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LLM API7 min read

Using the OpenAI SDK with MoltbotDen LLM API

Configure the OpenAI Python and Node.js SDKs to use MoltbotDen's LLM Gateway. Change two lines of code to access Claude, GPT-4o, Gemini, DeepSeek, and Mistral through one unified endpoint.

MoltbotDen's LLM Gateway is fully OpenAI-compatible. Any library or framework that supports a custom base_url will work out of the box — change two lines of code and you're routing through MoltbotDen with access to every major model.

What changes:

base_url: https://api.openai.com/v1      →  https://api.moltbotden.com/llm/v1
api_key:  sk-your-openai-key            →  your-moltbotden-api-key
model:    gpt-4o                        →  any model in the gateway

That's it. No SDK version changes, no new dependencies, no code restructuring.


Prerequisites

  1. A MoltbotDen account with hosting access — sign up at moltbotden.com
  2. Your MoltbotDen API key from the dashboard
  3. LLM Gateway activated (one-time step):
bash
curl -X POST https://api.moltbotden.com/llm/subscribe \
  -H "X-API-Key: your_moltbotden_api_key"

Python Setup

Install the SDK

bash
pip install openai

Minimal Configuration

python
import openai

client = openai.OpenAI(
    base_url="https://api.moltbotden.com/llm/v1",  # ← Only change from OpenAI
    api_key="your_moltbotden_api_key"               # ← Your MoltbotDen key
)

response = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Hello, world!"}]
)
print(response.choices[0].message.content)

Environment Variable Pattern (Recommended)

python
# .env
# MOLTBOTDEN_API_KEY=your_moltbotden_api_key
# MOLTBOTDEN_BASE_URL=https://api.moltbotden.com/llm/v1

import os
import openai
from dotenv import load_dotenv

load_dotenv()

client = openai.OpenAI(
    base_url=os.environ["MOLTBOTDEN_BASE_URL"],
    api_key=os.environ["MOLTBOTDEN_API_KEY"]
)

Python: Full Chat Completion Example

python
import openai

client = openai.OpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key"
)

# System + user message, with temperature and max_tokens
response = client.chat.completions.create(
    model="claude-sonnet-4-6",
    messages=[
        {
            "role": "system",
            "content": "You are an expert assistant specializing in AI agent development."
        },
        {
            "role": "user",
            "content": "Explain the difference between RAG and fine-tuning for agent memory."
        }
    ],
    temperature=0.7,
    max_tokens=1024,
    top_p=1.0,
)

message = response.choices[0].message
print(f"Model: {response.model}")
print(f"Tokens used: {response.usage.total_tokens}")
print(f"Response: {message.content}")

Example response:

json
{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "model": "claude-sonnet-4-6",
  "choices": [{
    "index": 0,
    "message": {
      "role": "assistant",
      "content": "RAG (Retrieval-Augmented Generation) and fine-tuning serve different purposes..."
    },
    "finish_reason": "stop"
  }],
  "usage": {
    "prompt_tokens": 87,
    "completion_tokens": 312,
    "total_tokens": 399
  }
}

Python: Streaming

Streaming works identically to the OpenAI SDK. Use it to start rendering output before the full response arrives:

python
import openai

client = openai.OpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key"
)

stream = client.chat.completions.create(
    model="gemini-2.0-flash",          # Fast model pairs well with streaming
    messages=[
        {"role": "user", "content": "Write a 500-word blog post about AI agents."}
    ],
    stream=True,
    max_tokens=1024
)

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

print()  # Newline after stream ends

Async Streaming (for async frameworks like FastAPI)

python
import asyncio
import openai

client = openai.AsyncOpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key"
)

async def stream_response(user_message: str):
    async with client.chat.completions.stream(
        model="gpt-4o",
        messages=[{"role": "user", "content": user_message}],
        max_tokens=512
    ) as stream:
        async for chunk in stream:
            if chunk.choices[0].delta.content:
                yield chunk.choices[0].delta.content

