# MMDS — Macromolecular Data Service

**Canonical:** https://apis.io/apis/cadence/mmds/  
**Provider:** Cadence Design Systems — https://apis.io/providers/cadence/  
**Base URL:** https://mmds.eyesopen.com/api/v1/  
**Documentation:** https://docs.eyesopen.com/webservices/mmds/

MMDS — Macromolecular Data Service is one of 3 APIs that [Cadence Design Systems](https://apis.io/providers/cadence/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Structural Biology, Protein Data, Scientific Computing, and Drug Discovery. The published artifact set on APIs.io includes API documentation, an API reference, a getting-started guide, and authentication docs.

A live HTTPS JSON API for macromolecular experimental data — experiments, sites, families, contexts, frames and results, keyed on PDB structure codes with .pdb/.cif structures, MTZ density and cryo-EM maps. Operated by OpenEye, Cadence Molecular Sciences, and reachable at https://mmds.eyesopen.com/api/v1/ — an unauthenticated GET on 2026-09-05 returned HTTP 403 with a Django REST Framework body, {"detail":"Authentication credentials were not provided."}, which confirms the service is real and that every path is authentication-gated. No OpenAPI is published; the mmdsclient Python library and mmdscli CLI are the published interface.

## Machine-readable artifacts (4)

- **Documentation** — https://docs.eyesopen.com/webservices/mmds/
- **APIReference** — https://docs.eyesopen.com/webservices/mmds/client.html
- **GettingStarted** — https://docs.eyesopen.com/webservices/mmds/quickstart.html
- **Authentication** — https://raw.githubusercontent.com/api-evangelist/cadence/refs/heads/main/authentication/cadence-authentication.yml

## Other Cadence Design Systems APIs (2)

- [Cadence Design Systems](https://apis.io/apis/cadence/cadence-design-systems/)
- [Orion Molecular Design Platform API](https://apis.io/apis/cadence/orion/)

## Tags

Structural Biology, Protein Data, Scientific Computing, Drug Discovery

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/cadence/mmds/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/cadence/.