# DeepSeek V4.1 Flash API — pricing & specs

DeepSeek V4.1 Flash, made by DeepSeek, accepts text and image input and returns text. On KeepRouter, DeepSeek V4.1 Flash costs $0.3000 per 1M input tokens and $1.20 per 1M output tokens, billed pay-as-you-go with no monthly fee; actual request cost depends on measured token usage. Call it through a compatible KeepRouter endpoint supported by its active route, with the model id `deepseek-flash`.

| Spec | Value |
|---|---|
| Maker | DeepSeek |
| Modality | Text, vision |
| Context window | 1,048,576 tokens |
| Max output | 393,216 tokens |
| Released | 2026-09-10 |
| Input price | $0.3000 per 1M tokens |
| Output price | $1.20 per 1M tokens |
| Cached input | $0.006000 per 1M tokens |
| Capabilities | Vision (image input), Chat completions, Streaming where supported, Tool calling where supported |
| Endpoint | POST /v1/chat/completions or POST /v1/messages (compatible chat routes) |
| Model id | `deepseek-flash` |

## Call it via compatible chat endpoint

Use POST /v1/chat/completions or, on compatible chat routes, POST /v1/messages; streaming and tool support depend on the model's active route.

### cURL

```bash
curl https://keeprouter.com/v1/chat/completions \
  -H "Authorization: Bearer $KEEPROUTER_KEY" -H "Content-Type: application/json" \
  -d '{"model":"deepseek-flash","messages":[{"role":"user","content":[{"type":"text","text":"What is in this image?"},{"type":"image_url","image_url":{"url":"https://keeprouter.com/logo-512.png"}}]}]}'
```

### Python

```python
import os
from openai import OpenAI
client = OpenAI(base_url="https://keeprouter.com/v1", api_key=os.environ["KEEPROUTER_KEY"])
r = client.chat.completions.create(model="deepseek-flash", messages=[{"role":"user","content":[{"type":"text","text":"What is in this image?"},{"type":"image_url","image_url":{"url":"https://keeprouter.com/logo-512.png"}}]}])
```

### JavaScript

```js
import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://keeprouter.com/v1", apiKey: process.env.KEEPROUTER_KEY });
const r = await client.chat.completions.create({ model: "deepseek-flash", messages: [{ role: "user", content: [{ type: "text", text: "What is in this image?" }, { type: "image_url", image_url: { url: "https://keeprouter.com/logo-512.png" } }] }] });
```

## Estimate API costs

At the current KeepRouter customer price, an example workload of 1,000 total input tokens, no cached input, and 500 output tokens per request costs approximately $0.000900 per request. At 100 requests per day, that is $2.70 over 30 days. This is a usage estimate, excluding processing fees, taxes, retries and application infrastructure. Actual usage, cache hits and supported generation durations need their own checks.

[Adjust quantities in the API cost calculator](/tools/api-cost-calculator?model=deepseek-flash).

## How to evaluate DeepSeek V4.1 Flash

DeepSeek V4.1 Flash is listed on KeepRouter as text, vision under the exact id `deepseek-flash`. Use /v1/chat/completions for the listed route; a maker's upstream features do not automatically apply to this gateway endpoint. The published context window is 1,048,576 tokens and the published output limit is 393,216 tokens. These are limits, not a recommended request size.

**First workload:** Start with a text question plus one representative image, then repeat the same question with text only. Compare answer quality, latency and billed input/output tokens.

**Before production:** For agent use, test tool calls and structured output on this exact model route before production; an OpenAI-compatible chat endpoint alone does not prove either feature.

### Agent setup paths

### OpenCode

OpenCode documents a custom OpenAI-compatible provider. Set baseURL to https://keeprouter.com/v1 and list `deepseek-flash` as a model; validate tool behavior on the exact route. [Official setup](https://opencode.ai/docs/providers).

```json
{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "keeprouter": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "KeepRouter",
      "options": {
        "baseURL": "https://keeprouter.com/v1",
        "apiKey": "{env:KEEPROUTER_API_KEY}"
      },
      "models": {
        "deepseek-flash": {
          "name": "DeepSeek V4.1 Flash"
        }
      }
    }
  }
}
```

### Continue

Continue documents provider: openai with a custom apiBase. Set apiBase to https://keeprouter.com/v1 and model to `deepseek-flash`; validate the selected feature and endpoint. [Official setup](https://docs.continue.dev/customize/model-providers/top-level/openai).

```yaml
name: KeepRouter
version: 0.0.1
schema: v1
models:
  - name: DeepSeek V4.1 Flash
    provider: openai
    model: deepseek-flash
    apiBase: https://keeprouter.com/v1
    apiKey: <YOUR_KEEPROUTER_API_KEY>
```


These are documented configuration paths; model-specific tool, streaming and multimodal behavior still needs a real request test.