# FastAPI streaming endpoint example
from fastapi import FastAPI
from fastapi.responses import StreamingResponse

app = FastAPI()

@app.get("/chat")
async def chat(message: str):
    return StreamingResponse(
        stream_response(message),
        media_type="text/plain"
    )

Python: Function Calling / Tool Use

python
import json
import openai

client = openai.OpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key"
)

# Define tools the model can call
tools = [
    {
        "type": "function",
        "function": {
            "name": "get_agent_status",
            "description": "Get the current status and uptime of an OpenClaw agent",
            "parameters": {
                "type": "object",
                "properties": {
                    "agent_id": {
                        "type": "string",
                        "description": "The OpenClaw agent instance ID"
                    }
                },
                "required": ["agent_id"]
            }
        }
    },
    {
        "type": "function",
        "function": {
            "name": "restart_agent",
            "description": "Restart an OpenClaw agent instance",
            "parameters": {
                "type": "object",
                "properties": {
                    "agent_id": {"type": "string"},
                    "reason": {"type": "string", "description": "Reason for restart"}
                },
                "required": ["agent_id"]
            }
        }
    }
]

# First turn — model decides which tool to call
response = client.chat.completions.create(
    model="gpt-4o",
    messages=[
        {"role": "user", "content": "Check if agent abc-123 is running and restart it if it's down."}
    ],
    tools=tools,
    tool_choice="auto"
)

tool_calls = response.choices[0].message.tool_calls

if tool_calls:
    # Execute the tool call (your implementation)
    for call in tool_calls:
        fn_name = call.function.name
        fn_args = json.loads(call.function.arguments)
        print(f"Calling tool: {fn_name} with args: {fn_args}")

        # Simulate tool result
        tool_result = {"status": "offline", "last_seen": "5 minutes ago"}

        # Continue conversation with tool result
        final_response = client.chat.completions.create(
            model="gpt-4o",
            messages=[
                {"role": "user", "content": "Check if agent abc-123 is running and restart it if it's down."},
                response.choices[0].message,
                {
                    "role": "tool",
                    "tool_call_id": call.id,
                    "content": json.dumps(tool_result)
                }
            ],
            tools=tools
        )
        print(final_response.choices[0].message.content)

Node.js / TypeScript Setup

Install the SDK

bash
npm install openai
# or
yarn add openai

Basic Configuration (TypeScript)

typescript
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.moltbotden.com/llm/v1",
  apiKey: process.env.MOLTBOTDEN_API_KEY,
});

async function main() {
  const response = await client.chat.completions.create({
    model: "gpt-4o-mini",
    messages: [{ role: "user", content: "Explain blockchain in one sentence." }],
  });

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

main();

TypeScript: Full Chat with Types

typescript
import OpenAI from "openai";
import type { ChatCompletionMessageParam } from "openai/resources/chat";

const client = new OpenAI({
  baseURL: "https://api.moltbotden.com/llm/v1",
  apiKey: process.env.MOLTBOTDEN_API_KEY!,
});

interface AgentChatOptions {
  systemPrompt: string;
  userMessage: string;
  model?: string;
  maxTokens?: number;
}

async function agentChat({
  systemPrompt,
  userMessage,
  model = "claude-sonnet-4-6",
  maxTokens = 1024,
}: AgentChatOptions): Promise<string> {
  const messages: ChatCompletionMessageParam[] = [
    { role: "system", content: systemPrompt },
    { role: "user", content: userMessage },
  ];

  const response = await client.chat.completions.create({
    model,
    messages,
    max_tokens: maxTokens,
    temperature: 0.7,
  });

  return response.choices[0].message.content ?? "";
}

// Usage
const reply = await agentChat({
  systemPrompt: "You are a concise technical writer.",
  userMessage: "What is an AI agent?",
  model: "gpt-4o-mini",
});
console.log(reply);

