/topics-v1 that pushes minimal change-notification events acr...39.3
Thin 82 Limited public surface area
Kalshi AsyncAPI SpecificationMachine-readable AsyncAPI description of the Kalshi WebSocket streaming API. Suitable for generating async ...39.1Kalshi WebSocket Streaming APIReal-time streaming feed for market data, order book updates, fills, and portfolio events on Kalshi. Docume...39.1TzKT WebSocket APIThe TzKT WebSocket API uses SignalR to deliver real-time push notifications to subscribed clients. Channels...39.1Reclaim.ai websocket APIThe websocket API from Reclaim.ai — 7 operation(s) for websocket.39.0Papercups Realtime Chat API (WebSocket / Phoenix Channels)Bidirectional realtime live chat over Phoenix WebSocket channels. Clients join conversation, conversation-l...38.5Polymarket WebSocketReal-time streaming feed for order book updates, trades, and market events on the Polymarket CLOB - used by...38.2Railway Logs APIGraphQL log surface for builds, deployments, environments, and HTTP traffic. Available both as point-in-tim...38.1CometChat Realtime & Client SDKClient SDKs (JavaScript, React, React Native, Android, iOS, Flutter, Ionic) connect over a managed WebSocke...38.0Layercode Realtime Voice APIBidirectional realtime WebSocket transport that streams base64 PCM microphone audio from the browser to Lay...37.9Bitso WebSocket APIReal-time streaming channels for trades, order-book diffs, and full order-book snapshots. Used by trading c...37.8TD Ameritrade Streaming Market Data APIProvides a WebSocket-based streaming API that delivers up-to-the-second market data including real-time Lev...37.6Vocode Realtime Streaming ConversationReal-time, bidirectional streaming conversation pipeline (StreamingConversation) in the open-source library...37.6Hyperliquid WebSocket APIReal-time WebSocket feed delivering order-book deltas, trades, candles, BBO, user fills, user funding, user...37.2SpacetimeDB HTTP APIThe SpacetimeDB HTTP API lets clients and tools interact with SpacetimeDB databases: publish and delete dat...36.9Bitstamp WebSocket APIReal-time WebSocket API providing live market data streams including order book updates, live trades, ticke...36.8Transports (WebRTC/WebSocket)Realtime media transport layer of the framework. Bidirectional audio, video, and data flow over Daily WebRT...36.8Qlik Sense Engine JSON APIWebSocket protocol API using JSON-RPC for interacting with the Qlik Associative Engine.36.7Qlik Engine JSON-RPC APIThe JSON-RPC API over WebSocket that enables interaction with the Qlik Associative Engine for Qlik Sense ap...36.6Gate WebSocket API v4Real-time WebSocket streams for market data (order books, trades, tickers, candlesticks) and private channe...36.5Blockchain.com WebSocket APIsReal-time WebSocket APIs covering two distinct surfaces — the Bitcoin / blockchain.info explorer socket (un...36.4Restream Chat APIWebSocket API for accessing and managing Restream Chat. Receive real-time chat messages from all connected ...36.4Restream Streaming Updates APIWebSocket API for real-time streaming status updates. Connect to wss://streaming.api.restream.io/ws with an...36.4Mattermost WebSocket APIReal-time WebSocket event stream for Mattermost v4. Clients connect to /api/v4/websocket, authenticate via ...36.1One Trading WebSocket Streams APIReal-time WebSocket API for market data (order book, price ticks, book ticker) and, after authenticating, p...36.11Forge Forex StreamWebSocket stream that delivers real-time bid/ask updates for subscribed forex and cryptocurrency pairs. Str...35.6Sui Websocket APIThe Websocket API from Sui — 2 operation(s) for websocket.35.5PTC ThingWorx WebSocket/AlwaysOn APIPTC ThingWorx AlwaysOn WebSocket API enables persistent bidirectional connections for industrial edge devic...35.4Bithumb WebSocket APIReal-time WebSocket API for streaming market data including tickers, order books, and trade executions, as ...34.9Photon Realtime Transport ProtocolThe core Photon protocol - NOT a REST or JSON API. Clients connect through a Name Server to a Master Server...34.9PowerTrade WebSocket FeedsReal-time WebSocket