# midas-nx-mcp

> A local MCP server. It lets AI apps such as Claude Desktop, Claude Code and Codex read the model open in MIDAS Gen NX / Civil NX, running on the same Windows PC, through the MIDAS NX Open API, and apply only the changes the user confirms. A personal project (alpha) built by a MIDAS IT team member; not an official MIDAS IT product. MIT license.

This file is a summary for AI agents helping a user install and use the server. Page for people: https://dennis5882.github.io/midas-nx-mcp/en/ (Korean: https://dennis5882.github.io/midas-nx-mcp/llms.txt)

## Key facts

- Transport: stdio. The AI app starts and stops the server; it is not a remote server.
- Command: `uvx midas-nx-mcp@latest` (PyPI package `midas-nx-mcp`)
- Claude Desktop bundle: `midas-nx-mcp-<version>.mcpb` from the latest GitHub release. Installs by double-click; no uv or Python needed.
- MCP Registry name: `io.github.Dennis5882/midas-nx-mcp`
- Requires: Windows, with Gen NX or Civil NX running on the same PC and its Open API connected (NX: `Apps > API Settings`).
- Keys: one MAPI key per product (`MIDAS_MAPI_KEY_GEN`, `MIDAS_MAPI_KEY_CIVIL`). A wrong key still reports "connected", so make sure the user has not swapped them. Never print a key in the chat or a log.

## Install (the order to guide the user through)

1. Ask which AI app the user has.
2. Claude Desktop: download the `.mcpb` from the latest release and double-click it. Enter the Gen / Civil keys; leave the unused product empty. Keys can be changed later under `Settings > Extensions`.
3. Other apps: install uv (`powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"`), then use one of the configurations below.
4. Check: with a model open in NX, call `check_connection(product="gen")`.

Claude Desktop config file (`Settings > Developer > Edit Config`, `claude_desktop_config.json`). After saving, quit the app completely (tray icon too) and start it again:

```json
{
  "mcpServers": {
    "midas-nx": {
      "command": "uvx",
      "args": ["midas-nx-mcp@latest"],
      "env": {
        "MIDAS_MAPI_KEY_GEN": "<Gen NX key>",
        "MIDAS_MAPI_KEY_CIVIL": "<Civil NX key>"
      }
    }
  }
}
```

Claude Code:

```bash
claude mcp add midas-nx -e MIDAS_MAPI_KEY_GEN=<gen-key> -e MIDAS_MAPI_KEY_CIVIL=<civil-key> -- uvx midas-nx-mcp@latest
```

Codex (`~/.codex/config.toml`):

```toml
[mcp_servers.midas-nx]
command = "uvx"
args = ["midas-nx-mcp@latest"]
env = { MIDAS_MAPI_KEY_GEN = "<Gen NX key>", MIDAS_MAPI_KEY_CIVIL = "<Civil NX key>" }
```

## Settings (environment variables)

| variable | default | meaning |
| --- | --- | --- |
| MIDAS_MAPI_KEY_GEN | - | Gen NX key. Needed for product="gen" |
| MIDAS_MAPI_KEY_CIVIL | - | Civil NX key. Needed for product="civil" |
| MIDAS_TIMEOUT | 20 | seconds per call. Short on purpose, so an NX dialog is noticed quickly |
| MIDAS_ANALYSIS_TIMEOUT | 300 | seconds for run_analysis |
| MIDAS_SAVE_TIMEOUT | 120 | seconds for save_copy |
| MIDAS_MAX_ROWS | 200 | most rows one call returns |
| MIDAS_OUTPUT_DIR | C:/temp | where captures and copies are written. Must already exist |

## Tools

Every tool takes `product` ("gen" or "civil"). If the user has not said which, ask.

Reading (nothing in the model changes):

- check_connection(product): connected or not, program name
- list_tables(product?, search?): the `/db` and `/DESIGN` tables
- describe_table(product, table): NX's own field schema for a `/db` table
- read_table(product, table, ids?, limit?): records, at most MIDAS_MAX_ROWS rows
- model_summary(product): counts of the main tables and the unit system
- read_model_info(product, what): project status, section properties, story check parameters (Gen only), current selection
- list_result_tables(search?): the result table types result_table accepts
- result_table(product, table_type, load_cases?, components?, keys?, limit?): an analysis result table
- capture_view(product, width?, height?): the NX window as a PNG

Changing (two steps):

- run_analysis(product): runs the analysis. NX first saves over the open file. A document never saved is refused.
- save_copy(product): Save As to a generated name in MIDAS_OUTPUT_DIR. NX then works on the copy.
- write_records(product, table, records, mode): creates (create) or updates (update) `/db` or `/DESIGN` records, up to 50 at once
- delete_records(product, table, ids): deletes records by id, up to 50 at once. Nodes used by elements are refused.

## Rules for the agent

1. Call a changing tool first without confirm_token to get a preview. Show the preview to the user, and only after the user explicitly agrees, call it again with the same arguments and that confirm_token. If the model changed in between, it is refused.
2. Any change discards NX's analysis results. Run the analysis again before reading results.
3. If the original file must be kept, call save_copy before run_analysis.
4. On a timeout or `waiting_for_nx_dialog`, do not retry. Tell the user to answer the dialog in the NX window.
5. Pass on NX's messages from the tools as they are ("no analysis result", "The project is not opened", ...). Do not report success just because nothing raised an error.
6. Not offered: new document, open document, import, emptying a table, running design checks, saving outside MIDAS_OUTPUT_DIR. Do not work around these.

## Links

- [Page for people](https://dennis5882.github.io/midas-nx-mcp/en/)
- [README](https://github.com/Dennis5882/midas-nx-mcp#readme): the full English documentation
- [Korean user guide](https://github.com/Dennis5882/midas-nx-mcp/blob/main/docs/user_guide_ko.md)
- [Latest release and .mcpb](https://github.com/Dennis5882/midas-nx-mcp/releases/latest)
- [PyPI](https://pypi.org/project/midas-nx-mcp/)
- [SDK midas-nx](https://github.com/Dennis5882/MIDAS-API-NX-SDK)
- [Issues](https://github.com/Dennis5882/midas-nx-mcp/issues)

## Author

Dennis (MIDAS IT) · sjj0507@midasit.com · [LinkedIn](https://www.linkedin.com/in/dennis58)