@csvtocsv/mcp

MCP server for csvtocsv.com — deterministic CSV transforms for AI agents.

Out of the box your agent gets:

• Amazon Flat File → Shopify Product CSV
• Any CSV → Amplitude Cohort import
• Any CSV → Cleaned CSV (header normalisation, value canonicalisation)

Transforms run on the hosted Worker at https://mcp.csvtocsv.com/mcp. This package is a thin stdio bridge: every JSON-RPC message is forwarded over HTTPS, so adapter additions and bug fixes ship without you reinstalling.

Quick start — Claude Desktop

Mint an API key at https://csvtocsv.com/account, then drop this into your claude_desktop_config.json:

{
  "mcpServers": {
    "csvtocsv": {
      "command": "npx",
      "args": ["-y", "@csvtocsv/mcp"],
      "env": {
        "CSVTOCSV_API_KEY": "csv_... (get yours at csvtocsv.com/account)"
      }
    }
  }
}

Restart Claude Desktop. Ask "list the CSV pairs csvtocsv supports" — the agent will call list_supported_pairs and report what's available. Hand it a CSV and ask for a target format; it picks the right pair_id and runs transform_csv.

Quick start — Cursor / Cline / Continue / any MCP client

Same shape — point the client at npx -y @csvtocsv/mcp and pass CSVTOCSV_API_KEY as an environment variable. Configuration UI varies by client; consult their MCP docs for where the JSON block lives.

Tools

list_supported_pairs

No arguments. Returns the full catalog of source → target pairs the server can transform. Call this first if you don't know which pair_id to pass to transform_csv.

transform_csv

{
  "pair_id": "amazon_to_shopify",
  "file_path": "/path/to/export.csv"
}

For local files, pass file_path — the stdio bridge reads the file and sends its contents directly to the server, so large CSVs stay out of the agent's context window. You can also pass csv_content (raw CSV text) or csv_url (an HTTP URL the server fetches).

Returns the transformed CSV plus stats (rows_in, rows_out, rows_dropped). Each successful call debits one credit from your account; failed calls don't debit. Mint keys at csvtocsv.com/account.

Environment variables

| Variable | Required | Default | Notes | | --- | --- | --- | --- | | CSVTOCSV_API_KEY | for transform_csv | — | Bearer token forwarded to the Worker. list_supported_pairs works without one. | | CSVTOCSV_MCP_URL | no | https://mcp.csvtocsv.com/mcp | Override for self-hosters or staging. |

How it works

agent client  ◄── stdio JSON-RPC ──►  npx @csvtocsv/mcp  ◄── HTTPS ──►  mcp.csvtocsv.com/mcp
                                       (this package)                    (hosted Worker)

The Worker is the source of truth: rate limits, the adapter library, the credit ledger, and the API-key auth all live there. This package is a 60-line proxy that exists to make the server reachable from agent runtimes that only speak stdio.

Self-hosting / source

Worker source: https://github.com/jakubtutaj/csvtocsv/tree/main/packages/mcp. Wrangler config in wrangler.toml deploys to your own Cloudflare account. Point CSVTOCSV_MCP_URL at your Worker's URL and you're running independent infrastructure.

License

MIT