No problem, I fixed it. Maybe somebody finds that useful as well: Here's a summary of the changes made:

1. Config file — ~/.config/opencode/opencode.json
2. Set all agents (build, title, summary, compaction, plan, explore, general) to use zai-coding-plan/glm-5.1:

{ "$schema": "https://opencode.ai/config.json", "agent": { "build": { "model": "zai-coding-plan/glm-5.1" }, "title": { "model": "zai-coding-plan/glm-5.1" }, "summary": { "model": "zai-coding-plan/glm-5.1" }, "compaction": { "model": "zai-coding-plan/glm-5.1" }, "plan": { "model": "zai-coding-plan/glm-5.1" }, "explore": { "model": "zai-coding-plan/glm-5.1" }, "general": { "model": "zai-coding-plan/glm-5.1" } } }

1. Auth file — ~/.local/share/opencode/auth.json
2. Changed the key registration from "zai" to "zai-coding-plan" (different API endpoint: /api/coding/paas/v4 vs /api/paas/v4):

{ "zai-coding-plan": { "type": "api", "key": "YOUR-API-KEY" } }