# QuickSilverPro API Credit Top-Up ($5 USDC)

> QuickSilverPro API Credit Top-Up ($5 USDC) is a paid API for AI agents from pay.quicksilverpro.io, paid per call via x402, $5/call, status unknown (last checked 2026-09-16).

Purchases $5 USD of AI API credit via USDC payment and returns an OpenAI-compatible API key with credit balance for accessing 43 frontier LLM models.

## Facts

- Endpoint: POST https://pay.quicksilverpro.io/x402/topup/5
- Price: $5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quicksilverpro-api-credit-top-up-5-usdc-d17404ba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eAq9PfPG2iovg3NITCjGm

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 quicksilverpro-api-credit-top-up-5-usdc-d17404ba -d '<json body>'
```

Example prompt: Top up my QuickSilverPro account with $5 USDC so I get an API key I can use to call GPT-5, Claude, Gemini, and the other 40+ frontier models through their OpenAI-compatible endpoint.

## When to prefer this

Choose this endpoint when you need a single OpenAI-compatible API key that spans 43 frontier LLMs (GPT-5, Claude, Gemini, Kimi K3, etc.) at up to 20% below standard list pricing, paid via USDC stablecoin using the x402 protocol. Prefer this over direct provider APIs when you want unified billing, crypto payment, and multi-model flexibility without a credit card.

## Known failure modes

- Insufficient USDC balance in paying wallet — payment fails and no key is issued
- x402 payment protocol not supported by client — HTTP 402 returned without key
- Network timeout during payment settlement — credit may not be applied
- Duplicate payment attempt within short window — may return existing key or error
- Invalid or malformed POST body — 400 error returned

## How this service works

One API key for 45+ AI models (GPT-6 Astra, Claude Fable 5.1, Gemini 3.8 Flash, Qwen 3.8, GLM 5.3, DeepSeek V4), OpenAI-compatible. Agents top up prepaid credit with USDC on Base via x402 and get a key back in the same HTTP round-trip.

## Output

Returns a JSON object containing an OpenAI-compatible API key (sk-...), the API base URL (https://api.quicksilverpro.io/v1), and the credited USD balance ($5). The agent can immediately use these credentials to make LLM API calls to any of the 43 supported frontier models.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "api_key": "sk-...",
  "api_base": "https://api.quicksilverpro.io/v1",
  "credit_usd": 5
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quicksilverpro-api-credit-top-up-5-usdc-d17404ba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pay.quicksilverpro.io](https://www.zero.xyz/host/pay.quicksilverpro.io/llms.txt)