Claude Code setup

Prerequisites: Environment check, API key.

Use Anthropic-compatible base URL https://apimaster.ai (site root — no /v1; OpenAI uses https://apimaster.ai/v1).

---

Windows

1. Open config folder

Win + R:

%userprofile%\.claude

2. settings.json

Create the file if missing:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://apimaster.ai",
    "ANTHROPIC_AUTH_TOKEN": "YOUR_API_KEY",
    "CLAUDE_CODE_ATTRIBUTION_HEADER": "0"
  }
}

Replace YOUR_API_KEY with your APIMaster console token. If auth fails, try ANTHROPIC_API_KEY with the same value (version-dependent).

3. Test

claude

Run /model claude-sonnet-4-6 (or another supported model) and send a message.

---

macOS

Command + Shift + G → ~/.claude — same settings.json as Windows.

claude

---

Troubleshooting

Symptom	Action
Prompts for Anthropic login	Verify ANTHROPIC_BASE_URL is https://apimaster.ai (no /v1)
401	Regenerate key; no extra spaces
Unknown model	Use ids from Supported models

Env vars only: short guide.