How to Use Official Tools in Kimi API

import os

import requests

BASE_URL = "https://api.moonshot.ai/v1"
API_KEY = os.environ["MOONSHOT_API_KEY"]
FORMULA_URI = "moonshot/web-search:latest"


def call(method: str, path: str, body: dict | None = None) -> dict:
    resp = requests.request(
        method,
        BASE_URL + path,
        headers={"Authorization": f"Bearer {API_KEY}"},
        json=body,
        timeout=120,
    )
    resp.raise_for_status()
    return resp.json()


# 1. Fetch the tool declarations
tools = call("GET", f"/formulas/{FORMULA_URI}/tools")["tools"]

messages = [
    {"role": "system", "content": "You are Kimi, an AI assistant provided by Moonshot AI."},
    {"role": "user", "content": "What is the latest news about Moonshot AI?"},
]

while True:
    # 2. Send the request with the tool declarations (include full tools in every request)
    resp = call("POST", "/chat/completions",
                {"model": "kimi-k3", "messages": messages, "tools": tools})
    message = resp["choices"][0]["message"]
    tool_calls = message.get("tool_calls") or []
    if not tool_calls:
        # No tool_calls: print the final answer
        print(message["content"])
        break

    # Keep the assistant message (with tool_calls) verbatim; later rounds must include it
    messages.append({k: v for k, v in message.items()
                     if k in ("role", "content", "tool_calls")})

    for tc in tool_calls:
        fn = tc["function"]
        # 3. Execute the fiber exactly as tool_calls specifies (arguments verbatim; billed here)
        fiber = call("POST", f"/formulas/{FORMULA_URI}/fibers",
                     {"name": fn["name"], "arguments": fn["arguments"]})
        ctx = fiber.get("context", {})
        result = ctx.get("output") or ctx.get("encrypted_output") or ""
        # 4. Return the result as a role=tool message; tool_call_id must match tool_calls[].id
        messages.append({"role": "tool", "tool_call_id": tc["id"], "content": result})

export FORMULA_URI="moonshot/web-search:latest"
export MOONSHOT_BASE_URL="https://api.moonshot.ai/v1"

curl -X POST ${MOONSHOT_BASE_URL}/formulas/${FORMULA_URI}/fibers \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $MOONSHOT_API_KEY" \
-d '{
  "name": "web_search",
  "arguments": "{\"query\": \"Please look up the latest news about Moonshot AI.\"}"
}'

curl ${MOONSHOT_BASE_URL}/formulas/${FORMULA_URI}/tools \
    -H "Authorization: Bearer $MOONSHOT_API_KEY"

{
  "object": "list",
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "web_search",
        "description": "Search the web for information",
        "parameters": {
          "type": "object",
          "properties": {
            "query": {
              "description": "What to search for",
              "type": "string"
            }
          },
          "required": [ "query" ]
        }
      }
    }
  ]
}

{
  "id": "chatcmpl-1234567890",
  "object": "chat.completion",
  "choices": [
    {
      "message": {
        "role": "assistant",
        "tool_calls": [
          {
            "id": "web_search:0",
            "type": "function",
            "function": {
              "name": "web_search",
              "arguments": "{\"query\": \"What is the RGB value of sky blue?\" }"
            }
          }
        ]
      },
      "finish_reason": "tool_calls"
    }
  ]
}

{
  "id": "fiber-f43p7sby7ny111houyq1",
  "object": "fiber",
  "created_at": 1753440997,
  "lambda_id": "lambda-f3w8y6qcoqgi11h8q7ui",
  "status": "succeeded",
  "context": {
    "input": "{\"name\":\"web_search\",\"arguments\":\"{\\\"query\\\": \\\"What is the RGB value of sky blue?\\\" }\"}",
    "encrypted_output": "----MOONSHOT ENCRYPTED BEGIN----+nf6...DSM=----MOONSHOT ENCRYPTED END----"
  },
  "formula": "moonshot/web-search:latest",
  "organization_id": "staff",
  "project_id": "proj-88a5894a985646b5902b70909748ba16"
}

messages = [
  /* other messages */
  { /* the return content of the previous round of the model */
    "role": "assistant",
    "tool_calls": [
      {
        "id": "web_search:0",
        "type": "function",
        "function": {
          "name": "web_search",
          "arguments": "{\"query\": \"What is the RGB value of sky blue?\" }"
        }
      }
    ]
  },
  { /* the information you need to supplement */
    "role": "tool",
    "tool_call_id": "web_search:0",  /* note that the id here needs to be aligned with the id in the previous tool_calls[] */
    "content": "----MOONSHOT ENCRYPTED BEGIN----+nf6...DSM=----MOONSHOT ENCRYPTED END----"
  }
]