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Moonshot AI

Kimi K3

Kimi’s flagship model for long-horizon coding and end-to-end knowledge work, with a 1M-token context window. Your use subject to Moonshot AI's Terms & Privacy Policies.

ReasoningTool UseImplicit CachingFile InputVision (Image)
Use with AI GatewayView docs
import { streamText } from 'ai'


const result = streamText({
  model: 'moonshotai/kimi-k3',
  prompt: 'Why is the sky blue?'
})
Read docs
OverviewAPIProvidersThroughputLatencyUptimeStatusSimilar

Getting started

Call Kimi K3 through AI Gateway with the AI SDK generateText and streamText functions, or through the OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages APIs by changing the base URL. AI Gateway authenticates the request and routes it to an available provider.

Install the AI SDK (pnpm add ai dotenv), create an API key from the API Keys page, and set it as AI_GATEWAY_API_KEY in your environment. Full setup is covered in the text generation quickstart.

index.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    prompt: 'Why is the sky blue?',
  });


  console.log(result.text);
}


main().catch(console.error);

Top-level parameters

The same Kimi K3 request in each API format AI Gateway supports.

top-level-params.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    system: 'You are a concise technical assistant.',
    prompt: 'Summarize the tradeoffs between static generation and SSR.',
    maxOutputTokens: 1024,
  });


  console.log(result.text);
}


main().catch(console.error);

Standard parameters like prompt, messages, temperature, and tools work as documented in the AI SDK docs. These are the parameters with model-specific behavior.

ParameterTypeRequiredDescription
modelstringYesModel ID in the form creator/model, e.g. moonshotai/kimi-k3. AI Gateway routes the request to an available provider.
maxOutputTokensnumberNoHard cap on generated tokens. Kimi K3 supports up to 1,000,000 output tokens. Reasoning tokens count toward this limit.
reasoning'provider-default' | 'none' | 'minimal' | 'low' | 'medium' | 'high' | 'xhigh'NoProvider-agnostic reasoning effort, available in AI SDK 7 or later. Maps to the provider’s native reasoning configuration; reasoning settings under providerOptions take precedence when both are set. See the Reasoning section below.
providerOptionsRecord<string, JSONValue>NoAI Gateway routing options under gateway, plus any provider-native options under the provider’s own namespace — see the table below.

Input limits

InputFormatsSourcesMax countMax sizeLimits
Text————Prompt and response share the 1M-token context window
Image—URL, base64, Uint8Array——Sent as image parts in messages; counts as input tokens
PDF—URL, base64, Uint8Array——Sent as file parts in messages; counts as input tokens

Provider options

Set AI Gateway routing options under providerOptions.gateway. For provider-specific options, pass them under the provider’s namespace as documented by the AI SDK.

Learn more in the AI SDK moonshotai provider docs.

provider-options.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    prompt: 'Why is the sky blue?',
    providerOptions: {
      gateway: {
        only: ['moonshotai', 'fireworks'],
      },
    },
  });


  console.log(result.text);
}


main().catch(console.error);

These AI Gateway routing options apply to every model. Provider-specific options pass through under the provider’s own namespace (for example providerOptions.anthropic) exactly as documented by the AI SDK.

ParameterTypeRequiredDescription
providerOptions.gateway.onlystring[]NoRestrict routing to these provider slugs. Requests fail over only within the listed providers.
providerOptions.gateway.orderstring[]NoPreferred provider order. Listed providers are tried first; unlisted providers remain available as fallbacks.
providerOptions.gateway.sort'cost' | 'ttft' | 'tps'NoRank candidate providers by price, time to first token, or tokens per second instead of the default routing order.
providerOptions.gateway.zeroDataRetentionbooleanNoRoute only to providers with a zero-data-retention policy for this model.

Routing across providers

AI Gateway serves the same model through multiple providers and fails over automatically. order expresses a preference while keeping every provider eligible; only is a hard allowlist — if none of the listed providers are available the request fails instead of falling back.

Options under a provider's own namespace (for example providerOptions.anthropic) are forwarded to that provider with the request. Providers ignore option namespaces that don't apply to them, so it is safe to set provider options alongside gateway routing options.

Reasoning

AI Gateway bridges reasoning across every API format. The AI SDK exposes a provider-agnostic top-level reasoning level (none, minimal, low, medium, high, or xhigh); the Chat Completions and Responses formats take the same effort under reasoning.effort; and the Anthropic Messages format uses a native thinking token budget. Whichever you send, the gateway maps it to the target model’s native configuration, converting between effort levels and token budgets as needed. Reasoning-related settings under providerOptions take full precedence over the top-level reasoning value and are never merged. Reasoning tokens typically count toward your output-token usage, though how they’re reported and billed varies by provider.

Learn more in the AI Gateway reasoning guide.

reasoning.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    prompt: 'Explain the Monty Hall problem step by step.',
    reasoning: 'high',
  });


  console.log(result.text);
}


main().catch(console.error);

Image input

Send images alongside text as message parts. Images count as input tokens.

image-input.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    messages: [
      {
        role: 'user',
        content: [
          { type: 'text', text: 'Describe this image.' },
          { type: 'image', image: 'https://example.com/photo.jpg' },
        ],
      },
    ],
  });


  console.log(result.text);
}


main().catch(console.error);

PDF input

Attach PDFs as file parts. Their contents count as input tokens.

pdf-input.ts
import { generateText } from 'ai';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    messages: [
      {
        role: 'user',
        content: [
          { type: 'text', text: 'Summarize this document.' },
          {
            type: 'file',
            mediaType: 'application/pdf',
            data: 'https://example.com/document.pdf',
          },
        ],
      },
    ],
  });


  console.log(result.text);
}


main().catch(console.error);

Tool calling

Expose tools the model can call. Define each tool’s inputs with a Zod schema.

tool-calling.ts
import { generateText, tool } from 'ai';
import { z } from 'zod';
import 'dotenv/config';


async function main() {
  const result = await generateText({
    model: 'moonshotai/kimi-k3',
    prompt: 'What is the weather in San Francisco?',
    tools: {
      getWeather: tool({
        description: 'Get the current weather for a location',
        inputSchema: z.object({ location: z.string() }),
        execute: async ({ location }) => ({ location, temperatureC: 18 }),
      }),
    },
  });


  console.log(result.text);
}


main().catch(console.error);