# đź“ś Release LexFCS Specification v0.3 **URL:** \ **Category:** General\ **Tags:** fcs\ **Created:** [23 June 2025 10:40 UTC](https://forum.clarin.eu/t/release-lexfcs-specification-v0-3/897 "2025-06-23T10:40:52Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![koerner](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.clarin.eu/koerner/32/80_2.png) [@koerner](https://forum.clarin.eu/u/koerner)\ **Post date:** [23 June 2025 10:40 UTC](https://forum.clarin.eu/t/release-lexfcs-specification-v0-3/897/1 "2025-06-23T10:40:52Z")
**Version 0.3** of the **LexFCS specification** has been released. It can be considered stable with regards to the data model, the FCS _Data Views_ and _Endpoint Description_. A few additions to the specification are still planned and being tested in [Text+](https://text-plus.org/en/) but those changes are optional and therefore backwards compatible. Centres planning to implement their own LexFCS endpoints are welcome to do so and should not have to fear breaking changes. ## What does LexFCS v0.3 contain? The LexFCS v0.3 specification can be considered semi-final. A few additions are planned but the framework to support lexical resources in the FCS is more or less finished. The LexFCS specification describes the (a) [data model](https://www.clarin.eu/sites/default/files/2025-05-21%20CLARIN%20Centre%20Meeting%20%E2%80%93%20LexFCS%20Thomas%20Eckart.pdf), which is basically an entry with different information fields like _lemma, pos, etymology, sentiment, synonym, ref, …_, the corresponding (b) Lex Data View, to serialize results, and (c) LexCQL query language, and (d) the extensions to the Endpoint Description, to describe “supported Lex Fields”, i.e. which information fields a lexical resource supports for querying and what is returned. ## Resources about LexFCS - Specification v0.3 on Zenodo: [Federated Content Search for Lexical Resources (LexFCS): Specification](https://zenodo.org/records/15706299) - Presentation on LexFCS at CLARIN Centre Meeting 2025: [slides](https://www.clarin.eu/sites/default/files/2025-05-21%20CLARIN%20Centre%20Meeting%20%E2%80%93%20LexFCS%20Thomas%20Eckart.pdf) - more at: [Zotero | Groups \> Federated Content Search](https://www.zotero.org/groups/5668488/federated_content_search) (general FCS publications) ## Software support? The CLARIN Java SRU/FCS libraries have been updated to support LexFCS v0.3. For FCS Endpoints the dependencies are: - [GitHub - clarin-eric/fcs-simple-endpoint](https://github.com/clarin-eric/fcs-simple-endpoint) - `eu.clarin.sru.fcs:fcs-simple-endpoint:1.11.2`. Support for LexFCS was added in [`1.9.0`](https://github.com/clarin-eric/fcs-simple-endpoint/blob/main/CHANGELOG.md#190---2025-04-04). - [GitHub - clarin-eric/fcs-sru-server](https://github.com/clarin-eric/fcs-sru-server/) - `eu.clarin.sru:sru-server:1.13.0` - [GitHub - clarin-eric/fcs-ql](https://github.com/clarin-eric/fcs-ql) - `eu.clarin.sru.fcs:fcs-ql:2.0.1`. Support for LexFCS query language LexCQL was added in [`1.0.0`](https://github.com/clarin-eric/fcs-ql/blob/main/CHANGELOG.md#100---2025-04-04). For FCS Clients those are: - [GitHub - clarin-eric/fcs-simple-client](https://github.com/clarin-eric/fcs-simple-client) - `eu.clarin.sru.fcs:fcs-simple-client:2.6.0`. Support for LexFCS was added in [`2.4.0`](https://github.com/clarin-eric/fcs-simple-client/blob/main/CHANGELOG.md#240---2025-04-02). - [GitHub - clarin-eric/fcs-sru-client](https://github.com/clarin-eric/fcs-sru-client/) - `eu.clarin.sru:sru-client:2.5.0`. The FCS SRU Aggregator and FCS Endpoint Valiator have also been updated to support LexFCS. More FCS resources are listed in the [Awesome FCS list](https://github.com/clarin-eric/awesome-fcs). ## See LexFCS in action LexFCS was proposed and developed in Text+ / Germany. There are already a few FCS Endpoints implementing LexFCS and offering lexical resources. The majority of resources is still in German (for now). LexFCS Demo with [custom frontend (see forum post)](https://forum.clarin.eu/t/how-to-integrate-the-fcs-search-into-you-own-website/505) and great visualization of the new _Lex Data View_: [Text+ FCS Vuetify Playground](https://tppssi-demo.saw-leipzig.de/lex/) LexFCS Aggregator: [https://fcs.text-plus.org/](https://fcs.text-plus.org/) and [https://alpha-fcs.text-plus.org/](https://alpha-fcs.text-plus.org/) ## Future plans The [FCS SRU Aggregator](https://github.com/clarin-eric/fcs-sru-aggregator/tree/feature/modules) (aka CLARIN ContentSearch) is currently being refactored to improve the code base (better reusability) and new frontend ([demo](https://clarin-eric.github.io/fcs-sru-aggregator-ui/), [code](https://github.com/clarin-eric/fcs-sru-aggregator-ui/)). Support for LexFCS will then be built-in for the Lex Data View and offer a new LexCQL query builder.