Twilio API
Send and receive SMS, voice, and WhatsApp messages.
Pricing: Paid | Free Tier: NoCommunication APIs
Browse curated APIs in the Communication category. Compare and evaluate top options for your project.
Slack API
Build bots and integrations in Slack.
Pricing: Free for Slack free workspaces; advanced features require paid plan | Free Tier: Yes
SendGrid API
Email delivery and marketing API.
Pricing: 60-day trial (100 emails/day), then Plan based | Free Tier: YesVonage API
SMS, voice, and verification APIs.
Pricing: Pay-as-you-go; limited free credits on signup | Free Tier: Yes
WhatsApp Business API
Integrate WhatsApp messaging at scale.
Pricing: Paid per message (conversation-based), Meta BSP required | Free Tier: No