API | Kimi K3.1 API — 1M Context, Thinking, Tools

moonshot/kimi-k3.1-pro/chat

Kimi K3.1 Pro is Moonshot AI's flagship model, released on 23 October 2026 as the first model in its K3.1 series; Moonshot describes it as its most capable open-weight model to date. Here it is one OpenAI-compatible chat endpoint: up to 1,048,576 tokens of input, text, images and video in the messages, function calling, streaming, and a reasoning_effort of low, high or max on every request.

Input $2Output $10per 1 million tokensCached input $0.20Cache write $2

Run model View API

Send a request

Examples use the selected endpoint’s public parameter definitions. Replace the API key and example media, then send the request from your server.

SDKs & integrations

POSThttps://api.spicyapi.ai/v1/chat/completions

API authentication

Keep the API key in the server environment variable SPICY_API_KEY. Use Bearer authentication and Content-Type: application/json for JSON requests.

Authorization: Bearer $SPICY_API_KEY

curl --fail-with-body -sN https://api.spicyapi.ai/v1/chat/completions \
  -H "Authorization: Bearer $SPICY_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "model": "moonshot/kimi-k3.1-pro/chat",
  "messages": [
    {
      "role": "user",
      "content": "Summarise the following release notes into three bullet points."
    }
  ],
  "stream": true
}' \
  | jq --unbuffered -Rrj 'select(startswith("data: ")) | .[6:] | select(. != "[DONE]") | fromjson | if .error then "\n[error] \(.error.message)\n" else (.choices[0].delta.content? // empty) end'

Generated from this model’s input schema — the same one the API validates every request against.

Keep one Idempotency-Key for each logical request. After a network interruption, do not automatically resend with a new key; retain request_id to investigate the accepted request. Idempotency does not replay an earlier chat stream.

Input parameters

Place the model parameters directly in the JSON request body alongside model. This endpoint does not use an input wrapper.

messagesarray<object>Required

Send Kimi K3.1 Pro an ordered conversation containing the source material for a source-backed project plan; keep tool results paired with tool_call_id.Kimi K3.1 Pro — Video uses inline bytes within the combined 14 MB media limit.

Default: Not specified
Constraints: minItems:1
maxItems:256

messages[].rolestringRequired within object

Role of the message author.

Default: Not specified
Allowed values: "system""developer""user""assistant""tool"

messages[].namestringOptional

Optional name identifying the speaker within its role.

Default: Not specified

messages[].contentstring | array | nullOptional

Message content, either plain text or a list of content parts.

Default: Not specified

{
  "type": [
    "string",
    "array",
    "null"
  ],
  "items": {
    "oneOf": [
      {
        "type": "object",
        "required": [
          "type",
          "text"
        ],
        "properties": {
          "text": {
            "type": "string"
          },
          "type": {
            "const": "text"
          }
        }
      },
      {
        "type": "object",
        "required": [
          "type",
          "image_url"
        ],
        "properties": {
          "type": {
            "const": "image_url"
          },
          "image_url": {
            "type": "object",
            "required": [
              "url"
            ],
            "properties": {
              "url": {
                "type": "string"
              }
            }
          }
        }
      },
      {
        "type": "object",
        "required": [
          "type",
          "video_url"
        ],
        "properties": {
          "type": {
            "const": "video_url"
          },
          "video_url": {
            "type": "object",
            "required": [
              "url"
            ],
            "properties": {
              "url": {
                "type": "string"
              }
            }
          }
        }
      }
    ]
  },
  "description": "Message content, either plain text or a list of content parts."
}

messages[].tool_callsarray<object>Optional

Tool calls the assistant requested in this message.

Default: Not specified

messages[].tool_call_idstringOptional

Identifier of the tool call this message answers. Required on tool messages.

Default: Not specified

messages[].reasoning_contentstringOptional

Reasoning text from a previous assistant reply, preserved when continuing a tool conversation.

