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 30 Complete, well-documented, and agent-ready

Customer.io App APIThe Customer.io App API is the workspace-management and outbound-messaging surface: trigger broadcasts, sen...87.3 Customer.io Reporting WebhooksCustomer.io's outbound message-lifecycle event stream. Eight event families — customer, email, sms, whatsap...87.3 Customer.io Track APIThe Customer.io Track API allows developers to send behavioral data and customer profile information into C...87.3 Elation Health Messaging APISecure direct messaging84.1 Elation Messaging APIManage message threads and thread members for provider and patient messaging workflows via the Elation API ...84.1 Transactional Messaging APISpecialized API for sending triggered, transactional messages including order confirmations, password reset...83.5 Salesforce Interaction Service APIThe Salesforce Interaction Service API enables automation and customization of the Bring Your Own Channel (...83.3 Salesforce Messaging APIOperations for creating and tracking email and SMS message sends, including triggered sends and transaction...83.3 HubSpot Engagement Communications APIThe communications API allows you to log WhatsApp, LinkedIn, or SMS messages to CRM record timelines. You c...82.4 OneSignal REST APIThe complete OneSignal REST API as OneSignal publishes it — OpenAPI 3.1.0, info.version 11.6, 39 paths and ...78.3 Nylas APIThe Nylas v3 REST API provides programmatic access to email, calendar, contacts, meeting notetaking, schedu...76.2 SendPulse Chatbots Service APICross-channel chatbot service — account information, listing bots across every messenger channel, and dialo...75.7 SendPulse Facebook Messenger Chatbot APIFacebook Messenger chatbots — bots, subscribers, variables, flows and campaigns, with persistent menus and ...75.7 SendPulse Instagram Chatbot APIInstagram chatbots — bots, subscribers, variables, flows and campaigns, including comment-triggered flows a...75.7 SendPulse SMS APIMobile messaging: phone-book management, SMS campaign orchestration and delivery reporting.75.7 SendPulse Telegram Chatbot APITelegram chatbots — bots, subscribers, variables, flows, campaigns, chats, inline keyboards and custom comm...75.7 SendPulse TikTok Chatbot APITikTok chatbots — direct-message automation and comment-reply workflows for TikTok Business accounts.75.7 SendPulse Viber APIViber rich-media broadcast messaging with images, buttons and automatic SMS fallback (non-chatbot).75.7 SendPulse Viber Chatbot APIViber chatbots — bots, subscribers, variables, flows and campaigns with rich media, buttons and carousels.75.7 SendPulse WhatsApp Chatbot APIWhatsApp Business chatbots — bots, subscribers, variables, flows, campaigns, chats and pre-approved templat...75.7 Mapp Engage APIThe Mapp Engage REST API (REST 2.0, incremental version v19) exchanges data between external systems and Ma...74.7 Vessel Chat Unified APIThe Vessel Chat Unified API normalizes chat platform objects across Slack and Microsoft Teams under /api/un...72.1 Adobe Journey Optimizer APIDesign, trigger and inspect cross-channel customer journeys and campaigns — including message delivery, con...71.2 LINE Messaging APIThe core LINE bot API — 73 operations for replying, pushing, multicasting, broadcasting and narrowcasting m...71.2 Facebook Messenger Platform APIBuild conversational experiences on the Messenger platform. The Messenger Platform API enables businesses t...68.6 Facebook WhatsApp Business Platform APISend and receive messages, manage business profiles, and automate customer communications through the Whats...68.6 CleverTap Campaign APIProgrammatically create and manage push, email, SMS, web, and in-app campaigns and retrieve message status ...68.2 ActiveCampaign WhatsApp APIThe WhatsApp API from ActiveCampaign — 13 operation(s) for listing, retrieving, updating and deleting Whats...67.2 Business Messaging API8x8 Business Messaging (Chat Apps) API for sending and receiving rich messages over WhatsApp Business, RCS,...67.1 SMS API8x8 Connect SMS API for single and batch A2P SMS delivery worldwide, with sender ID handling, encoding cont...67.1

