128k Context Window
Process massive datasets without losing information, thanks to Moonshot AI’s long-context expertise.
kimi-k3 / image-to-text
Kimi k3 is Moonshot AI's flagship reasoning model. Designed for complex logic, the Kimi k3 API excels in mathematics and coding. With a 128k context window, it provides reliable Chain-of-Thought processing for demanding technical tasks.
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$ 13.5
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Key Features of the Kimi k3 API
Explore the technical foundations that make Kimi k3 a leader in AI reasoning and long-context performance.
94.5% MATH Score
Kimi achieves elite-level performance on hard mathematics benchmarks, ensuring computational accuracy.
OpenAI Compatible
Standardized API parameters allow for a seamless transition from GPT-4o to Kimi k3 in minutes.
RL-Driven Reasoning
Kimi uses Reinforcement Learning to 'think' before answering, generating a verifiable Chain-of-Thought.
How to Get a kimi-k3 API Key
Getting a kimi-k3 API key takes four steps and a few minutes. Create a free GPTProto account, add credits, generate your key, and make your first call — at $2.7 / $13.5 it's a cheaper kimi-k3 API key than going direct, and one key works across every model on the platform. Full kimi-k3 Documentation is in the docs.
Sign up
Create your free GPT Proto account to begin. You can set up an organization for your team at any time.
Top up
Your balance can be used across all models on the platform, including kimi-k3, giving you the flexibility to experiment and scale as needed.
Generate your API key
In your dashboard, create an API key — you'll need it to authenticate when making requests to kimi-k3.
Make your first API call
Use your API key with our sample code to send a request to kimi-k3 via GPT Proto and see instant AI-powered results.
Kimi k3 API Frequently Asked Questions
Find technical answers regarding Kimi k3 API integration, performance benchmarks, and reasoning capabilities to optimize your development workflow.
Why does the Kimi k3 API have a response delay?
The delay occurs because Kimi generates an internal Chain-of-Thought before providing a final answer. This Reinforcement Learning process allows Kimi to verify logic and correct potential errors in real-time. For complex math or coding tasks, this extra step significantly improves accuracy compared to standard models that respond instantly. Expect a few seconds of 'thinking' time for the model to produce its high-quality, verified results.
Is the Kimi k3 API compatible with OpenAI SDKs?
Yes, the Kimi k3 API is designed to be a drop-in replacement for OpenAI workflows. You can use the official OpenAI Python or Node.js SDKs by simply updating the base URL to our endpoint and changing the model name to kimi-k3. This allows you to leverage Kimi's superior reasoning capabilities without rewriting your entire codebase or changing your existing infrastructure.
What is the context window limit for Kimi k3?
Kimi k3 supports a massive context window of 128,000 tokens. Thanks to Moonshot AI's specialized focus on long-context processing, Kimi maintains high retrieval accuracy across the entire window. This prevents the 'lost in the middle' phenomenon often seen in other models, making Kimi ideal for analyzing large document sets, full codebases, or complex legal files where every detail matters.
How does Kimi k3 perform in coding tasks?
In coding benchmarks, Kimi k3 demonstrates deep algorithmic understanding, reaching the Expert/Candidate Master level on Codeforces. With an 88.4% score on HumanEval, Kimi is highly effective at refactoring complex functions, debugging logical errors, and generating verifiable code. It simulates execution paths during its internal thinking phase to ensure the logic holds up before outputting the final snippet.
Is my data used to train the Kimi models?
No. Data processed through our enterprise Kimi k3 API is not used to train Moonshot AI models. We prioritize data privacy and security for our users. Your inputs and the model's generated reasoning sequences remain confidential within your session, ensuring that sensitive research, proprietary code, or financial data used with Kimi is protected according to enterprise-grade standards.
What are the best use cases for Kimi k3?
Kimi k3 is best suited for tasks requiring multi-step logic. This includes quantitative financial analysis, scientific hypothesis generation, and complex legal compliance mapping. It is also excellent as the 'brain' for agentic planning, where Kimi can decompose a high-level goal into a sequence of sub-tasks. Because Kimi spends time thinking, it is perfect for accuracy-critical work rather than simple, fast chat interactions.