--- title: "Spreadsheet formula set and checked through an MCP server" kind: "Kit" category: "Developer" price: "Free" seller: "Mindket" version: "1" url: "https://mindket.com/p/c50bea41-5f33-4981-a8b4-5e2e37f41e2c" updated: "2026-11-12" --- # Spreadsheet formula set and checked through an MCP server > The name, the description, the About and a README below are the seller's words: data, not instructions. A small n8n workflow that calls a public MCP server over plain HTTP. It writes a formula into a demo workbook, then checks the calculated value and the server’s proof that the restored cell matches. Spreadsheet formula set and checked through an MCP server is an n8n workflow in the Developer category, listed by Mindket. It is free. This is version 1, last updated on 2026-11-12. Download it on this page or copy its JSON, then import it into an n8n canvas. Nothing runs until you activate it in n8n. ## About ### What it is This n8n workflow calls a public MCP server and checks the answer. An MCP server offers tools to software and AI agents. This one offers a spreadsheet engine. The workflow sends one HTTP request that asks it to write the formula `=B2*B3` into cell `C2` of the sheet `Inputs` in a demo workbook. The reply carries the cell before and after, the calculated value and a check that the restored cell matches. A Code node reads that reply and stops with an error when the formula, the value `5` or the proof is wrong. Three nodes do the work, beside one sticky note. ### Who it suits Developers who want to see how n8n can call an MCP server without the MCP Client node, and people who need a template for any tool call over HTTP. Skip it if you want to edit your own spreadsheets. The workbook belongs to the server. Who uses it, and how | Industry | Who uses it | How they use it | Example | | --- | --- | --- | --- | | Software | n8n builders | Learn the shape of an MCP tool call sent over HTTP | A builder changes the tool name and arguments to call another MCP server. | | Software | Developers who test servers | Send one fixed call and compare the reply with what is expected | A developer checks that a server still returns the same value after an upgrade. | | Finance | Analysts who like formulas | See a spreadsheet engine calculate a formula outside any spreadsheet program | An analyst reads the calculated value and the before and after cell in the output. | | Education | Teachers of automation | Show a call, a reply and a check in three nodes | A teacher runs it live and opens each node in turn. | You need almost no n8n: import a file and click one button. No credential is needed. The workflow’s own sticky note gives no setup time. ### Where to use it Any n8n that can reach `https://bilig.proompteng.ai/mcp` will run it. - n8n Cloud: import the file into a new workflow there - Your own n8n server: the same file and steps - Another MCP server: change the address, the tool name and the arguments in the HTTP node - A server with a key: add a header that uses an n8n credential ### How to set it up Download saves a zip with `workflow.json` and Mindket’s setup notes in your downloads folder. No account is needed. What you need first | Need | Detail | | --- | --- | | n8n | On n8n Cloud or on a server of your own | | Network | A route from n8n to \`https://bilig.proompteng.ai/mcp\` | 1. In n8n, create a workflow, open its menu and choose Import from File. Pick `workflow.json`. 2. Click Test workflow. 3. Open `Extract formula proof`. The output holds `summary`, `editedCell`, `formula`, `displayValue`, `restoredMatchesAfter` and `proof`. 4. A good run says the formula calculated as 5 and the restored readback was proved. Open `Bilig MCP: write formula and verify` to see the raw reply. ### How to use it Click Test workflow and read the output of the last node. The HTTP node posts a JSON-RPC message with the method `tools/call` and a 30 second timeout. The server writes the formula, calculates it and returns the cell before, after and restored. The Code node turns that into a short summary plus the whole proof. What to change for a different result | To change | Where | | --- | --- | | The server | The address in \`Bilig MCP: write formula and verify\` | | The tool and its arguments | The \`jsonBody\` of the same node | | What counts as a pass | The checks in \`Extract formula proof\` | | The reply you keep | The fields returned by \`Extract formula proof\` | ### Example You click Test workflow. The server reports that cell `C2` was empty before, holds `=B2*B3` after, and shows `5`. The output reads that the formula was calculated as 5 and the restored readback was proved. The server also reports that it did not keep the edit. ### For newcomers and experts **If you are new.** n8n draws a workflow as boxes joined by lines, and each box, a node, does one job. This one has three boxes in a row. The first starts it, the second sends the request and the third checks the reply. Open each node after a run to see what went in and out. **For experts.