DeepSeekText Generation/v1/ai/chat

DeepSeek V4.1 Flash API

Access DeepSeek V4.1 Flash through one API key. DeepSeek Ultra-Cheap Sparse MoE.

DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder architecture. V4.1 Flash is the model for very high-volume work — extraction, summarisation, classification, drafting — where the per-call price has to be close to zero.

Full Docs Get API Key

Takes 30 seconds.

DeepSeek V4.1 Flash API pricing

Pay per request from your YepAPI balance — no subscription, no monthly minimum. Prices updated October 25, 2026.

Token type	Price
Input	$0.44 / 1M tokens
Output	$1.77 / 1M tokens
Context window	1.0M tokens

What it costs	Per job	Per 1,000
Chat reply1K input + 500 output tokens	$0.0013	$1.33
RAG answer8K input + 800 output tokens	$0.0049	$4.94
Agent step with tools30K input + 2K output tokens	$0.017	$16.74
Long document summary100K input + 2K output tokens	$0.048	$47.54

4,900+

Developers

2.3M+

API calls served

184

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see DeepSeek V4.1 Flash respond in real time.

POST/v1/ai/chatdeepseek/deepseek-v4.1-flash

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

DeepSeek V4.1 Flash specs

Provider	DeepSeek
Model ID	deepseek/deepseek-v4.1-flash
Endpoint	/v1/ai/chat
Type	Text Generation
Context window	1.05M tokens
Max output	384K tokens
Reasoning	No
OpenAI-compatible	Yes — /v1/ai/chat/completions

How to get a DeepSeek V4.1 Flash API key

1
Create an account
Sign up at yepapi.com with Google or email. It takes about 30 seconds.
2
Create an API key
Open the dashboard, go to API Keys and create a key. Copy it — it starts with yep_sk_.
3
Call DeepSeek V4.1 Flash
Send a request to /v1/ai/chat with the x-api-key header and model "deepseek/deepseek-v4.1-flash".
4
Pay as you go
Usage is billed per request from your balance. Top up any amount; there is no subscription.

Strengths

✓

Near-zero cost

$0.44 per 1M input and $1.77 per 1M output tokens.

✓

New CED architecture

DeepSeek's first Causal Encoder-Decoder model, activating 8B parameters on input and 16B on output.

✓

1M context, 384K output

Handles up to 1,048,576 input tokens and returns up to 384,000 output tokens per call.

✓

Image input

Accepts text and images.

Quick start

Copy this snippet and start making calls with DeepSeek V4.1 Flash.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "deepseek/deepseek-v4.1-flash",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

DeepSeek V4.1 Flash vs similar models

Every model below runs on the same API key — switch by changing the model ID.

Model	Provider	Price	Context
DeepSeek V4.1 Flash	DeepSeek	$0.44 in / $1.77 out per 1M	1.0M
DeepSeek V4 Flash	DeepSeek	$0.13 in / $0.27 out per 1M	1.0M
DeepSeek V3.2	DeepSeek	$0.41 in / $0.62 out per 1M	164K
DeepSeek V4.1 Flash Economy	DeepSeek	$0.35 in / $1.42 out per 1M	1.0M
DeepSeek V4 Pro 0813	DeepSeek	$0.97 in / $2.92 out per 1M	1.0M
DeepSeek R1 0528	DeepSeek	$0.74 in / $3.18 out per 1M	164K
Nemotron 3 Super	NVIDIA	$0 in / $0 out per 1M	262K
Qwen3.7 Flash	Qwen	$0.04 in / $0.19 out per 1M	1M

Why use DeepSeek V4.1 Flash through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

DeepSeek V4.1 Flash API — pricing, context window & access

DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder architecture. It pairs a 1,048,576-token context window with up to 384,000 output tokens per response, at $0.44 per 1M input and $1.77 per 1M output tokens through YepAPI.

Through YepAPI you call DeepSeek V4.1 Flash on an OpenAI-compatible endpoint with a single key — the same key that reaches GPT-6, Claude, Gemini, Grok and the SEO, SERP and scraping APIs. Input: text, images.

What is DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder architecture. It activates 8B parameters on input and 16B on output, which is how it reaches $0.44 / $1.77 per 1M tokens while keeping a 1,048,576-token context window, up to 384,000 output tokens, and image input. It accepts text, images as input, handles up to 1,048,576 tokens of context and returns up to 384,000 output tokens per call.

Build with DeepSeek V4.1 Flash via YepAPI

YepAPI serves DeepSeek V4.1 Flash on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to deepseek-v4.1-flash (or the full deepseek/deepseek-v4.1-flash). Function calling, structured outputs and reasoning settings pass straight through, and switching to any other model on the platform is a one-string change per request.

DeepSeek V4.1 Flash API pricing — $0.44 / 1M input, $1.77 / 1M output

DeepSeek V4.1 Flash costs $0.44 per 1M input tokens and $1.77 per 1M output tokens through YepAPI, pay per token with no minimums. Failed calls are never charged, and every request is itemised in your dashboard API Logs so you can see exactly what a very long response cost.

DeepSeek V4.1 Flash use cases

V4.1 Flash is the model for very high-volume work — extraction, summarisation, classification, drafting — where the per-call price has to be close to zero.

Start generating in 30 seconds

Pay per call, no subscriptions.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

DeepSeek V4.1 Flash costs $0.44 per 1M input tokens and $1.77 per 1M output tokens through YepAPI, billed per request with no monthly fee. For example, a chat reply (1K input + 500 output tokens) costs about $0.0013.

Sign up at yepapi.com (Google or email, about 30 seconds), open the dashboard and create an API key. The same key works for DeepSeek V4.1 Flash and every other model — no separate DeepSeek account or waitlist.

Use "deepseek/deepseek-v4.1-flash" as the model on /v1/ai/chat. The short alias "deepseek-v4.1-flash" also works.

Yes. Point the OpenAI SDK at https://api.yepapi.com/v1/ai with your YepAPI key and set model to "deepseek/deepseek-v4.1-flash". Streaming works the same way, so existing OpenAI code only needs the base URL and key changed.

DeepSeek V4.1 Flash supports a 1.0M token context window with up to 384K output tokens per request.