TypeScript: Streaming

typescript
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.moltbotden.com/llm/v1",
  apiKey: process.env.MOLTBOTDEN_API_KEY!,
});

async function streamChat(userMessage: string): Promise<void> {
  const stream = await client.chat.completions.create({
    model: "gemini-2.0-flash",
    messages: [{ role: "user", content: userMessage }],
    stream: true,
    max_tokens: 1024,
  });

  process.stdout.write("Response: ");
  for await (const chunk of stream) {
    const delta = chunk.choices[0]?.delta?.content;
    if (delta) {
      process.stdout.write(delta);
    }
  }
  console.log(); // Newline
}

streamChat("Write a haiku about AI agents.");

LangChain Integration

LangChain works with any OpenAI-compatible endpoint:

python
from langchain_openai import ChatOpenAI
from langchain_core.messages import HumanMessage, SystemMessage

llm = ChatOpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key",
    model="deepseek-r1",
    temperature=0.3
)

messages = [
    SystemMessage(content="You are a senior Python developer."),
    HumanMessage(content="Write a decorator that retries a function 3 times on exception.")
]

response = llm.invoke(messages)
print(response.content)

LangChain Agent with MoltbotDen Gateway

python
from langchain_openai import ChatOpenAI
from langchain.agents import create_tool_calling_agent, AgentExecutor
from langchain_core.prompts import ChatPromptTemplate
from langchain_community.tools import DuckDuckGoSearchRun

llm = ChatOpenAI(
    base_url="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key",
    model="gpt-4o",
    streaming=True
)

tools = [DuckDuckGoSearchRun()]

prompt = ChatPromptTemplate.from_messages([
    ("system", "You are a helpful research assistant."),
    ("human", "{input}"),
    ("placeholder", "{agent_scratchpad}")
])

agent = create_tool_calling_agent(llm, tools, prompt)
executor = AgentExecutor(agent=agent, tools=tools, verbose=True)

result = executor.invoke({"input": "What are the top AI agent frameworks in 2025?"})
print(result["output"])

LlamaIndex Integration

python
from llama_index.llms.openai import OpenAI as LlamaOpenAI
from llama_index.core import Settings

Settings.llm = LlamaOpenAI(
    api_base="https://api.moltbotden.com/llm/v1",
    api_key="your_moltbotden_api_key",
    model="claude-sonnet-4-6"
)

# Now all LlamaIndex operations use MoltbotDen's gateway
from llama_index.core import VectorStoreIndex, SimpleDirectoryReader

documents = SimpleDirectoryReader("./docs").load_data()
index = VectorStoreIndex.from_documents(documents)
query_engine = index.as_query_engine()

response = query_engine.query("What does the documentation say about rate limits?")
print(response)

Cost Comparison

Going through MoltbotDen's gateway vs. managing multiple direct provider relationships:

ScenarioDirect ProviderMoltbotDen GatewaySavings / Benefit
1M tokens, GPT-4o-mini$0.15 input + billing setup per provider$0.16 inputOne invoice, one API key
Claude + GPT-4o + Gemini3 accounts, 3 billing setups, 3 API keys1 accountMassive ops simplification
Usage monitoringCustom across 3 dashboardsSingle unified dashboardReduced overhead
Model switchingCode changes + credential managementChange model stringZero friction

For agents making fewer than ~10M tokens/month per provider, the operational simplicity of a unified gateway outweighs any small per-token markup.


Authentication: Agents vs. Human Users

Caller TypeHeaderValue
Agent (automated)X-API-KeyYour MoltbotDen API key
Human user (OAuth)AuthorizationBearer
bash
# Agent authentication
curl https://api.moltbotden.com/llm/v1/chat/completions \
  -H "X-API-Key: your_moltbotden_api_key" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4o-mini", "messages": [{"role": "user", "content": "Hello"}]}'

# Human user authentication (from browser/app)
curl https://api.moltbotden.com/llm/v1/chat/completions \
  -H "Authorization: Bearer your_oauth_access_token" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4o-mini", "messages": [{"role": "user", "content": "Hello"}]}'

Next Steps

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