The model I reach for first now isn't Opus. It's GLM 5.2 — a free, open-source model that's days old, runs right inside Claude Code, and on most of my daily work is so close to Opus (5x the price) I genuinely can't tell them apart. I gave both the exact same prompts. Here's the honest result.
- Same prompts, both models. A sponsorship CRM app: GLM's was complete and worked (Opus's looked a hair nicer) for $0.40 vs $3. A Minecraft voxel world and an orbiting solar system: both nailed first try, and side-by-side you can't tell which came from which.
- Where Opus won. A 30-second launch video. Opus shipped it in one clean 51-min run; GLM broke when its context filled up and needed retries — still $2 vs $14. Opus only really pulls ahead on the longest, hardest jobs.
- Why it's cheap. 700B+ parameters but only ~40B switch on per task (mixture-of-experts), plus a ~1M-token window that holds your whole project. About 5–6x cheaper than Opus per token, and the gap widens on big jobs.
- Why open-source matters. When Fable 5 got switched off overnight, everyone building on it had no say. An open model nobody can switch off is worth more than the price tag.
- Run it three ways. OpenRouter (pay-as-you-go, ~2-min setup — point Claude Code at it with a tiny settings.json), Z.ai's flat ~$18/mo plan (daily use, official), or fully local for private data (but that needs ~$10k of hardware, so most people start on OpenRouter).
My take: it doesn't replace Opus — it replaces most of when I used to reach for it. GLM's my default now; Opus stays in my back pocket for the jobs that have to be perfect first try.
📎 Full GLM 5.2 guide PDF pinned below — every build, the benchmarks, the cost, and the exact setup.
Every prompt and the full setup are free inside The AI Accelerator (19k+ members).
👉 If you got it running, what's the first thing you'd build with it? Drop it below.
[Watch the video here ▶️]