DeepSeek V4.1 Flash is live on Mixlayer

Mixlayer Team·October 9, 2026

DeepSeek released V4.1 Flash on September 10, and the month since has been fun to watch. People have pointed it at a 67,000-line codebase, had it build playable games from a single prompt, and asked it to make its own motion design showreel. One of you tried to use it in our Discord before we'd even switched it on. It's on now.

The model

DeepSeek V4.1 Flash is a mixture-of-experts model with a 552B-parameter backbone. Only 8B parameters are active while it reads your prompt, and 16B while it writes the answer. We serve it in FP8, with text in and text out.

Model ID: deepseek/deepseek-v4.1-flash
Context: 262K tokens
Price: $0.30 per million input tokens, $1.20 per million output tokens
Capabilities: reasoning and tool calls

Reasoning effort, your way

V4.1 Flash thinks by default at DeepSeek's native High effort. The model uses a sliding effort scale from 1 to 100, and Mixlayer passes it through. Use the standard names (none, low, high, max) or send a number directly:

{ "reasoning_effort": 60 }

In the Responses API, that's "reasoning": { "effort": 60 }. none turns thinking off, low maps to 50, high to 75 and max to 100. These values aren't fixed token budgets, so leave enough output tokens for both the thinking and the answer.

Three things to try

Fix a real bug in your own repo. Run it inside your coding agent (we have guides for Codex CLI and Hermes), paste in a real issue, and ask for the root cause and the smallest fix. Ask it not to simplify the requirements. A few early users said it sometimes solves an easier version of the problem than the one you gave it.

Build something playable from one prompt. Ask for a tower defense game as a single HTML file with no external libraries. Save the reply as an .html file and open it.

Turn thinking up to max. Set reasoning_effort to "max" and ask for a 15-second motion graphics showreel in one HTML file. Then let it think.

From the API, it's the OpenAI SDK with our base URL:

from openai import OpenAI

client = OpenAI(base_url="https://mixlayer.ai/v1", api_key="YOUR_MIXLAYER_KEY")
reply = client.chat.completions.create(
    model="deepseek/deepseek-v4.1-flash",
    reasoning_effort="max",
    messages=[{"role": "user", "content": "Make a dynamic 15-second motion graphics showreel..."}],
)

We're still tuning capacity this week, so if anything looks slow or off, tell us in Discord or by email. The DeepSeek V4.1 Flash guide has the full reasoning table.