market-data feeds (reference data, top-of-book, order books, trades, index and settleme...34.6Wazo Websocket Event Stream (wazo-websocketd)WebSocket gateway onto the Wazo internal event bus. An authenticated client subscribes to named platform ev...34.6AISStream AIS Stream APIReal-time global AIS vessel-tracking stream delivered over a single WebSocket at "wss://stream.aisstream.io...34.4WazirX WebSocket APIEndpoints for WebSocket authentication token generation34.4Argmax Local ServerA local transcription server for macOS that is API-compatible with the Deepgram Speech-to-Text (Live) API, ...34.3Capital.com WebSocket APIThe Capital.com WebSocket API streams real-time market data, supporting up to 40 concurrent instruments and...34.3Aevo Exchange WebSocket APIReal-time WebSocket API for Aevo exchange providing low-latency streams for orderbook updates, trade feeds,...34.1zkSync Era WebSocketWebSocket variant of the zkSync Era JSON-RPC endpoint for real-time eth_* subscriptions (newHeads, logs, pe...33.9Urban Sky SDK (Real-time Balloon Telemetry)Real-time balloon telemetry feed delivered over WebSocket via the Urban Sky SDK (JavaScript and Python, dis...33.8LiteLLM Realtime APIProvides /realtime WebSocket endpoints for real-time model interactions with load balancing and guardrails ...33.7Alpaca Market Data Streaming APIReal-time market data over WebSocket. Stocks stream at wss://stream.data.alpaca.markets/v2/{feed} (iex, sip...33.5eToro Market Data APIProvides REST and WebSocket access to real-time and historical market data for all asset classes available ...33.4LiveChat Webhooks and RTM APIAsynchronous event surfaces for LiveChat. HTTP webhooks registered through the Configuration API and the Ag...33.4Respeecher Space Real-Time TTS APILow-latency real-time text-to-speech that begins streaming audio in under 200ms via three transports - one-...33.0Matrixport WebSocket APIThe WebSocket API from Matrixport — 1 operation(s) for websocket.32.9Perp V1 Market Maker APISigned, high-performance interface for connecting trading bots to the perp.com V1 matching engine: a privat...32.9HTX WebSocket APIThe HTX WebSocket API provides a two-way real-time channel for subscribing to market data (klines, market d...32.7LiveKit Signaling Protocol (WebSocket)Bi-directional WebSocket signaling protocol used by LiveKit clients to coordinate WebRTC sessions with the ...32.4QuickNode Core RPC APIMulti-chain JSON-RPC, REST, and gRPC endpoints across 77+ blockchains (Ethereum, Solana, Polygon, Arbitrum,...32.4Spring WebFlux WebSocketReactive WebSocket support for full-duplex, bidirectional communication in WebFlux applications. Provides W...32.4Mantle WebSocket (Mainnet)WebSocket endpoint for real-time JSON-RPC subscriptions on Mantle mainnet - new blocks, new pending transac...32.2Bitquery Streaming SubscriptionsGraphQL subscriptions over WebSocket for real-time blockchain data - live DEX trades, transfers, pending tr...32.1Helius Solana RPCSolana JSON-RPC and WebSocket endpoints with enhanced WebSockets, archival data, and staked connections.31.7Syndica ChainStream APIChainStream is Syndica's real-time Solana data streaming API. It consolidates updates from multiple validat...31.7Syndica Solana RPC (WebSocket) APIStandard Solana RPC PubSub WebSocket service supporting accountSubscribe, programSubscribe, signatureSubscr...31.7Courier Inbox Real-Time APIWebSocket service that delivers Inbox messages and message-state events (read, unread, opened, archived, cl...31.6Lightpanda CDP WebSocket InterfaceLightpanda's primary programmable interface. The browser runs as a CDP server (`lightpanda serve`) and expo...31.4Lightpanda CloudManaged, hosted CDP browser endpoints reached over secure WebSocket (e.g. `wss://euwest.cloud.lightpanda.io...31.4Pushover Open Client APIReal-time client API for Pushover. Combines a WebSocket channel at wss://client.pushover.net/push that stre...31.4Vert.x WebA set of building blocks for building web applications and RESTful HTTP microservices with Vert.x. Provides...31.4Infura JSON-RPC APIMulti-chain JSON-RPC over HTTPS and