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midas-nx Getting Started Guide (no prior programming experience needed)

This guide is for structural engineers who use MIDAS Gen NX/Civil NX daily but have never written a line of Python before. It walks through everything from installing Python to running your first script, in order, so you can follow it start to finish in one sitting.

midas-nx is an employee-led open-source project, built by a MIDAS IT employee from hands-on product and API verification work. It is not an officially released or supported MIDAS IT product — please report problems with this SDK or guide on GitHub Issues rather than to MIDAS IT product support, which does not cover it.

If you already write code, README.md's Quick Start is faster. This guide is for the step before that — for anyone who isn't sure what Python even is yet.

Before you start

  • A Windows PC (this guide is written for Windows)
  • MIDAS Gen NX or Civil NX installed, with a valid license
  • An internet connection (the SDK talks to MIDAS's cloud relay server)

Step 1: Install Python

midas-nx requires Python 3.12 or 3.13 — those are the versions this SDK is tested against.

  1. Go to https://www.python.org/downloads/. The button there usually offers the latest release; if that's already labeled 3.12 or 3.13 you're fine, but if it offers something newer, use that page's "All releases" link to get 3.12 or 3.13 specifically instead.
  2. Run the installer. Make sure to check the "Add python.exe to PATH" checkbox at the bottom of the first screen before clicking "Install Now." Skipping this means your command prompt won't recognize python later.
  3. Once installed, verify it worked. Search for "cmd" in the Start menu to open Command Prompt, then type:
python --version

You should see Python 3.12.x or Python 3.13.x. If you already had an older Python installed (e.g. Python 3.10.x), install 3.12 or 3.13 as above — pip install will refuse midas-nx on anything older in the next step. If you get 'python' is not recognized as an internal or external command, you missed the PATH checkbox in step 2 — reinstall Python and check it this time.

Step 2: Install midas-nx

In the same Command Prompt window:

python -m pip install midas-nx

(python -m pip rather than a bare pip avoids installing into the wrong Python if you have more than one version on your machine — worth using even if you've only ever seen pip install package written the other way.)

You'll see Successfully installed midas-nx-... when it's done.

Step 3: Get a MAPI key

The MAPI-Key is the authentication key this SDK uses to talk to MIDAS Gen NX/Civil NX. You don't get it from Python — you get it from inside the MIDAS Gen NX (or Civil NX) application itself.

  1. Launch MIDAS Gen NX (or Civil NX).
  2. In the top menu, open Apps and click API Settings.
  3. The screen shows a Base URL and a MAPI-Key. Click the Copy button next to each to copy it.
  4. Click Connected. If it succeeds, Status switches to Connected — that's what confirms Open API is actually active.

Want a fresh key (e.g. you think one leaked)? Click Refresh next to it. The old key is invalidated immediately.

⚠️ Treat it like a password while it's live. The scripts below paste the key directly into the code, which is fine for a one-off file on your own machine — but don't commit that file to Git, paste it into a public chat/issue, or share a screenshot that shows it. If you think a key leaked, just click Refresh above for a new one; the old one still expires when you close the app.

🌏 No need to guess which regional server you're on. Use the Base URL shown on that same screen — it's correct for any region, including China's separate server. If it differs from the SDK's default global relay (moa-engineers.midasit.com), add base_url="the copied value" to the MidasClient(...) call below.

Step 4: Write and run your first script (read-only)

Risk level: 1 — read-only (see Risk levels).

Open Notepad (or VS Code, or any text editor) and paste the following exactly as-is. Just replace "paste_the_key_you_copied_in_step_3_here" with your actual key.

from midas_nx import MidasClient, Product
from midas_nx.db.node_element import Node

# Using Civil NX instead? Change this to product=Product.CIVIL.
client = MidasClient(mapi_key="paste_the_key_you_copied_in_step_3_here", product=Product.GEN)

print(client.verify_connection())

nodes = Node.items(client=client)
print(f"Connected. Found {len(nodes)} node(s) in the current model.")

Save the file as first_script.py (your Desktop or any folder works fine).

In Command Prompt, navigate to the folder where you saved it and run it. For example, if you saved it to your Desktop:

cd Desktop
python first_script.py

You should see something like:

{'status': 'connected', 'keyVerified': True}
Connected. Found 3 node(s) in the current model.

(The exact node count depends on whatever model you currently have open — 0 is a perfectly normal answer if it's a blank project.)

This script only reads data. It cannot create, change, or delete anything in your model, no matter which project you run it against — safe to try against real work.

If something goes wrong

  • MidasConnectionError: check that Gen NX/Civil NX is running and Open API is connected. This SDK's error messages end with a (Hint: ...) telling you what to check.
  • MidasAuthError: make sure you pasted the key from step 3 exactly. Keys can change when you restart the app — get a fresh one and paste it in again if this happens.
  • Behind a corporate firewall: see "Connectivity troubleshooting" for the exact port/address info to hand to your IT team.

