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Connect to everything your agents need, without writing the infrastructure to get there.

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Maximise agent efficiency – faster responses, increased accuracy, fewer tokens used.

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StackOne
Connectors
Connect

Connect to everything your agents need, without writing the infrastructure to get there.

Secure

Enterprise-grade controls to ensure your agent always meets security & compliance standards.

Optimize

Maximise agent efficiency – faster responses, increased accuracy, fewer tokens used.

Use-Cases
Pricing
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MCP Gateway

MCP Gateway
for Vertex AI Agents

One MCP gateway to connect Vertex AI to 470+ enterprise SaaS apps. No auth hassle. Token-efficient by design. Security and governance built-in.

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DrataGPLocalyzeFlipMindtoolsScreenloop

What is an MCP gateway?

An MCP gateway (also called an MCP aggregator) is a single endpoint that connects an AI agent to multiple MCP servers via the open Model Context Protocol (opens in new tab). Some gateways act as proxies, routing traffic to MCP servers customers operate themselves. Others provide the underlying MCP servers as a managed service.

StackOne is the managed kind. We provide pre-built MCP servers for 470+ enterprise SaaS apps, including ones with no official MCP server today. For each app you connect, StackOne provides the MCP protocol layer, the SaaS API integration, action coverage, and the auth orchestration framework. Authentication is configured per app per organization — your team registers OAuth credentials with the SaaS provider, links them in StackOne, and end users then authorize access through that flow. Once set up, the agent reaches every connected app through one URL, with token storage, refresh, and per-user scoping handled by StackOne.

StackOne's MCP gateway — SOC2, HIPAA, CCPA, and GDPR compliant — bundles 470+ pre-built SaaS integrations exposing 28,000+ actions, all reachable from your Vertex AI agent through one URL.

Act across all your apps
from inside Vertex AI

One MCP gateway, every enterprise SaaS your Vertex AI agent
could ever need to act on.

Coverage

470+ connectors.
28,000+ tested actions.

Every action is built and maintained by StackOne, tested against the live API, and updated when vendors change their endpoints.

Browse all connectors

Trust

Auth & governance,
simplified.

StackOne handles OAuth, API keys, refresh, and scopes for every connector, giving enterprise IT full control through auth configs in a multi-tenant setup.

Agent Auth

Performance

Agent context window,
managed.

Tool Discovery and Code Mode keep your Vertex AI agent's context lean — only relevant actions, no raw response noise. Sharper agents, lower token costs.

Tools Discovery

Security

Agent security,
built in.

Defender scans every MCP tool response for prompt injection in real time. Up to 97.44%¹ detection, 0.2% false positives. SOC2, HIPAA, CCPA, GDPR compliant.

Prompt Injection Defense

¹ Jayavibhav test, 65,000 samples.

Connect Vertex AI
to more apps in 4 steps

From auth config to first agent tool call in 5 minutes.

1

Wire StackOne as an MCPToolset in your ADK agent.

In Agent Development Kit (ADK) Python, wrap the StackOne gateway URL in MCPToolset and pass it as a tool on your LlmAgent. Deploy via Agent Engine — available to every agent in your GCP project.

Python — ADK Agent 
from google.adk.agents import LlmAgent
from google.adk.tools.mcp_tool import (
    MCPToolset, StreamableHTTPConnectionParams,
)

stackone = MCPToolset(
    connection_params=StreamableHTTPConnectionParams(
        url="https://api.stackone.com/mcp",
        headers={"Authorization": f"Bearer {STACKONE_TOKEN}"},
    )
)

agent = LlmAgent(
    model="gemini-2.5-flash",
    name="enterprise_agent",
    tools=[stackone],
)
View ADK MCP docs (opens in new tab)
2

Connect each SaaS integration in StackOne.

OAuth or API key per app, done once in your dashboard. Tokens stay server-side.

salesforce
workday
stripe
linear
github
Browse all connectors
3

Scope agent actions.

Read-only, specific objects, or per-role exposure. Toggle from the StackOne dashboard.

List records (enabled)
Get record (enabled)
Read related (enabled)
Update record (disabled)
Delete record (disabled)
Agent Auth
4

Let your Vertex AI agent call StackOne in plain English.

StackOne maps the agent's tool call to the right action in the right system. Done.

"Sync this week's Salesforce opportunities into BigQuery and open a Linear ticket for any deal blocking the Q3 forecast."

Vertex AI
salesforce_list_opportunities
Completed
linear_create_issue
Completed
team: Revenue Operations
priority: high
result: REV-512 created

Synced 38 Salesforce opportunities to BigQuery. Filed REV-512 for the 4 deals blocking Q3.

