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io.github.Bishop81/csvto-mcp

Local CSV, JSON and Excel conversion. Files are never uploaded and never enter the context.

Open source Open in the app JSON README (API)

About

Local CSV, JSON and Excel conversion. Files are never uploaded and never enter the context.

Details

Kind
MCP servers
Topic
Files & documents
Publisher
bishop81
Origin
official
Category
ferramentas
Transport
local
Version
0.1.2
Last push
2026-08-30T03:50:35Z
Repository state
ativo
Language
TypeScript
License
MIT
Added
2026-08-31 13:00:08
Updated
2026-08-31 13:00:08
Origin id
io.github.Bishop81/csvto-mcp

README

# csvto

CSV, JSON and Excel conversion that runs where your data already is.

- **[`csvto-mcp`](packages/mcp)** — an MCP server. Point your AI assistant at a file
  path; it converts locally and writes the result beside it. Nothing is uploaded, and
  file contents never pass through the model's context.
- **[`@csvto/core`](packages/core)** — the conversion engine. No DOM, no `fs`, no
  network, so the same tested code runs in a browser, in a local MCP process, or on a
  server.

The same engine powers the browser tools at **[csvtosite.com](https://csvtosite.com)**,
where conversion happens client-side and files are likewise never uploaded.

## Install the MCP server

```
claude mcp add csvto -- npx -y csvto-mcp
```

Or in any MCP client's config:

```json
{
  "mcpServers": {
    "csvto": { "command": "npx", "args": ["-y", "csvto-mcp"] }
  }
}
```

Requires Node 18+. Full tool list and behaviour: [packages/mcp/README.md](packages/mcp/README.md).

## Types are inferred per column, not per cell

This is the part that matters, and where most converters quietly corrupt data. A column
converts to numbers **only if every value in it survives the round trip exactly**. If one
value would change, the whole column stays text:

- `01234` keeps its leading zero instead of becoming `1234`
- A 16-digit account number stays itself instead of becoming `1.23457E+14`
- `1250.50` keeps its trailing zero instead of becoming `1250.5`
- A column never ends up as a mix of numbers and strings

Verified in tests: `01234` survives a CSV → xlsx → CSV round trip intact.

## Develop

```
npm install
npm test          # 49 tests
npm run build
```

`packages/core` must stay environment-free — no `window`, no `fs`, no `fetch`. That
constraint is what lets one tested engine serve every surface.

## Licence

MIT

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