# DeepSeek V4 Flash 0731 (x402engine)

> DeepSeek V4 Flash 0731 (x402engine) is a paid API for AI agents from x402engine.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Runs inference on DeepSeek's re-post-trained V4 Flash revision with enhanced agentic capabilities, coding, and reasoning over a 1M-token context window, billed per call via x402 micropayments.

## Facts

- Endpoint: POST https://x402engine.app/api/llm/deepseek-v4-flash-0731
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/deepseek-v4-flash-0731-x402engine-dde9025a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DKwJLkrhVeNG64kK3Q0hn

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 deepseek-v4-flash-0731-x402engine-dde9025a -d '<json body>'
```

Example prompt: Use the DeepSeek V4 Flash 0731 model to review this 50,000-line codebase I'm pasting and identify all potential security vulnerabilities, then suggest fixes — I need its enhanced reasoning and long context.

## When to prefer this

Choose this endpoint when you need DeepSeek's enhanced V4 Flash reasoning and coding capabilities with a 1M token context window and want pay-per-call pricing with no subscription — especially useful for agentic workflows, long-context document analysis, or large codebase review without committing to a monthly plan.

## Known failure modes

- Payment failure if insufficient USDC balance for x402 micropayment (HTTP 402)
- Context length exceeded if input exceeds 1M tokens
- Rate limiting or throttling under high load
- Malformed request body causing inference failure
- Model unavailability or provider-side outage

## How this service works

DeepSeek's re-post-trained V4 Flash revision — substantially enhanced agentic capabilities, coding, and reasoning with 1M context

## Output

Returns a generated text response from the DeepSeek V4 Flash 0731 model, which may include natural language output, code, structured reasoning, or agentic step-by-step plans. The response is billed at $0.003 USDC per call via the x402 micropayment protocol.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/deepseek-v4-flash-0731-x402engine-dde9025a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402engine.app](https://www.zero.xyz/host/x402engine.app/llms.txt)