"Services or tools available for free without requiring an API key" matching MCP servers:

A read-only MCP server for Portal.io that enables browsing proposals, users, contacts, and catalog items through secure HMAC-signed API requests.

A production-ready MCP server that connects AI assistants to the D-Tools System Integrator platform, enabling natural language management of AV projects, clients, catalogs, tasks, service orders, and purchase orders.

Exposes native OnlyFans and Fansly access as MCP tools, letting agents read fans, messages, media, earnings, posts, transactions and subscribers across connected creators, with opt-in outbound writes. It also provides CRM tags, smart links, webhooks and bulk exports through a single API key.

Enables AI assistants to look up customers, orders, products, and stock; take role-restricted actions such as creating orders and handling refunds; enforce business rules; and maintain a tamper-evident audit log.

Exposes internal company services as LLM-callable MCP tools, enabling AI agents to perform business operations like customer management, order processing, and support ticketing through natural language.

Enables MCP clients to search and execute 360 operations across Holded's accounting, sales, inventory, contacts, CRM, projects, team, calendar, inbox, and developer APIs. Supports read and write calls with an API key, including a read-only mode.

Enables AI agents to interact with ActiveNet OpenAPI services for managing organizations, activities, customers, facilities, and more.

A comprehensive Model Context Protocol (MCP) server that provides complete access to the Recharge Storefront API endpoints. Enables AI assistants to manage subscriptions, customers, orders, and billing through a standardized interface.

Finds, filters, and verifies local-business leads on demand; every returned email carries a verification receipt (verifier, verdict, timestamp). Credit-based with per-key spend budgets; 25 free validated leads at signup.

Enables AI agents to extract structured firmographic data from public LinkedIn company URLs, returning fields like name, industry, size, and headquarters.

Connects to Salesforce scratch orgs and allows AI to generate and insert realistic nested test records via natural language descriptions using the Composite Tree REST API.

Enables AI assistants to securely access and interact with Odoo data through natural language, supporting full CRUD operations, OAuth 2.1 and API key authentication, and granular per-model permissions.

MCP server that provides mock APIs and deterministic seed data for ERP/OMS, WMS, and CRM systems, enabling supply chain data exploration and integration testing.

Provides Claude agents with CRM contact lookup, action logging, and prompt cost auditing tools. Includes a Streamlit UI to demo the same tools without an MCP client.

Unifies CRM and productivity tool APIs behind a single interface, letting AI agents and developers create, update, delete, and list records across Zoho, HubSpot, Odoo, Google Sheets, Gmail, and Google Calendar without handling platform-specific schemas.

This MCP server simplifies interaction with the ConnectWise Manage API through API discovery, execution, and a fast memory system for efficient workflows.

Enables interaction with the HaloPSA API for managing tickets, clients, assets, and more through natural language commands in Claude Desktop.

Enables AI-assisted field service management through the Service Fusion API, including job lookup, customer management, dispatch, invoicing, and equipment tracking.

MCP server for B2B lead generation and company search using the Generect Live API. Provides tools to search leads, companies, generate emails, and get lead by URL.

Enables AI agents and scripts to run a Booksy Biz account through your own signed-in Chrome session, exposing 28 tools for appointments, open slots, time off, clients, services, staff, reviews, Message Blasts, and reports over MCP, REST, or Python. Read-only mode and confirmation-gated client-facing actions let you plan schedules, reschedules, and outreach with human approval.

Self-hosted Fresha API and MCP server in Python: 17 Fresha tools for appointments, clients, services, team and reviews, on the session of your own Chrome. Personal use.

Enables AI agents to read and change jobs, job status, customers, quotes with line items, invoices, quote and invoice email, payments, and Scheduler bookings in an account by reusing the user's own signed-in Chrome session, with no official API keys needed. Ships read-only hints and confirmation prompts for tools that reach other people, and can be run over stdio or streamable HTTP.

Integrates with HubSpot CRM APIs via the Model Context Protocol, enabling management of contacts, companies, deals, tickets, notes, engagements, workflows, and more through natural language.

Enables MCP clients to inspect and authenticate with Podio APIs, manage items, tasks, apps, spaces, and communications, search Podio data, and generate TypeScript field configurations.

Sales intelligence for DACH & EU SMEs — lead scoring, ICP fit, CRM enrichment & writeback.

Official Cursor plugin enabling natural-language management of your SideShift company—discovering creators, managing campaigns and contracts, communicating with your network, and inspecting analytics through a secure OAuth-linked MCP server.

Enables AI agents and scripts to access clients, estimates, invoices, payments, and reports from a user's own Joist account through their Chrome session, over MCP or a local REST API.

Enables AI assistants to access and manage HeadHunter job platform data, including vacancies, resumes, negotiations, and employer settings via 167+ tools.

Enables AI agents to manage GoHighLevel sub-account CRM data, including contacts, custom fields, tags, workflows, and calendar configurations through natural language.

Find professional email addresses from name + company domain. Tests 15+ patterns against MX records with confidence scoring, with pay-per-call via x402.