Feature

Server-Sent Events & Streaming Responses

Incrementally streamed HTTP responses.

116 providers 861 APIs 110 declared variants

Responses stream token-by-token or event-by-event over a long-lived HTTP connection. The default delivery mode for LLM completions and progressive result sets.

116 API providers on the APIs.io network offer server-sent events & streaming responses. The highest-rated are SendGrid, Adobe, Anthropic, Plaid, Mailchimp.

Providers

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

Exemplar 15 Complete, well-documented, and agent-ready
SendGridSendGrid is a cloud-based email delivery platform, acquired by Twilio in 2019, that provides transactional ...44 published contracts82.9AdobeAdobe provides APIs and developer resources for its creative, document, and experience cloud platforms. Dev...4 published contracts80.9AnthropicAnthropic is an AI safety company and the creator of the Claude family of large language models (Opus, Sonn...6 published contracts80.6PlaidPlaid is a US financial-technology company and data-network aggregator that provides an API platform for bu...74 published contracts80.2MailchimpMailchimp is an Intuit company providing a marketing automation platform and email marketing service for ma...4 published contracts79.7Adobe SuiteAdobe operates one of the largest first-party API estates in software: 70 published OpenAPI and Swagger con...70 published contracts78.8GoogleGoogle Docs is an online word processing and PDF editing tool that is part of Google Workspace. It provides...9 published contracts77.9CloseClose is an inside-sales CRM with calling, email, SMS, and WhatsApp built in. The Close API exposes leads, ...4 published contracts75.8Massive (formerly Polygon.io)Polygon (Polygon.io, rebranded as Massive in early 2026) provides real-time and historical market data APIs...70 published contracts71.6CanvaCanva is the visual design platform used by hundreds of millions of people, and it exposes four distinct de...1 published contract70.9Auth0Auth0 (now part of Okta) is a leading identity-as-a-service platform providing authentication and authoriza...3 published contracts70.5Amazon S3Amazon Simple Storage Service (S3) is an object storage service offering industry-leading scalability, data...2 published contracts70.2NVIDIA NIMNVIDIA NIM (NVIDIA Inference Microservices) is a catalog of GPU-accelerated, containerized AI inference mic...3 published contracts68.0CumulocityCumulocity is an enterprise AIoT (Artificial Intelligence of Things) platform that connects, manages, and a...17 published contracts67.5PluralsightAPIs for the Pluralsight technology skills and engineering intelligence platform, providing access to cours...30 published contracts67.3
Strong 22 Solid coverage with minor gaps
FireblocksFireblocks is an institutional digital-asset and stablecoin infrastructure company providing MPC-secured cu...7 published contracts65.5FastlyFastly is an edge cloud platform that helps customers create great digital experiences quickly, securely, a...22 published contracts65.2CensysCensys is an internet intelligence and attack surface management platform that continuously scans the publi...3 published contracts65.0FactsetFactSet creates flexible, open data and software solutions for tens of thousands of investment professional...142 published contracts63.5Amazon NovaAmazon Nova is a new generation of state-of-the-art foundation models from Amazon that deliver a compelling...1 published contract62.1BarndoorBarndoor AI is the control plane for agentic AI, providing secure access and governance for AI agents and M...1 published contract62.0RaygunRaygun is an application monitoring platform that combines Crash Reporting, Real User Monitoring (RUM), and...2 published contracts61.6GiphyGIPHY is the world's largest library of GIFs, stickers, animated emoji, and Clips (GIFs with sound), with a...1 published contract59.8YoutubeYouTube APIs provide programmatic access to YouTube data including videos, playlists, channels, user intera...5 published contracts59.8Amazon Location ServiceAmazon Location Service provides location-based services including maps, places, routes, trackers, and geof...1 published contract59.0Amazon EFSAmazon Elastic File System (EFS) provides a simple, serverless, set-and-forget elastic file system for use ...1 published contract58.4MetaCollection of Meta (Facebook) platform APIs for social networking, messaging, advertising, content publishi...19 APIs58.0Amazon Global AcceleratorAmazon Global Accelerator is a networking service that improves the performance and availability of applica...1 published contract57.8Google Quantum AIGoogle Quantum AI is Google's quantum-computing research and engineering arm, building superconducting quan...1 published contract57.7PerplexityPerplexity AI is an answer engine that delivers accurate answers to complex questions using large language ...1 published contract57.0Leonardo.AILeonardo.AI is an Australian generative-AI company (acquired by Canva in July 2024) offering a Production A...14 published contracts56.9Amazon MediaConnectAWS Elemental MediaConnect is a high-quality transport service for live video that provides the reliability...1 published contract55.7SoracomSoracom is a global IoT cellular connectivity and platform provider headquartered in Tokyo, founded in 2014...10 published contracts55.7Amazon IoT SiteWiseAWS IoT SiteWise is a managed service that makes it easy to collect, store, organize, and monitor industria...1 published contract55.5Amazon Data ExchangeAWS Data Exchange makes it easy to find, subscribe to, and use third-party data in the cloud. Qualified dat...1 published contract55.1PipedrivePipedrive is a sales CRM and pipeline management tool focused on small and mid-market teams. The Pipedrive ...4 published contracts55.0Amazon MediaTailorAWS Elemental MediaTailor is a channel assembly and personalized ad-insertion service that enables you to m...1 published contract54.9
