SMS and MMS deep-dive reference. Covers SMS-specific error codes, message filtering troubleshooting ("Messages Being Filtered or Blocked?" diagnostic checklist), MMS media support (US/CA/AU only), and SMS pumping indicators. For sending SMS, use twilio-send-message instead. Use this skill only when debugging SMS delivery issues or needing SMS-specific details not in the consolidated send skill.
Install
npx skills add twilio/ai --skill twilio-sms-send-messagenpx skills add twilio/ai --skill twilio-sms-send-message -a claude-code -gnpx skills add twilio/ai --skill twilio-sms-send-message -a codex -ggemini skills install https://github.com/twilio/ai.git --path skills/twilio/twilio-sms-send-messagegh skill install twilio/ai twilio-sms-send-messagegit clone --depth 1 https://github.com/twilio/ai /tmp/twilio__ai
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/twilio__ai/skills/twilio/twilio-sms-send-message ~/.claude/skills/twilio-sms-send-message # Claude Code
cp -R /tmp/twilio__ai/skills/twilio/twilio-sms-send-message ~/.agents/skills/twilio-sms-send-message # Codex, Cursor, Gemini CLI, Copilot, OpenCode