Excel MCP server: Claude and ChatGPT calculate with your spreadsheet.
A published SpreadAPI service is also a tool for AI assistants. The assistant sends the values, your workbook calculates, and the assistant answers with your numbers. This is not an MCP server that edits Excel files; it runs your formulas.
- Unit price per month
- $45.00
- Net per month
- $1,096.54
- Net total, 12 months
- $13,158.48
- Sales tax
- $953.99
A drawn example with the demo workbook's values. The owner decides how results are presented, here: total first, then a table.
The AI asks your spreadsheet. It does not guess.
A language model is good at understanding a question and bad at exact arithmetic and business rules. With a service, the arithmetic happens in your workbook, the same way every time.
"That should come to roughly $14,000, depending on your discount tiers."
An estimate. The model does not know your price list, and may answer differently next time.
"$14,112.47 in total: $13,158.48 net plus $953.99 sales tax."
Calculated by the workbook. Same inputs, same result, and the call is in your usage log.
Three ways an AI uses a service.
Connect your account
Add one address in Claude or ChatGPT and sign in. The assistant reaches every service you allow, and you decide what it may do.
Hand out one service
Each service has its own MCP address, public or protected by a token. The other person only calculates; your workbook stays with you.
Let an agent build services
Over the connection to your account, an agent creates a workbook, defines parameters, tests and publishes, within the rights you give it.
https://spreadapi.io/mcphttps://spreadapi.io/api/mcp/service/{serviceId}Good to know
Does the AI see my formulas?
No. Over the address of a service it sees the inputs and results you marked and the descriptions you wrote, nothing else of the workbook. Only an assistant you connect to your own account with the right to edit can read cells and formulas, because it needs them to build services.
Can it change my service?
Over a service's own address it only calculates. Building and publishing need a connection to your account with those rights.
Can I tell the AI how to present results?
Yes, in the service's AI definition, for example "Name the total first, then list the items as a table." Assistants usually follow it; it cannot be guaranteed.
Do AI calls count?
Yes, like any other call of a published service. They appear in the usage of the service under the channel AI.