Developing 35 Usable, with meaningful gaps to close
MoniepointMoniepoint is Africa's all-in-one financial platform for small and medium-sized businesses and individuals ...13 published contracts53.8ClaudeAnthropic's Claude AI assistant API for natural language processing and conversation.1 published contract53.6Adobe Creative CloudAdobe Creative Cloud is a suite of software and cloud services for graphic design, video editing, web devel...4 published contracts53.4BridgeBridge (Bridge Interactive / Bridge Data Output) is a Zillow Group company that runs the Bridge Platform — ...3 published contracts52.8US Census BureauThe U.S. Census Bureau is the federal statistical agency responsible for producing data about the American ...7 published contracts52.3ToolhouseToolhouse is a Backend-as-a-Service platform for building, deploying, and managing "AI workers" (Toolhouse'...1 published contract51.8Adobe Creative SuiteAdobe Creative Suite is a collection of professional software applications for graphic design, video editin...4 published contracts51.7IntercomIntercom is an AI-powered customer service platform that enables businesses to build seamless customized ex...1 published contract51.7RunwayRunway is an applied AI research company that builds generative AI tools for creative professionals. Their ...9 published contracts51.7AxoniusAxonius is a cybersecurity asset management platform (Axonius Asset Cloud) that aggregates device, user, cl...1 API51.4Benchmark MineralsBenchmark Mineral Intelligence is the world's leading market intelligence and price reporting agency for th...4 published contracts50.7AudatexAudatex (a Solera company) provides automotive claims and repair solutions with data and technology service...6 published contracts50.3LivepeerLivepeer is a decentralized video infrastructure network. Independent orchestrators run GPU hardware to pro...7 published contracts49.8Amazon DMSAWS Database Migration Service (AWS DMS) helps you migrate databases to AWS quickly and securely. The sourc...2 published contracts49.6TensorTensor is the Solana-native NFT marketplace and trading protocol founded by Tensor HQ and now stewarded by ...2 published contracts49.0VesselFinderVesselFinder is a maritime intelligence company operating a global AIS vessel-tracking network (terrestrial...2 published contracts48.8OpenRouterOpenRouter is an API platform that provides unified access to multiple AI language models through a single ...1 published contract48.7AssertibleAssertible provides a reliable first line of defense against web service failures by providing simple and p...1 published contract48.2PerforcePerforce Software provides enterprise-scale development tools, including version control, application lifec...1 published contract48.2OpsGenieOpsGenie is an incident management and alerting platform, now part of Atlassian, that helps operations team...12 published contracts48.1AlgorandAlgorand is a pure proof-of-stake blockchain platform designed for speed, security, and decentralization. I...4 published contracts47.5BlockfrostBlockfrost is a RESTful API service providing access to the Cardano blockchain and its ecosystem. It serves...3 published contracts47.1IMDb-APICommunity web service (operated under the IMDb-API / TV-API brand) providing movie, TV series and cast info...1 published contract46.5Triton OneTriton One is a high-performance Solana RPC and blockchain infrastructure provider operating globally distr...3 published contracts46.4BlockdaemonBlockdaemon is an institutional blockchain infrastructure company founded in 2017 by Konstantin Richter. It...11 APIs44.8EVE OnlineEVE Online is a massively multiplayer online (MMO) space game published by CCP Games. The EVE Online third-...7 published contracts44.0HerokuHeroku is a cloud platform as a service (PaaS) that enables developers to build, run, and operate applicati...1 published contract43.4RollbarRollbar is a real-time error tracking and monitoring platform for software teams. It automatically captures...4 published contracts43.3MarineTrafficMarineTraffic is the leading maritime intelligence and AIS ship-tracking platform — now part of Kpler. The ...9 published contracts43.2ForethoughtForethought is a San Francisco-based generative AI customer-support platform. Its multi-agent product suite...2 published contracts42.7Apache JMeterApache JMeter is an open-source Java application designed for load testing functional behavior and measurin...1 published contract41.4LangflowLangflow is an open-source low-code visual builder for AI agents, RAG pipelines, and LangChain-based workfl...1 published contract41.4LoadsmartLoadsmart is a digital freight technology company and 4PL that connects shippers, carriers, warehouses, and...2 published contracts41.0NOAA — National Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration (NOAA) is the United States scientific and regulatory a...1 published contract40.5MubertMubert is a generative AI music platform that composes royalty-free, DMCA-free music in real time from mill...2 published contracts40.2
Thin 24 Limited public surface area