Default: Not specified

{
  "type": "array",
  "x-ui": {
    "order": 100,
    "widget": "chat-messages",
    "primary": true
  },
  "items": {
    "type": "object",
    "allOf": [
      {
        "if": {
          "required": [
            "reasoning_content"
          ]
        },
        "then": {
          "properties": {
            "role": {
              "const": "assistant"
            }
          }
        }
      }
    ],
    "required": [
      "role"
    ],
    "properties": {
      "name": {
        "type": "string",
        "description": "Optional name identifying the speaker within its role."
      },
      "role": {
        "enum": [
          "system",
          "developer",
          "user",
          "assistant",
          "tool"
        ],
        "type": "string",
        "description": "Role of the message author."
      },
      "content": {
        "type": [
          "string",
          "array",
          "null"
        ],
        "items": {
          "oneOf": [
            {
              "type": "object",
              "required": [
                "type",
                "text"
              ],
              "properties": {
                "text": {
                  "type": "string"
                },
                "type": {
                  "const": "text"
                }
              }
            },
            {
              "type": "object",
              "required": [
                "type",
                "image_url"
              ],
              "properties": {
                "type": {
                  "const": "image_url"
                },
                "image_url": {
                  "type": "object",
                  "required": [
                    "url"
                  ],
                  "properties": {
                    "url": {
                      "type": "string"
                    }
                  }
                }
              }
            },
            {
              "type": "object",
              "required": [
                "type",
                "video_url"
              ],
              "properties": {
                "type": {
                  "const": "video_url"
                },
                "video_url": {
                  "type": "object",
                  "required": [
                    "url"
                  ],
                  "properties": {
                    "url": {
                      "type": "string"
                    }
                  }
                }
              }
            }
          ]
        },
        "description": "Message content, either plain text or a list of content parts."
      },
      "tool_calls": {
        "type": "array",
        "items": {
          "type": "object"
        },
        "description": "Tool calls the assistant requested in this message."
      },
      "tool_call_id": {
        "type": "string",
        "description": "Identifier of the tool call this message answers. Required on tool messages."
      },
      "reasoning_content": {
        "type": "string",
        "description": "Reasoning text from a previous assistant reply, preserved when continuing a tool conversation."
      }
    },
    "additionalProperties": false
  },
  "maxItems": 256,
  "minItems": 1,
  "description": "Conversation history in order, oldest message first."
}

response_formatobjectOptional

Request text or structured JSON from Kimi K3.1 Pro for a source-backed project plan, then check the JSON against the fields your application expects.

Default: Not specified

tool_choicestring | objectOptional

For Kimi K3.1 Pro, tool_choice accepts auto / none / required / function; return each executed function’s result with its original tool_call_id.

Default: Not specified

parallel_tool_callsbooleanOptional

In a Kimi K3.1 Pro turn, this switch permits proposals for several independent functions; the application still controls their execution.

Default: true

toolsarray<object>Optional

Give Kimi K3.1 Pro up to 128 OpenAI-format function definitions for a source-backed project plan; your application checks arguments and performs the proposed operations.

Default: Not specified
Constraints: maxItems:128

stopstring | arrayOptional

Stop Kimi K3.1 Pro with one sequence or up to four sequences; the matched marker is omitted from the final text.

Default: Not specified
Constraints: minLength:1
minItems:1
maxItems:4

reasoning_effortstringOptional

Kimi K3.1 Pro accepts low, high, max, with max as the default; compare effort settings on a source-backed project plan while monitoring output-token usage.

Default: "max"
Allowed values: "low""high""max"

max_tokensintegerOptional

For Kimi K3.1 Pro, max_tokens defaults to 4,096 and allows at most 1,048,576 output tokens, including any billable reasoning; reserve enough for a source-backed project plan.

