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 17 Complete, well-documented, and agent-ready

SMS/MMS APIAPI for sending SMS and MMS messages, managing mobile numbers, and handling keyword-based subscriptions.83.5 HubSpot Engagement Communications APIThe communications API allows you to log WhatsApp, LinkedIn, or SMS messages to CRM record timelines. You c...82.4 Braze SMS APIUse the Braze SMS Endpoints to manage your users phone numbers in your subscription groups.81.2 MoEngage Content and Templates APICreate, update, and search reusable content across channels — email templates (V1 and V2), push templates, ...75.8 MoEngage Inform APIUnified transactional messaging infrastructure for building and managing transactional alerts across SMS, E...75.8 SendPulse SMS APIMobile messaging: phone-book management, SMS campaign orchestration and delivery reporting.75.7 GetResponse Sms APIThe Sms area of the GetResponse API v3 — 1 operation(s) across 1 path(s), split by tag from the provider-pu...74.1 Iterable SMS APISend SMS messages and manage SMS-specific delivery settings.73.9 Bloomreach Engagement APIREST API for the Bloomreach Engagement marketing automation and CDP platform, enabling customer tracking, s...73.7 SMTP2GO Email APIREST API for sending transactional emails and SMS, managing sender domains, SMTP users, API keys, templates...73.6 SMTP2GO SMS APISend and receive SMS messages73.6 Vibes Platform APIThe complete Vibes Platform REST API as Vibes publishes it — 48 paths and 75 operations across the Acquisit...72.6 Leadping Sms APISends and manages SMS and MMS communications through Leadping. Use these endpoints to send messages, upload...72.2 Zoom Phone APIThe Zoom Phone API is the administrative and operational REST API for Zoom's cloud phone system. The harves...72.1 Infobip SMS APISMS (Short Message Service) is the most extensive messaging service available in terms of reach and coverag...71.0 Matomo MobileMessaging APIThe Matomo MobileMessaging API exposes 12 operations of the Matomo Reporting API (module `MobileMessaging`)...67.3 SMS API8x8 Connect SMS API for single and batch A2P SMS delivery worldwide, with sender ID handling, encoding cont...67.1

Strong 35 Solid coverage with minor gaps

SAP Emarsys SMS Partner Callbacks APIPublished by SAP Emarsys as OpenAPI 3.0.3 with 2 operation(s). Part of the SMS Partner API, which SAP Emars...66.4 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 Postscript Messages APISend promotional, transactional or conversational SMS and MMS to an existing subscriber, and read the resul...64.3 Postscript Partner APIThe Postscript Partner API v2 enables partners and Shopify shops to manage SMS subscribers, read opt-in key...64.3 Sendlane APIREST API for managing contacts, lists, campaigns, automations, custom fields, sender profiles, tags, and cu...63.9 Swisscom Phone Number Validation APITwo-factor authentication API that starts an SMS token validation flow against an MSISDN and then verifies ...63.8 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 Dotdigital v2 APIThe legacy v2 REST framework, still the only home for many capabilities — email and SMS campaigns, programs...63.4 Frontegg SMS APIThe SMS API from Frontegg — 7 operation(s) for sms.63.3 Verizon SMS APISMS messaging to devices62.8 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 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 Kixie Event APIThe primary Kixie automation surface. A single POST endpoint on the apig.kixie.com gateway that dispatches ...60.5 Crescendo Lab SMS APITransactional (1-to-1) SMS send + status.59.1 The Mobile First Company SMS APISend SMS messages to phone numbers using your Allo numbers.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 CloudTalk Sms APISms handling.59.0 RingCentral SMS APIThe SMS API from RingCentral — 2 operation(s) for sms.58.2 Insider One Contact APIPer-channel subscription state and first-party segment upload. v1 unsubscribes from the channel database; v...57.6 Insider One SMS APITransactional single and bulk SMS sending, plus SMS campaign, overall, transactional and OTP/Verify analyti...57.6 Insider One Verify (OTP) APIOne-time-passcode channels and templates for SMS and WhatsApp: create and update channels, manage OTP templ...57.6 Splitit Text-to-Pay APIAPI enabling merchants to initiate Splitit installment payment flows via SMS, email, and QR codes as part o...57.5 Microsoft Azure Communication Services APIAzure Communication Services provides multichannel communication APIs that enable developers to add voice, ...57.3 Route Mobile SMS APIRoute Mobile's core A2P SMS platform — single, bulk, scheduled and personalised SMS submission over HTTPS, ...57.2 Telstra SMS APISend, retrieve, and check status of SMS messages.56.2 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 32 Usable, with meaningful gaps to close

