---
pretty_name: mGENRE title trie + Wikidata QID lookup + QID attributes (impresso NEL assets)
license: cc-by-nc-4.0
language:
  - multilingual
  - af
  - am
  - ar
  - as
  - az
  - be
  - bg
  - bm
  - bn
  - br
  - bs
  - ca
  - cs
  - cy
  - da
  - de
  - el
  - en
  - eo
  - es
  - et
  - eu
  - fa
  - ff
  - fi
  - fr
  - fy
  - ga
  - gd
  - gl
  - gn
  - gu
  - ha
  - he
  - hi
  - hr
  - ht
  - hu
  - hy
  - id
  - ig
  - is
  - it
  - ja
  - jv
  - ka
  - kg
  - kk
  - km
  - kn
  - ko
  - ku
  - ky
  - la
  - lg
  - ln
  - lo
  - lt
  - lv
  - mg
  - mk
  - ml
  - mn
  - mr
  - ms
  - my
  - ne
  - nl
  - no
  - om
  - or
  - pa
  - pl
  - ps
  - pt
  - qu
  - ro
  - ru
  - sa
  - sd
  - si
  - sk
  - sl
  - so
  - sq
  - sr
  - ss
  - su
  - sv
  - sw
  - ta
  - te
  - th
  - ti
  - tl
  - tn
  - tr
  - uk
  - ur
  - uz
  - vi
  - wo
  - xh
  - yo
  - zh
task_categories:
  - text-retrieval
tags:
  - entity-linking
  - named-entity-linking
  - entity-disambiguation
  - text2text-generation
  - mgenre
  - marisa-trie
  - wikidata
  - constrained-decoding
  - impresso
size_categories:
  - 10M<n<100M
viewer: false
---

# mGENRE title trie + Wikidata QID lookup — impresso NEL assets

Three [`marisa-trie`](https://github.com/s-yata/marisa-trie) native binaries that
support **multilingual entity linking with mGENRE**. They are the runtime assets
for the [`impresso-project/nel-mgenre-multilingual`](https://huggingface.co/impresso-project/nel-mgenre-multilingual)
model as run by the [`impresso-inference`](https://github.com/impresso/impresso-inference)
harness:

- a **title prefix tree** that constrains beam search to valid Wikipedia titles,
- a **`(language, title) → Wikidata QID` lookup** for offline QID resolution, and
- a **`QID → (class, birthdate)` attribute table** for offline post-linking filters
  (disambiguation drop, birthdate anachronism, entity-type repair).

Both are mmap-loaded at startup, so cold start is **seconds regardless of file
size** (the legacy pickle path took ~57 min).

## Files

| File | Size | Format | Role |
|---|---|---|---|
| `titles_lang_all105_marisa_trie_with_redirect.marisa` | ~600 MB | `marisa_trie.Trie` (native `.save`/`.mmap`) | Prefix tree of valid `Title >> lang` token-id sequences (105 languages, redirects included). Drives constrained beam search via a `prefix_allowed_tokens_fn` callback. |
| `lang_title2wikidataID-normalized_with_redirect.marisa` | ~200 MB | `marisa_trie.BytesTrie` | Maps `f"{lang}\x1f{title}"` → the lex-smallest Wikidata QID (ASCII). Resolves generated titles to QIDs offline. |
| `qid2attrs.marisa` | ~70 MB | `marisa_trie.RecordTrie` (fmt `"<Bi"`) | Maps each Wikidata `QID` → `(class_code, birth_days)`. Per-QID attributes for offline post-linking filters. |

The two GENRE-derived files hold **~89 million keys** each (`all105` = the 105
languages of the underlying mBART-50 / mGENRE vocabulary); `qid2attrs.marisa` holds
**~20.2 million keys** — one per distinct QID reachable through the lookup.