Default: 4096
Constraints: minimum:1
maximum:1048576

{
  "type": "object",
  "required": [
    "messages"
  ],
  "x-pricing": {
    "billingMode": "formula",
    "variantFields": []
  },
  "properties": {
    "stop": {
      "type": [
        "string",
        "array"
      ],
      "x-ui": {
        "order": 65,
        "widget": "text",
        "affects_price": false
      },
      "items": {
        "type": "string",
        "maxLength": 32,
        "minLength": 1
      },
      "maxItems": 4,
      "minItems": 1,
      "minLength": 1,
      "description": "Sequences that end the reply as soon as the model writes one; the matched text is not returned."
    },
    "tools": {
      "type": "array",
      "x-ui": {
        "order": 35,
        "widget": "json"
      },
      "items": {
        "type": "object"
      },
      "maxItems": 128,
      "description": "Tool definitions the model may call."
    },
    "messages": {
      "type": "array",
      "x-ui": {
        "order": 100,
        "widget": "chat-messages",
        "primary": true
      },
      "items": {
        "type": "object",
        "allOf": [
          {
            "if": {
              "required": [
                "reasoning_content"
              ]
            },
            "then": {
              "properties": {
                "role": {
                  "const": "assistant"
                }
              }
            }
          }
        ],
        "required": [
          "role"
        ],
        "properties": {
          "name": {
            "type": "string",
            "description": "Optional name identifying the speaker within its role."
          },
          "role": {
            "enum": [
              "system",
              "developer",
              "user",
              "assistant",
              "tool"
            ],
            "type": "string",
            "description": "Role of the message author."
          },
          "content": {
            "type": [
              "string",
              "array",
              "null"
            ],
            "items": {
              "oneOf": [
                {
                  "type": "object",
                  "required": [
                    "type",
                    "text"
                  ],
                  "properties": {
                    "text": {
                      "type": "string"
                    },
                    "type": {
                      "const": "text"
                    }
                  }
                },
                {
                  "type": "object",
                  "required": [
                    "type",
                    "image_url"
                  ],
                  "properties": {
                    "type": {
                      "const": "image_url"
                    },
                    "image_url": {
                      "type": "object",
                      "required": [
                        "url"
                      ],
                      "properties": {
                        "url": {
                          "type": "string"
                        }
                      }
                    }
                  }
                },
                {
                  "type": "object",
                  "required": [
                    "type",
                    "video_url"
                  ],
                  "properties": {
                    "type": {
                      "const": "video_url"
                    },
                    "video_url": {
                      "type": "object",
                      "required": [
                        "url"
                      ],
                      "properties": {
                        "url": {
                          "type": "string"
                        }
                      }
                    }
                  }
                }
              ]
            },
            "description": "Message content, either plain text or a list of content parts."
          },
          "tool_calls": {
            "type": "array",
            "items": {
              "type": "object"
            },
            "description": "Tool calls the assistant requested in this message."
          },
          "tool_call_id": {
            "type": "string",
            "description": "Identifier of the tool call this message answers. Required on tool messages."
          },
          "reasoning_content": {
            "type": "string",
            "description": "Reasoning text from a previous assistant reply, preserved when continuing a tool conversation."
          }
        },
        "additionalProperties": false
      },
      "maxItems": 256,
      "minItems": 1,
      "description": "Conversation history in order, oldest message first."
    },
    "max_tokens": {
      "type": "integer",
      "x-ui": {
        "unit": "tokens",
        "order": 80,
        "widget": "number",
        "advanced": false,
        "affects_price": false
      },
      "default": 4096,
      "maximum": 1048576,
      "minimum": 1,
      "description": "Maximum number of tokens to generate in the reply."
    },
    "tool_choice": {
      "type": [
        "string",
        "object"
      ],
      "x-ui": {
        "order": 30,
        "widget": "json"
      },
      "description": "Controls whether and which tool the model may call."
    },
    "response_format": {
      "type": "object",
      "x-ui": {
        "order": 25,
        "widget": "json"
      },
      "description": "Requested reply format, such as plain text or a JSON object."
    },
    "reasoning_effort": {
      "enum": [
        "low",
        "high",
        "max"
      ],
      "type": "string",
      "x-ui": {
        "order": 70,
        "widget": "radio"
      },
      "default": "max",
      "description": "How much reasoning the model spends before answering."
    },
    "parallel_tool_calls": {
      "type": "boolean",
      "x-ui": {
        "order": 33,
        "widget": "switch",
        "affects_price": false
      },
      "default": true,
      "description": "Whether the model may request more than one tool call in a single turn."
    }
  },
  "x-image-token-limit": 24576,
  "x-input-token-limit": 1048576,
  "additionalProperties": false,
  "x-max-tokens-includes-reasoning": true
}

