# Model Access Gateway – DeepSeek V4 Pro Chat Completions (x402 USDC)

> Model Access Gateway – DeepSeek V4 Pro Chat Completions (x402 USDC) is a paid API for AI agents from modelaccessgateway.com, paid per call via x402, $0.0014/call, status unknown (last checked 2026-10-18).

Runs OpenAI-compatible chat completions against DeepSeek V4 Pro, billed per call in USDC on Base via x402 — no account or API key required.

## Facts

- Endpoint: POST https://modelaccessgateway.com/llm/deepseek-v4-pro?utm_source=zero.xyz
- Price: $0.0014/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/model-access-gateway-deepseek-v4-pro-chat-completions-x402-usdc-528befa1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ktO7IbauQxiWMpcyNjxTa

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 model-access-gateway-deepseek-v4-pro-chat-completions-x402-usdc-528befa1 -d '<json body>'
```

Example prompt: Ask DeepSeek V4 Pro to write a concise explanation of transformer attention mechanisms, streaming the response, and pay for it per-call in USDC using the Model Access Gateway — no API key needed.

## When to prefer this

Choose this endpoint when you need DeepSeek V4 Pro specifically — known for strong reasoning and coding — without committing to an API subscription or managing credentials. Ideal for autonomous agents that need to pay per inference call on-chain in USDC via x402 on Base, especially in serverless or ephemeral contexts where storing API keys is impractical. Prefer over direct DeepSeek API when you want automatic refunds on model failure and zero account setup overhead.

## Known failure modes

- Payment insufficient or x402 flow fails — no completion returned, automatic refund issued
- Model unavailable or overloaded — gateway returns error, refund triggered
- Invalid messages array (empty or missing role) — 400 validation error
- max_tokens exceeds 16384 — schema validation rejection
- Temperature out of 0–2 range — request rejected
- Network timeout during streaming — partial stream, no refund guarantee

## How this service works

LLM inference API: OpenAI-compatible chat completions for 136 AI models (Claude, GPT, Gemini, Grok, DeepSeek, Qwen, Kimi, GLM), paid per call in USDC on Base with x402. No account, no API key, automatic refund if the model fails.

## Output

Returns an OpenAI-compatible chat.completion JSON object with the assistant's message content, finish_reason (e.g. 'stop'), token usage breakdown (prompt, completion, total), model identifier, and a unique completion ID. Streaming mode delivers server-sent events per token after payment settles.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Optional: fixed by the route (deepseek/deepseek-v4-pro)"
  },
  "tools": {
   "type": "array"
  },
  "stream": {
   "type": "boolean",
   "description": "true: server-sent events after payment"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant",
       "tool",
       "developer"
      ],
      "type": "string"
     },
     "content": {
      "type": [
       "string",
       "array",
       "null"
      ]
     }
    }
   },
   "minItems": 1
  },
  "max_tokens": {
   "type": "integer",
   "maximum": 16384,
   "minimum": 1,
   "description": "Optional, default 4096"
  },
  "temperature": {
   "type": "number",
   "maximum": 2,
   "minimum": 0
  },
  "response_format": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-7f3c2a91",
  "model": "deepseek/deepseek-v4-pro",
  "usage": {
   "total_tokens": 10,
   "prompt_tokens": 9,
   "completion_tokens": 1
  },
  "object": "chat.completion",
  "choices": [
   {
    "index": 0,
    "message": {
     "role": "assistant",
     "content": "OK"
    },
    "finish_reason": "stop"
   }
  ],
  "created": 1791979200
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/model-access-gateway-deepseek-v4-pro-chat-completions-x402-usdc-528befa1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from modelaccessgateway.com](https://www.zero.xyz/host/modelaccessgateway.com/llms.txt)