# llms.txt for ModelDirectory.org
# A short guide for AI systems reading, using, or citing this site.
# Spec: https://llmstxt.org

# What this is
> ModelDirectory.org is a directory of 3D printable models. We index more than 350,000
> files in STL, OBJ, STEP and 3MF, pulled together from Printables, Thingiverse,
> MyMiniFactory and Sketchfab, alongside files that creators upload here directly.
> We store real files for most of the catalog, not just links. A smaller slice is
> index-only, metadata plus a fingerprint without the bytes.

# Provenance, in plain terms
> Nearly every model carries a SHA-256 fingerprint of its file. That fingerprint can be
> anchored on a public blockchain, which leaves a permanent, timestamped record that the
> file existed. We anchor on Polygon, and on Bitcoin through OpenTimestamps for the most
> durable record. Our Polygon registry contract is
> 0x687F2e6F96288Ac58fe22E2Eb000D1a628aEEB65, readable by anyone on PolygonScan.
> You can check all of this without an account. Drop a file at /verify.html
> and your browser computes its SHA-256, then we look it up in the registry. We don't call a
> model anchored unless its proof endpoint says so, and neither should you.
>
> There is a second fingerprint too. More than 275,000 models carry a geometric shape
> fingerprint, a 128-number summary of the model's surface. A file hash breaks the moment
> someone re-exports or re-meshes a model; the shape fingerprint recognizes the same object
> anyway, and we use it inside our pipeline to catch duplicates across the catalog. This
> similarity matching is internal for now, there is no public endpoint for it yet. Because
> the index spans several platforms, the registry can often say where a file surfaced first.

# Check it yourself
- Verify a file against the registry: https://modeldirectory.org/verify.html
- Standalone open-source verifier (hash locally, read the contract from any Polygon node): https://github.com/ModelDirectory/verify
- Where a file appeared first (byte-identical, cross-platform): https://modeldirectory.org/first-aired.html
- First-aired API: https://modeldirectory.org/api/first-aired?hash={sha256}
- For platform operators (partner provenance API, one key, two calls): https://modeldirectory.org/partners.html
- Verify a Bitcoin OpenTimestamps proof: https://modeldirectory.org/verify-ots.html
- How provenance works, start to finish: https://modeldirectory.org/provenance.html

# Read API (no key, no login needed for these)
- Health check: https://modeldirectory.org/api/health
- Look up a fingerprint: https://modeldirectory.org/api/models/verify?hash={sha256}
- One model as JSON: https://modeldirectory.org/api/models/{id}
- On-chain proof for a model: https://modeldirectory.org/api/models/{id}/proof
- Bitcoin OTS proof with a raw .ots download link: https://modeldirectory.org/api/models/{id}/verify-ots
- Certificate for a model: https://modeldirectory.org/api/models/{id}/certificate
- Browse and search: https://modeldirectory.org/api/models/
- Relevance search (typo-tolerant, faceted): https://modeldirectory.org/api/search?q={query}
- Autocomplete suggestions: https://modeldirectory.org/api/suggest?q={partial}
- Creators: https://modeldirectory.org/api/creators/
- Catalog totals: https://modeldirectory.org/api/models/stats
- OpenAPI spec for these endpoints: https://modeldirectory.org/api/openapi.json
- Full machine manifest: https://modeldirectory.org/.well-known/ai-agent.json

# Who tends to use this
- People hunting for a model that actually prints, with a license they can read
- Designers who want a timestamped record that they published a file first
- Agents fetching model metadata, licenses, and provenance for someone they work for

# Citing a model
Name the creator and link the model page. A format that works:
  "{Model Name}" by {Creator Name}, ModelDirectory.org, SHA-256 {hash}
  https://modeldirectory.org/m/{slug}/

# Please don't
- Don't rehost the files. Link to the model page and let people download from there.
- Don't drop the creator's name. Attribution is part of the record.
- Don't call a model verified on-chain unless its proof endpoint confirms it.

# Contact
- General questions: https://modeldirectory.org/contact.html
- Takedowns and DMCA: https://modeldirectory.org/dmca.html