Skip to main content Announcing Tool Policies: AI agent permissions down to the field Read the announcement
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.

For SaaS products Embedded AI agent integrations Give your product's agent every system your customers use.
Pricing
Login
Book Demo Start Free
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.

Pricing
Book Demo Start Free
Live 8 Actions

Proton MCP Server
for AI Agents

Connect your AI agent to StackOne's Proton MCP server and give it ready-to-use MCP tools out of the box. Auth, tool execution, and security all managed.

Start Free Book Demo Read Docs →
Proton logo
Proton MCP Server
Built by StackOne StackOne
DrataGPLocalyzeFlipMindtoolsScreenloop

Coverage

8 Agent Actions

Read-only access to Proton. Extend your agent's capabilities with custom actions.

MCP Actions → Build Actions →

Authentication

Agent Tool Authentication

Per-user OAuth in one call. Your Proton MCP server gets session-scoped tokens with zero credentials stored on your infra.

Agent Auth →

Security

Agent Protection

Every Proton tool response scanned for prompt injection in milliseconds, with 88.7% accuracy, all running on CPU.

Prompt Injection Defense →

Performance

Max Agent Context. Min Cost.

Free up to 96% of your agent's context window to enhance reasoning and reduce cost, on every Proton call.

Tools Discovery →

What is the Proton MCP Server?

A Proton MCP server lets AI agents read Proton data through the Model Context Protocol, Anthropic's open standard for connecting LLMs to external tools. StackOne's Proton MCP server ships with pre-built actions, fully extensible via the Connector Builder, plus managed authentication, prompt injection defense, observability, and agent execution runtime. Connect it from MCP clients like Claude Desktop, Claude Code, Cursor, Goose, and VS Code, or from agent frameworks like OpenAI Agents SDK, LangChain, and Vercel AI SDK.

All Proton MCP Tools

Every StackOne action for Proton, ready for your agent. Read-only, scoped to exactly what you need.

Groups

  • List Groups

    List groups in the connected Proton organization through the SCIM API.

  • Get Group

    Get one group of the connected Proton organization through the SCIM API.

Unified Groups

  • List Unified Groups

    List unified groups in the connected Proton organization.

  • Get Unified Group

    Get a unified Proton group by ID.

Unified Users

  • List Unified Users

    List unified users in the connected Proton organization.

  • Get Unified User

    Get a unified Proton user by ID.

Users

  • List Users

    List users in the connected Proton organization through the SCIM API.

  • Get User

    Get one user of the connected Proton organization through the SCIM API.

Set Up Your Proton MCP Server in Minutes

One endpoint. Any framework. Your agent is talking to Proton in under 10 lines of code.

MCP Clients

Claude Desktop setup guide
Claude Code setup guide
Cursor setup guide
Goose setup guide

Agent Frameworks

Claude Desktop
{
  "mcpServers": {
    "stackone": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote@latest",
        "https://api.stackone.com/mcp?x-account-id=<account_id>",
        "--header",
        "Authorization: Basic <YOUR_BASE64_TOKEN>"
      ]
    }
  }
}

Check More developer MCP Servers

Wiz

696+ actions

IONOS

501+ actions

Workiva

266+ actions

KnowBe4

259+ actions

HighLevel

251+ actions

WorkOS

234+ actions

SAP Concur

232+ actions

All developer MCP Servers →

Platform Resources

Comparing BM25, TF-IDF, and Hybrid Search for MCP Tool Discovery

Benchmarking BM25, TF-IDF, and hybrid search for MCP tool discovery across 916 tools. The 80/20 TF-IDF/BM25 hybrid hits 21% Top-1 accuracy in under 1ms.

10 min

Indirect Prompt Injection Defense for MCP Tools: A Technical Guide

MCP tools that read emails, CRM records, and tickets are indirect prompt injection vectors. Here's how we built a two-tier defense that scans tool results in ~11ms.