Strong 52 Solid coverage with minor gaps

SAP Emarsys SMS Partner Service APIPublished by SAP Emarsys as OpenAPI 3.0.3 with 5 operation(s). Part of the SMS Partner API, which SAP Emars...66.4 Weave Messaging APITwo-way SMS/text messaging with patients.65.5 ServiceNow Email APIThe ServiceNow Email API provides REST endpoints for sending email messages from the Now Platform. It allow...64.8 Swisscom Receive SMS APIInbound SMS API that exposes message inboxes so applications can receive texts from customers and build two...63.8 Swisscom Text Messaging (SMS) APIApplication-to-person SMS sending over the Swisscom messaging infrastructure with onward delivery to 260+ o...63.8 Dotdigital CPaaS APIThe Communications Platform as a Service estate under /cpaas — omnichannel outbound and inbound messaging a...63.4 Hootsuite Inbox 2.0 APIThe Inbox 2.0 (formerly Sparkcentral) customer-conversation API — CRM contact attribute write-back, the Vir...63.3 Vendasta Conversation APIConversations AI service API for the unified inbox that centralises SMS, web chat, voice and other channels...63.3 IBM Cloud Event NotificationsRoute event notifications from IBM Cloud services to communication channels such as email, SMS, webhooks, a...62.6 IBM Event StreamsFully managed Apache Kafka service for high-throughput event streaming, event ingestion, and event stream d...62.6 Slack Incoming Webhooks APISlack Incoming Webhooks provide a simple way to post messages from external sources into Slack. Creating an...62.3 Cloudflare Email Routing APIThe Cloudflare Email Routing API enables developers to create and manage custom email addresses and routing...62.0 KPN Email-to-SMS APIConverts inbound email into SMS messages delivered over the KPN network. Documented on the KPN Developer po...61.9 KPN SMS APISend SMS through the KPN network.61.9 KPN SMS Campaigns APISend and schedule bulk SMS campaigns over the KPN network. Documented on the KPN Developer portal; no publi...61.9 KPN SMS Inbound APIThis API is designed to inform users about the response schema they will receive on their webhook when an S...61.9 Parley Secure Messenger APIThis API enables a secure communication between your agent/bot desktop and the client website/mobile app.61.9 Tracebuzz Social Media Webcare APIThe SocialMediaWebcare API allows you to organise and manage your inbound and outbound social media channel...61.9 Vonage Messages API (via KPN)Encapsulates multiple APIs to interact with our various channels such as WhatsApp Business, SMS, MMS, Viber...61.9 Vonage SMS API (via KPN)Vonage's SMS API allows you to send and receive text messages to users around the globe through simple REST...61.9 Sprout Social APIThe Sprout Social Public API provides programmatic access to publishing, analytics, messaging, listening, a...61.3 Instagram Messaging APISend and receive messages on Instagram using the Messenger Platform, enabling customer service and automate...60.9 Messenger Platform APIBuild messaging experiences on Facebook Messenger including chatbots, rich media messages, and customer ser...60.9 WhatsApp Business Management APIManage WhatsApp Business accounts, phone numbers, message templates, and business profiles programmatically.60.9 WhatsApp Cloud APISend and receive messages, manage phone numbers, and build messaging experiences on WhatsApp using Meta's c...60.9 Unified.to messaging APIThe messaging API from Unified.to — 5 operation(s) for messaging.60.4 Red Hat Streams for Apache Kafka Bridge APIHTTP bridge API for producing and consuming messages to Apache Kafka topics without requiring a native Kafk...59.1 Transmit Message APICurrent v2 REST API covering SMS, MMS, WhatsApp and RCS, plus API-managed webhooks with event-type filterin...59.1 Transmit SMS APIClassic v1 REST API — fully supported, not deprecated. SMS sending with single-request multi-recipient batc...59.1 Wunderkind Text Message APIRESTful endpoints for delivering text messages from platforms external to the Wunderkind ecosystem (ESP, CD...59.1 Community messaging APIThe messaging API from Community — 1 operation(s) for messaging.58.9 RingCentral SMS APIThe SMS API from RingCentral — 2 operation(s) for sms.58.2 RingCentral Voicemail APIThe RingCentral Voicemail API enables retrieval, playback, and management of voicemail messages, including ...58.2 Lichess Messaging APIPrivate messages with other players. 58.1 Zendesk Sunshine Conversations APIThe Zendesk Sunshine Conversations API is a messaging platform that lets you unify messages from every chan...58.1 Glowmarkt Notification System APIAlerting and messaging for Glow-based applications. Defines alert types, manages per-channel and per-cultur...57.6 Insider One Gateway API (OAuth 2.0)The OAuth 2.0 gateway: WhatsApp v2 transactional and conversational send, plus webhook settings registratio...57.6 Insider One Mail APITransactional email sending (9,000 requests/second) with dynamic fields, attachments and customer-supplied ...57.6 Insider One SMS APITransactional single and bulk SMS sending, plus SMS campaign, overall, transactional and OTP/Verify analyti...57.6 Insider One Web Push APICreate, launch and delete single web push campaigns from your own backend, plus web push top-metrics, overa...57.6 Insider One WhatsApp APITransactional and conversational WhatsApp sending — template, text, media, location, button-reply and carou...57.6 Microsoft Azure Event Grid APIAzure Event Grid is a fully managed event routing service that enables developers to build event-driven arc...57.3 Pabbly Chatflow APIREST API for Pabbly Chatflow, a WhatsApp Business messaging platform. 33 documented operations covering 18 ...57.3 Route Mobile RCS Business Messaging APIRich Communication Services business messaging — verified sender messaging with rich cards, carousels and s...57.2 Route Mobile Viber Business Messages APIViber Business Messages — login, single and bulk message submission (text, image, video, file and template ...57.2 Route Mobile WhatsApp Business APIRoute Mobile is a Meta Business Solution Provider for the WhatsApp Business Platform. The API covers JWT lo...57.2 Azure Event Hubs Messaging APIEvent-driven messaging API for publishing and consuming events via AMQP 1.0, Kafka, and HTTPS protocols. Su...57.1 Amazon Q Developer in Chat Applications APIAPI for Amazon Q Developer in chat applications, which enables integration of Amazon Q Developer capabiliti...56.0 Podium APIREST API for managing customer communications including messaging, reviews, payments, webchat, contacts, au...55.6 Telia Bulk Messaging SMPP APISMPP v3.4-style binary protocol interface into the Telia Company Bulk Messaging Platform, reached over TLS ...55.2 Telia Bulk Messaging SMS Callback APIThe webhook half of Telia's Bulk Messaging REST surface. Customers must implement a Receive SMS (mobile ori...55.2 Telia Bulk Messaging SMS REST APIJSON REST API for submitting mobile-terminated SMS through the Telia Company Bulk Messaging Platform, with ...55.2

