How to Use the Google Pub/Sub Topic MCP in LangChain

Q: How does Google Pub/Sub Topic interact with LangChain?

The pubsubpublishmessage tool allows your LangChain agent to send data out as a message. This acts as an event trigger for other services listening on that specific Google Pub/Sub Topic.

LangChain: Build multi-step reasoning chains using Google Pub/Sub Topic events.

See Vinkius in Action

Works with every AI agent you already use

…and any MCP-compatible client

MCP Servers — Included with Plan

Connect Google Pub/Sub Topic MCP to LangChain

Create your Vinkius account to connect Google Pub/Sub Topic to LangChain — we handle the hosting, security, and runtime updates so you don't have to. No server setup required.

GDPR Included with Plan

Setup Google Pub/Sub Topic with LangChain

Ask AI about this MCP

ChatGPT

Claude

Perplexity Vinkius runs on Gemini

Gemini

Grok

Triggering Cloud Events in Chains

Your agent can use the `pubsub_publish_message` tool to push data directly onto a specific Google Pub/Sub Topic. This lets you build complex, multi-step pipelines where one stage's output triggers an external cloud event. The chain’s flow is determined by your logic: the agent decides when and what kind of message needs sending. The results from this MCP are then fed into subsequent nodes in your graph.

Observing Pub/Sub Interactions

You get full visibility on how messages hit the Google Pub/Sub Topic via LangSmith tracing. You can track latency and resource usage for every single call to this MCP server. This detailed record shows exactly what data was sent, who triggered it, and how much that interaction cost in tokens.

Integrating External APIs

Don't write wrapper code just to hit a cloud service. You link the Google Pub/Sub Topic directly into your agent’s toolset. This makes integrating complex, asynchronous backend systems trivial. You can combine this MCP with vector stores and databases—all within one execution graph.

Setup guide

Set up Google Pub/Sub Topic MCP in LangChain

Prerequisites

Python 3.10+ installed
langchain-mcp-adapters + langgraph packages
Active Vinkius subscription with a valid endpoint token

1

Install dependencies
Run pip install langchain-mcp-adapters langgraph langchain-openai. The MCP adapters package converts MCP tools into native LangChain BaseTool objects.
2

Connect via HTTP transport
Use MultiServerMCPClient with "transport": "http" pointing to your Vinkius endpoint. Replace [YOUR_TOKEN_HERE] with your token from cloud.vinkius.com.
3

Create a ReAct agent
Pass the discovered tools to create_react_agent() from LangGraph. The agent automatically routes Google Pub/Sub Topic tool calls through the MCP protocol.
4

Run with any LLM
Swap ChatOpenAI for ChatAnthropic, ChatGoogleGenerativeAI, or any LangChain-compatible model. The MCP tools work identically across all providers.

agent.py

from langchain_mcp_adapters.client import MultiServerMCPClient
from langgraph.prebuilt import create_react_agent
from langchain_openai import ChatOpenAI

async with MultiServerMCPClient({
    "google-pubsub-topic-mcp": {
        "transport": "http",
        "url": "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp",
    }
}) as client:
    tools = client.get_tools()

    agent = create_react_agent(
        ChatOpenAI(model="gpt-4o"),
        tools,
    )
    result = await agent.ainvoke({
        "messages": "List recent Google Pub/Sub Topic transactions"
    })
    print(result["messages"][-1].content)

Get your connection token →

Independent Platform Disclaimer: Vinkius is an independent platform and is not affiliated with, endorsed by, sponsored by, verified by, or otherwise authorized by Google Pub/Sub Topic. All third-party trademarks, logos, and brand names are the property of their respective owners. Their use on this website is strictly for informational purposes to identify service compatibility and interoperability.

Why Choose Vinkius

Vinkius connects your tools to AI with real-time monitoring and automatic cost savings — all from one dashboard.

Connect Google Pub/Sub Topic now

Real-time monitoring

Live

visibility into every interaction

Connect your favorite tools to your AI and see exactly what's happening — every request, every response, in real time.

Built-in savings

60%

lower AI costs

Vinkius compresses data between your apps and your AI automatically. Lower bills every month — no configuration required.

Single dashboard

One

place for every integration

Every tool your AI connects to, managed from a single screen. One account, complete control.

Common questions about Google Pub/Sub Topic MCP in LangChain

The `pubsub_publish_message` tool allows your LangChain agent to send data out as a message. This acts as an event trigger for other services listening on that specific Google Pub/Sub Topic.

Yes. While stateless by default, you can manage persistent context using the client session. This means your agent remembers previous steps when deciding to publish a message via the Google Pub/Sub Topic.

The tool accepts standard string and dictionary inputs, which get serialized into the message payload. This gives you flexibility for publishing structured data or simple event notifications.

LangSmith provides a detailed audit trail that captures all inputs and outputs of the tool call. You can pinpoint exactly when, where, and why a message was published.

The MCP handles standard string/dictionary payloads. Since the credentials are used in transit only via Vinkius's zero-trust proxy, your keys never sit on disk.

Use it with your favorite AI tools

Connect this server to Cursor, Claude, VS Code, and more.

OpenAI Agents SDK sdk-python

Google ADK sdk-python

Pydantic AI sdk-python

Vercel AI SDK sdk-typescript