DeepSeek: DeepSeek V4 Flash 0731 (Thinking)

deepseek-v4-flash-0731:thinking

DeepSeek V4 Flash 0731 (Thinking) costs $0.065 per million input tokens and $0.208 per million output tokens, supports 1.05M context, and is available through the OpenAI-compatible API.

DeepSeek V4 Flash 0731 Thinking enables reasoning by default on the re-post-trained Mixture-of-Experts model with a 1M-token context window, built for coding, reasoning, and agent workflows.

Modalities

Text → Text

Input / output price

$0.065 / $0.208 per 1M

Context

1.05M · max output 131K

Capabilities

ReasoningTool callingLong contextOpen weights

Pricing

Billed per token actually used and deducted from your credits.

ItemUSD per 1M tokens
Input$0.065
Output$0.208
Cached input$0.0169

Calculator

Drag the sliders to estimate what this model will cost.

Per request
$0.00036
Per day
$0.1807
Per month (30 days)
$5.42

DeepSeek V4 Flash 0731 (Thinking): input $0.065/M · output $0.208/M · cached input $0.0169/M

Request with these settings
curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "deepseek-v4-flash-0731:thinking", "max_tokens": 800,
       "messages": [{"role": "user", "content": "…"}]}'

Code samples

OpenAI-compatible. Set the base URL to https://api.geniusrelaygpt.com/v1 and the model to deepseek-v4-flash-0731:thinking.

curl https://api.geniusrelaygpt.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-v4-flash-0731:thinking",
    "stream": true,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Use it in a client: Cursor · Cline · SillyTavern · Codex

Parameters

Common OpenAI parameters can be passed as-is.

temperaturetop_pmax_tokensstreamstoppresence_penaltyfrequency_penaltyseed

FAQ

How is DeepSeek V4 Flash 0731 (Thinking) billed?
Input is $0.065 and output is $0.208 per million tokens; cached input is $0.0169. The charge for every request is listed in Usage Logs in the console.
How long is the context window?
1.05M tokens. In a long conversation every turn is billed for the full input, so keep the history under control.
Does it support streaming?
Yes. Add "stream": true to the request to receive server-sent events in the OpenAI format.
DeepSeek V4 Flash 0731 (Thinking) API pricing · GeniusRelay