Go outside the founder brief and research the real market before the plan is written: the exact communities, newsletters, and venues where the user's ICP already sits, how comparable products launched and what worked, the problem in strangers' own words, and the rivals and openings the user never mentioned. Saves docs/gtm-cofounder/market-research.md with a link for every finding.
Install
npx skills add AIDevGTM/gtm-cofounder --skill research-the-marketnpx skills add AIDevGTM/gtm-cofounder --skill research-the-market -a claude-code -gnpx skills add AIDevGTM/gtm-cofounder --skill research-the-market -a codex -ggemini skills install https://github.com/AIDevGTM/gtm-cofounder.git --path skills/19-research-the-marketgh skill install AIDevGTM/gtm-cofounder research-the-marketgit clone --depth 1 https://github.com/AIDevGTM/gtm-cofounder /tmp/AIDevGTM__gtm-cofounder
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/AIDevGTM__gtm-cofounder/skills/19-research-the-market ~/.claude/skills/research-the-market # Claude Code
cp -R /tmp/AIDevGTM__gtm-cofounder/skills/19-research-the-market ~/.agents/skills/research-the-market # Codex, Cursor, Gemini CLI, Copilot, OpenCode