# Using z.ai with Claude Code

## Why
z.ai provides GLM models as a drop-in replacement for Anthropic's API in Claude Code.
Much cheaper: $6-60/month vs $100-200/month for Claude Max.

## Setup

### 1. Get API Key
- Go to https://z.ai/model-api
- Register/login
- Create API key at https://z.ai/manage-apikey/apikey-list

### 2. Configure Claude Code

Edit `~/.claude/settings.json`:

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

### 3. Open new terminal, run `claude`

That's it.

## Switching Back to Anthropic

Remove or comment out the env block in `~/.claude/settings.json`:

```json
{
}
```

Or just delete the three env vars. Open new terminal.

## Optional: Model Mapping

To control which GLM model is used for each tier, add to the env block:

```json
{
    "env": {
        "ANTHROPIC_AUTH_TOKEN": "your_zai_api_key_here",
        "ANTHROPIC_BASE_URL": "https://api.z.ai/api/anthropic",
        "API_TIMEOUT_MS": "3000000",
        "ANTHROPIC_DEFAULT_OPUS_MODEL": "glm-4.7",
        "ANTHROPIC_DEFAULT_SONNET_MODEL": "glm-4.7",
        "ANTHROPIC_DEFAULT_HAIKU_MODEL": "glm-4.5-air"
    }
}
```

## Notes
- GLM-4.7 is the current best model on z.ai
- glm-4.5-air is lighter/faster for haiku tasks
- MCP tools, skills, and all Claude Code features work normally
- If something breaks, just revert settings.json and restart