# GPT-5.6 Luna Half-Price Plus Subscription (x402)

> GPT-5.6 Luna Half-Price Plus Subscription (x402) is a paid API for AI agents from gpt55.558686.xyz, paid per call via x402, $10/call, status down (last checked 2026-10-13).

Purchases or activates a half-price GPT Plus-equivalent weekly subscription via x402 USDC payment on Base, returning a confirmation and generated text summary.

## Facts

- Endpoint: POST https://gpt55.558686.xyz/v1/tools/gpt55-plus-half-price-subscription?utm_source=zero.xyz
- Price: $10/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gpt-5-6-luna-half-price-plus-subscription-x402-eec270b0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dWymtOpdnQysP2mlX3yCq

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability gpt-5-6-luna-half-price-plus-subscription-x402-eec270b0 -d '<json body>'
```

Example prompt: Sign me up for the half-price GPT Plus weekly subscription using my account ID acc_8821 and buyer ID buyer_4492 — the official monthly Plus price is $20 and I want the discounted weekly plan.

## When to prefer this

Choose this endpoint when you want to programmatically purchase a discounted weekly GPT-equivalent subscription using USDC on Base via x402, specifically for accounts tied to the GPT-5.6 Luna proxy service. Prefer this over direct OpenAI billing when seeking reduced-cost access or when operating in a crypto-native payment environment.

## Known failure modes

- Payment failure if USDC wallet balance is insufficient for the $10 per call price
- Invalid or missing buyerId/accountId causing rejection
- Subscription already active for account leading to duplicate error
- x402 payment protocol negotiation failure with agent fallback required
- Malformed requestedWeeklyValueUsd causing validation error

## How this service works

GPT-5.6 Luna API Base USDC and OpenAI-compatible x402 chat: one request for $0.00293, paid by browser wallet or a quote-first agent fallback.

## Output

Returns a JSON object with an 'ok' boolean, a 'tool' field identifying the subscription action ('gpt55PlusHalfPriceSubscription'), and a 'summary' field containing a generated text confirmation of the subscription activation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "buyerId": {
   "type": "string",
   "maxLength": 160
  },
  "buyer_id": {
   "type": "string",
   "maxLength": 160
  },
  "accountId": {
   "type": "string",
   "maxLength": 160
  },
  "requestId": {
   "type": "string",
   "maxLength": 160
  },
  "account_id": {
   "type": "string",
   "maxLength": 160
  },
  "request_id": {
   "type": "string",
   "maxLength": 160
  },
  "officialPlusMonthlyUsd": {
   "type": "number",
   "minimum": 0
  },
  "weeklyOfficialValueUsd": {
   "type": "number",
   "minimum": 0
  },
  "requestedWeeklyValueUsd": {
   "type": "number",
   "minimum": 0
  },
  "official_plus_monthly_usd": {
   "type": "number",
   "minimum": 0
  },
  "weekly_official_value_usd": {
   "type": "number",
   "minimum": 0
  },
  "requested_weekly_value_usd": {
   "type": "number",
   "minimum": 0
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "tool": "gpt55PlusHalfPriceSubscription",
  "summary": "Generated text."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gpt-5-6-luna-half-price-plus-subscription-x402-eec270b0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gpt55.558686.xyz](https://www.zero.xyz/host/gpt55.558686.xyz/llms.txt)