Step 5: Add data to a blank model (optional — this changes your model)

Risk level: 2 — limited addition (see Risk levels).

Before running this, open Gen NX/Civil NX yourself and start a new, empty project through the GUI (File > New Project, or similar) — this script adds data to whatever project is currently open, it does not create one. Unlike Step 6 below, it never calls doc.new_project(), so there's nothing for it to discard.

from midas_nx import MidasClient, Product
from midas_nx.db.node_element import Node

# Using Civil NX instead? Change this to product=Product.CIVIL.
client = MidasClient(mapi_key="paste_the_key_you_copied_in_step_3_here", product=Product.GEN)

Node.create({1: {"X": 0, "Y": 0, "Z": 0}, 2: {"X": 0, "Y": 0, "Z": 3.2}}, client=client)

nodes = Node.items(client=client)
print(f"Added 2 nodes. The model now has {len(nodes)} node(s).")

Run it the same way as Step 4. You should see Added 2 nodes. The model now has 2 node(s). (more, if the blank project you opened wasn't actually empty), and switching to Gen NX will show two new points in the model.

Step 6: Build a whole model (optional — this changes your model)

Risk level: 4 — high risk (see Risk levels). doc.new_project() discards unsaved work, which is why this step is optional and separate from Steps 4 and 5.

Step 4 proved your connection works, and Step 5 added data safely to a model you prepared yourself. If you'd like to see midas-nx build an entire model from scratch — including creating the project itself — here's the same example the MIDAS-API manual uses. Read the warning first.

⚠️ This script calls doc.new_project(), which discards any unsaved work in whatever document is currently open in Gen NX/Civil NX — even work unrelated to this script. Only run it against a blank project, or one you don't mind losing unsaved changes in. If you have a real model open, save it first (or close it and start a new blank project).

from midas_nx import MidasClient, Product, doc
from midas_nx.db.node_element import Element, Node
from midas_nx.db.project import Unit
from midas_nx.db.properties.material import Material
from midas_nx.db.properties.section import Section

# Using Civil NX instead? Change this to product=Product.CIVIL.
client = MidasClient(mapi_key="paste_the_key_you_copied_in_step_3_here", product=Product.GEN)

doc.new_project(client=client)
Unit.update({1: {"DIST": "M", "FORCE": "KN"}}, client=client)

Material.create(
    {1: {"TYPE": "CONC", "NAME": "C24",
         "PARAM": [{"P_TYPE": 1, "STANDARD": "KS01(RC)", "DB": "C24"}]}},
    client=client,
)
Section.create(
    {1: {"SECTTYPE": "DBUSER", "SECT_NAME": "Column",
         "SECT_BEFORE": {"USE_SHEAR_DEFORM": True, "SHAPE": "SB", "DATATYPE": 2,
                          "SECT_I": {"vSIZE": [0.6, 0.6]}}}},
    client=client,
)
Node.create({1: {"X": 0, "Y": 0, "Z": 0}, 2: {"X": 0, "Y": 0, "Z": 3.2}}, client=client)
Element.create({1: {"TYPE": "BEAM", "MATL": 1, "SECT": 1, "NODE": [1, 2]}}, client=client)
doc.save(client=client)

print("Success! Check Gen NX — a column should now be in the model.")

Run it the same way as Step 4 (save as a .py file, run with python). You should see Success! Check Gen NX... printed, and switching to the Gen NX window will show a new 0.6m x 0.6m concrete column, 3.2m tall.

The material/section combination above (C24/KS01(RC)) was live-verified against a real Gen NX and Civil NX session on 2026-07-22 (see docs/live_verification_notes.md) — this script uses confirmed values, not an untested guess, so it's meant to just work.

Next steps

  • Keep going with an AI coding assistant. Once you know the pattern above, you don't need to memorize or hand-write every call yourself. Show this script to Claude Code, ChatGPT, GitHub Copilot, or similar, and ask in plain language — "make a 20m beam instead of a column," "add a load combination" — and it'll turn that into real midas-nx code. This SDK is built to make that easy (type hints, clear error messages). Before you run anything it writes, see Safe start: building with an AI coding assistant for a context pack to give it and a checklist to review its code against.
  • More realistic examples: the examples/python/ folder on GitHub (beam load combinations, wind loads, construction stages, ...) — a good thing to show your AI assistant as a "build me something like this" reference.
  • Full list of what's implemented: ROADMAP.md
  • More detailed usage and design notes: README.md

If you got stuck anywhere following this guide, please open a GitHub issue — it helps make the guide better for the next person.