WebSockets across 23+ networks (Ethereum, Linea, Polygon, Arbitrum, Opt...31.3Whop Realtime WebSocket APIBidirectional realtime WebSocket for Whop apps - custom app messages and chat/feed updates - connected and ...31.3Synthetix WebSocket Info APIPublic WebSocket API for real-time Synthetix market data subscriptions including live market prices, candle...31.2Synthetix WebSocket Trade APIAuthenticated WebSocket API for real-time trading operations and account event streaming on Synthetix. Supp...31.2Portainer websocket APICreate exec sessions using websockets31.1WalletConnect Relay (SDK-mediated)WalletConnect v2 relay network for end-to-end encrypted JSON-RPC pairing between dApps and wallets. Accesse...31.1Alchemy Node API (JSON-RPC)Multi-chain JSON-RPC over HTTPS and WebSockets covering standard eth_*, solana, and other chain methods, pl...30.9Nostr Protocol (NIP-01)NIP-01 defines the core Nostr protocol: event format (id, pubkey, created_at, kind, tags, content, sig), cl...30.6Nostr Relay WebSocket InterfaceA Nostr relay is a WebSocket server that accepts signed events, stores them subject to its own policy, and ...30.6Rev AI Streaming Speech-to-Text APIReal-time speech transcription via WebSocket connections supporting up to 10 concurrent streams with a 3-ho...30.5Qlik Engine JSON APIWebSocket-based JSON-RPC API for direct interaction with the Qlik Associative Engine.30.4Exotel AgentStream Voice Streaming APIDocumented WebSocket (wss://) voice-streaming API. When a call reaches a Voicebot or Stream applet, Exotel ...29.9ACTIV Web One API (AtlasFeed)WebSocket-based (WebAssembly) JavaScript/TypeScript market data API for browser and Node.js, installed as n...29.5Morgan Stanley API Platform (WebSocket Streaming)Alongside its REST APIs, the Morgan Stanley API Platform exposes streaming WebSocket APIs for onboarded ins...29.3Huly Platform SDKThe @hcengineering/api-client Node.js package provides typed programmatic access to the Huly Platform. It e...28.6Rime TTS APIRealtime text-to-speech API supporting streaming HTTP, WebSocket, and SSE delivery for Arcana and Mist mode...28.1BitMart Futures WebSocket APIThe BitMart Futures WebSocket API streams real-time derivatives market data and account updates through per...28.0BitMart Spot WebSocket APIThe BitMart Spot WebSocket API delivers real-time streaming market data and private account updates via per...28.0Litecoin Space WebSocket APIA real-time WebSocket API provided by Litecoin Space (litecoinspace.org) for subscribing to live Litecoin n...28.0OWASP ZAP websocket APIThe websocket API from OWASP ZAP — 6 operation(s) for websocket.27.7AVEVA PI System REST APIThe AVEVA PI System REST API (PI Web API) provides RESTful HTTP access to time- series sensor data, asset m...26.8CoinEx WebSocket API v2 - FuturesReal-time WebSocket API for CoinEx futures and perpetual contract markets. Supports streaming subscriptions...26.4CoinEx WebSocket API v2 - SpotReal-time WebSocket API for CoinEx spot markets. Supports streaming subscriptions for market depth, trade f...26.4
Emerging 36 Early or largely undocumented
Arkham Entity Intelligence APIREST and WebSocket API for programmatic access to Arkham's entity dataset - resolve addresses to entities, ...26.1Arkham Exchange WebSocket APIWebSocket API for Arkham Exchange streaming market data and private account events - real-time ticker, dept...26.1Ultraleap Tracking WebSocketAn open-source WebSocket server from Ultraleap that restores the LeapJS-compatible websocket surface remove...25.9AgentOS Runtime APIPre-built FastAPI runtime that exposes 50+ REST, SSE, and WebSocket endpoints for running agents, teams, an...25.8Sei Websocket APISubscribe/unsubscribe are reserved for websocket events.25.1XRPL WebSocket API (Mainnet)WebSocket interface to the XRP Ledger mainnet supporting all JSON-RPC methods plus real-time subscriptions ...24.8XRPL WebSocket API (Testnet)WebSocket interface to the XRP Ledger Altnet testnet for development and testing. Supports real-time subscr...24.8CoinAPI EMS Trading APICoinAPI's Execution Management System (EMS) is a unified, multi-exchange