What is an MCP server?

MCP is an open standard for connecting AI applications to other software, first published by Anthropic in November 2024. It splits the work three ways. The host is the AI app you talk to. Inside it, a client keeps one dedicated connection to each server. The server is the program at the other end, which gives the host access to one service or one set of data.

• Tools: actions the AI can call. Each has a name, a plain-language description and a JSON Schema for its inputs, so the model can judge when a tool fits and what to pass it.
• Resources: information the AI can read for context, such as the contents of a file, a database record or the response from an API.
• Prompts: reusable templates the server offers, such as instructions for a common task with worked examples.

When you connect a server, the host requests its list of tools (a tools/list request) and adds them to what the model may use. If the model decides a tool answers your request, the host sends a tools/call request with the arguments, hands the result back to the model and the conversation carries on. Every message underneath is JSON-RPC 2.0, which is why one server works in any app that speaks MCP.

Most business tools offer the remote kind. Setting one up means pasting a URL into your AI app’s connector settings, signing in to the service and approving access. A local server takes more effort, because it has to be installed and kept running on your own machine.

• Check who publishes it. A server can do whatever its tools allow with the access you grant, so prefer the one run by the service itself over an unofficial copy.
• Read the sign-in screen. It should name the account the server will act on. Be wary of any set-up that asks you to paste a password into a chat.
• Approve actions that change things. Apps such as Claude and ChatGPT can ask before a tool runs, so read the request when it sends, deletes or spends something.
• Treat tool results as information, not orders. A DM, email or web page fetched by a tool can contain text written to steer the AI, so don’t let it act on directions you never gave.
• Disconnect servers you stop using, either in the AI app’s settings or in the service’s own dashboard.

A server can also come back to you in the middle of a task. MCP calls this elicitation: rather than guess, the server asks the user for a missing detail or a confirmation.

DMFast runs a remote MCP server so people can manage Instagram and Facebook auto-replies from ChatGPT, Claude and other MCP apps. In Claude it’s added as a custom connector; ChatGPT needs developer mode switched on first. You sign in to DMFast and press Allow, so the AI app never sees your Instagram password, and it can act only on the account you connected.

Connecting through MCP lifts none of Meta’s limits. Asked to message someone, the server can send a DM only within 24 hours of that person’s last message, the same rule every app on Meta’s API follows.