 Open-source realtime media infrastructure with the Agents framework, SIP, and phone numbers MCPOpenAPIllms.txt | realtime+4 | MCP+2 | — | api-key, Messaging | 5/5 | | |
 Email API for developers with React Email, batch sending, and an official MCP server MCPOpenAPIllms.txt | email+3 | MCP+2 | — | api-key, Messaging | 5/5 | | |
 Voice agent platform handling telephony, turn-taking, interruptions, and warm transfers MCPOpenAPIllms.txt | voice-agents+3 | MCP+2 | — | api-key, Messaging | 5/5 | | |
 Support inbox, tickets, and conversations over API and a remote MCP server MCPOpenAPIllms.txt | support+3 | MCP+2 | — | m2m-oauth, Messaging | 4/5 | | |
 Notification infrastructure API — workflows, preferences, and multi-channel delivery for agent output MCPOpenAPIllms.txt | notifications+2 | MCP+2 | — | api-key, Messaging | 4/5 | | |
 Post, search, and automate in Slack workspaces via API or the official admin-approved MCP server MCPOpenAPIllms.txt | slack+3 | MCP+2 | — | bot-token, Messaging | 4/5 | | |
 SMS, voice, WhatsApp, and verification APIs, with an official MCP server over the platform MCPOpenAPIllms.txt | sms+4 | MCP+2 | — | api-key, Messaging | 4/5 | | |
 Customer engagement platform; remote MCP for segments, campaigns, content, and analytics (OAuth). MCPllms.txt | mcp+3 | MCP+1 | — | m2m-oauth, Messaging | 3/5 | | |
 Agentic CRM for service businesses with bookings, loyalty, and messaging. MCPllms.txt | mcp+2 | MCP+1 | — | api-key, Messaging | 3/5 | | |
 AI meeting assistant; hosted Fellow MCP for transcripts, summaries, action items, and participants. MCPllms.txt | mcp+3 | MCP+1 | — | m2m-oauth, Messaging | 3/5 | | |
 B2C CRM and messaging with llms.txt and official MCP for agents. MCPllms.txt | mcp+3 | MCP+1 | — | api-key, Messaging | 3/5 | | |
 Email marketing and automation with llms.txt and hosted MCP for agents. MCPllms.txt | mcp+2 | MCP+1 | — | api-key, Messaging | 3/5 | | |
 CX AI agent platform; remote MCP lets assistants inspect, edit, and test agents via OAuth. MCPllms.txt | mcp+3 | MCP+1 | — | m2m-oauth, Messaging | 3/5 | | |