## Public model usage evidence

OpenRouter identifies the corresponding variant as [`deepseek/deepseek-v4.1-flash`](https://openrouter.ai/deepseek/deepseek-v4.1-flash). The figures below are OpenRouter token volume, not API call counts, KeepRouter traffic or market-wide usage.

- **Model total:** 18.6T prompt + completion tokens over 7 days through 2026-09-26. [OpenRouter ranking](https://openrouter.ai/rankings?view=week).
- **Hermes Agent (agent):** 5.2T tokens attributed to this exact model in OpenRouter's public Apps block; observed 2026-09-28. The model page does not state the Apps block's measurement window. [OpenRouter model apps](https://openrouter.ai/deepseek/deepseek-v4.1-flash).
- **pi (agent):** 2.07T tokens attributed to this exact model in OpenRouter's public Apps block; observed 2026-09-28. The model page does not state the Apps block's measurement window. [OpenRouter model apps](https://openrouter.ai/deepseek/deepseek-v4.1-flash).

App attribution is opt-in and reflects traffic through OpenRouter. It does not prove the app uses KeepRouter, endorse this gateway, or establish a model quality ranking. Tokenizers and windows can differ; do not add the weekly total to the app figures.

Source: OpenRouter rankings through 2026-09-26 and model Apps observed 2026-09-28. Rankings data CC BY 4.0.

## Published examples and cases

OpenRouter's [model-specific Apps view](https://openrouter.ai/deepseek/deepseek-v4.1-flash) publicly attributes traffic to Hermes Agent and pi. This is a public adoption signal, not a published implementation study or a KeepRouter customer claim.

## Source and verification boundary

[Official DeepSeek V4.1 Flash documentation](https://api-docs.deepseek.com/updates/). KeepRouter's live catalog is authoritative for the customer price and enabled endpoint shown here; the maker remains authoritative for upstream model capabilities and limits.

## Pricing and implementation guides

- [DeepSeek API pricing and cached-token cost](https://keeprouter.com/blog/deepseek-api-pricing-cache-estimation)
- [Calculate your API workload cost](https://keeprouter.com/tools/api-cost-calculator)
- [KeepRouter API keys: move from free to paid models](https://keeprouter.com/blog/keeprouter-api-key-free-to-paid)

## Guides

- [Call DeepSeek V4.1 Flash with the OpenAI SDK](https://keeprouter.com/use-cases/openai-sdk.md)

## Related models

- [DeepSeek V3.1](https://keeprouter.com/models/deepseek-v3.1.md) by DeepSeek — $0.2100 per 1M input tokens and $0.7900 per 1M output tokens
- [DeepSeek V4 Pro](https://keeprouter.com/models/deepseek-v4-pro.md) by DeepSeek — $1.32 per 1M input tokens and $3.96 per 1M output tokens
- [DeepSeek V3.2](https://keeprouter.com/models/deepseek-v3.2.md) by DeepSeek — $0.2288 per 1M input tokens and $0.3432 per 1M output tokens
- [Codestral](https://keeprouter.com/models/codestral-latest.md) by Mistral AI — $0.3000 per 1M input tokens and $0.9000 per 1M output tokens
- [Claude Sonnet 5.5](https://keeprouter.com/models/claude-sonnet-5-5.md) by Anthropic — $4.00 per 1M input tokens and $10.00 per 1M output tokens
- [Claude Sonnet 4.6](https://keeprouter.com/models/claude-sonnet-4-6.md) by Anthropic — $3.00 per 1M input tokens and $15.00 per 1M output tokens

## More

- [All models & pricing](https://keeprouter.com/models.md)
- [Quickstart](https://keeprouter.com/docs/quickstart.md)
- [Get an API key](https://keeprouter.com/login?returnTo=%2Fconsole%2Fkeys%3Fmodel%3Ddeepseek-flash)

_Catalog facts and prices last changed 2026-10-03._
_Page content reviewed 2026-09-28._