## Provenance & construction

These files are converted, byte-faithfully, from Facebook Research's **GENRE**
public downloads at `https://dl.fbaipublicfiles.com/GENRE/`:

- `titles_lang_all105_marisa_trie_with_redirect.pkl` (~582 MB) — a pickled
  GENRE `MarisaTrie` wrapper. Conversion extracts the inner `marisa_trie.Trie`
  and re-saves it as a bare native binary so it can be `mmap`-ed directly.
- `lang_title2wikidataID-normalized_with_redirect.pkl` (~3.9 GB) — a
  `dict[(lang, title), str | set[QID]]`. Conversion streams it into a
  `marisa_trie.BytesTrie`, collapsing multi-QID values to the **lex-smallest
  QID** at build time (so the runtime does a single trie lookup instead of an
  ~8-minute normalisation pass per launch).

The conversion is performed by the `impresso-nel-stage-assets` tool in
[`impresso-inference`](https://github.com/impresso/impresso-inference)
(`src/impresso_inference/tasks/nel/cli/stage_assets.py`). Nothing about the entity
inventory is added or removed — this is a **format/packaging re-host** of the
GENRE data for fast startup.

### QID attributes (`qid2attrs.marisa`)

Unlike the two files above, `qid2attrs.marisa` is **not** derived from GENRE — it is
built from **Wikidata** so that post-linking filters run fully offline (no live
Wikidata/Wikipedia HTTP calls). It is keyed by Wikidata QID and each value is a
fixed 5-byte record (`marisa_trie.RecordTrie`, struct format `"<Bi"`):

| Field | Type | Meaning |
|---|---|---|
| `class_code` | `uint8` (`B`) | Coarse entity class: `0=other`, `1=org`, `2=loc`, `3=person`, `4=disambiguation`. The numeric order is the resolution **priority** (higher wins on multi-class QIDs). |
| `birth_days` | `int32` (`i`) | Earliest date of birth as **days since `0001-01-01`** (proleptic Gregorian). Sentinel `-2147483648` (`-2**31`) means *no/unusable birthdate* (absent, BCE, or imprecise). |

**Coverage** (from the ~20.2 M linkable QIDs): `other` 38.9 %, `loc` 32.5 %,
`person` 18.2 %, `disambiguation` 6.0 %, `org` 4.4 %; **16.5 %** carry a birthdate
(~90 % of the `person` class).

**Construction** — by the `impresso-nel-stage-qid-attrs` tool
(`src/impresso_inference/tasks/nel/cli/stage_qid_attrs.py`):

1. Enumerate the **linkable universe** = the distinct QID *values* of
   `lang_title2wikidataID-normalized_with_redirect.marisa` (the only QIDs mGENRE can emit).
2. Pull attributes from the [QLever](https://qlever.dev/api/wikidata) Wikidata endpoint:
   - **class** via `wdt:P31/wdt:P279*` against fixed roots — person `wd:Q5`,
     organization `wd:Q43229`, location `wd:Q27096213` + `wd:Q42124`, and
     disambiguation pages via direct `wdt:P31 wd:Q4167410`;
   - **birthdate** via the earliest `wdt:P569` (conservative: only the earliest claim).
3. Intersect with the linkable set and pack one record per QID.

**Role.** In `impresso-inference` the NEL writer looks up each linked QID here to:
drop **disambiguation pages**; drop **person** mentions whose birthdate is *after* the
article's publication date (an impossible, i.e. wrong, link); and **repair entity
types** (e.g. an `org`-tagged mention whose QID is actually a location or person).

## Intended use

Pair with `impresso-project/nel-mgenre-multilingual` (mGENRE, an mBART-50
sequence-to-sequence entity linker). mGENRE emits strings of the form
`"Wikipedia_Title >> xx"`:

- The **trie** restricts generation to valid titles at every decoder step
  (prevents hallucinated pages).
- The **lookup** turns the generated `(title, lang)` into a Wikidata QID without
  any live Wikipedia/Wikidata HTTP calls — suitable for offline / batch inference.