crypto trading API that lets insti...24.7CoinAPI Market Data APINormalized cryptocurrency market data covering more than 350 exchanges and 28,000+ assets. Provides trades,...24.7Pendle Real-Time Feeds (Socket.IO)Real-time data feeds delivered over Socket.IO from `https://api-v2.pendle.finance/pendle-v2`. Clients conne...24.6Apache TinkerPop Gremlin Server APIThe Gremlin Server provides WebSocket and HTTP endpoints for submitting Gremlin traversals to a remote grap...23.5ACTIV OnePlatform Web API (One API)WebSocket/WebAssembly JavaScript API for the ACTIV OnePlatform (Options Atlas), delivering real-time stream...23.0WhistleWhistle is a cross-platform HTTP, HTTPS, HTTP/2, WebSocket, and TCP debugging proxy tool. It lets developer...22.9Qlik Engine APIJSON-RPC WebSocket API for interacting with the Qlik Associative Engine, creating and manipulating apps, an...22.6Lyra WebSocket APIWebSocket API for real-time streaming of market data, order book updates, ticker subscriptions, and private...22.4Bitget WebSocket APIReal-time WebSocket API providing public and private channels for market data (tickers, candles, order book...22.0QuoteMedia Streaming Data Feed APIEnterprise tick-by-tick streaming feed for real-time or delayed Level 1 and Level 2 market data, normalized...22.0Mock Service WorkerMock Service Worker (MSW) is an open-source library for mocking REST, GraphQL, WebSocket, and Server-Sent E...21.9RestfoxRestfox is a lightweight, offline-first web HTTP client for testing REST APIs, similar to Postman but brows...20.3Abios Atlas APIAtlas is the Abios REST and WebSocket data API delivering fixtures, live match state, historical stats, pla...19.2CoinDCX Streaming Socket.IO APIReal-time Socket.IO streaming at stream.coindcx.com for public spot and futures market data (orderbook dept...19.1Dash Insight REST APIOpen-source REST and WebSocket API for querying the Dash Core (layer 1) blockchain. Provides endpoints for ...19.1FirecampFirecamp is an open-source API development platform for designing, testing, and documenting REST, GraphQL, ...17.9CentrifugoAn open-source language-agnostic realtime messaging server providing WebSocket, SSE, HTTP streaming, and We...17.0GraphQL SubscriptionsA GraphQL operation type that delivers realtime updates to clients, typically carried over WebSocket using ...17.0Phoenix ChannelsThe realtime layer of the Elixir Phoenix Framework — soft-realtime channels, presence, and pub/sub built on...17.0Socket.IOA widely deployed open-source realtime engine for Node.js (with clients across JavaScript, Java, Swift, Kot...17.0WebSocketA full-duplex communication protocol over a single TCP connection, standardized by the IETF as RFC 6455 and...17.0Netflix Zuul Push MessagingZuul Push Messaging enables server-to-client push communications over WebSockets and Server Sent Events (SS...16.9Flowdesk Platform ConnectFlowdesk Platform Connect is the developer API for programmatic OTC spot trading. It offers a REST interfac...16.6Soketi Pusher-Compatible APIImplements the Pusher protocol (channels, private channels, presence channels, encrypted channels) for drop...15.7Jakarta WebSocketJakarta WebSocket defines a standard API for creating server and client endpoints that communicate using th...15.0Mango v4 Fills FeedLow-latency WebSocket feed (service-mango-fills) that parses Mango V4 Perp and Openbook event queues and em...15.0Mango v4 Orderbook FeedLow-latency WebSocket feed (service-mango-orderbook) that parses Mango V4 Perp and Openbook spot bookside a...15.0Qlik Engine APIJSON-RPC API for interacting with the Qlik Associative Engine.14.2tldraw Sync (Multiplayer)tldraw provides a multiplayer sync layer (WebSocket-based) that customers can self-host or use through tldr...14.0
Minimal 2 Almost no public developer surface
Parallel Finance JSON-RPC (polkadot.js)Substrate/Polkadot JSON-RPC interface to the Parallel Finance parachain, accessed over WebSocket with the p...8.6MayStreet High Performance Query (HPQ) APILow-latency, near-time market data query API delivered as a streaming WebSockets service so clients can pro...7.8

