← Blog

DeepSeek V4 Flash: free API, OpenAI-compatible

How to call DeepSeek V4 Flash for free through InferAll's OpenAI-compatible endpoint. Hosted on NVIDIA NIM, $0 within the free tier, works with the OpenAI SDK you already have.

InferAll Team

4 min read
DeepSeekDeepSeek V4free LLM APINVIDIA NIMOpenAI APIopen sourcedeveloper tools

Update, 2026-09-02 — this model is not currently responding. deepseek-ai/deepseek-v4-flash-0731 is still listed in the free catalogue and has not been retired, but every request we made on 2026-09-01/02 timed out: eight consecutive probes, at ceilings from 45 up to 110 seconds, zero responses. The snippets below are correct and will work if the model recovers.

To run them today, substitute a model that is answering — as of this update minimaxai/minimax-m3, which returned in under 1.5 seconds on the same endpoint and is $0 in/out on the same free tier. ⚠️ We are describing latency we measured on two days, not a permanent verdict: a slow model is not a retired one, and this page will not be rewritten as though it were. Check GET /ai/v1/models for what is live before trusting any roster in an article, including this one.

DeepSeek V4 is one of the strongest open-weight model families for reasoning, coding, and agentic work, and through InferAll you can call it free via NVIDIA NIM. The available model is deepseek-ai/deepseek-v4-flash-0731, tuned for cost-efficient, lower-latency work. No credit card, $0 within the free tier, and it works with the OpenAI SDK you already have.

Model Best for
deepseek-ai/deepseek-v4-flash-0731 Cost-efficient, lower-latency, high-volume

It is $0 on the free NVIDIA NIM tier.


Quick start (Python)

from openai import OpenAI

client = OpenAI(
    base_url="https://api.inferall.ai/v1",
    api_key="ifu_your_key_here",  # get one at inferall.ai/keys, no card required
)

# Fast, cost-efficient, great default
response = client.chat.completions.create(
    model="deepseek-ai/deepseek-v4-flash-0731",
    messages=[{"role": "user", "content": "Refactor this function for readability: ..."}],
    max_tokens=512,
)

print(response.choices[0].message.content)

The only change from calling OpenAI directly is the base_url. Your existing code, streaming, and tool use all work unchanged.


TypeScript

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.inferall.ai/v1",
  apiKey: process.env.INFERALL_API_KEY,
});

const response = await client.chat.completions.create({
  model: "deepseek-ai/deepseek-v4-flash-0731",
  messages: [{ role: "user", content: "Write a SQL migration to add a nullable column." }],
  max_tokens: 400,
});

console.log(response.choices[0].message.content);

Why call DeepSeek V4 through InferAll

It's genuinely $0 in / $0 out. DeepSeek V4 runs on NVIDIA NIM (NVIDIA Inference Microservices) on their DGX Cloud infrastructure, which InferAll exposes at $0. No inference cost to pass through, so it stays $0 per call within the free-plan daily request caps (50 chat / 100 text / day, reset 00:00 UTC) — activate via the $5 starter pack at /billing.

One key for DeepSeek and everything else. The same ifu_... key also calls Kimi K3, Gemma, Nemotron, and other free open models, plus paid GPT-4.1, Claude Opus 4, and Gemini 2.5 when you need a frontier model. Switch by changing one string; no juggling provider keys.

OpenAI-compatible. Standard chat.completion responses, streaming, tool use, and JSON mode, all working with whatever OpenAI client you already have. Moving from gpt-4o-mini to deepseek-ai/deepseek-v4-flash-0731 is a one-line model-string change.


Pro vs Flash — which to use

Start with Flash. It handles the majority of coding, refactoring, summarization, and structured-output tasks at lower latency, and it's free. Step up to Pro when you hit a genuinely hard reasoning or multi-step agentic problem where you can feel Flash struggling. Since both are $0 on the free tier, the only real cost of using Pro is latency — so use Flash by default and reserve Pro for the hard cases.


Compare it yourself

The best way to pick a model is to watch several answer the same prompt. The full free roster is one call away — curl https://api.inferall.ai/ai/v1/models — so you never hardcode a list that goes stale.

Sign up at inferall.ai/keys, then activate via the $5 starter pack at /billing — 25 free NIM calls come before any payment; the $5 becomes spendable balance for premium providers and unlocks ongoing access to the 25+ NIM open models at $0 in/out (within the free-plan daily request caps).