VeriskVerisk (formerly ISO) is a leading data analytics and technology company serving the insurance, energy, and...1 published contract39.0DoclingDocling is an open-source toolkit for parsing diverse document formats — PDF, DOCX, PPTX, XLSX, HTML, image...2 published contracts38.3SplitSplit, now part of Harness Feature Management and Experimentation, is a feature flag and experimentation pl...2 published contracts38.0Capella SpaceCapella Space operates a constellation of synthetic aperture radar (SAR) satellites and provides on-demand,...1 published contract37.9KreaKrea is a real-time AI creative suite that lets designers, filmmakers, brand teams, and everyday creators g...1 published contract37.8SyndicaSyndica is a Solana-only infrastructure company building developer infrastructure for Web3. Its production ...4 APIs36.4Google Apps ScriptThe Apps Script API provides programmatic access to manage Google Apps Script projects, deployments, and ex...1 published contract36.1CATCAT is the brand name and ticker symbol for Caterpillar Inc. (NYSE: CAT), the world's leading manufacturer ...1 published contract34.4RiskifiedRiskified (NYSE RSKD) is an Israeli ecommerce risk-management platform that uses machine learning and a glo...7 APIs34.2Ariba Guided BuyingSAP Ariba Guided Buying provides a consumer-like shopping experience for enterprise procurement, enabling e...2 APIs34.1ScenarioScenario is a Paris- and San Francisco-headquartered AI platform for game asset generation founded in 2021 ...5 APIs34.0AspenTechAspenTech (Aspen Technology, Inc.) is a global leader in industrial software for asset optimization across ...1 published contract33.0GreenlyGreenly is a Paris-headquartered (with offices in London and New York) carbon accounting platform focused o...1 published contract32.3nOpsnOps is an AI-powered cloud cost visibility and optimization platform that helps organizations reduce their...1 published contract32.3Amazon Audit ManagerAWS Audit Manager helps you continuously audit your AWS usage to simplify how you assess risk and complianc...1 published contract30.5Baker HughesBaker Hughes is an energy technology company providing solutions to energy and industrial customers worldwi...2 APIs30.1Lex MachinaLex Machina is a legal analytics platform owned by LexisNexis that transforms raw court documents and docke...2 published contracts29.9Alliance for OpenUSDThe Alliance for OpenUSD (AOUSD) is a Linux Foundation project dedicated to promoting interoperability of 3...2 APIs29.8Volvo CarsVolvo Cars is a Swedish premium automotive OEM (headquartered in Gothenburg, owned by Geely) that operates ...4 APIs29.4BlenderBlender is the free and open source 3D creation suite supporting the entirety of the 3D pipeline including ...2 APIs29.3Affiliated Managers GroupAffiliated Managers Group (AMG) is a global asset management company that partners with outstanding indepen...4 published contracts28.9Imgiximgix is a real-time image processing and CDN service that helps developers optimize images, improve page s...1 published contract28.3Apache TapestryApache Tapestry is a component-oriented framework for creating highly scalable web applications in Java. It...1 API27.2Apache POIApache POI is a Java API for manipulating various file formats based upon the Office Open XML standards (OO...1 published contract27.0
Emerging 16 Early or largely undocumented
Three.jsThree.js is an open-source JavaScript 3D library originally created by Ricardo Cabello (mrdoob) in 2010 and...6 APIs24.4ChainguardChainguard builds, secures, and maintains a catalog of hardened, minimal container images and software supp...6 APIs24.3HPE Aruba NetworkingHPE Aruba Networking is the networking business unit of Hewlett Packard Enterprise (NYSE HPE), born of Arub...10 APIs22.3WiresharkWireshark is the world's foremost and widely-used free and open-source network protocol analyzer. It lets y...1 API20.6SardineSardine is a San Francisco-based fraud prevention, AML compliance, and risk management platform for fintech...6 APIs20.5EcologiEcologi is a Bristol, UK climate action platform and B Corp founded in 2019 that lets individuals and busin...2 APIs19.4Bloomberg IndicesBloomberg Indices are a comprehensive family of fixed income, equity, commodity, and multi-asset benchmark ...3 APIs19.1TradewebTradeweb Markets is a leading global operator of electronic marketplaces for rates, credit, equities, and m...5 APIs19.0Bloomberg Query Language (BQL)Bloomberg Query Language (BQL) is a proprietary query language for accessing, filtering, aggregating, and c...2 APIs18.6AstroPayAstroPay is a Uruguay-founded fintech and electronic money institution offering a multicurrency wallet, vir...20 APIs16.6CerteroCertero is an enterprise IT Asset Management (ITAM) software vendor whose flagship CerteroX platform unifie...6 APIs16.2Babylon.jsBabylon.js is an Apache-2.0 licensed, TypeScript-first open-source 3D engine and rendering framework sponso...18 APIs15.1CMA CGMCMA CGM is a Marseille-headquartered French container shipping, logistics, and port operator and the third-...6 APIs14.2Glass HealthGlass Health is a San Francisco-based clinical AI company founded in 2021 by Dereck Paul (CEO) and Graham R...11.8TransDigm GroupTransDigm Group is a leading global designer, producer, and supplier of highly engineered aerospace compone...11.5AutoGen StudioAutoGen Studio is a low-code / no-code developer GUI from Microsoft Research for rapidly prototyping, compo...11.2
Minimal 4 Almost no public developer surface