Developing 108 Usable, with meaningful gaps to close

Optus SMS Suite Campaign Manager APIREST API v1 for programmatic control of SMS marketing campaigns — creating and managing recipient lists, me...54.0 Optus SMS Suite HTTPS APILegacy GET-based HTTPS interface for SMS integration, covering message sending, delivery receipts, and inbo...54.0 Optus SMS Suite MMS MM7 APIImplementation of the 3GPP MM7 SOAP protocol for sending and receiving MMS, carrying text, image, audio, vi...54.0 Optus SMS Suite REST API v1JSON REST API for sending single and bulk SMS from The Optus SMS Suite, including scheduled sends, broadcas...54.0 Optus SMS Suite REST Email APICompanion REST API to the SMS gateway for scheduling and sending plain-text transactional email over a sepa...54.0 Optus SMS Suite SMPP APIDirect SMSC connectivity over SMPP 3.3 and 3.4 with mandatory TLS, offering high-throughput binary messagin...54.0 Optus SMS Suite SMS Gateway REST API v2High-volume asynchronous SMS API using UUID-based message tracking, mandatory delivery-receipt (DLR) callba...54.0 Optus SMS Suite SOAP APIWSDL-described SOAP interface for SMS integration supporting custom source addressing, message classificati...54.0 Airtel IQ SMS APIThe messaging half of Airtel IQ, Airtel's network-embedded CPaaS suite. Sends single, bulk, CSV-batch and c...53.9 MTN Medallia SMS V2Provides a RESTful API to expose SMS capability.53.7 MTN Notification V1To facilitate notifications. Allows 3PPs to register and have notifications processed to them from the appl...53.7 MTN Notification v2To facilitate notifications. Allows 3PPs to register and have notifications processed to them from the appl...53.7 MTN SMSMTN SMS Messaging API allowing developers to include SMS messaging in their applications.53.7 MTN SMS V2Provides a RESTful API to expose SMS capability.53.7 MTN SMS v3 APIProvides a Restful API to expose SMS capability for sending of messages , Mobile originating messages and D...53.7 MTN USSD interfaceProvides a RESTful API to expose USSD capability.53.7 Leanplum Messaging APIThe Messaging API from Leanplum — 3 operation(s) for messaging.53.2 Vonage Conversations APIBuild multi-channel conversation experiences with threading across SMS, voice, and messaging channels. Mana...53.2 Artera Messaging API (MAPI)Artera's outbound SMS API, marketed to health systems and Artera Marketplace vendors as the SendMessage API...53.1 OCI Email Delivery APIREST APIs for sending high-volume and application-generated emails through Oracle Cloud Infrastructure, wit...53.0 OCI Notifications APIPublish and subscribe messaging service for setting up communication channels using topics and subscription...53.0 OCI Queue APIServerless messaging service for decoupling application components with reliable message delivery, supporti...53.0 OCI Streaming APIManaged messaging service for ingesting and consuming high-volume data streams in real time, compatible wit...53.0 Microsoft Teams Bot Framework APIAPI for building conversational bots that interact with users in Microsoft Teams through the Bot Framework.52.9 Apple Push Notification Service (APNs)Send push notifications to iOS, macOS, watchOS, and tvOS devices.52.8 Qubership MaaS (Messaging as a Service) APIThe REST API for Qubership MaaS, Netcracker's open-source messaging-as-a-service component that provisions ...52.8 Genesys Messaging APIMessaging52.7 Syniverse 10DLC APIUS 10DLC (10-digit long code) campaign provisioning — create, retrieve, suspend and resume campaigns, attac...52.3 Syniverse Omni-Channel Messaging API (SCG)The Syniverse Communication Gateway (SCG) API — the core of the Syniverse Developer Community platform. 72 ...52.3 KORE SMS APIThe KORE SMS API programmatically exchanges short messages with IoT devices on KORE connectivity. Three ope...51.9 MuleSoft Anypoint MQ APIThe Anypoint MQ API provides a cloud messaging service built on the Anypoint Platform for asynchronous mess...51.9 Nextiva SMS Messaging APISend outbound SMS messages from a Nextiva user. Inbound SMS arrives as a workitem on the SDK event stream r...51.9 Arthur Conversations APIThreaded conversations and messages between managers, tenants, owners and contractors, with attached assets...51.8 ManyChat REST APIREST API for managing subscribers, custom fields, tags, bot fields, flows, and sending messages in ManyChat...51.6 ManyChat Sending APISend Dynamic Block content and trigger automations for a subscriber across Messenger, Instagram and WhatsAp...51.6 NHS App APIIntegrate with the NHS App to deliver messages and content to citizens and to link into NHS App journeys. O...51.5 NHS Notify (Communications Manager) APINational service for sending messages to people about their health and care across channels (NHS App, SMS, ...51.5 TPG Telecom Messaging Hub Contacts APIContacts Management API for the Vodafone Business Messaging Hub, providing CRUD over contacts, lists and cu...51.3 TPG Telecom Messaging Hub REST APIThe SMS/MMS REST API of the Vodafone Business Messaging Hub, listed on the product page as "Access to our R...51.3 Hostaway Messaging APIUnified guest messaging across Airbnb, Vrbo, Booking.com, Expedia, email, SMS, and WhatsApp. Resources incl...51.2 Nash Messaging APIMessaging51.2 Platform Events APIEvent-driven architecture API for publishing and subscribing to custom events for app integration. Supports...51.1 Zoom Mail APIThe Zoom Mail API enables developers to programmatically access and manage mailbox data including draft man...51.1 Zoom Team Chat APIThe Zoom Team Chat API enables developers to integrate messaging into applications and automate workflows w...51.1 phone-com-apiPhone.com v4 ("Phoenix") JSON REST API for managing accounts, extensions, devices, phone numbers, call rout...50.7 LSEG Messenger Bot SDKSDK for building intelligent, compliant messaging bots within the LSEG Messenger platform. Enables sending,...50.6 Messenger Side by Side APIAPI allowing external applications to connect with and pass information into LSEG Messenger. Requires user ...50.6 Emotive Sensus Webhooks APIInbound webhook receiver on the Emotive API gateway — create subscribers singly and in bulk, set profile pr...50.0 WhatsApp Flows APIAPI for creating structured, interactive forms and multi-step flows within WhatsApp conversations, enabling...49.9 WhatsApp On-Premises APIThe self-hosted version of the WhatsApp Business API that allowed businesses to run the API on their own in...49.9 Azure Integration APIREST APIs for Azure integration services including Service Bus, Event Grid, Logic Apps, and API Management ...49.8 Localytics Transactional Push APIProgrammatic push messaging delivery. Submit a batch of pushes for an application targeting customer_ids, a...49.8 Mobile Messaging Exchange - Account AdministrationAccount administration and lookup reporting for the Tata Communications Mobile Messaging Exchange (A2P/whol...49.4 Mobile Messaging