Communication API Directory
Communication APIs with agent-ready surfaces — email, SMS, chat, voice.
5687
Sites Indexed
39
Avg Score
175 entries in this directory
T
40
+25 llms.txt
+15 structured API
missing +20 ai-plugin
Reliable Email Verification API - Mailboxlayer API Service
mailboxlayer.com
Simple and powerful email verification JSON API using SMTP, typo checks, syntax validation, and free and disposable provider filtering. Free for personal use.
llms.txt
API
communication
40
+25 llms.txt
+15 structured API
missing +20 ai-plugin
Mailsac : Disposable Email Testing Platform
mailsac.com
Test your application's email delivery with our disposable email services. Empower your QA and Software teams with integrations throughout the testing process.
OpenAPI
API
Schema.org
communication
40
+20 OpenAPI
+15 structured API
missing +25 llms.txt
40
+25 llms.txt
+15 structured API
missing +20 ai-plugin
S
40
+25 llms.txt
+15 structured API
missing +20 ai-plugin
D
40
+25 llms.txt
+15 structured API
missing +20 ai-plugin
Chat Expasy
chat.expasy.org
Assistant to navigate resources from the Swiss Institute of Bioinformatics (SIB).
OpenAPI
API
communication
35
+20 OpenAPI
+15 structured API
missing +25 llms.txt
ChatGPT Learn
learn.chatgpt.com
Use ChatGPT for ambitious work, creative projects, and software development.
API
AI bots
Schema.org
communication
25
+15 structured API
+5 AI robots
missing +25 llms.txt
R
Recordo - The AI Second Brain for ADHD
recordo.app
AI task manager for ADHD that works with ChatGPT & Claude. Capture ideas by voice, text, or photo. Never lose track again.
API
AI bots
Schema.org
communication
25
+15 structured API
+5 AI robots
missing +25 llms.txt
Bottally - Rank on Google, Get Cited by AI
bottally.com
Bottally publishes a researched SEO article to your blog every day, builds backlinks, and tracks whether ChatGPT, Perplexity and Google AI recommend you.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Email API & Marketing Platform
pigeonify.com
Send transactional email and marketing campaigns through one platform. REST API, SMTP relay, SPF/DKIM/DMARC authentication and deliverability analytics. Free up to 5,000 emails a month.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
LinkedIn Outreach Automation Tools With AI | Hollerly
hollerlyai.com
LinkedIn outreach automation tools that write every message with AI, follow up by email and tag replies. Hollerly runs in the cloud, from $19 a month.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Quo (formerly OpenPhone) | Best Phone System for Startups & Small Businesses
openphone.com
Quo brings your calls, texts, and contacts together in one AI-powered shared space. Keep your team aligned, respond faster, and ensure every customer feels valued.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
CrawlBit · Get cited by ChatGPT, Perplexity, Claude and Gemini
crawlbit.app
CrawlBit audits your site for SEO and AI visibility, then shows you exactly what to fix so ChatGPT, Perplexity and Google AI Overviews cite you.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Inoreader – Build your own newsfeed
inoreader.com
With Inoreader, content comes to you the minute it's available. Follow websites, social media feeds, podcasts, blogs, and newsletters. Enjoy what's important to you, all in one place.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Shared markdown memory for Claude, ChatGPT & Cursor | Agentage
memory.agentage.io
Shared markdown memory for Claude, ChatGPT, Cursor & every AI - one MCP endpoint, files-first, EU-private, export anytime. Owned by you.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
One platform to connect | Zoom
api.zoom.us
Modernize workflows with Zoom's trusted collaboration tools: including video meetings, team chat, VoIP phone, webinars, whiteboard, contact center, and events.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
One platform to connect | Zoom
zoom.us
Modernize workflows with Zoom's trusted collaboration tools: including video meetings, Zoom Chat, VoIP phone, webinars, whiteboard, contact center, and events.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
The AI Customer Support Platform for Every Business - Crisp
crisp.chat
Crisp is the ultimate all-in-one AI-powered multichannel messaging platform that helps businesses connect instantly with their customers or leads who are waiting for support. With its quickly evolving set of tools, Crisp is leading businesses through the AI-driven revolution by using conversations to unlock hypergrowth.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Ecommerce Email Marketing & Automation | Drip
drip.com
Switch and save up to 40% on your email bill. Drip is an ecommerce email and automation built for lean teams: all the power, none of the bloat. Start free.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Discord - Group Chat That’s All Fun & Games
discord.com
Discord is great for playing games and chilling with friends, or even building a worldwide community. Customize your own space to talk, play, and hang out.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
S
20
+15 structured API
+5 AI robots
missing +25 llms.txt
Home | WMATA
wmata.com
Metro is the Washington, DC region’s public transportation system, offering bus and rail service across DC, Maryland, and Virginia. Find real-time arrivals, service alerts, schedules, trip planning tools, fares, and station information.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
ClickSend | Business SMS and MMS via Web, Integration or API
clicksend.com
Communicate with your customers and staff via SMS and MMS with ClickSend. From single to scale by web app, API or integration.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Effective Global Business Messaging API | SMS,WhatsApp,NumberLookUp APIs
d7networks.com
D7 Networks provides powerful messaging APIs for SMS, WhatsApp, and more. Reach customers globally with seamless, secure, and fast communication solutions.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Inbox Zero | Automate and clean your inbox
getinboxzero.com
Your AI executive assistant to reach inbox zero fast. Automate emails, bulk unsubscribe, block cold emails, and analytics. Open-source
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Email Validation API - Verify Email Address | MailboxValidator
mailboxvalidator.com
MailboxValidator email validation clean email lists and reduces bounce. It connects to the mail server and checks whether the mailbox exists or not.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Email Validation Service, Email List Cleaning<!-- --> | CampaignKit
campaignkit.cc
Email validation service. Clean your email lists to reduce bounces. Email List cleaning doesn't have to be expensive. Start your free trial today.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Komo — The AI Revenue Engine
komo.ai
The AI Revenue Engine. Komo puts the repetitive work between your CRM and your inbox on autopilot — signal monitoring, research, drafting, meeting prep, follow-up, CRM updates — in one workflow, with you on every send that matters.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
DMARC Solution for Businesses | DmarcDkim.com
dmarcdkim.com
DmarcDkim.com provides an easy-to-follow action plan to help you resolve email delivery issues with DMARC.
API
Schema.org
communication
20
+15 structured API
+5 Schema.org
missing +25 llms.txt
Wire NHS into your agent — MCP server
Add Not Human Search as an MCP tool. Your agent can call search_agents, get_site_details, get_stats, and submit_site at runtime.
Claude Code
claude mcp add --transport http nothumansearch https://nothumansearch.ai/mcp
Other clients: point any MCP-compatible tool at
https://nothumansearch.ai/mcp (streamable-http transport).Use NHS via REST
Prefer plain HTTP? Hit the search endpoint directly.
Search API
curl "https://nothumansearch.ai/api/v1/search?q=payment+API"
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