DeepSeek V4 Flash

DeepSeek V4 Flash via AnyFast OpenAI-compatible API. Fast, capable, and easy to integrate.

DeepSeek V4 Flash is available through AnyFast via an OpenAI-compatible interface. It features thinking mode, function calling, and JSON mode support.

Key capabilities

• OpenAI-compatible — Works as a drop-in replacement with the OpenAI SDK
• Thinking mode — Supports reasoning with configurable effort levels
• Function calling — Call tools and functions natively
• JSON mode — Structured output via response_format
• Long context — Handles large documents and multi-turn conversations
• Streaming — Supports real-time token streaming via SSE
• Prompt caching — Automatic cache with hit/miss token reporting

Quick example

cURL

curl https://www.anyfast.ai/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-v4-flash",
    "messages": [
      { "role": "user", "content": "Explain quantum entanglement in simple terms." }
    ]
  }'

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://www.anyfast.ai/v1"
)

response = client.chat.completions.create(
    model="deepseek-v4-flash",
    messages=[
        {"role": "user", "content": "Explain quantum entanglement in simple terms."}
    ]
)

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

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://www.anyfast.ai/v1"
)

stream = client.chat.completions.create(
    model="deepseek-v4-flash",
    messages=[
        {"role": "user", "content": "Write a short poem about the sea."}
    ],
    stream=True
)

for chunk in stream:
    print(chunk.choices[0].delta.content or "", end="")

Parameters

Parameter	Type	Required	Description
model	string	Yes	Must be deepseek-v4-flash
messages	array	Yes	List of { role, content } objects. Supports system, user, assistant, tool roles.
thinking	object	No	Enable/disable thinking: {"type": "enabled"} or {"type": "disabled"}. Optional reasoning_effort: high, max, low, medium.
max_tokens	integer	No	Maximum tokens to generate
temperature	float	No	0–2. Controls randomness. Default: 1
stream	boolean	No	Enable SSE streaming. Default: false
stream_options	object	No	{"include_usage": true} includes token usage in the final streaming chunk
top_p	float	No	Nucleus sampling threshold. Default: 1
stop	string / array	No	Sequences that stop generation (up to 16)
response_format	object	No	{"type": "json_object"} for JSON mode
tools	array	No	List of function tools for function calling
tool_choice	string / object	No	Control tool selection: none, auto, required, or specific function
user_id	string	No	Custom user ID for content safety and KVCache isolation

API Reference

View the interactive API playground for DeepSeek V4 Flash.