Kimi K2.5 API: Complete Guide & Tutorial 2026

Kimi K2.5 is Moonshot AI's most advanced language model, offering an exceptional 200K token context window — one of the longest available from any Chinese AI provider. It excels at long-document understanding, coding, and multilingual tasks, making it a strong competitor to DeepSeek V4 and GPT-4o.

In this guide, you'll learn everything about the Kimi K2.5 API: how to get started, pricing, code examples in Python and Node.js, and a direct comparison with other models.

What is Kimi K2.5?

Kimi K2.5 is developed by Moonshot AI, a leading Chinese AI research company. The model family includes:

• Kimi K2.5 — Flagship model with 200K context window
• Moonshot V1 (8K) — Standard model for short-form tasks
• Moonshot V1 (128K) — Extended context variant for long documents

Kimi K2.5 stands out for its exceptional long-context understanding, capable of processing entire books, lengthy codebases, and multi-turn conversations in a single session.

Kimi K2.5 API Pricing

Model	Input (per 1M tokens)	Output (per 1M tokens)	Context
Kimi K2.5	$0.55	$1.80	200K
Moonshot V1 (128K)	$0.30	$0.80	128K
Moonshot V1 (8K)	$0.30	$0.80	8K
DeepSeek V4 Pro (for comparison)	$0.14	$0.28	128K
GPT-4o (for comparison)	$2.50	$10.00	128K

Getting Started: Kimi K2.5 API Tutorial

Step 1: Get Your API Key

To access the Kimi K2.5 API, you can use AIWave — the only gateway that provides OpenAI-compatible access to Kimi models without requiring a Chinese phone number. Get $0.20 starter credit instantly.

→ Sign up at AIWave and grab your API key in under 2 minutes.

Step 2: Install & Configure

The Kimi K2.5 API is fully OpenAI-compatible. Use the standard SDK:

pip install openai

Or for Node.js:

npm install openai

Step 3: Make Your First API Call

Python Example — Long Document Analysis:

from openai import OpenAI

client = OpenAI(
    base_url="https://aiwave.live/v1",
    api_key="***"
)

response = client.chat.completions.create(
    model="kimi-k2.5",
    messages=[
        {"role": "system", "content": "You are an expert document analyst."},
        {"role": "user", "content": "Analyze the key arguments in this 50-page legal document and provide a structured summary with key clauses, risks, and recommendations."}
    ],
    max_tokens=4096
)

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

Node.js Example:

import OpenAI from 'openai';

const client = new OpenAI({
    baseURL: 'https://aiwave.live/v1',
    apiKey: '***'
});

const response = await client.chat.completions.create({
    model: 'kimi-k2.5',
    messages: [
        { role: 'system', content: 'You are a code review assistant.' },
        { role: 'user', content: 'Review this Python codebase for bugs and suggest improvements.' }
    ]
});

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

Step 4: Streaming with Large Context

from openai import OpenAI

client = OpenAI(
    base_url="https://aiwave.live/v1",
    api_key="***"
)

# Process a long document with streaming
with open("long_document.txt", "r") as f:
    document = f.read()

stream = client.chat.completions.create(
    model="kimi-k2.5",
    messages=[
        {"role": "user", "content": f"Summarize this document in bullet points:\n\n{document[:150000]}"}
    ],
    stream=True
)

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

Why Choose Kimi K2.5?

Unmatched 200K Context Window

Kimi K2.5's 200K context window is significantly larger than DeepSeek V4's 128K and GPT-4o's 128K. This makes it ideal for processing entire books, lengthy legal documents, comprehensive codebases, and extended customer support conversations.

Strong Coding Ability

Kimi K2.5 demonstrates competitive performance on programming tasks, particularly for Python, JavaScript, and Go. It excels at code review, refactoring, and generating documentation for large codebases.

Multilingual Excellence

While strong in English, Kimi K2.5 truly shines in Chinese language tasks — making it the go-to choice for developers building bilingual applications.

Kimi K2.5 vs DeepSeek V4 vs GPT-4o

Feature	Kimi K2.5	DeepSeek V4 Pro	GPT-4o
Context Window	200K 🏆	128K	128K
Input Price (1M tokens)	$0.55	$0.14 🏆	$2.50
Long-Document Processing	⭐⭐⭐⭐⭐ 🏆	⭐⭐⭐⭐	⭐⭐⭐⭐
Coding	⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐
Chinese Language	⭐⭐⭐⭐⭐ 🏆	⭐⭐⭐⭐	⭐⭐⭐
Reasoning	⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐
No Chinese Phone Required	✅ AIWave	✅ AIWave	N/A

Using Kimi K2.5 with Other Models

One of the advantages of using AIWave is that you can access multiple models — including Kimi K2.5, DeepSeek V4, GLM-5, ERNIE 4.0 (Baidu), and Qwen — through a single API key. Simply change the model parameter:

# Switch between models with one parameter change
models = ["kimi-k2.5", "deepseek-v4-pro", "glm-5", "ernie-4.0"]

for model in models:
    response = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "Explain your key features."}]
    )
    print(f"{model}: {response.choices[0].message.content[:50]}...")

Kimi vs DeepSeek: Which Should You Choose?

The choice between Kimi K2.5 and DeepSeek V4 depends on your use case:

• Long document analysis → Kimi K2.5 (200K context)
• Cost-sensitive applications → DeepSeek V4 Pro ($0.14/M tokens)
• Chinese language apps → Kimi K2.5 (best Chinese proficiency)
• Coding and reasoning → DeepSeek V4 Pro (top-tier at lower cost)
• Best all-round value → DeepSeek V4 Flash ($0.07/M tokens)

With AIWave, you don't have to choose — both are available under one API key, and you can switch between them by changing a single parameter.

Frequently Asked Questions

What is Kimi K2.5 and who created it?

Kimi K2.5 is the latest model from Moonshot AI (月之暗面), a Beijing-based AI research company. It's their most advanced language model with a 200K context window.

Can I use Kimi K2.5 without a Chinese phone number?

Yes. AIWave provides access to Kimi K2.5 without requiring a Chinese phone number. Just sign up with your email and get $0.20 starter credit to start.

Is Kimi K2.5 better than DeepSeek V4?

They excel in different areas. Kimi K2.5 has a larger context window (200K vs 128K) and better Chinese language ability. DeepSeek V4 Pro is more cost-effective ($0.14 vs $0.55/M input tokens) and has stronger reasoning capabilities.

Does Kimi K2.5 support function calling?

Kimi K2.5 supports function calling and streaming, making it suitable for production applications. It's fully OpenAI-compatible through the AIWave API.

What is the difference between Kimi K2.5 and Moonshot V1?

Kimi K2.5 is Moonshot AI's latest flagship, offering improved performance over the Moonshot V1 series. Moonshot V1 (8K and 128K variants) are older generation models available at a lower price point.

from openai import OpenAI

client = OpenAI(api_key="sk-YOUR_KEY", base_url="https://aiwave.live/v1")

resp = client.chat.completions.create(
    model="kimi-k2.5",
    messages=[{"role": "user", "content": open("contract.txt").read()[:200000]}],
)
print(resp.usage)   # check how much of that context you actually paid for