Use when the question is about *how to call* Sendmux cheaply, not what to send: choosing batch vs. looped sends, mailbox search/count/batch-read vs. full fetches, sync deltas, cursor pagination, ETags/conditional requests, idempotency keys, or picking between MCP, the sendmux CLI, an SDK, or direct HTTP.
Install
npx skills add Sendmux/skills --skill sendmux-token-efficient-usagenpx skills add Sendmux/skills --skill sendmux-token-efficient-usage -a claude-code -gnpx skills add Sendmux/skills --skill sendmux-token-efficient-usage -a codex -ggemini skills install https://github.com/Sendmux/skills.git --path skills/sendmux-token-efficient-usagegh skill install Sendmux/skills sendmux-token-efficient-usagegit clone --depth 1 https://github.com/Sendmux/skills /tmp/Sendmux__skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/Sendmux__skills/skills/sendmux-token-efficient-usage ~/.claude/skills/sendmux-token-efficient-usage # Claude Code
cp -R /tmp/Sendmux__skills/skills/sendmux-token-efficient-usage ~/.agents/skills/sendmux-token-efficient-usage # Codex, Cursor, Gemini CLI, Copilot, OpenCode