Exchange - CDR Report APICall/message detail record reporting for the Tata Communications Mobile Messaging Exchange, returning messa...49.4 SAP Event Mesh APIMessaging APIs for event-driven architecture supporting AMQP, MQTT, and REST protocols.49.0 Luma Health Messaging & Engagement APITwo-way patient messaging, engagements and engagement events/settings, appointment reminders, and patient m...48.9 WeChat Mini Programs Server APIBackend HTTPS/JSON APIs that Mini Program operators call from their own servers to authenticate user sessio...48.8 WeChat Official Accounts APIHTTPS/JSON APIs for WeChat Official Accounts (Subscription Accounts and Service Accounts) — the publishing ...48.8 WeChat Work (WeCom) APIServer API for Enterprise WeChat / WeCom — Tencent's enterprise collaboration suite. All calls are HTTPS/JS...48.8 Oracle Transactional Event Queues (TxEventQ)Kafka-compatible event streaming and message queuing built into Oracle Database.47.8 Gmail APISend and read email, manage drafts and labels, and handle mailbox settings.47.5 Google Chat APIBuild bots and integrations for Google Chat.47.5 Telegram Messaging APIMethods for sending messages and media46.9 SAP Event Mesh APIThe SAP Event Mesh API provides access to the event brokering service within SAP Business Technology Platfo...46.8 SAP Integration Suite Advanced Event Mesh APIThe SAP Integration Suite Advanced Event Mesh (AEM) REST API provides management capabilities for event bro...46.8 Workday Integration Messaging APIThe Messaging API from Workday Integration — 2 operation(s) for messaging.46.8 CrossEngage File Attachments APISingle-operation API for uploading files to be attached to messages sent through stories or campaigns. A pa...46.7 StackOne Unified Messaging APIStackOne Unified Messaging API standardizes communication workflows across platforms, with consistent data ...46.7 Azure Service BusAzure Service Bus is a fully managed enterprise message broker with message queues and publish-subscribe to...46.6 GP Connect Send Document FHIR APISend a PDF consultation summary or clinical document to a patient's registered GP practice. Used when a pat...46.6 Cisco Webex APIREST API for Webex collaboration platform enabling messaging, meeting management, device control, and admin...46.4 Google Chat APIThe Google Chat API enables developers to build Chat apps that bring services and resources into Google Cha...45.2 China Mobile Internet Capability Open Platform中国移动互联网能力开放平台 at dev.10086.cn is the operator's application-facing capability marketplace, describing itsel...45.1 Twitch Chat APIManage chat settings, emotes, badges, and announcements44.9 SK Telecom OVS APIOVS is SK Telecom's road-event alerting service. Twelve documented operations covering customer company loo...44.5 IronMQ v3IronMQ is a high-performance hosted message queue that lets you pass messages and events between processes ...44.4 Apache Kafka Messaging APIThe core Kafka messaging protocol for producing and consuming records to/from topics using the native Kafka...44.3 Khoros Care APIsKhoros Care developer surface for agent-based social customer service — the event-driven Automation Framewo...44.2 Khoros Flow APIsKhoros Flow developer APIs for building conversational bots and custom chat clients — the Flow Socket API (...44.2 Whoosh Programmable Messaging APIWhoosh! is Totogi's Application-to-Person (A2P) messaging API, launched in September 2023 and positioned as...44.2 Plivo Message APISend and retrieve SMS, MMS, and WhatsApp messages.44.0 Plivo Powerpack APIThe Plivo Powerpack API creates and manages Powerpacks — pools of numbers that distribute outbound messagin...44.0 Trellix Data Exchange Layer (DXL) APIMessaging fabric API that enables real-time communication between security tools and data sharing across th...43.5 Roblox Engine API Messaging APICross-server messaging service43.4 Pharmacy Unified API - CommunicationPatient-communication and group-messaging operations within the Pharmacy Unified API - creating and editing...42.6 Pharmacy Unified API - InboxOperations for the pharmacy PlusOne inbox within the Pharmacy Unified API - retrieving the main inbox, sent...42.6 Kno2 Messaging APISEND surface - draft, populate, attach, and send messages.42.4 TIBCO Messaging APIEnterprise messaging API supporting EMS (Enterprise Message Service) and FTL (Fast Transport Layer).42.4 Rokid Sprite Enterprise OpenAPIThe Rokid Glass3 / Sprite Enterprise cloud API. Device registration lookup and real-time telemetry, message...42.2 Chatfuel Broadcasting APIProgrammatically send messages and trigger flows/blocks to a specific bot user on Messenger, Instagram, or ...41.8 NATS Messaging APIAsynchronous messaging API supporting core pub-sub, request-reply, queue groups, and JetStream persistent m...41.8 Everbridge Communications APIThe Everbridge Communications API provides endpoints for managing communication templates, categories, rese...41.6 Message Exchange for Social Care and Health (MESH) APIExchange messages and data files between NHS organisations using MESH, the national messaging infrastructur...41.6 Pusher Channels APIPub/sub channels over WebSocket (client) and HTTP (server publish). Public, private, and presence channels ...41.6 Chatfuel Broadcasting APIHTTP API for sending any block or flow from a bot to a user via a POST request, including targeting users b...41.5 Veterans Affairs Messaging APIThe Messaging API from Veterans Affairs — 20 operation(s) for messaging.41.1 Signal Android SDKSignal-Android is the open-source Android client for the Signal encrypted messaging platform. It provides t...41.0 Signal Desktop SDKSignal-Desktop is the open-source desktop client for the Signal encrypted messaging platform, built with El...41.0 Signal iOS SDKSignal-iOS is the open-source iOS client for the Signal encrypted messaging platform. It delivers end-to-en...41.0 Signal Protocol SpecificationsThe Signal Protocol Specifications define the core cryptographic protocols that underpin Signal's end-to-en...41.0 Jupyter Kernel Messaging ProtocolWebSocket-based messaging protocol for communication between Jupyter clients and computational kernels. Sup...40.8 The Interaction Company Of California Messaging APISend messages to Poke programmatically.40.5 Chatwoot Client APIThe Client API is designed for building custom messaging interfaces for end users. Authenticates using inbo...40.4 Submittable Messaging APIMessage attachments.40.1 Telesign Messaging APISend and track SMS messages40.1 Appgain Notify APIThe messaging send service. A single POST /{projectId}/send endpoint whose channel is selected by the top-l...39.6 Appgain OmniChannel Messaging APIREST API for sending multi-channel campaigns (rich push notifications, email, SMS, web push), creating smar...39.6 Burner APIOAuth 2.0 REST API for programmatic access to Burner line management, messaging (SMS/MMS) and configuration...39.4