Optus SMS Suite 2FA REST APIHosted two-factor authentication API that creates an SMS one-time-code challenge for a mobile handset with ...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 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 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 1NCE SMS APISMS Management53.7 Vonage SMS APISend and receive SMS messages53.2 Artera Messaging API (MAPI)Artera's outbound SMS API, marketed to health systems and Artera Marketplace vendors as the SendMessage API...53.1 VaultRE APIThe core VaultRE REST API - the open API a third-party developer integrates an agency website or applicatio...52.8 VaultRE Integrator APIA distinct set of endpoints that operate at the integrator level rather than at an individual agency-accoun...52.8 Replicant Outbound APIPlaces outbound AI voice calls and SMS messages through Replicant against a pre-configured campaign, and no...52.6 Syniverse Omni-Channel Messaging API (SCG)The Syniverse Communication Gateway (SCG) API — the core of the Syniverse Developer Community platform. 72 ...52.3 Amazon SNS SMS APIOperations for managing SMS messaging attributes and phone number opt-out lists.52.0 CAMARA One Time Password SMS APICAMARA One Time Password SMS 1.1.1 as certified under GSMA Open Gateway. Sends a one-time password by SMS t...51.9 KORE SMS APIThe KORE SMS API programmatically exchanges short messages with IoT devices on KORE connectivity. Three ope...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 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 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 Tamara In-Store Checkout APIGenerate Tamara checkout sessions for brick-and-mortar stores through SMS payment links or QR codes that cu...48.9 Sendbird Business Messaging APIThe Sendbird Business Messaging API enables omnichannel customer engagement through SMS, WhatsApp, and othe...48.0 Microsoft SMS APISend SMS messages47.8 StackOne Unified Marketing APIStackOne Unified Marketing API standardizes campaign management across platforms, streamlining messages (SM...46.7 Bird Phone Numbers APISearch, purchase, and manage phone numbers inventory programmatically. Supports number search by country an...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 Wispr AI SMS APIThe SMS API from Wispr AI — 2 operation(s) for sms.43.7 Appgain Notify APIThe messaging send service. A single POST /{projectId}/send endpoint whose channel is selected by the top-l...39.6 Burner APIOAuth 2.0 REST API for programmatic access to Burner line management, messaging (SMS/MMS) and configuration...39.4 Rentberry SMS APISMS39.3

Thin 24 Limited public surface area

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 SMSAPI SMS APIThe SMS API from SMSAPI — 1 operation(s) for sms.38.6 Zoca Tasks APIThe Zoca tasks and automation service. 785 paths and 855 operations under /tasks/api/v1 covering the AI con...38.2 Telkomsel SMS APIApplication-to-person SMS - regular and premium sends plus delivery-status polling.37.9 Xoxoday Reward Links APIAPI for creating and sending personalized reward links via email, SMS, or chat. Supports campaign managemen...37.9 ClickSend SMS APISend and view SMS messages.37.5 Adapter Sms APIThe Sms API from Adapter — 1 operation(s) for sms.36.8 microsoft-azure-communication-services SMS APIThe SMS API from microsoft-azure-communication-services — 1 operation(s) for sms.35.1 JustCall REST APIREST API for placing calls, sending SMS and MMS messages, managing contacts, phone numbers, users, and call...34.8 JustCall SMS APISend and manage SMS/MMS messages.34.8 Onomondo SMS APISend SMS to devices and retrieve SMS usage.34.5 Pushbullet HTTP APIREST API for sending and managing pushes, devices, chats, channels, subscriptions, and file uploads across ...33.6 46elks SMS APISend and receive text messages.33.4 Engagespot Notifications APIThe Engagespot REST API enables sending multi-channel notifications to users, listing and deleting notifica...32.9 Messaging APIsA portfolio of messaging APIs including SMS Middle East and Africa, Messaging Pro Cameroon, Voice as a Serv...32.1 Aircall Messaging APISend and receive SMS/MMS and group messages.31.7 Africa's Talking SMS APISend single and bulk SMS and fetch inbox messages.31.4 engageSPARK SMS APIThe SMS API from engageSPARK — 4 operation(s) for sms.31.4 Hologram SMS APIThe SMS API from Hologram — 1 operation(s) for sms.31.2 Dialpad SMS APISend and receive SMS and MMS.30.7 Exotel SMS APISend SMS and retrieve message details.29.9 ClickSend SMS Sms APIThe Sms API from ClickSend SMS — 6 operation(s) for sms.28.3 Deutsche Telekom SMS APIProgrammatically send and receive text messages in practically every country through Deutsche Telekom's CPa...27.6

