obscura

# Third-Party Notices

Obscura includes tokenizer vocabulary data compatible with OpenAI's
`tiktoken` project. The implementation, encoding definitions, source URLs, and
asset hashes were validated against the upstream project. Obscura preserves
the following upstream notice:

## OpenAI tiktoken

MIT License

Copyright (c) 2022 OpenAI, Shantanu Jain

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

The Presidio-Research dataset snapshots committed under
`eval/datasets/presidio_research/` are excluded from the Hex package and carry
their own license and notice files in that directory. Optional model weights,
tokenizers, caches, and exported ONNX assets are not bundled with Obscura.

## TNER OntoNotes Model

The optional `tner/roberta-large-ontonotes5` checkpoint used by `:balanced`
and `:accurate` is not bundled, distributed, sublicensed, or licensed by
Obscura. LDC directly confirmed on 2026-07-22 that commercial use requires an
LDC for-profit membership under the applicable OntoNotes terms. Obscura does
not grant or verify that authorization. LDC did not conclusively answer the
separate checkpoint-redistribution question. See
`docs/model-asset-licensing.md` before preparing this external asset.