Thin 83 Limited public surface area

Instagram Messaging APIThe Messenger API support for Instagram consolidates Instagram and Facebook Page messaging into a unified p...39.0 Orange Business Messaging Pro Cameroon APICameroon-specific A2P messaging platform for enterprise SMS, USSD, and rich messaging deliveries to Orange ...38.9 Orange Business SMS Middle East and Africa APIA2P SMS delivery API for Orange Middle East and Africa footprint. Supports transactional, OTP, and marketin...38.9 Ada Conversations APIRead and manage conversations handled by the Ada AI Agent across all supported channels.38.5 CloudEvents AMQP Protocol BindingThe AMQP protocol binding for CloudEvents defines how events are mapped to OASIS AMQP 1.0 messages. In stru...38.5 CloudEvents Kafka Protocol BindingThe Kafka protocol binding for CloudEvents defines how events are mapped to Apache Kafka messages. It speci...38.5 CloudEvents NATS Protocol BindingThe NATS protocol binding for CloudEvents defines how events are mapped to NATS messages. It enables CloudE...38.5 Zoho CliqThe Zoho Cliq REST API v2 allows developers to extend their web applications by programmatically managing c...38.5 Zoho MailThe Zoho Mail REST API allows developers to fetch email conversations and integrate Zoho Mail into applicat...38.5 FedNow ISO 20022 Message SpecificationsThe core scheme messaging surface of the FedNow Service. FedNow is ISO 20022 native and defines message typ...38.2 Lodgify Messaging APIGuest conversation threads and messages.38.1 Smoobu Messaging APIReservation messages and unified inbox threads.37.6 Backendless Messaging APIPublish-subscribe messaging, push notifications, and email.37.5 IBM MQ JMS APIJava Message Service API for IBM MQ.37.5 Roblox Open Cloud Messaging ServiceThe Messaging Service Open Cloud API publishes messages to a topic that running game servers can subscribe ...37.5 SleekFlow Messaging APISend messages, files, and internal notes; check conversation windows.37.5 Purplebricks Messaging APIThreaded messaging between customers, sellers and local property experts: message threads, individual messa...36.9 Atom Customers APIREST service for managing the customer (cliente) records behind Atom's WhatsApp conversations. The provider...36.8 Atom WhatsApp Templates APIREST service for sending pre-approved WhatsApp template messages from an account's official WhatsApp number...36.8 Mattermost REST APIREST API v4 for managing users, teams, channels, posts, threads, files, integrations, plugins, webhooks, sl...36.1 Mattermost WebSocket APIReal-time WebSocket event stream for Mattermost v4. Clients connect to /api/v4/websocket, authenticate via ...36.1 ABC Trainerize Messaging APISend in-app messages and upload attachments / meal-plan PDFs to clients.35.6 McAfee Data Exchange Layer (DXL) APIMessaging fabric for real-time security data exchange and integration.35.2 Whippy Messaging APISend SMS / MMS, email, and fax messages.35.1 Photon Chat APIA separately billed Photon Cloud service (its own AppId type) for text messaging, presence, and friend list...34.9 Chert Messaging APIProgrammatic send/receive/route over iMessage — 1:1 and group chats, attachments, rich links, tapbacks, typ...34.8 CleanCloud Messaging APICustomer/store messaging and push notification tokens.34.7 Wazo Presence & Chat API (wazo-chatd)Presence and chat microservice. Tracks user, line and refresh-token presence (including Microsoft Teams pre...34.6 Apache EventMesh Messaging APIEvent-driven messaging via TCP, HTTP, and gRPC protocols. Events follow the CloudEvents specification. Supp...34.5 Application Research Messaging APIMessaging portable resource operations34.5 KakaoTalk Message APIKakaoTalk Message sends template-based messages from a Kakao-Linked app to the authenticated user themselve...34.5 KakaoTalk Sharing APIKakaoTalk Sharing lets external apps and websites share rich "Feed", "List", "Location", "Calendar", "Comme...34.5 GroupMe API v3REST + JSON API for GroupMe groups, memberships, messages, chats, likes, blocks, users, and bots, plus a Ba...34.1 PubNub REST APISingle REST surface for publish, subscribe (long-poll), presence, history, signal, and App Context. Pub/Sub...34.1 Telnyx Messaging APIThe Messaging API from Telnyx — 8 operation(s) for messaging.34.0 Pushbullet HTTP APIREST API for sending and managing pushes, devices, chats, channels, subscriptions, and file uploads across ...33.6 Termii Messaging APISend single, bulk, and number-based messages.33.6 Zulip REST APIThe Zulip REST API powers the Zulip web and mobile apps. It provides programmatic access to messages, strea...33.6 LiveChat Agent Chat APIREST and RTM APIs for agents to manage chats, send messages, transfer conversations, and update statuses. A...33.4 LiveChat Customer Chat APIREST and RTM APIs for customers to start and participate in chats with agents on LiveChat-powered websites....33.4 Modal Dicts and QueuesDistributed key-value store (modal.Dict) and distributed queue (modal.Queue) for passing state and messages...33.3 Towns ProtocolTowns Protocol is an open, decentralized messaging protocol built on Base. Builders integrate via first-par...33.1 Scroll Native BridgeCanonical L1 L2 bridge for ETH, ERC-20, and