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What is MCP?

MCP (Model Context Protocol) is an open protocol that allows AI agents to connect to external tools and services. Think of it as a universal adapter that lets your agent interact with Slack, HubSpot, Calendly, and any other service.

How MCP Works

  1. Agent receives user request - “Send an email to john@example.com”
  2. Agent decides to use a tool - Determines SendGrid tool is needed
  3. MCP protocol bridges the connection - Standardized communication
  4. Connector executes the action - Actually sends the email via SendGrid API
  5. Result returns to agent - “Email sent successfully”

Key Concepts

Connectors

Connectors are MCP-compatible servers that provide tools to your agent.

Tools

Tools are individual actions your agent can perform through a connector.

Tool Calling

When your agent needs to use a tool:
  1. Agent analyzes user request - Understands what action is needed
  2. Agent selects appropriate tool - Chooses “send_email” from SendGrid connector
  3. Agent prepares parameters - Extracts to, subject, body from context
  4. MCP executes tool - Connector sends the email
  5. Agent receives result - Uses response to continue conversation

Two Types of Connectors

1. Pre-built Connectors

BoostGPT provides 30+ ready-to-use connectors:
  • Managed by BoostGPT - We handle hosting, updates, and maintenance
  • Checked before it is saved - A credential the vendor refuses never becomes a connection
  • Connected once - The workspace holds it; each agent is then allowed to use it
Example: connecting SendGrid

2. External MCP Servers

Connect any MCP-compatible server from the internet:
  • You provide the URL - Point to any MCP server
  • Third-party or self-hosted - Host your own or use community servers
  • Custom tools - Access specialized tools not in our library
Example: Connecting external server

MCP Protocol Flow

Authentication

Signing in (connectors and remote servers)

API Key (External Servers)

Security

Pre-built Connectors

  • OAuth 2.0 - Industry-standard secure authentication
  • Encrypted storage - Tokens encrypted at rest
  • Scoped permissions - Only request necessary permissions
  • Revokable access - Disconnect anytime from Dashboard

External Servers

  • HTTPS required - All MCP servers must use HTTPS
  • You control access - Manage authentication yourself
  • Audit logs - See all tool executions in agent Insights

Real-World Example

An agent that keeps the marketing site honest

MCP vs Direct API Integration

Supported Tool Types

MCP connectors can provide various tool types:

Data Access

  • Read data (emails, contacts, files)
  • Search and filter
  • Query databases

Actions

  • Send messages
  • Create records
  • Update information
  • Delete items

Scheduled Tasks

  • Set reminders
  • Schedule events
  • Automate workflows

Real-time

  • Subscribe to events
  • Stream data
  • Webhooks

Building Your Own Connector

Want to create a custom MCP connector? See our guide:

Creating Connectors

Build your own MCP connector

MCP Protocol Spec

Technical protocol details

Debugging Tools

Agent Insights

View all tool executions:

Test in Playground

Limitations

Rate limits

Every service has its own, and they are the vendor’s to enforce: HubSpot allows 100 requests per 10 seconds, most AI providers meter by tokens or images, and a free tier is usually stricter than a paid one. When a vendor refuses a call, the agent is told in the vendor’s own words rather than being left to guess. BoostGPT counts calls too — every connector call is logged and charged against your plan’s allowance, whichever connector made it.

Permissions

An agent can only use what you have connected and left switched on:
A tool switched off in a connection’s settings is invisible to the agent — it is not offered and then refused.

How many connections

Each plan allows a number of connections, not connectors: two connections of the same service — a live Stripe and a test one — count as two. The Connectors screen shows where you stand against your plan in its header, and creating one past the limit is refused before anything is made.

Next Steps

Quickstart

Connect your first service

Browse Connectors

See all available connectors

Build Custom

Create your own connector

Remote MCP servers

Connect a server the vendor runs