Score breakdown

Frequency
67.5
log-scaled weighted occurrences
Breadth
6.0
spread across providers
Quality lift
47.4
mean composite of providers using it
Cohesion
23.8
strength of nearest seed neighbor

Related tags

Real-Time 114 co-occurrences Market Data 76 co-occurrences Streaming 100 co-occurrences Trading 63 co-occurrences Exchange 29 co-occurrences Cryptocurrency 51 co-occurrences Futures 19 co-occurrences Options 21 co-occurrences

Where this tag comes from

Api tag237
Provider tag72
Openapi tag10
Openapi op tag26

Cohort brief

Auto-generated

The 219 providers in the APIs.io catalog tagged WebSocket, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.

Providers
219
all scored
Mean Kin Score
38.9
+18.2 vs catalog 20.7
Mean Agent Readiness
22.4
+12.7 vs catalog 9.7
Spread
7.8–76.7
median 38.8 · σ 13.1
How the 219 split by band
Exemplar 7Strong 20Developing 79Thin 77Emerging 34Minimal 2
Facet averages, against the whole catalog
FacetThis cohortCatalogDifferenceScored
Contract Quality 46 17.5 +28.5 219
Developer Ergonomics 36.6 17.9 +18.7 219
Operational Transparency 28.7 11.3 +17.4 219
Access Clarity 35.4 22.3 +13.1 219
Discoverability 72.9 60.4 +12.5 219
Contract Governance 13.2 6.4 +6.8 219

A facet is averaged over the members that carry it, not over the whole cohort — the “Scored” column is that count. Averaging an absent facet as zero would score our own coverage gaps as the providers’ posture.

What this cohort publishes
ArtifactThis cohortCatalogDifference
MCP server (any) 28% 16% +12
MCP server (first-party) 10% 7% +3
Agent Skills 0% 0% 0
OAuth scopes 9% 9% 0
Security 98% 88% +10
Arazzo workflows 5% 2% +3
Governance rules 53% 13% +40

mcp_pct counts any mcp/ artifact including ones API Evangelist derived from the provider OpenAPI; mcp_first_party_pct counts only servers the provider publishes. Prefer the latter.

Top by Kin Score
  1. 1 Twelve Data 76.7
  2. 2 Polygon 71.5
  3. 3 Kraken 70.6
  4. 4 Heroic Labs 70.4
  5. 5 fal 69.7
  6. 6 Bullish 67.3
  7. 7 8x8 67.1
  8. 8 SiftingIO 66.1
  9. 9 Amazon API Gateway 65.8
  10. 10 Solana 65.8
Top by Agent Readiness
  1. 1 S&P Global 63.7
  2. 2 CryptoCompare 60.2
  3. 3 Polygon 57.3
  4. 4 Morningstar 56.8
  5. 5 Lukka 52
  6. 6 Twelve Data 48.7
  7. 7 Tradier 45.5
  8. 8 BuiltWith 45
  9. 9 8x8 43.3
  10. 10 SiftingIO 41.5
All 219 members of this roster resolve to a scored provider in the catalog.Generated from the catalog build of 25 August 2026, across 26891 providers, using the same computation served by the APIs.io cohort API. Briefs are published for rosters of 5 or more scored providers; below that a distribution is not meaningful.

Work with this as data

Every tag here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for tags

7 MCP tools reach this
  • find_tagsBrowse and filter every tag in the catalog.
  • get_cohortThis tag as a scored cohort — every provider carrying it, with scores.
  • cohort_statsPRO — the distribution across this tag: mean, median, band split, adoption rates.
  • cohort_rankingsPRO — the leaderboard, on composite AND agent-readiness axes.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools

Call it yourself

curl for this page
This tag 
curl "https://apis.io/api/v1/tags/websocket"
All tags 
curl "https://apis.io/api/v1/tags?limit=25"
As a scored cohort 
curl "https://apis.io/api/v1/cohorts/tag/websocket"
The distribution (Pro) 
curl "https://apis.io/api/v1/cohorts/tag/websocket/stats" \
  -H "X-API-Key: $APIS_IO_KEY"

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