arbitrary messages between Ethereum mainnet and Scroll. Backed...33.0 Sarj AI Developer API Messaging APIThe messaging API from Sarj AI Developer API — 8 operation(s) for messaging.32.9 WATI WhatsApp Business APITenant-scoped REST API for sending WhatsApp template and session messages, managing contacts, assigning ope...32.9 Spring Integration AMQP AdapterAMQP channel adapters and gateways for Spring Integration. Provides RabbitMQ message-driven and polling inb...32.4 Spring Integration Kafka AdapterKafka channel adapters for Spring Integration. Provides message-driven inbound adapters, outbound channel a...32.4 Spring WebFlux WebSocketReactive WebSocket support for full-duplex, bidirectional communication in WebFlux applications. Provides W...32.4 Botpress Chat APIWebhook-based REST API for sending and receiving chat messages with deployed Botpress bots. Endpoint patter...32.3 Symphony Pod APIThe Symphony Pod API provides core platform services including user management, stream (room) management, c...32.3 KrakenD Async AgentThe KrakenD Async Agent enables event-driven API consumption by connecting KrakenD to message brokers and e...32.1 Messaging APIsA portfolio of messaging APIs including SMS Middle East and Africa, Messaging Pro Cameroon, Voice as a Serv...32.1 Strimzi Operator APIThe Strimzi Operator API is expressed through Kubernetes Custom Resource Definitions (CRDs). Operators are ...32.1 Apache ActiveMQ BrokerThe ActiveMQ Classic broker provides high-performance asynchronous messaging through multiple protocol inte...31.8 Qualia APIThe Qualia API is a read-write GraphQL API over the Qualia title, escrow and closing platform. It lets part...31.8 Aircall Messaging APISend and receive SMS/MMS and group messages.31.7 Garmin inReach Portal ConnectEnterprise API for organizations to integrate inReach satellite communicator data — two-way messaging, loca...31.6 Apache Pulsar Messaging APIPulsar messaging protocol for producing and consuming messages on topics, with support for multiple subscri...31.4 Matrix Client-Server APIREST API used by Matrix clients to communicate with a homeserver, covering login, room creation and managem...31.3 Hologram Messaging APIThe Messaging API from Hologram — 1 operation(s) for messaging.31.2 Crisp Realtime (Webhooks + RTM) v1Crisp realtime surface combining HTTP Web Hooks (signed plugin hooks and unsigned website hooks) and the So...31.0 RabbitMQ AMQP Messaging APIAMQP 0-9-1 messaging protocol for producing and consuming messages via exchanges, queues, and bindings with...30.5 Service Cloud Live Agent APIAPI for real-time chat and messaging with customers.29.8 XMTP Android SDKNative Kotlin SDK for integrating XMTP encrypted messaging into Android applications. Supports wallet-based...29.7 XMTP iOS SDKNative Swift SDK for integrating XMTP encrypted messaging into iOS applications. Provides wallet-based auth...29.7 XMTP JavaScript/TypeScript SDKClient SDK for browsers and Node.js enabling applications to send and receive end-to-end encrypted messages...29.7 XMTP Network gRPC APICore gRPC-based API for the XMTP decentralized messaging network. Provides operations for sending and retri...29.7 Kafka Consumer APIAPI for subscribing to topics and processing streams of records.29.6 Kafka Producer APIAPI for publishing streams of records to Kafka topics.29.6 Vault12 Zax Cryptographic Relay APIOpen-source NaCl-based cryptographic relay operated as asynchronous "dead drops" for end-to-end-encrypted d...29.6 Apache Kafka Admin APIApache Kafka's Admin REST API enables creating and managing topics, partitions, consumer groups, and cluste...29.5 Apache ServiceMix Messaging APIThe Messaging API from Apache ServiceMix — 1 operation(s) for messaging.29.5 NATS Management APINATS is a lightweight, high-performance messaging system for distributed applications. Its management API p...29.5 AMQP Messaging APIAsyncAPI specification for AMQP messaging patterns including publish/subscribe, request/reply, and point-to...29.3 Vetspire Conversations & Communications APIGraphQL operations over the Conversations and Marketing domains - client messaging threads (SMS/email), tem...28.9 Mainstay APIAdmitHub/Mainstay REST API v1.0 for syncing student and employee records and engagement data between Mainst...28.5 Agora Chat APIThe Agora Chat API provides scalable in-app messaging with one-to-one chat, group chat, chat rooms, threads...28.2 Agora Signaling API (RTM)The Agora Signaling API (formerly Real-Time Messaging / RTM) provides real-time low-latency synchronization...28.2 Replyr Platform APIREST API for the Replyr operator console at app.replyr.ai. Covers business account details, admins and team...27.9 Deutsche Telekom Rich Communication Services APIImprove customer experience using Rich Communication Services for branded, interactive messaging that exten...27.6 Deutsche Telekom SMS APIProgrammatically send and receive text messages in practically every country through Deutsche Telekom's CPa...27.6 AsyncAPI SpecificationThe AsyncAPI Specification is an open standard for describing asynchronous and event-driven APIs. It provid...27.3 Outlook Mail APIAPI for accessing and managing email messages through Microsoft Outlook.26.8

