# step.parts

12,000+ open source STEP parts for your next CAD project

## Preferred machine endpoints

- Paginated parts API: https://api.step.parts/v1/parts
- Single part API: https://api.step.parts/v1/parts/din913_set_screw_m3x3
- Local/dev STEP route: https://www.step.parts/step/din913_set_screw_m3x3.step
- OpenAPI contract: https://api.step.parts/v1/openapi.json
- Catalog schema and field semantics: https://api.step.parts/v1/catalog/schema
- Compact discovery index: https://api.step.parts/v1/catalog/parts.index.json

## Catalog fields

API catalog records contain:

- id: stable snake_case ASCII identifier
- name: human-readable part name
- description: source-authored summary text
- category: broad open-string aisle, such as fastener, bearing, stock, profile, spacer, pin, or motion
- family: optional but strongly encouraged product/part family for faceting and related grouping when a natural grouping exists; use commodity families such as socket-head-cap-screw or t-slot-extrusion, and product/platform families such as damiao, feetech, raspberry-pi, or arduino for actuators/electronics
- tags: supplemental reusable type, function, material, interface, or feature labels; category, family, standard, model/SKU, dimension, manufacturer, alias, and provenance values live in dedicated fields
- aliases: alternate names and compact lookup strings
- standard: optional standard object with body, number, and designation
- stepSource: optional direct URL to a live STEP/STP source file
- productPage: optional product page URL for the STEP file
- attributes: part-specific scalar facts such as thread, lengthMm, bore1Mm, material, profileSeries, or slotSizeMm
- stepUrl: URL for the canonical STEP file; local/dev resolves through /step/{id}.step and production uses a commit-pinned GitHub LFS media URL
- glbUrl: absolute Vercel Blob URL for the GLB preview
- pngUrl: absolute Vercel Blob URL for the PNG thumbnail
- byteSize: STEP file size in bytes
- sha256: STEP file SHA-256 checksum

The paginated API returns matching records with absolute pageUrl, apiUrl, glbUrl, and pngUrl values; stepUrl resolves locally in dev/test and to GitHub LFS media in production.

## Catalog freshness

- Catalog part count: 12734
- Catalog last modified: 2018-10-20T01:46:40.000Z
- Catalog SHA-256: 05a527749de56cf65c30030e5456b4dbef67ea7c9a5ff712996efdb26be0833e
- API and machine-readable catalog endpoints include ETag and Last-Modified headers.

## API query parameters

- q: metadata search across id, name, description, category, family, stepSource, productPage, tags, aliases, standard fields, attribute keys, and attribute values
- tag: repeated supplemental tag filter; values within tag are ORed
- category, family, standard: repeated filters for dedicated metadata fields; values within one field are ORed, and selected facet fields are ANDed together
- page: 1-based result page
- pageSize: result page size; defaults to 100 and is capped at 500

Unfiltered results start with a fixed 100-part showcase, then continue in stable source catalog order. Filtered results are ordered by stable source catalog order.

Examples:

- https://api.step.parts/v1/parts?q=M3&tag=screw&page=2
- https://api.step.parts/v1/parts?pageSize=100
- https://api.step.parts/v1/parts?category=fastener&family=socket-head-cap-screw&standard=ISO%204762
- https://api.step.parts/v1/parts?q=lengthMm%2012
- https://api.step.parts/v1/parts/din913_set_screw_m3x3

## Common agent tasks

- Find ISO 4762 socket head cap screws: https://api.step.parts/v1/parts?category=fastener&family=socket-head-cap-screw&standard=ISO%204762
- Find M3 screw-like parts: https://api.step.parts/v1/parts?q=M3&tag=screw
- Resolve an alias such as SHCS: https://api.step.parts/v1/parts?q=SHCS
- Search attribute names and values: https://api.step.parts/v1/parts?q=lengthMm%2012
- Get a cheap id/name index before fetching details: https://api.step.parts/v1/catalog/parts.index.json
- Fetch one part and use its stepUrl/glbUrl/pngUrl/pageUrl: https://api.step.parts/v1/parts/din913_set_screw_m3x3
- Discover field meanings and family-specific attributes: https://api.step.parts/v1/catalog/schema
- Generate tools from the API contract: https://api.step.parts/v1/openapi.json

## Asset URL patterns

- Part page: https://www.step.parts/parts/%7Bid%7D
- Local/dev STEP file route: https://www.step.parts/step/%7Bid%7D.step
- Production STEP files: commit-pinned GitHub LFS media URLs exposed as stepUrl
- GLB preview: use the absolute glbUrl returned by the API record
- PNG thumbnail: use the absolute pngUrl returned by the API record

## Usage notes

- Use /v1/parts when you need filtered results, pagination metadata, facet counts, or absolute URLs.
- Use /v1/openapi.json to generate API clients or agent tools.
- Use /v1/catalog/schema to understand field meanings, result ordering, and family-specific attribute meanings.
- Use /v1/catalog/parts.index.json for compact discovery before fetching one record or a paginated result page.
- Download through stepUrl; production STEP URLs redirect to GitHub LFS media, and downloaded STEP files can be verified with the sha256 field.
- Individual STEP, GLB, and PNG assets are discoverable from catalog records, not listed individually in the sitemap.

Current catalog size: 12734 parts.
Example id: din913_set_screw_m3x3