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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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Affinity MCP Server
for AI Agents

Connect your AI agent to StackOne's Affinity MCP server and give it 34 MCP tools out of the box. Auth, tool execution, and security all managed.

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Affinity MCP Server
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Coverage

34 Agent Actions

Create, read, update, and delete across Affinity — and extend your agent's capabilities with custom actions.

MCP Actions → Build Actions →

Authentication

Agent Tool Authentication

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

Agent Auth →

Security

Agent Protection

Every Affinity tool response scanned for prompt injection in milliseconds — 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 Affinity call.

Tools Discovery →

What is the Affinity MCP Server?

A Affinity MCP server lets AI agents read and write Affinity data through the Model Context Protocol — Anthropic's open standard for connecting LLMs to external tools. StackOne's Affinity MCP server ships with 34 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 Affinity MCP Tools

Every action from Affinity's API, ready for your agent. Create, read, update, and delete — scoped to exactly what you need.

Current Users

  • Get Current User

    Retrieve information about the currently authenticated user

Opportunities

  • List Opportunities

    Retrieve a paginated list of all opportunities (deals) in Affinity

Opportunitys

  • Create Opportunity

    Create a new opportunity (deal) in Affinity

  • Get Opportunity

    Retrieve a specific opportunity by its ID

  • Update Opportunity

    Update an existing opportunity in Affinity

  • Delete Opportunity

    Delete an opportunity from Affinity

Organizations

  • Create Organization

    Create a new organization (company) in Affinity

  • List Organizations

    Retrieve a paginated list of all organizations (companies) in Affinity

  • Get Organization

    Retrieve a specific organization by its ID

  • Update Organization

    Update an existing organization in Affinity

  • Delete Organization

    Delete an organization from Affinity

Persons

  • Create Person

    Create a new person (contact) in Affinity

  • List Persons

    Retrieve a paginated list of all persons (contacts) in Affinity

  • Get Person

    Retrieve a specific person by their ID

  • Update Person

    Update an existing person in Affinity

  • Delete Person

    Delete a person from Affinity

Lists

  • List Lists

    Retrieve all lists (pipelines) in Affinity

Get Lists

  • Get List

    Retrieve a specific list by its ID

Entries

  • List List Entries

    Retrieve all entries in a specific list

Entrys

  • Create List Entry

    Add an entity to a list in Affinity

  • Get List Entry

    Retrieve a specific list entry by its ID

  • Delete List Entry

    Remove an entry from a list in Affinity

Notes

  • Create Note

    Create a new note associated with a person, organization, or opportunity

  • List Notes

    Retrieve notes associated with a specific person, organization, or opportunity

  • Get Note

    Retrieve a specific note by its ID

  • Update Note

    Update an existing note in Affinity

  • Delete Note

    Delete a note from Affinity

Interactions

  • List Interactions

    Retrieve interactions (emails, meetings, etc.) associated with a person, organization, or opportunity

  • Get Interaction

    Retrieve a specific interaction by its ID

Fields

  • List Fields

    Retrieve field metadata definitions available in Affinity

Field Values

  • Create Field Value

    Set a field value on an entity in Affinity

  • List Field Values

    Retrieve field values for a specific entity in Affinity

  • Update Field Value

    Update an existing field value in Affinity

  • Delete Field Value

    Delete a field value from an entity in Affinity

Affinity AI Agent Use Cases

Connect your AI agent to Affinity and help your team scale the sales operations they run by hand today.

Post-Demo Follow-Up

Use StackOne to connect your AI agent to your CRM, email, and calendar tools to automate post-demo follow-up.

View
SalesforceHubSpotPipedriveGongFirefliesGmailMicrosoft OutlookGoogle Calendar
Deal Risk Scoring

Use StackOne to connect your AI agent to your CRM, email, and calendar tools to automate deal risk scoring and pipeline alerts.

View
SalesforceHubSpotPipedriveZoho CRMCloseFreshsalesGmailOutlook
Outbound Prospecting

Use StackOne to connect your AI agent to your CRM, sales engagement, and messaging tools to automate outbound prospecting.

View
SalesforceHubSpotOutreachSalesloftLemlistPipedriveCloseGmail
More Sales & CRM use cases

Set Up Your Affinity MCP Server in Minutes

One endpoint. Any framework. Your agent is talking to Affinity 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 CRM MCP Servers

Salesforce

380+ actions

Keap

158+ actions

Zoho CRM

127+ actions

Pipedrive

121+ actions

Freshsales

120+ actions

JustCall

88+ actions

Pardot

88+ actions

All CRM MCP Servers →

Platform Resources

MCP Code Mode: Keeping Tool Responses Out of Agent Context

Anthropic's code_execution processes data already in context. Custom MCP code mode keeps raw tool responses in a sandbox. 14K tokens vs 500.

11 min

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 200+ Connector Builds Taught Us

MCP wraps APIs, it doesn't replace them. After building 200+ connectors that serve both, here's when each approach wins.

14 min read

Affinity MCP Server FAQ

Does StackOne have a Affinity MCP server?
Yes. StackOne offers a hosted Affinity MCP server with 34 pre-built actions, 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.
Affinity MCP server vs direct API integration — what's the difference?
A Affinity MCP server and direct API integration serve different use cases. Direct API integration is for software-to-software — backend code calling Affinity. A Affinity MCP server is for AI agents — MCP clients like Claude and Cursor, plus framework agents built with OpenAI, LangChain, or Vercel AI — discovering and calling Affinity at runtime. StackOne provides both.
How does Affinity authentication work for AI agents?
Affinity authentication for AI agents works through a StackOne Connect Session. Create one via the dashboard or the SDK — you get an auth link and ready-to-paste config for Claude Desktop, Cursor, and other MCP clients. Your user authenticates their own Affinity account; StackOne handles token exchange, storage, and refresh. Credentials never reach the LLM, and each user is isolated via origin_owner_id.
Are Affinity MCP tools vulnerable to prompt injection?
Yes — Affinity MCP tools can be vulnerable to indirect prompt injection. Any tool that reads user-written content — 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 — regex patterns in ~1ms, then a MiniLM classifier in ~4ms. 88.7% accuracy, CPU-only.
What is the context bloat of a Affinity agent and how do I avoid it?
Context bloat happens when Affinity tool schemas and API responses eat your Affinity agent's memory, preventing it from reasoning effectively. A single Affinity query can return a massive JSON response, and connecting multiple tools compounds the problem. Tools Discovery and Code Mode reduce context bloat — loading only relevant tools per query and keeping raw responses out of the agent's context.
Can I limit which actions my Affinity agent can access?
Yes — you can limit which actions your Affinity 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 Affinity MCP server?
Yes — you can create custom agent actions for your Affinity MCP server using Connector Builder. It's an integration agent your coding assistant (Claude Code, Cursor, or Copilot) can invoke to research Affinity's API, generate production-ready connector YAML, test against the live API, and validate before you ship.
When should I NOT use a Affinity MCP server?
Skip a Affinity MCP server if your integration is purely software-to-software — direct Affinity 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 Affinity actions at runtime.
What AI frameworks and AI clients does the StackOne Affinity MCP server support?
The StackOne Affinity 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.

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