Authentication

Every request is authenticated with your Primex API key (prx-…). The gateway accepts both common header styles on all routes, so whichever SDK you use will work:

Header	Style	Typical client
Authorization: Bearer prx-…	OpenAI	OpenAI SDK, Cursor, Windsurf, Codex
x-api-key: prx-…	Anthropic	Anthropic SDK, Claude Code, Cline

Examples

# OpenAI style
curl https://gateway.primexos.com/v1/chat/completions \
  -H "Authorization: Bearer prx-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-5.5","messages":[{"role":"user","content":"hi"}]}'

# Anthropic style
curl https://gateway.primexos.com/v1/messages \
  -H "x-api-key: prx-YOUR_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-opus-4-8","max_tokens":256,"messages":[{"role":"user","content":"hi"}]}'

Keeping keys safe

• Never commit keys to source control or ship them in client-side code. Use environment variables (OPENAI_API_KEY, ANTHROPIC_API_KEY).
• Your key can spend from your AI account. Treat it like a wallet credential.
• Rotate a key immediately if it may have leaked. See API Keys.

Errors

Status	Meaning
401	Missing or invalid key.
402	No available credits or plan allowance. Review billing in the Primex app.
400	Malformed request (bad model name, unsupported params).
429	Rate or concurrency limited. Back off and retry.
5xx	Upstream/gateway error. You are not charged (see Billing).