PaperLocale

Verified, layout-preserving academic PDF translation with pluggable model providers and domain-specific terminology packs.

中文说明

The demo below is generated from PaperLocale's own one-page, double-column PDF fixture. It contains formula text, a vector table, and an embedded image; no copyrighted paper is redistributed.

Status

PaperLocale is under active development. The first release focuses on one strict pipeline:

1. collect translatable segments from a PDF layout engine;
2. translate them with one explicitly selected provider;
3. reject translations that lose formulas, style tags, numbers, units, abbreviations, URLs, DOIs, or required terminology;
4. rebuild the PDF without changing its page geometry;
5. render every page and produce a reviewable QA report.

The project does not promise bitwise-identical typography. Chinese text naturally changes line breaks. Its promise is narrower and testable: preserve the page structure and protected scientific content, and fail before rendering when that contract is broken.

Implemented providers and gates

• codex-local: local-only translation through an authenticated Codex CLI session;
• openai-compatible: BYOK access to OpenAI and compatible endpoints;
• an auditable manual ChatGPT Web bridge that exports hash-bound prompts and imports strict JSON responses without browser login, scraping, or automation;
• qwen-mt: BYOK access to Qwen-MT's dedicated translation endpoint, with one-segment checkpoints and domain-pack terminology intervention;
• an extensible atmospheric-science pack with terminology and evaluation cases;
• a resumable collect -> translate -> validate -> render -> qa -> accept workflow;
• page geometry, image-object, vector-drawing, blank-page, placeholder, and all-page visual checks.

PaperLocale never reads or copies Codex authentication files. ChatGPT-managed Codex access is for trusted local use only and is not exposed as a public translation API.

Domain packs

The first built-in pack is atmospheric-science. A pack contains a manifest, glossary, prompt rules, and evaluation cases. New disciplines can be added without changing the translation pipeline.

python -m paperlocale domain-check atmospheric-science
python -m paperlocale validate-segments \
  --segments segments.jsonl \
  --translations translations.jsonl \
  --domain atmospheric-science

Evaluate a real Provider on every public domain case and save candidates next to their references:

paperlocale provider-eval \
  --provider codex-local \
  --model gpt-5.6-sol \
  --reasoning-effort high \
  --domain atmospheric-science \
  --output provider-eval.json

The report automatically evaluates only the hard content contract and exact reference matches. It never treats string similarity as semantic accuracy; every candidate remains marked for manual domain review.

Install

Python 3.10–3.13 and Poppler's pdftoppm are required for the complete workflow. Stable PaperLocale releases are published on PyPI through attested Trusted Publishing. The audited maintainer procedure and release evidence are documented in docs/PYPI_PUBLISHING.zh-CN.md. PaperLocale 0.4.2 adds --unattended and the audited repair commands documented below. To run this checkout, use the normal non-editable install path python -m pip install ".[layout]". The v0.4.0 manual ChatGPT Web bridge is documented in docs/CHATGPT_WEB_MANUAL.zh-CN.md for its copy/paste workflow and usage-limit boundary.

For v0.5.0, install the exact public release with:

python -m venv .venv
source .venv/bin/activate
python -m pip install "paperlocale[layout]==0.5.0"
paperlocale --version
paperlocale domain-check atmospheric-science

Quick start

For a single non-interactive command that produces a complete candidate PDF, use --unattended. The codex-local provider invokes structured codex exec --ephemeral in the background; it does not open or wait for a Codex conversation window:

paperlocale run paper.pdf --run-dir runs/paper \
  --provider codex-local \
  --model gpt-5.6-sol \
  --reasoning-effort high \
  --domain atmospheric-science \
  --unattended

The command automatically adopts only deterministic reference matches and deterministic layout-safety passthroughs, then translates, validates, rebuilds, and generates all-page machine QA. On success it prints the exact candidate PDF path under runs/paper/render_output/. References remain unchanged under the default preserve policy, and unsafe split layout objects remain byte-for-byte unchanged with an audit record. A "complete candidate PDF" therefore means that all pages and collected segments are closed, not that formulas, references, or unsafe fragments are forcibly converted to Chinese.

Unattended mode does not fabricate human visual acceptance: the final state is still qa_generated. Provider, content-contract, or machine-QA failures exit with an explicit error and retain valid checkpoints; rerun the same command to resume. PaperLocale never silently switches providers.

The supervised workflow remains available when reference boundaries should be reviewed manually:

In 0.5.0, run performs one bounded vector restoration by default; use --no-restore-source-vectors to disable it. Recovery verifies both PDF hashes, retains a backup, and reruns full QA. Other failures remain explicit. Matching checks path geometry, style and multiplicity; zero opacity, existing drawings and text positions are protected.

