Agents quit early — patches land, tests still red. Zagens harnesses DeepSeek V4 on Windows: phased runs, review loops, verify before done. • Phased work — checklist, auto-continue, gates before steps close • Review pipeline — explore, implement, review; loops on failure • One window — tree, terminal, diffs, turn-by-turn replay • Cost panel — tokens, cache hits, savings per session • Approvals, skills, MCP — you control risky scripts & tools Local-first. BYOK. Windows preview.