Can you call DeepSeek-V3.1-250821 with the OpenAI SDK you already use?

Yes. DeepSeek-V3.1-250821 is reachable through an OpenAI-compatible endpoint, so an existing OpenAI SDK client works after pointing the base URL at MixRoute and setting the model parameter to deepseek-v3.1-250821 . Keep your current request and response handling.

Does DeepSeek-V3.1-250821 have a free tier?

DeepSeek-V3.1-250821 is billed per use and the record publishes no free-tier allowance. The current published rates are input $0.5600 per 1M tokens and output $1.6800 per 1M tokens. Trial credit or promotional quota is tied to your account rather than to the model, so check the console before planning around a free tier.

When was DeepSeek-V3.1-250821 released, and is it still maintained?

DeepSeek-V3.1-250821 was released on 2025-08-21. Its catalog status is stable. Check the model page for deprecation notices before you build a long-lived integration on it.

What should you evaluate before moving production traffic to DeepSeek-V3.1-250821?

Before switching production traffic to DeepSeek-V3.1-250821, run a pilot on a representative slice of your traffic and check output quality, latency at peak concurrency, and cost per request. Verify the error and retry behaviour, and confirm the request limits you depend on match your plan.

What is the rate limit for DeepSeek-V3.1-250821?

The current model record does not publish a numeric rate limit for DeepSeek-V3.1-250821. Confirm the quota for your plan in the console, then run a short load test at your expected concurrency to establish the effective ceiling before production.

Model detail

DeepSeek-V3.1-250821

Provided by DeepSeek

Delisted Pay-as-you-go

DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 base with a two-phase long-context training process, reaching up to 128K tokens, and uses FP8 microscaling for efficient inference. Users can control the reasoning behaviour with the `reasoning` `enabled` boolean. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#enable-reasoning-with-default-config) The model improves tool use, code generation, and reasoning efficiency, achieving performance comparable to DeepSeek-R1 on difficult benchmarks while responding more quickly. It supports structured tool calling, code agents, and search agents, making it suitable for research, coding, and agentic workflows. It succeeds the [DeepSeek V3-0324](/deepseek/deepseek-chat-v3-0324) model and performs well on a variety of tasks.

Model specs

Model ID: deepseek-v3.1-250821

Context length: 128K
Max output: 32K
I/O modalities
Released: 2025-08

API endpoints

One MixRoute gateway, OpenAI-compatible

OpenAI-compatible /v1/chat/completions POST

Pricing

Flat rate, unit: /1M Tokens

Input

$0.5600 /1M Tokens

Completion

$1.6800 /1M Tokens

Cache read

$0.0700 /1M Tokens

Selection summary

Quickly judge whether it fits your workload

What is this model good for?

DeepSeek-V3.1 is a large hybrid reasoning model

DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates.

What should you check before using it?

128,000 context, 32,000 output tokens

DeepSeek model that supports reasoning, tool calling and structured output.

Why use it through MixRoute?

Swap the base URL, keep the DeepSeek-V3.1-250821 client

MixRoute serves DeepSeek-V3.1-250821 on the OpenAI-compatible endpoint /v1/chat/completions; point your existing client at https://api.mixroute.ai/v1 with the model ID deepseek-v3.1-250821 and re-run your integration tests.

Capabilities & compatibility

Unconfirmed capabilities stay "Unknown," no guesses

Tool calling

DeepSeek-V3.1-250821 supports function and tool calls.

EX Send a tools definition; the response returns tool_calls to execute and feed results back.

Structured output

DeepSeek-V3.1-250821 can produce JSON-formatted output on demand.

EX response_format: { type: "json_schema" } forces valid JSON output.

Streaming

DeepSeek-V3.1-250821 supports streamed responses.

EX stream: true streams tokens incrementally, so chat UIs render as they arrive.

Prompt caching

DeepSeek-V3.1-250821 supports prompt caching under supported routing conditions.

EX Keep the system prompt and tool definitions at the start of the request; repeated prefixes are automatically billed at the cache-read rate.

OpenAI SDK

Call DeepSeek-V3.1-250821 through MixRoute's OpenAI-compatible endpoint.

EX Change base_url to https://api.mixroute.ai/v1; everything else follows the OpenAI style.

Token cost estimator

Live estimate from this page's pricing, not an actual bill

Input tokens Max per request 128K

Output tokens Max per request 32K

Requests / month

Cache hit rate 0%

Share of the same prefix read repeatedly, up to 100%

FAQ

DeepSeek-V3.1-250821 is a reasoning model. Reasoning effort can be tuned per request. Lower effort settings cut reasoning tokens and cost for routine work; reserve higher settings for problems that need deeper search. Measure quality at two or three settings before fixing one in production.

Get started

01

Create an API key

Generate a key in the Console; one key calls every model.
02

Set the base URL

Fully OpenAI SDK-compatible; just swap the URL to connect.

https://api.mixroute.ai/v1
03

Specify the model ID

In the request's model field, enter:

deepseek-v3.1-250821

Create an API key

New users get $5 in free credits

Test this model and alternate routes with the same request format

Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.

Create an API key View integration docs