Emerging 41 Early or largely undocumented

Spring Batch 5.1 Integration APISpring Batch integration with Spring Integration for remote partitioning, remote chunking, and message-driv...25.5 Nitric Queue ResourceSDK resource for declaring durable message queues for batch and deferred processing. Nitric maps it to a cl...25.1 Twilio API (reference provider)Reference provider with strong agent-readiness signals on the messaging side — published OpenAPI, idempoten...25.0 Urbit HTTP API (Tlon)The Urbit ship HTTP API (Eyre channels) that powers Tlon Messenger. Clients authenticate to a ship with its...25.0 tyntec Conversations APIOne API for WhatsApp Business, Viber, and SMS. Send single (POST /messages) or bulk (POST /bulks) messages,...24.8 tyntec SMS APISend and receive text messages over tyntec's global A2P SMS network. Send via POST /messaging/v1/sms, retri...24.8 Gupshup Messaging APISend WhatsApp session messages.23.9 Gupshup SMS APIBroadcast SMS to a single number or many numbers programmatically via POST /msg on the /sm surface. Note - ...23.9 Spring Cloud Stream Core APICore programmatic API for building message-driven microservice applications. Provides functional programmin...23.2 Spring Cloud Stream Kafka BinderApache Kafka binder for Spring Cloud Stream providing Kafka producer and consumer binding configuration, Ka...23.2 Spring Cloud Stream RabbitMQ BinderRabbitMQ binder for Spring Cloud Stream providing AMQP-based messaging with support for exchanges, queues, ...23.2 myBots Tenant APIThe bearer-gated REST API the Mia AI application calls to operate a tenant's agents, subscription and chann...21.7 Skype URIs APISkype URIs provide a mechanism for launching Skype actions from web pages and applications. Developers can ...21.7 App.net Stream APIThe App.net Stream API — a RESTful, OAuth 2.0-secured social API covering posts, users, follows, channels/m...21.3 Bloomberg IB (Instant Bloomberg)Secure messaging platform built into the Bloomberg Terminal enabling real-time communication between financ...21.1 DAS Web APIThe DAS Web API (DASWebAPI) is DAS Technology's REST API for the CDXP platform, served from api.digitalairs...20.7 MassTransit Messaging FrameworkMassTransit provides a consistent abstraction on top of message transports like RabbitMQ, Azure Service Bus...20.5 Lufthansa Cargo CargoIMP APIPrior-agreement API product listed as CargoIMP in the portfolio, referencing the legacy IATA Cargo Intercha...20.3 Lufthansa Cargo CargoXML APIPrior-agreement API product named CargoXML in the Lufthansa Cargo portfolio, referencing the IATA Cargo-XML...20.3 Descartes B2B API ConnectivityReal-time B2B connectivity over the Descartes Global Logistics Network, complementing traditional EDI. Prov...20.1 MQTT ProtocolMQTT (Message Queuing Telemetry Transport, ISO/IEC 20922) is a lightweight pub/sub messaging protocol widel...19.9 Singtel CPaaS SMS APIApplication-to-person SMS sending and receiving for business applications, sold as part of the Singtel CPaa...19.8 Lazada Chat (IM) APIBidirectional buyer-seller messaging API for in-app conversations on Lazada — including sending and retriev...19.7 TranZak SMS APIREST API for sending marketing bulk SMS messages and OTP/verification codes. Supports up to 500 recipients ...19.4 Hostfully REST APIHostfully Property Management Platform REST API v3.x covering properties (single and multi-unit), leads (in...18.9 LivePerson Conversational Cloud APIComprehensive set of REST APIs for managing conversations across messaging channels, including agent operat...18.8 LivePerson Messaging Operations APIReal-time and historical operational metrics for messaging conversations, including queues, agent activity,...18.8 Xcel Energy Messaging APIText and HTML messages targeted at end-users.18.1 Subsplash Groups and Messaging APIManage groups, group membership, and messaging, and trigger push notifications and in-app messages through ...17.2 JD Open Platform Customer Service APICustomer service (客服) APIs integrate with JD's IM and service workflows — letting merchants pull customer i...16.6 Microsoft Teams APIBuild apps and bots for Microsoft Teams collaboration platform.16.2 Moxtra REST APIMoxtra's REST API for building embedded collaboration experiences, covering users, binders (workspaces), pa...15.9 Naver Cloud SENS Messaging APISENS (Simple & Easy Notification Service) sends SMS, LMS, MMS, Alimtalk (KakaoTalk channel), Friend Talk, a...15.8 POSIX Message Queues APIPOSIX message queue interfaces for exchanging messages between processes with priority support.15.8 AsyncAPI SpecificationAsyncAPI is the open standard for describing event-driven and message-driven APIs across protocols such as ...15.4 AMQPAdvanced Message Queuing Protocol. AMQP 1.0 is both an OASIS standard and an International Standard (ISO/IE...14.9 IBM MQEnterprise messaging middleware from IBM. Long the de facto standard for assured-once message delivery in r...14.9 NATSCNCF incubating high-performance, lightweight messaging system designed for cloud, edge, and IoT. Supports ...14.9 STOMPSimple (or Streaming) Text Oriented Messaging Protocol. Lightweight, text-based wire protocol for message-o...14.9 NATS JetStreamPersistence layer for the NATS messaging system providing at-least-once and exactly-once streaming, key/val...14.8 Jakarta MessagingThe Jakarta Messaging (formerly Java Message Service) specification for enterprise messaging and asynchrono...12.4

