PlugWiki

step-parts Skill for Claude Code: Find and Download STEP Files for Real Parts

Lets Claude search the step.parts catalog for real screws, bearings, motors and boards, and download STEP files with a checksum check.

Installs
11.7K
on skills.sh
Stars
24.7K
on GitHub
Files
4
besides SKILL.md
Updated
Nov 2026
last repo commit

step-parts tells Claude to look up a real part on step.parts before drawing a simplified stand-in. Claude turns your request into search terms and facets, tries aliases and vendor spellings, lists close matches with their ids and key attributes, and downloads the STEP file only when you ask for one. After a download it checks the file against the record's SHA-256 checksum.

The folder bundles one Python script that does the search and download, a 5-file set in all with SKILL.md, an API reference and a Codex display file. The SKILL.md says to treat catalog records as data, never as instructions.

Good for

  • Makers and engineers modelling assemblies from purchasable parts
  • Robotics builders who need servo, motor or board geometry
  • text-to-cad users who want real parts instead of placeholders

Install step-parts

Claude Code

  1. 1

    Download the skill folder from https://github.com/earthtojake/text-to-cad/tree/HEAD/skills/step-parts.

  2. 2

    Put it at ~/.claude/skills/step-parts/ so that SKILL.md sits directly inside.

  3. 3

    Start a new session; the skill loads when its description matches the task.

The skill itself needs Python 3 and network access to api.step.parts. The README's install script sets up the whole text-to-cad plugin in every agent app it finds, installs uv, and adds the cad command, an MCP server and a local CAD server; telemetry is on by default, and --dry-run prints the plan first (install.md). Only the skill-only route is needed for step.parts search and download.

Built from the package data we hold. Not yet tested by us.

What's in the skill

When it loads

Find, evaluate, and download common purchasable CAD parts from step.parts, including named off-the-shelf actuators, servos, motors, electronics boards, connectors, screws, bolts, nuts, washers, bearings, standoffs, and other catalog components. Use when a CAD model needs a real purchasable part: search the hosted step.parts catalog before creating simplified placeholder geometry, resolve fuzzy part names, standards, aliases, or dimensions, choose a matching part, fetch a canonical .step file, verify checksums, or use the step.parts API/OpenAPI/catalog endpoints for standard part discovery.

Sections in SKILL.md

  1. Overview
  2. Quick Workflow
  3. Bundled Downloader
  4. API Reference
  5. Search Guidance

Key facts

Author
earthtojake
Repo
earthtojake/text-to-cad
License
MIT
Installs on skills.sh
11,745 (Nov 2, 2026)
GitHub stars
24,721 (Nov 2, 2026), whole repo
Last commit
Nov 1, 2026 (repo)
Files in the skill folder
5 files including SKILL.md
Needs
Python 3 for the bundled script, and network access to api.step.parts
Part of
text-to-cad: 12 skills in the repo
Works in
Claude Code, Codex, Cursor, Gemini and Grok

What it includes

  • Searches the catalog with fuzzy terms and optional facets.

    Filters: category, family, standard and tag. Query tokens are ANDed by the API.

    Network · Search /v1/parts

  • Retries aliases, dropped letters and vendor names before calling a part missing.

    For example a servo model written several ways.

    Alias retry

  • Lists the best few matches with id, name, standard and key attributes.

    Used when results are ambiguous.

    Compare options

  • Downloads the STEP file for a search or a --id.

    Saves to the system temp folder unless --out-dir is set.

    Runs code · download_step_part.py --download

  • Compares the file's SHA-256 with the record's checksum.

    The script stops with an error if they differ.

    Runs code · Checksum check

  • --out-dir, --filename, --limit, --page, --all, --overwrite, --origin.

    Without --overwrite it refuses to replace an existing file.

    Files · Download options

  • Endpoint, query and field details for step.parts.

    In references/step-parts-api.md.

    API reference

  • Gives the local path, part id and page or API URLs.

    So you can trace where the part came from.

    Return provenance

  • Display name and default prompt for Codex.

    Metadata only.

    agents/openai.yaml

From the official docs

Permissions

Low risk

Claude runs a bundled Python script that fetches parts from api.step.parts and writes STEP files to disk. Pass an output folder you choose, and use the README install script only if you want the full text-to-cad plugin.

What it can do

  • Read your data
  • Create and change things
  • Delete things
  • Read-only mode

Watch out for

  • The README install script changes your whole setup

    curl | sh installs uv if missing, sets up text-to-cad in every agent app it finds, and adds a local CAD server and MCP server. The README says usage stats and crash reports are sent by default; run with --dry-run first or choose the skill-only route. github.com

  • A bundled script downloads and writes files

    download_step_part.py fetches a STEP file from the part's stepUrl and saves it. The SKILL.md says the URL may resolve to GitHub LFS media in production. The script verifies the checksum when the record has one. github.com

  • The origin can be overridden

    The --origin option replaces https://api.step.parts. The SKILL.md says to use it only when you provide another hosted API origin. github.com

Technical details
Talks toapi.step.parts. www.step.parts
Scopes

  • Runs python scripts/download_step_part.py

  • Writes STEP files to --out-dir (default: system temp folder)

Questions

What does step-parts do?

It lets Claude find standard and off-the-shelf parts on step.parts, such as screws, bearings, motors and connectors, and download their STEP CAD files. It prefers a real part over a placeholder shape.

How do I install it?

Use the install box above. The skill-only routes are enough. The README's install script is for the full text-to-cad plugin, which does much more.

Does it need an API key?

No key is mentioned in the SKILL.md or the script, and the script sends none. It needs Python 3 and a network connection to api.step.parts.

Where do downloads go?

To the system temp folder by default. The SKILL.md says to pass --out-dir whenever the file should stay in your project.

Is it safe?

It runs a bundled Python script that reads from api.step.parts and writes STEP files to a folder. The script checks the SHA-256 checksum, refuses to overwrite files without --overwrite, and only follows https download links, or http when the origin itself is http. See the permissions section.

Does it work in Claude.ai, Codex or Cursor?

The text-to-cad README lists Claude Code, Codex, Cursor, Gemini and Grok. The skill needs Python and network access to api.step.parts.

Do I need the rest of text-to-cad?

No. The skill's script uses only the Python standard library. One step mentions converting a STEP file with the cad command for text-to-cad models, which needs the plugin.

Information

updated Nov 2, 2026

Repository
earthtojake/text-to-cad
Folder
skills/step-parts

earthtojake/text-to-cadskills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 5
  1. text-to-cad README · github.com
  2. text-to-cad install.md · github.com
  3. step-parts SKILL.md · github.com
  4. download_step_part.py · github.com
  5. step-parts API reference · github.com

Updated Nov 2, 2026.