Last30Days Skill is an open-source AI agent skill that researches any topic across Reddit, X (Twitter), Bluesky, YouTube, TikTok, Instagram, Hacker News, Polymarket, and the broader web from the past 30 days, then synthesizes findings into grounded summaries with citations. The tool employs a two-pass query expansion system that first broadens the initial query to capture related terms, then refines results through cross-platform convergence detection. Results are ranked using a composite relevance score combining text similarity, engagement velocity, source authority, and temporal recency. The Polymarket integration adds unique outcome-aware scoring across five factors for probability-weighted insights. Features include smart discovery that finds relevant communities automatically, comparative analysis mode for X vs Y queries, deduplication and pattern identification across sources, auto-save to markdown files, and per-project .env configuration. Built with a Python engine and Node.js 22+ for Twitter GraphQL, with 455+ tests across all modules. Supports installation as a Claude Code Plugin, Gemini CLI extension, or manual setup.