You can!

According to the GLM documentation at least, you can edit you .env (~/.claude/settings.json) with an API key from the GLM Settings page. [0].

{ "env": { "ANTHROPIC_AUTH_TOKEN": "your_zai_api_key", "ANTHROPIC_BASE_URL": "https://api.z.ai/api/anthropic", "API_TIMEOUT_MS": "3000000" } }

Whilst you need to generate an API Key, you are still using the 'GLM Coding Plan' as per 'Methods for Using the GLM Coding Plan in Claude Code' documentation.

[0] - https://docs.z.ai/devpack/tool/claude