With preserve, deterministic reference regions are copied with their original glyphs and layout instead of being typeset again. This prevents overlapping or partially translated bibliographies. Ambiguous or missing reference headings are not guessed. Existing maps are never silently rewritten; repair a candidate with restore-reference-layout --run-dir runs/paper, then rerun QA and review. Cross-column publisher continuations are no longer treated as bibliography. This release does not guarantee lossless output for every unknown layout: OCR/scans, uncollected source text, formula placement and caption formatting still require review. Successful machine QA remains qa_generated, not accept.

Use the same resumable command to initialize the run, collect layout segments, translate, validate, rebuild, and generate all-page QA:

# Uses the authenticated Codex CLI session on this trusted local machine.
paperlocale run paper.pdf --run-dir runs/paper \
  --provider codex-local \
  --model gpt-5.6-sol \
  --reasoning-effort high \
  --domain atmospheric-science

# The first invocation stops after collection for reference review.
paperlocale confirm-references --run-dir runs/paper \
  --segment-id manually-confirmed-reference-segment-id \
  --confirmed-by "Your name"

# Rerun the original paperlocale run command after confirmation.
paperlocale run paper.pdf --run-dir runs/paper \
  --provider codex-local \
  --model gpt-5.6-sol \
  --reasoning-effort high \
  --domain atmospheric-science

# Inspect every image under runs/paper/qa/comparisons/ before acceptance.
paperlocale accept --run-dir runs/paper --reviewed-by "Your name"

If a stage fails, rerun the same paperlocale run command. The manifest resumes from the last completed stage and every accepted segment is reused, including valid rows from a batch that also produced rejected candidates. Those candidates and their contract errors are stored in rejected_translations.jsonl. The command deliberately stops at qa_generated; it never records human acceptance. Once translation is complete, a resume command does not need --provider or API credentials.

If a rejected segment is genuinely non-translatable, such as a pure formula or an author-name list, confirm it explicitly instead of adding artificial Chinese text or weakening the global CJK gate:

paperlocale confirm-passthrough --run-dir runs/paper \
  --segment-id confirmed-nontranslatable-segment-id \
  --reason "Pure formula with no translatable prose" \
  --confirmed-by "Your name"

The audited map binds the source PDF and segments.jsonl hashes. Confirmed segments must remain byte-for-byte equal to their source, never reach the Provider, and can safely resolve a rejected partial batch without repeating already accepted model calls.

Before any Provider call, PaperLocale also compares collected segments with the source PDF's exact visible page text. A segment that starts or ends inside the same ASCII word (for example Figu + re ... perio + d), or a short ASCII segment absent from visible page text, is written to segment_safety_review.jsonl and blocks translation. Inspect that local file, then confirm every listed ID with confirm-passthrough. v0.3.2 deliberately keeps these objects unchanged; full translation requires upstream adjacent- object context or merge support.

The default reference policy is preserve. PaperLocale writes every segment to reference_review.jsonl, automatically selects only long segments that match the source PDF's exact REFERENCES region, and requires explicit confirmation before any model call. Automatically matched IDs do not need to be repeated; omit --segment-id when no manual additions are needed. If page columns or post-reference sections cause a reviewed false positive, repeat --exclude-segment-id ID on confirm-references; only IDs from the current automatic set can be excluded, and every exclusion is recorded in the bound map. The confirmed map is bound to the source PDF and segments.jsonl hashes. Use --reference-policy translate-titles to translate work titles only; reference rows do not use body-domain glossary gates.

The current released BabelDOC may still re-typeset an unchanged reference paragraph. The object-level fix is proposed upstream in BabelDOC #610 and PR #611; PaperLocale does not carry a local PDF overlay workaround while that review is pending.

The schema 4 run manifest binds the domain-pack content hash, provider, model, reasoning effort, Codex CLI version history, collect/render layout-engine versions, and any human-confirmed passthrough map. A Codex run therefore requires an explicit --model.

When vector objects disappear, QA records their page, bounding box, and area, and draws red boxes at the expected locations in both comparison panels. When the original source paths should remain at those locations, replay only the exactly missing paths through PaperLocale's controlled command:

paperlocale restore-source-vectors --run-dir runs/paper \
  --description "Restore source vectors confirmed missing by machine QA"

The command requires a current QA report whose source and translated hashes match the manifest. It only inspects pages where QA records source_vector_drawings > translated_vector_drawings, matches missing paths at 0.01 PDF-point precision, rejects text, page-geometry, or image changes, backs up the candidate, and records repair_history. Other independently repaired candidates can still use the audited import path:

paperlocale apply-vector-repair --run-dir runs/paper \
  --repaired-pdf repaired-paper.pdf \
  --description "Restore page 1 link vector icons"

The command rejects candidates that alter text, page geometry, or image counts, backs up the previous PDF, appends repair_history, and requires QA and human acceptance to run again.