In `impresso-inference`, the NEL task auto-downloads whichever file is missing
from this dataset on first launch. See that repo's
`src/impresso_inference/tasks/nel/` for the full pipeline.

## How to load

```python
import marisa_trie

# Title trie — constrained decoding
trie = marisa_trie.Trie()
trie.mmap("titles_lang_all105_marisa_trie_with_redirect.marisa")

# (lang, title) -> QID lookup
lookup = marisa_trie.BytesTrie()
lookup.mmap("lang_title2wikidataID-normalized_with_redirect.marisa")
qid = lookup[f"en\x1fGermany"][0].decode("ascii")   # -> "Q183"

# QID -> (class, birthdate) attributes
from datetime import date, timedelta
CLASS = {0: "other", 1: "org", 2: "loc", 3: "person", 4: "disambiguation"}
BIRTH_NONE, EPOCH = -2**31, date(1, 1, 1)
attrs = marisa_trie.RecordTrie("<Bi")
attrs.mmap("qid2attrs.marisa")
class_code, birth_days = attrs["Q42"][0]            # Douglas Adams -> (3, 712657)
cls = CLASS[class_code]                              # -> "person"
birth = None if birth_days == BIRTH_NONE else EPOCH + timedelta(days=birth_days)  # -> 1952-03-11
```

**Token-id encoding (trie only).** marisa-trie stores keys as UTF-8 strings, so
mGENRE token ids are encoded per character as `chr(t)` for `t < 55000` and
`chr(t + 10000)` otherwise — a 10 000-codepoint shift that skips the UTF-16
surrogate range. This matches the upstream GENRE byte layout; any consumer of the
trie must apply the same shift when decoding allowed-token sets. Keys are
`Title >> lang` token sequences.

## Licensing

Released under **CC BY-NC 4.0 (non-commercial)**, inherited from the upstream
[facebookresearch/GENRE](https://github.com/facebookresearch/GENRE) data the trie and
lookup are derived from. The underlying knowledge base is public: Wikidata
identifiers are **CC0**, and Wikipedia titles are **CC BY-SA**. Use for
non-commercial research consistent with the GENRE license.

`qid2attrs.marisa` contains only **Wikidata facts** (`P31`/`P279`/`P569`), which are
**CC0**; its QID selection follows the GENRE-derived lookup above, so it is
distributed here under the same non-commercial terms for consistency.

## Citation

The trie and lookup originate from mGENRE:

```bibtex
@article{de-cao-etal-2022-multilingual,
  title   = "Multilingual Autoregressive Entity Linking",
  author  = "De Cao, Nicola and Wu, Ledell and Popat, Kashyap and Artetxe, Mikel
             and Goyal, Naman and Plekhanov, Mikhail and Zettlemoyer, Luke and
             Cancedda, Nicola and Riedel, Sebastian and Petroni, Fabio",
  journal = "Transactions of the Association for Computational Linguistics",
  volume  = "10",
  year    = "2022",
  address = "Cambridge, MA",
  publisher = "MIT Press",
  url     = "https://aclanthology.org/2022.tacl-1.16",
  doi     = "10.1162/tacl_a_00460",
  pages   = "274--290"
}
```

## Acknowledgements

Repackaged for historical-newspaper entity linking by the
[Impresso project](https://impresso-project.ch) — an interdisciplinary effort on
historical media analysis across languages, time, and modalities. Funded by the
Swiss National Science Foundation ([CRSII5_173719](http://p3.snf.ch/project-173719),
[CRSII5_213585](https://data.snf.ch/grants/grant/213585)) and the Luxembourg
National Research Fund (grant No. 17498891).

- Model: [`impresso-project/nel-mgenre-multilingual`](https://huggingface.co/impresso-project/nel-mgenre-multilingual)
- Code: [`impresso/impresso-inference`](https://github.com/impresso/impresso-inference)
- Upstream data: [facebookresearch/GENRE](https://github.com/facebookresearch/GENRE)