# DeepSeek V4 Flash 0731 — API, capabilities & pricing | Y-API

> DeepSeek V4 Flash 0731 is the publisher’s official V4 Flash release, following the earlier preview. It remains a text-only model; its post-training revision focuses on coding, reasoning and agent tasks.

This is the markdown representation of https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4-flash-0731. Generated by `scripts/generate-seo-assets.mjs` from the same copy the page renders — do not edit by hand.

Model ID: `deepseek/deepseek-v4-flash-0731`

Sources reviewed: 2026-10-04. Y-API catalog snapshot: 2026-10-04.

## Choosing this model

Selection advice by Y-API. The checks below are suggested evaluations, not published test results.

### Where to start

Use the dated ID when you want to compare a specific Flash revision on patch generation or tool-driven maintenance. Preserve the failing test alongside each prompt so regressions are visible.

### What to watch for

A dated model name improves experiment traceability but does not freeze a gateway’s serving configuration. Do not silently replace the earlier unsuffixed ID and treat past results as measurements of this revision.

## Model specifications

These are OpenRouter model-level specifications, not a Y-API compatibility test. A particular route may accept fewer input formats, parameters or tokens. Verify the features you need with a small request; a successful text response does not validate vision or tool calling.

| Field | Value |
| --- | --- |
| Context window | 1,048,576 tokens |
| Input | Text |
| Output | Text |
| Listed on OpenRouter | 2026-07-31 |
| Parameters listed by OpenRouter | `frequency_penalty`, `include_reasoning`, `logit_bias`, `logprobs`, `max_tokens`, `min_p`, `parallel_tool_calls`, `presence_penalty`, `reasoning`, `reasoning_effort`, `repetition_penalty`, `response_format`, `seed`, `stop`, `structured_outputs`, `temperature`, `tool_choice`, `tools`, `top_a`, `top_k`, `top_logprobs`, `top_p` |

## Estimate your cost

| Price basis | Input / 1M tokens | Output / 1M tokens |
| --- | --- | --- |
| Account credit | $0.15 | $0.30 |
| Cash equivalent | $0.015 | $0.03 |

$1 paid adds $10 of credit. Cash equivalent = credit consumed ÷ 10; this is not the model publisher’s list price.

Input tokens / request: 1000. Output tokens / request: 500. Number of requests: 1000.

Estimated credit consumed: $0.30. Estimated cash equivalent: $0.03.

Illustrative token budget, not measured usage or a quote. Includes input and output; excludes separate media charges, cache discounts and retries. Include billed reasoning tokens in your output budget where applicable. Actual billing follows usage returned by the service.

### Same token budget, different models

| Model | Estimated credit consumed | Estimated cash equivalent |
| --- | --- | --- |
| [DeepSeek V4 Flash 0731](https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4-flash-0731) | $0.30 | $0.03 |
| [DeepSeek V4 Flash 0423](https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4-flash) | Free — no credit deducted | Free — no credit deducted |
| [DeepSeek V4.1 Flash](https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4.1-flash) | $0.70 | $0.07 |

## Use the API

These minimal, text-only requests use the exact Y-API model ID. They do not demonstrate image, audio, video, file or tool support. The output limit also needs room for reasoning; an empty answer with finish_reason=length can mean the budget was exhausted.

Set the TOKEN environment variable to a key from your console. Run this on your server or locally; never expose a key in browser code or a public repository.

### A task to try

A Python average function returns sum(xs) / len(xs). Define behavior for an empty list and write two tests before proposing a fix.

```bash
curl --fail-with-body --silent --show-error --max-time 120 \
  'https://api.y-api.bestvirtualgoods.com/v1/chat/completions' \
  -H "Authorization: Bearer ${TOKEN:?Set TOKEN first}" \
  -H 'Content-Type: application/json' \
  --data-binary @- <<'JSON'
{
  "model": "deepseek/deepseek-v4-flash-0731",
  "messages": [
    {
      "role": "user",
      "content": "A Python average function returns sum(xs) / len(xs). Define behavior for an empty list and write two tests before proposing a fix."
    }
  ],
  "max_tokens": 4096
}
JSON
```

```python
import json
import os
import sys
import urllib.error
import urllib.request

payload = {
  "model": "deepseek/deepseek-v4-flash-0731",
  "messages": [
    {
      "role": "user",
      "content": "A Python average function returns sum(xs) / len(xs). Define behavior for an empty list and write two tests before proposing a fix."
    }
  ],
  "max_tokens": 4096
}

request = urllib.request.Request(
    "https://api.y-api.bestvirtualgoods.com/v1/chat/completions",
    data=json.dumps(payload).encode("utf-8"),
    headers={
        "Authorization": "Bearer " + os.environ["TOKEN"],
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=120) as response:
        result = json.load(response)
    print(json.dumps(result, ensure_ascii=False, indent=2))
except urllib.error.HTTPError as error:
    print(error.read().decode("utf-8"), file=sys.stderr)
    raise SystemExit(1)
```

### How to evaluate the result

The response should choose and document an empty-input contract, test it and preserve the nonempty case. Run the tests rather than judging the patch by appearance.

## Before you choose

### Why keep the 0731 suffix in my request?

It selects this catalog entry rather than the earlier Flash entry. Record it with sampling settings and tool versions so later evaluations compare identifiable configurations.

## Sources & scope

Technical facts come from the cited model page and, where available, its linked publisher card. A card describes that checkpoint; it is not proof of the weights a gateway serves. Prices come only from the Y-API catalog. We do not claim measured latency, uptime or benchmark scores for this endpoint.

- [OpenRouter model page & specifications](https://openrouter.ai/deepseek/deepseek-v4-flash-0731)
- [Publisher model card linked by OpenRouter](https://huggingface.co/deepseek-ai/DeepSeek-V4-Flash-0731)
- [Y-API catalog & prices (JSON)](https://y-api.bestvirtualgoods.com/models.json)

## Models to compare

Compare these alternatives on the same inputs. Their descriptions explain different roles; a lower price does not establish equivalent quality.

### [DeepSeek V4 Flash 0423](https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4-flash)

DeepSeek V4 Flash 0423 is the earlier, text-only Flash entry in the V4 family. Its sparse mixture-of-experts design targets coding and conversation workloads with a long context window; it is distinct from the later 0731 revision.

### [DeepSeek V4.1 Flash](https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4.1-flash)

DeepSeek V4.1 Flash adds native image understanding to the Flash line. Its Causal Encoder-Decoder architecture separates input processing from output generation, with a design aimed at input-heavy coding and computer-use workflows.

## Links

- HTML version of this page: https://y-api.bestvirtualgoods.com/models/deepseek/deepseek-v4-flash-0731
- Site index for agents: https://y-api.bestvirtualgoods.com/llms.txt
- Full reference (single file): https://y-api.bestvirtualgoods.com/llms-full.txt
- OpenAPI 3.1 spec: https://y-api.bestvirtualgoods.com/openapi.json
- Model catalog (JSON, no key needed): https://y-api.bestvirtualgoods.com/models.json
- API base URL: `https://api.y-api.bestvirtualgoods.com/v1`
- Contact: support@bestvirtualgoods.com
- Model catalog: https://y-api.bestvirtualgoods.com/models
- Integration guide: https://y-api.bestvirtualgoods.com/docs