Connect Vertex AI to
any Enterprise MCP server

One MCP gateway, 470+ pre-built SaaS connectors Vertex AI can act on right away.

Need another connector? Build one with the AI Connector Builder

Get Vertex AI
to do more across your stack

Cross-app workflows your Vertex AI agent now runs in seconds instead of click-throughs.

Customer 360

> Pull Salesforce account context and join it with BigQuery product usage for the next-best action.

SalesforceKeapZoho CRMPipedriveFreshsalesJustCallPardotAircall
HR & Workforce

> Reconcile Workday hires with their GitHub access in seconds.

UKG ReadyWorkday (Rest and Soap)FactorialHiBobOracle Fusion HCMHumaansSAP SuccessFactorsClockify
Finance & Billing

> Reconcile Stripe revenue with the NetSuite GL for month-end close.

KlaviyoStripeMagentoSquareBigCommerceShopifyEventbriteWooCommerce
Engineering & DevOps

> Open a Linear ticket from a Sentry alert and notify the on-call channel.

Azure DevOpsCloudflareBitbucketGitLabLinearTerraformSupabaseOneLogin
Explore more AI agent use cases

Connect any Enterprise AI Agent
to the StackOne MCP Gateway

Same 470+ MCP servers. Same agent context. Pick yours.

Notion AI Agent
Glean
Microsoft 365 Copilot
Atlassian Rovo
ServiceNow Now Assist
SAP Joule
IBM watsonx Orchestrate
Snowflake Cortex
Databricks Agent Bricks
AWS Bedrock AgentCore
Intercom Fin
Zendesk
Retool Agents
Cohere North Soon
Perplexity Comet

Frequently Asked Questions

Vertex AI agents consume external MCP servers through the Agent Development Kit (ADK). In a few lines of Python, wrap the StackOne gateway URL in an MCPToolset with StreamableHTTPConnectionParams, pass it as a tool on your LlmAgent, and deploy via Agent Engine. 470+ pre-built SaaS connectors are reachable through that single toolset. Full walkthrough in the ADK MCP tools docs. Now part of the Gemini Enterprise Agent Platform.
An MCP gateway (also called an MCP aggregator) is a single endpoint that connects an AI agent to multiple MCP servers via the Model Context Protocol. Some gateways route traffic to MCP servers customers operate themselves; others provide the MCP servers as a managed service. StackOne is the managed kind — we provide pre-built MCP servers for 470+ enterprise SaaS apps, including ones with no official MCP server today. Authentication is configured per app per organization: your team registers OAuth credentials with the SaaS provider, links them in StackOne, and end users authorize access through that flow. Once set up, the agent reaches every connected app through one URL.
You can connect Vertex AI to 470+ live MCP servers through StackOne — one managed MCP server for every enterprise app in the catalog, spanning CRM, HRIS, ATS, ticketing, finance, and more (Salesforce, Workday, Greenhouse, ServiceNow, NetSuite, HubSpot, and Zendesk among them). Each is reachable through the single gateway URL, so you add them all with one connection instead of wiring up servers app by app. Browse and search the full list in the directory on this page, or build one with the AI Connector Builder.
Google's first-party MCP servers cover Google-owned data (BigQuery, Maps, Cloud SQL via MCP Toolbox, plus Apigee adapters). StackOne adds the other 470+ operational SaaS — every app reachable through one MCPToolset instead of one per app, auth managed once in the dashboard, and tool definitions loaded only when relevant to the prompt.
Credentials sit at three layers: your StackOne API token (embedded in the gateway URL passed to StreamableHTTPConnectionParams headers, stored as a Secret Manager secret in your GCP project), SaaS connector credentials (server-side in your StackOne dashboard), and per-user OAuth or session tokens (server-side, scoped per user). StackOne stores OAuth tokens and API keys, refreshes them automatically, and only exposes the actions you've authorized to the agent.
Skip the StackOne MCP gateway when any of these is true:
  • Google's first-party MCP servers (BigQuery, Maps, Cloud SQL via MCP Toolbox) cover your apps
  • You only use a handful of actions across a few apps
  • You don't need multi-tenancy, per-user permissions, or per-action scoping
  • Indirect prompt injection isn't a concern
  • Your MCP provider already does tool discovery and server-side execution to keep the agent context lean

Connect All Your Apps to Vertex AI.

One MCP gateway, 470+ pre-built SaaS connectors. Set up in 5 minutes.

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