Read the result

With stream set to false, the request returns the completed chat response directly. Read choices[].message; no task polling is needed. Set stream to true when your client supports Server-Sent Events.

Completed response example

{
  "id": "chatcmpl_example",
  "object": "chat.completion",
  "created": 1788652800,
  "model": "moonshot/kimi-k3.1-pro/chat",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Here is a concise summary of the release notes."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 32,
    "completion_tokens": 14,
    "total_tokens": 46
  }
}

The response example is illustrative. usage reports token counts; token counts and charges depend on your actual request.

SDKs & integrations

Use SpicyAPI in your app, terminal, AI assistant or visual workflow. Choose a setup guide below.

SDKs

TypeScript · Python · Go · PHP · Java

CLI

Terminal commands and automation scripts.

MCP

Claude Code · Cursor · Codex

Agent Skill

Reusable instructions for your AI assistant.

n8n

Self-hosted community nodes and importable HTTP Request templates for n8n Cloud.

ComfyUI

Image, video and audio workflows on a node canvas.

More integrations

SillyTavern Telegram / Discord App proxy OpenAI SDK LangChain Vercel AI SDK

Browse ready-to-use workflows

This is a chat model, so it works wherever the OpenAI chat API works: keep your client, change the base URL, and select this model by its ID.

Point any OpenAI-compatible client here

export OPENAI_BASE_URL="https://api.spicyapi.ai/v1"
export OPENAI_API_KEY="$SPICY_API_KEY"

aider --model openai/moonshot/kimi-k3.1-pro/chat

Anything that speaks the OpenAI chat API works the same way — SDKs, the Vercel AI SDK, LangChain, aider, Cline. The MCP server and the spicyapi CLI cover asynchronous media tasks. Per-tool setup is in the developer hub.

Use it in SillyTavern and roleplay apps

In SillyTavern, RisuAI, Agnai or any app with an OpenAI-compatible setting, paste the base URL below and your API key, then pick moonshot/kimi-k3.1-pro/chat as the model. Browser calls are allowed, and sliders this model does not take are ignored instead of rejected.

Base URL: https://api.spicyapi.ai/v1
Model: moonshot/kimi-k3.1-pro/chat

SillyTavern guide RisuAI, Agnai and more SillyTavern extension

Use it in ComfyUI

Install the SpicyAPI nodes from ComfyUI Manager or with the command below, then pick moonshot/kimi-k3.1-pro/chat in the SpicyAPI Chat node to use this model inside a ComfyUI graph.

cd ComfyUI/custom_nodes
git clone https://github.com/spicyapi-ai/comfyui-spicyapi

Workflow examples Setup guide Source on GitHub

The embedded panel reads the same schema as this page, so it cannot drift from the API. If your docs need the content to be searchable, read the JSON under /api/embed/models/ and render it yourself.

<iframe src="https://spicyapi.ai/embed/en/models/kimi-k3-1-pro/api?model=moonshot%2Fkimi-k3.1-pro%2Fchat" width="100%" height="560" loading="lazy" title="Request example" style="border:1px solid rgba(0,0,0,.12)"></iframe>

Open the panel

Workbench

Send a request

API authentication

Input parameters

Read the result

SDKs & integrations

Use it in SillyTavern and roleplay apps

Use it in ComfyUI