Any system with a programmatic interface can be wrapped in an MCP server. The most common enterprise integrations in production deployments are: CRM systems (Salesforce, HubSpot — exposing contact lookup, deal status, activity logging as MCP tools), databases (PostgreSQL, MySQL, BigQuery — read-only query interfaces scoped to specific schemas, with row-level security enforced at the MCP layer), ticketing and project management (Jira, ServiceNow, Linear — issue creation, status retrieval, comment posting), document and knowledge stores (Confluence, SharePoint, Notion — search, retrieve, and update pages), communication platforms (Slack, Teams — message posting, channel listing, user lookup), ERP systems (SAP, Oracle — inventory queries, purchase order status, financial data reads), and internal REST and GraphQL APIs. The MCP server acts as the single, controlled entry point — the AI model never has direct access to the underlying system.