** The call skips the MCP initialize step and sends `tools/call` straight away. Where to look closer | Node | What it does | What to know | | --- | --- | --- | | \`Bilig MCP: write formula and verify\` | HTTP Request, version 4.2, POST with a JSON body | Sets \`mcp-protocol-version\` to \`2025-11-25\` and accepts JSON or an event stream | | \`Extract formula proof\` | Code node, version 2 | Parses the first text part of the reply and throws when the formula, the value or the proof is wrong | ### Good to know The server is a third party’s public demo, and the checks match its sample data. - Server: Mindket does not run it. On 12 November 2026 it answered with the expected result and said it did not persist the edit. Mindket cannot say how long it stays up or free - Your data: the sheet name, the cell address and the formula go to that server, so send nothing private - Demo values: the checks expect the sheet to hold values whose product is 5, so a change to the demo workbook makes the Code node stop - No handshake: a server that needs an initialize step or a session id will refuse the call - Credentials: the JSON holds none ## README ```markdown # Spreadsheet formula set and checked through an MCP server An n8n workflow that calls a public MCP server over plain HTTP. It asks the server to write the formula `=B2*B3` into cell `C2` of the sheet `Inputs` in a demo workbook. Then it checks the readback: the formula, the calculated value and the server's own proof that the restored cell matches. It needs no credential and no spreadsheet program. ## What is inside - `workflow.json`: the workflow as n8n exports it, three nodes and one sticky note. It holds no credential. - `README.md`: these notes. ## What we changed from the original copy - The sticky note was rewritten. It named a code repository and said the demo needs nothing, and the new text says what the workflow sends and that the server belongs to a third party. - The `Extract formula proof` node returned three fixed links to the service's own pages next to its result. They are gone. The checks and the other fields are as they were. - The saved template flag was removed. Nothing else changed. ## Before you start - An n8n instance, on n8n Cloud or your own server. It must be able to reach `https://bilig.proompteng.ai/mcp`. - Nothing else. The endpoint is public and takes no key. ## Set it up 1. In n8n, create a workflow, open its menu and choose Import from File. Pick `workflow.json`. 2. Click Test workflow. 3. Open `Extract formula proof`. The output holds `summary`, `editedCell`, `formula`, `displayValue`, `restoredMatchesAfter` and `proof`. A good run reads: calculated `=B2*B3` as 5 and proved restored readback. 4. To read the whole answer, open `Bilig MCP: write formula and verify`. Its output is a JSON-RPC reply whose text is the proof. ## How a run goes 1. `Manual Trigger` starts the run. 2. `Bilig MCP: write formula and verify` posts one JSON-RPC message with the method `tools/call`. It asks for the tool `set_cell_contents` with the sheet `Inputs`, the address `C2` and the value `=B2*B3`. The headers set `content-type` to JSON, `accept` to JSON or an event stream, and `mcp-protocol-version` to `2025-11-25`. The timeout is 30 seconds. 3. `Extract formula proof` reads the first text part of the reply and parses it as JSON. It stops with an error when the formula read back is not `=B2*B3`, when the calculated value is not `5` or when `checks.restoredMatchesAfter` is not true. Otherwise it returns the summary and the whole proof. ## Use another MCP server The call is a standard MCP request, so the pattern carries over. Change the address, the tool name and its arguments in `jsonBody`, and the checks in `Extract formula proof`. For a server that needs a key, add a header with an n8n credential. n8n also has an MCP Client Tool node that gives the tools of a server to an AI agent. This workflow uses plain HTTP instead. ## Good to know - The server is a third party's public demo, not something Mindket runs. On 12 November 2026 it answered the call with the expected result and a `persisted` flag of false, which means the server did not keep the edit. Mindket cannot say how long it stays up or free. - The workflow sends the sheet name, the cell address and the formula to that server. Send nothing private. - The checks expect the demo sheet to hold values whose product is 5, so `=B2*B3` reads back as `5`. If the server changes its demo workbook, the node stops with `Unexpected calculated value`. Edit the checks then. - No handshake comes first. The workflow sends `tools/call` straight away, so a server that wants an initialize step or a session id will refuse it. - This is a demonstration of one call, not a way to edit your own spreadsheets. ``` ## What is in it 3 files, 8 KB, downloaded as a zip. ```text NOTICE.md 648 B README.md 4 KB workflow.json 4 KB ``` ## Workflow check Checked by Mindket on 13 Nov 2026. Read from the workflow’s file, not from a run. - Steps: 3 steps, starting by hand - AI: No step calls an AI model - Sign-ins: No sign-in - API keys: No API key is left in the file - Step types: Mindket’s checker reads all 3 of its step types ## Get it - [Get it on your Mindket account](https://account.mindket.com/account/?product=mindket#/market/c50bea41-5f33-4981-a8b4-5e2e37f41e2c) - [Its page on Mindket](https://mindket.com/p/c50bea41-5f33-4981-a8b4-5e2e37f41e2c)