Is the Step Parts skill free?

Yes. The skill itself is free from earthtojake/step.parts. SkillProof publishes the install command and an independent test verdict at no cost.

What is the Step Parts SkillProof Score?

9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.

How do I install Step Parts?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use Step Parts with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

Step Parts

Search the step.parts catalog and download checksum-verified STEP files for standard CAD parts

by earthtojake · earthtojake/step.parts

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 9.6/10
Tested: Jul 31, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · 25afdbd

Fetched SKILL.md and spot-checked all 3 referenced files (script, references/step-parts-api.md, agents/openai.yaml) — all HTTP 200. Ran the bundled download_step_part.py against the live api.step.parts: search returned the correct ISO 4762 M3x12 record, and --download saved a real 58826-byte valid ISO-10303-21 STEP file to disk with checksumVerified:true (sha256 confirmed with shasum). Baseline without the skill produces no valid STEP asset (would require a manual McMaster/TraceParts login or a fabricated file with no checksum); the skill produced a verified canonical file plus provenance URLs. Security scan of the 207-line script found no shell exec, base64, or secret handling — pure urllib.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 9/10
Docs & honesty 5/5

What Step Parts does

Searches the hosted step.parts catalog for standard off-the-shelf CAD parts (screws, bolts, nuts, washers, bearings, standoffs, connectors) and downloads canonical .step files with sha256 verification via a bundled Python downloader. Triggers when the user wants to find a standard part by fuzzy name, standard, or dimensions, resolve aliases, or fetch and verify a STEP file. Uses the api.step.parts /v1 endpoints (search, per-part record, catalog index, OpenAPI) rather than scraping HTML.

How to install Step Parts

git clone --depth 1 https://github.com/earthtojake/step.parts.git /tmp/step-parts-src
mkdir -p ~/.claude/skills
cp -R /tmp/step-parts-src/skills/step-parts ~/.claude/skills/step-parts
# Requires: python3 (stdlib only — urllib, hashlib; no pip installs)
# Live hosted API at https://api.step.parts (no key). Downloader: ~/.claude/skills/step-parts/scripts/download_step_part.py
# Example: python3 ~/.claude/skills/step-parts/scripts/download_step_part.py "M3 socket head 12" --download --out-dir /tmp/step-parts

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger Step Parts

/step-parts Search the step.parts catalog and download checksum-verified STEP files for standard CAD parts

It also activates on plain-language prompts like these:

Find a screw matching these dimensions on step.parts
Download the STEP file for this bearing
Resolve this fuzzy part name to a standard

Frequently asked questions

Is the Step Parts skill free?: Yes. The skill itself is free from earthtojake/step.parts. SkillProof publishes the install command and an independent test verdict at no cost.
Does Step Parts work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 31, 2026. Verdict: Tested · Works. Fetched SKILL.md and spot-checked all 3 referenced files (script, references/step-parts-api.md, agents/openai.yaml) — all HTTP 200. Ran the bundled download_step_part.py against the live api.step.parts: search returned the correct ISO 4762 M3x12 record, and --download saved a real 58826-byte valid ISO-10303-21 STEP file to disk with checksumVerified:true (sha256 confirmed with shasum). Baseline without the skill produces no valid STEP asset (would require a manual McMaster/TraceParts login or a fabricated file with no checksum); the skill produced a verified canonical file plus provenance URLs. Security scan of the 207-line script found no shell exec, base64, or secret handling — pure urllib.
What is the Step Parts SkillProof Score?: 9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.
How do I install Step Parts?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use Step Parts with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.