12 min

MCP vs A2A: Architecture, Security, and When to Use Each

MCP vs A2A: what each protocol standardizes, how they differ, their shared security risks including indirect prompt injection, and when to use one, both, or a hybrid architecture.

12 min

MCP vs API: What Hundreds of Connector Builds Taught Us

MCP wraps APIs, it doesn't replace them. After building hundreds of connectors that serve both, here's when each approach wins.

14 min read

Proton MCP Server FAQ

Does StackOne have a Proton MCP server?
Yes. StackOne offers a hosted Proton MCP server, and every action is tested and QA'd by StackOne. Connect it to Claude, Cursor, and any other MCP client, or to any agent framework through the AI Action SDK. It ships with managed agent authentication, prompt injection defense, and tool discovery with server-side execution that preserve your agent's context window and keep reasoning performance.
Proton MCP server vs direct API integration: what's the difference?
A Proton MCP server and direct API integration serve different use cases. Direct API integration is for software-to-software work, where backend code calls Proton. A Proton MCP server is for AI agents that discover and call Proton at runtime, such as MCP clients like Claude and Cursor, plus framework agents built with OpenAI, LangChain, or Vercel AI. StackOne provides both.
How does Proton authentication work for AI agents?
Proton authentication for AI agents works through a StackOne Connect Session. Create one via the dashboard or the SDK to get an auth link and ready-to-paste config for Claude Desktop, Cursor, and other MCP clients. Your user authenticates their own Proton account; StackOne handles token exchange, storage, and refresh. Credentials never reach the LLM, and each user is isolated via origin_owner_id.
Are Proton MCP tools vulnerable to prompt injection?
Yes. Proton MCP tools can be vulnerable to indirect prompt injection. Any tool that reads user-written content, such as documents, messages, tickets, records, or free-text fields, is a potential vector. StackOne Defender scans every tool response before it enters the agent's context. It runs regex patterns in ~1ms, then a MiniLM classifier in ~4ms. Accuracy is 88.7%, and it runs entirely on CPU.
What is the context bloat of a Proton agent and how do I avoid it?
Context bloat happens when Proton tool schemas and API responses eat your Proton agent's memory, preventing it from reasoning effectively. A single Proton query can return a massive JSON response, and connecting multiple tools compounds the problem. Tools Discovery reduces it by loading only the tools relevant to each query.
Can I limit which actions my Proton agent can access?
Yes. You can limit which actions your Proton agent can access directly from the StackOne dashboard. Toggle actions on or off, or restrict them to specific accounts, with no code changes to your agent. Session tokens can be scoped to exact actions so if one leaks, exposure stays contained.
Can I create custom agent actions for my Proton MCP server?
Yes. You can create custom agent actions for your Proton MCP server using Connector Builder. It's an integration agent your coding assistant (Claude Code, Cursor, or Copilot) can invoke to research Proton's API, generate production-ready connector YAML, test against the live API, and validate before you ship.
When should I NOT use a Proton MCP server?
Skip a Proton MCP server if your integration is purely software-to-software, because direct Proton API integration is simpler when no AI agent is involved. For deterministic, compliance-critical operations (financial transactions, regulatory reporting), direct API gives you predictable behavior without agent-driven decision-making. MCP shines when AI agents need to dynamically discover and call Proton actions at runtime.
What AI frameworks and AI clients does the StackOne Proton MCP server support?
The StackOne Proton MCP server supports both. MCP clients (paste-and-go apps): Claude Desktop, Claude Code, Cursor, VS Code, Goose. Agent frameworks (code SDKs you build with): OpenAI Agents SDK, Anthropic, Vercel AI, Google ADK, CrewAI, Pydantic AI, LangChain, LangGraph, Azure AI Foundry.

Put your AI agents to work

All the tools you need to build and scale AI agent integrations, with best-in-class connectivity, execution, and security.

Start Free Book Demo