Minimal 6 Almost no public developer surface

SMS Messaging HubA2P SMS messaging gateway for sending one-time-passcodes, alerts, and marketing messages to Vodafone subscr...8.7 Sectra HL7 Integration InterfaceHL7 v2 messaging interface for exchanging orders, scheduling, worklist, and results/reports between Sectra ...8.5 ISAAC Messaging APIModeled interface for driver-to-dispatch messaging and in-cab workflow forms exchanged through the ISAAC pl...8.4 Inmarsat IsatData Pro Messaging APIThe IsatData Pro (IDP) Messaging API is a web service for sending and receiving short binary messages over ...8.2 Rakuten CPaaS SMS / Messaging APICarrier-grade SMS API for sending and receiving A2P and P2A SMS at scale on the Rakuten Mobile network, wit...7.9 MirrorFly Chat Platform APIToken-authenticated REST API for building in-app chat, split into User APIs and Admin APIs (users, contacts...1.5

Score breakdown

Frequency

77.5

log-scaled weighted occurrences

Breadth

12.4

spread across providers

Quality lift

45.6

mean composite of providers using it

Cohesion

24.1

strength of nearest seed neighbor

Where this tag comes from

Provider tag326

Api tag319

Openapi tag31

Openapi op tag117

Cohort brief

Auto-generated

The 451 providers in the APIs.io catalog tagged Messaging, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.

Providers

451

of 452 on the roster

Mean Kin Score

37.5

+16.8 vs catalog 20.7

Mean Agent Readiness

21.7

+12.0 vs catalog 9.7

Spread

0.6–87.3

median 37.6 · σ 19.3

How the 451 split by band

Exemplar 30Strong 56Developing 125Thin 117Emerging 68Minimal 55

Facet averages, against the whole catalog

Facet	This cohort	Catalog	Difference	Scored
Contract Quality	40.8	17.5	+23.3	451
Developer Ergonomics	36	17.9	+18.1	451
Access Clarity	37.3	22.3	+15	451
Operational Transparency	25.6	11.3	+14.3	451
Discoverability	70.3	60.4	+9.9	451
Contract Governance	13.6	6.4	+7.2	451

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

Artifact	This cohort	Catalog	Difference
MCP server (any)	32%	16%	+16
MCP server (first-party)	16%	7%	+9
Agent Skills	0%	0%	0
OAuth scopes	24%	9%	+15
Security	95%	88%	+7
Arazzo workflows	8%	2%	+6
Governance rules	32%	13%	+19

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 Brevo 87.3
2 Customer.io 87.3
3 Elation Health 84.1
4 Salesforce Marketing Cloud 83.5
5 Salesforce 83.3
6 Amazon Pinpoint 83.1
7 HubSpot 82.4
8 Braze 81.2
9 Amazon SES 79.7
10 Svix 79.2

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/messaging"

All tags

curl "https://apis.io/api/v1/tags?limit=25"

As a scored cohort

curl "https://apis.io/api/v1/cohorts/tag/messaging"

The distribution (Pro)

curl "https://apis.io/api/v1/cohorts/tag/messaging/stats" \
  -H "X-API-Key: $APIS_IO_KEY"

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Messaging

Providers using this tag (451)

APIs with this tag (320)