What Providers Actually Declared

This feature is a canonical term. These are the free-text strings providers wrote in their own apis.yml that map onto it.

$110B+ digital assets secured; $10B+ staked on Blockdaemon validators; 250K+ nodes launched; 80+ protocols3D assets and a Volvo simulator surface for digital and immersive product experiences.3D model generation via Rodin V2 and 3D model asset management3rd-largest container carrier worldwide; fleet of 593 vessels and 4.5M TEU capacity6,000+ expert witnesses trackedAIS vessel positions (live + delayed)API Test AssertionsAfrica's largest merchant acquirer — ~10M business and individual accounts, $17B monthly TPV, 26M daily payments processedAssertionsAssessment AccessAssessment and PlanAssessment delegation to process owners and resource ownersAsset DiscoveryAsset LibraryAsset Library SystemAsset ManagementAsset Management IntegrationAsset Manager DAM and Asset CleanupAsset ModelingAsset Performance ManagementAsset PipelineAsset ResolutionAsset TelematicsAsset TrackingAsset editingAsset storage (5 GB Free, 100/500 GB paid)Carbon Project Assessment Framework (CPAF) and Nature Project Assessment Framework (NPAF)Cards-as-a-Service issuing for businesses (virtual and physical, branded)Certification: third-party conformity assessment via TÜV Rheinland and TÜV SÜDChainStream real-time streaming API — transactionsSubscribe, slotsSubscribe, blocksSubscribe over WebSocket JSON-RPC 2.0 at wss://chainstream.api.syndica.ioChannel AssemblyClaude Managed Agents (beta) — Agents, Sessions, Environments with SSE streaming and managed sandboxesContent management and digital asset managementContext Variables — typed values (string, number, boolean, list, object) passed into Solve conversationsCross-Asset Data AccessCustom AssemblyDeployment Tracking — release markers correlated with new/regressed error groupsDigital Asset ManagementDigital Twin Manager (DTM) — asset modeling, hierarchies, computed smart functions, custom propertiesDispute Resolve — automated chargeback representment and evidence assembly across major payment gateways

Showing 40 of 110 declared variants

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