# What is MCP? > MCP (Model Context Protocol) is an open standard that lets AI apps like ChatGPT or Claude connect to other programs. The AI can then act on your behalf, for example log time or draft an invoice. The official description compares MCP to a USB-C port for AI apps: one plug for many devices. Source: https://back-bone.io/en/blog/was-ist-mcp Published: 2026-10-21 · Updated: 2026-10-22 Category: Guides MCP (Model Context Protocol) is an open standard that lets AI apps like ChatGPT or Claude connect to other programs. The AI can then act on your behalf, for example log time or draft an invoice. The official description compares MCP to a USB-C port for AI apps: one plug for many devices. **TL;DR · Key facts** - **MCP** is an open standard that lets AI apps like ChatGPT or Claude work with other programs. - **Sign-in without a token:** you sign in to Backbone and approve. You can revoke at any time. - **The same plan limits** as in the app. A public API for your own scripts is Coming soon. - **The owner** can switch AI connections off for the workspace. ## What is MCP? An MCP server tells an AI app: "These are the things you can do with me." The AI app calls them when you ask for something and shows you the result. ## How does MCP work? - **Host app:** the program you chat in, such as ChatGPT, Claude or Claude Code. - **Server:** the program that offers something. For you, that is Backbone. - **Tools:** the individual things the server offers, for example "create a time entry" or "list open invoices". Example: you type in Claude "Log 2 hours yesterday on Muster GmbH". Claude sees that a Backbone tool fits, calls it and gets back that the entry exists. Then it answers you. **Sign-in without a token:** you do not paste a password or key into the AI app. Instead you sign in to Backbone and confirm on a consent screen which workspaces the app may use. This runs on OAuth, the same principle as "Sign in with Google". You can revoke the approval at any time. ## What can Backbone do through MCP? Almost everything Backbone does works in the app, in the chat and through MCP, with the same tools behind it: - **Time:** log time, start, pause and book the timer, change entries, find unbilled hours. - **Clients and projects:** create, change and set budgets. - **Invoices and quotes:** draft them, also from your hours, turn quotes into invoices, issue and send, mark as paid, set up recurring invoices. - **Dunning:** find open items, preview and send reminders, pause dunning. - **Receipts and bookkeeping:** upload receipts and have them read, view bank transactions, match receipts to payments, request missing receipts from your team, book cash payments, send the month to your bookkeeper. - **Numbers:** report hours, revenue, utilisation and profitability. - **Team and settings:** invite members, set roles and rights, change company details, numbering, email texts and reminder levels. - **Wiki:** read your company wiki and write pages. What the AI writes waits for your review. - **Questions:** "How many hours went into Muster GmbH in September?" Sending, issuing and deleting always need your confirmation first. MCP follows the **same plan limits** as the app, for example for invoices and receipts. The connector is included in every plan. To set it up: [Connect Backbone to ChatGPT](https://back-bone.io/en/blog/backbone-chatgpt-verbinden) or [Connect Backbone to Claude](https://back-bone.io/en/blog/backbone-claude-verbinden). ## What is the AI allowed to do? **The AI works with your role and only with what you allow.** - **You decide.** On the consent screen you pick the workspaces and see up front what the app can do. - **Confirmation for sensitive actions.** Before the AI sends or deletes anything, it asks you first. Bank and payment details change only in the app, not through the chat. - **Some things stay in the app.** The AI cannot: change your password or email, delete the account or workspace, transfer ownership, use Stripe checkout or the customer portal, grant bank access or create a workspace. - **The owner can switch it off.** In Settings › Integrations, AI connections can be forbidden for the workspace. They are on by default. - **Revoking is instant.** The same page lists connected apps with "Revoke". Anthropic's advice holds for every app: connect only servers you trust. ## What is the difference between MCP and an API? An API is built for developers who write their own scripts. MCP is built for AI apps that decide themselves which tool fits your question. AI apps connect to Backbone through the connector with sign-in. A **public API** for your own scripts is Coming soon. > My goal is to optimise and automate back-office tasks so that we founders can focus on what matters most. > > Automating back-office work with AI agents and AI integrations is the future – that's why I built Backbone! ## How Backbone does it Your back office in the chat. In the app, or in a chat with ChatGPT, Claude and many more. 1. **Track your time** One sentence in the chat. The hours are in your week. 2. **Bill your hours** What you tracked goes on the invoice. 3. **Who's overdue?** One question, every open invoice. 4. **Receipts matched automatically** Upload the statement. Clear matches assign themselves. 5. **Permissions per person** Everyone gets what they need. Their AI gets no more. 6. **Send the reminder** You approve. Only then does it go out. 7. **Review, then approve** The AI drafts. You check it and issue it. ## Frequently asked questions ### Do I need to know how to code? No. You copy an address, sign in and approve. ### Can the AI keep my data or learn from it? That depends on the provider of the AI app (for example OpenAI or Anthropic) and your contract there. Backbone cannot promise it for them. Read your AI provider's privacy information. ### Is MCP only for ChatGPT and Claude? No. MCP is an open standard and many development and AI tools support it. We have guides for ChatGPT, Claude and Claude Code. ### How is this different from Billy? [Billy](https://back-bone.io/en/features/backbone-ai), our friendly AI ghost, is the chat inside the app. MCP brings the same functions into the AI app you already use. **Connect Backbone to your AI app** Copy the address, sign in, approve. 7-day trial, card required. - [Try for 7 days](https://back-bone.io/en/sign-up) --- General information, not legal or tax advice and no review of your case. Details on providers and laws can change. For your case, follow your tax adviser. Checked on 22/10/2026 Sources: Model Context Protocol, official introduction (modelcontextprotocol.io)