API Documentation

Auto-Provisioned Trial Keys

Mnexium automatically provisions trial API keys for anonymous users. When you make a request without an x-mnexium-key header, we create a trial key based on your device fingerprint (IP + User-Agent).

How it works

• First request without a key → new trial key created
• Same device, no key → same trial key reused (no key returned)
• Different device → different trial key
• Trial keys have no expiry — they work until claimed or revoked

Response with Provisioned Key

When a new trial key is provisioned, it's returned in both the response headers and body:

// Response Headers
X-Mnx-Key-Provisioned: mnx_trial.abc123...
X-Mnx-Claim-Url: https://mnexium.com/claim

// Response Body
{
  "choices": [...],
  "mnx": {
    "chat_id": "...",
    "subject_id": "...",
    "provisioned_key": "mnx_trial.abc123...",
    "claim_url": "https://mnexium.com/claim"
  }
}

Important: save your key

The full trial key is only returned once when first provisioned. Save it immediately — subsequent requests from the same device won't return the key again.

Key Recovery with regenerate_key

If a trial key is unavailable, use regenerate_key: true to issue a replacement key. The previous key is revoked while project data is preserved.

const response = await fetch("https://mnexium.com/api/v1/chat/completions", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "x-openai-key": "sk-..."
    // No x-mnexium-key
  },
  body: JSON.stringify({
    model: "gpt-4o-mini",
    messages: [{ role: "user", content: "Remember that I prefer dark mode" }],
    mnx: {
      regenerate_key: true  // Forces new key
    }
  })
});

// Response includes new key in headers + body

Claiming Your Trial Key

Convert your trial key to a full account to access the dashboard, create more keys, and manage your data.

1. Go to mnexium.com/claim
2. Paste your trial key (e.g., mnx_trial.abc123...)
3. Sign in or create an account
4. Click "Claim This Key" — your key and project are now linked to your account

✓ Data preserved

All memories, chats, and profiles created during your trial are transferred to your account.

Trial Key Limits

Trial keys have the same usage limits as regular keys. Usage is tracked per fingerprint.