Emerging 11 Early or largely undocumented

Airship Email & SMS APISend email and SMS messages alongside push.25.5 Updox Secure Conversation APIManage secure two-way patient conversations (secure text/SMS threads), with Secure Conversation Management ...25.2 tyntec SMS APISend and receive text messages over tyntec's global A2P SMS network. Send via POST /messaging/v1/sms, retri...24.8 Gupshup SMS APIBroadcast SMS to a single number or many numbers programmatically via POST /msg on the /sm surface. Note - ...23.9 Pushwoosh Messaging APISend push notifications, email, SMS and in-app messages to user audiences.22.2 Azure Communication ServicesAzure Communication Services (successor to Skype developer APIs) provides cloud-based communication APIs fo...21.7 DAS Web APIThe DAS Web API (DASWebAPI) is DAS Technology's REST API for the CDXP platform, served from api.digitalairs...20.7 Singtel CPaaS SMS APIApplication-to-person SMS sending and receiving for business applications, sold as part of the Singtel CPaa...19.8 TranZak SMS APIREST API for sending marketing bulk SMS messages and OTP/verification codes. Supports up to 500 recipients ...19.4 HireVue Text Recruiting / Match and ApplySMS and chat-based candidate engagement, text recruiting, and Match and Apply flows that move candidates fr...18.0 Naver Cloud SENS Messaging APISENS (Simple & Easy Notification Service) sends SMS, LMS, MMS, Alimtalk (KakaoTalk channel), Friend Talk, a...15.8

Minimal 3 Almost no public developer surface

Brand RegistrationRegisters a sender brand for A2P SMS and Verified Caller flows so that consumer handsets display branded se...8.7 SMS Messaging HubA2P SMS messaging gateway for sending one-time-passcodes, alerts, and marketing messages to Vodafone subscr...8.7 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

Score breakdown

Frequency

68.3

log-scaled weighted occurrences

Breadth

5.2

spread across providers

Quality lift

58.6

mean composite of providers using it

Cohesion

24.1

strength of nearest seed neighbor

Where this tag comes from

Api tag120

Provider tag154

Openapi tag33

Openapi op tag83

Cohort brief

Auto-generated

The 191 providers in the APIs.io catalog tagged SMS, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.

Providers

191

all scored

Mean Kin Score

47.9

+27.2 vs catalog 20.7

Mean Agent Readiness

28.6

+18.9 vs catalog 9.7

Spread

0.6–87.3

median 51.9 · σ 20

How the 191 split by band

Exemplar 33Strong 48Developing 42Thin 39Emerging 15Minimal 14

Facet averages, against the whole catalog

Facet	This cohort	Catalog	Difference	Scored
Contract Quality	51.3	17.5	+33.8	191
Access Clarity	49.8	22.3	+27.5	191
Developer Ergonomics	44.4	17.9	+26.5	191
Operational Transparency	37.6	11.3	+26.3	191
Discoverability	74.6	60.4	+14.2	191
Contract Governance	17.8	6.4	+11.4	191

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)	48%	16%	+32
MCP server (first-party)	23%	7%	+16
Agent Skills	0%	0%	0
OAuth scopes	30%	9%	+21
Security	98%	88%	+10
Arazzo workflows	7%	2%	+5
Governance rules	28%	13%	+15

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 Salesforce Marketing Cloud 83.5
4 Amazon Pinpoint 83.1
5 HubSpot 82.4
6 Mailchimp 81.5
7 Braze 81.2
8 Regal 79.6
9 Close 79.1
10 Stannp 78.5

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

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Tools for tags

7 MCP tools reach this

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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

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This tag

curl "https://apis.io/api/v1/tags/sms"

All tags

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

As a scored cohort

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

The distribution (Pro)

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

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SMS

Providers using this tag (191)

APIs with this tag (122)