# x402 AI Gateway Model List

> x402 AI Gateway Model List is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the list of available LLMs, their tiers, per-token prices, and usage caps for the x402 AI inference gateway payable in USDG/USDC on-chain.

## Facts

- Endpoint: POST https://x402-services-production.up.railway.app/api/ai/models
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ai-gateway-model-list-a3d9d16a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_R-lySTR9F2Eic0oGfdWP-

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 x402-ai-gateway-model-list-a3d9d16a -d '<json body>'
```

Example prompt: What AI models are available on the x402 inference gateway right now, and what are their pricing tiers and token caps?

## When to prefer this

Use this endpoint when you need a machine-readable catalog of LLMs available through a pay-per-call stablecoin gateway, especially when your agent needs to dynamically select a model based on price or tier, or when you want to verify which models accept USDG on Robinhood Chain vs USDC on other chains. Prefer over manual documentation lookups when building agents that need to self-configure model selection at runtime.

## Known failure modes

- Payment not sent or insufficient — gateway returns 402 Payment Required
- Empty or malformed POST body may cause 400 Bad Request
- Service temporarily unavailable — 503 from Railway hosting
- Model list may be stale if cached; real-time availability not guaranteed

## How this service works

AI Gateway model list: available LLMs per tier with prices and caps. The FIRST LLM inference gateway payable in USDG on Robinhood Chain (also USDC on Base/Polygon/Arbitrum/Solana). Send {}.

## Output

A structured list of available LLM models organized by tier, including model names/identifiers, per-token or per-call pricing, usage caps, supported stablecoins (USDG, USDC), and supported blockchain networks (Robinhood Chain, Base, Polygon, Arbitrum, Solana).

## 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": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-ai-gateway-model-list-a3d9d16a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-services-production.up.railway.app](https://www.zero.xyz/host/x402-services-production.up.railway.app/llms.txt)