# A minimal OPTIMADE server fed by an httk-core entry provider.

This is the runnable version of the example in ``docs/serving_providers.md``:
a provider serving a custom ``widgets`` entry type alongside the standard
``references`` entry type, with declared relationships between them, wired
into a server with ``adapter_from_providers``. The declared
``RelatedEntry`` objects are served automatically as the OPTIMADE
relationships block (with per-identifier ``meta``), resolved by
``include=references``, and filterable both by id (``references.id HAS
"ref-1"``) and by related properties (``references.title CONTAINS "study"``)
without any hand-wired filter handlers. See ``examples/demo_server/`` for the
lower-level wiring this automates.

```{literalinclude} ../../../examples/provider_server/serve.py
:language: python
:lines: 15-
```