If visual review finds a broken caption that cannot be repaired at segment level, replace only an explicitly reviewed page rectangle:

paperlocale apply-text-repair --run-dir runs/paper \
  --page 27 \
  --rect 40 120 500 160 \
  --replacement "Figure 5 corrected caption" \
  --font-file /path/to/NotoSansCJKsc-Regular.otf \
  --font-size 9.5 \
  --single-line \
  --description "Repair a split-token figure caption"

The command verifies that the font contains every replacement glyph, removes text only inside the rectangle while preserving page geometry, images, links, existing vectors, and outside text, and rejects overflow. It subsets the repair font before embedding it without rewriting existing PDF font programs, and records the font and subset hashes, byte reduction, before/after text, geometry, PDF hashes, and backup in repair_history. QA and human acceptance must then run again. Use a locally licensed font and do not commit it to the repository; a TTF/OTF usually produces cleaner extraction metadata than a font collection, but every result still goes through the same QA warnings and visual review. --single-line measures the subset font's actual width, ascender, and descender and rejects a shallow rectangle before modification if the line does not fit; omit it when normal textbox wrapping is intended.

For a reviewed fragment that must only be removed, pass an explicit empty replacement and omit the font options:

paperlocale apply-text-repair --run-dir runs/paper \
  --page 2 --rect 120 29 144 39 --replacement '' \
  --description "Remove a reviewed split-token fragment"

Removal mode embeds no font, records text-removal in repair_history, and still enforces the same rectangle, outside-text, page, image, link, vector, backup, QA, and human-acceptance gates. Whitespace-only replacements are rejected.

Every recorded PDF repair can be reversed from the current chain tail only:

paperlocale rollback-last-repair --run-dir runs/paper \
  --reason "Remove the last audited repair before rebuilding QA"

The command requires the current PDF to match the tail after_sha256 and its backup to match before_sha256. It restores that exact backup, moves the entry from repair_history to repair_rollback_history, returns the run to rendered, and invalidates the old QA and visual-acceptance binding. It cannot skip newer repairs; run machine QA and full visual review again after rollback.

For a BYOK OpenAI-compatible endpoint:

export PAPERLOCALE_API_KEY="your-key"
paperlocale run paper.pdf --run-dir runs/paper \
  --provider openai-compatible \
  --base-url https://api.example.com/v1 \
  --model your-model \
  --domain atmospheric-science

Remote compatible endpoints must use HTTPS. Plain HTTP is accepted only for loopback services on localhost, 127.0.0.1, or ::1.

For Alibaba Cloud Bailian's dedicated Qwen-MT endpoint, keep the API key in an environment variable and select the explicit provider. The base URL is the API version prefix and must not include /chat/completions:

export PAPERLOCALE_API_KEY="your-DashScope-key"
paperlocale run paper.pdf --run-dir runs/paper \
  --provider qwen-mt \
  --base-url https://dashscope.aliyuncs.com/compatible-mode/v1 \
  --model qwen-mt-plus \
  --domain atmospheric-science

Qwen-MT receives only one source segment per request. PaperLocale derives its language codes, domain instruction, and glossary terms from the selected domain pack, validates every returned segment, and saves each accepted result before starting the next request. API keys are sent only in the Authorization header and are never written to the run manifest.

For explicit stage-by-stage control, the same production path remains available as init-run -> collect -> reference-review/confirm-references -> optional confirm-passthrough -> translate -> validate -> render -> qa -> accept.

See the detailed Chinese guide, ROADMAP, ARCHITECTURE, domain-pack guide, Codex for Open Source readiness, and PROVENANCE.

Citation and community

Research and teaching users can cite the software through CITATION.cff; GitHub exposes the same metadata through its “Cite this repository” control. Participation in issues, pull requests, and reviews follows the PaperLocale Code of Conduct.

Development

Unit tests do not call a model or require the layout engine:

python -m pip install -e ".[test]"
python -m unittest discover -s tests -v

After layout-engine upgrades, run the deterministic full-path smoke test:

python -m pip install -e ".[layout,test]"
python scripts/layout_smoke.py \
  --output tmp/layout-smoke-001 \
  --demo-gif tmp/layout-smoke-001.gif

The script intentionally stops before visual acceptance and prints the comparison image to inspect. The scheduled compatibility workflow repeats this real CLI check weekly against the newest pdf2zh-next release allowed by the declared dependency range.

Contributing

Start with the scoped good first issues, or read CONTRIBUTING.md. Current entry points cover an ecology domain pack, Ubuntu installation verification, and independent review of the atmospheric-science Provider evaluation.

License

GNU Affero General Public License v3.0 only. This choice is aligned with the AGPL-licensed PDF layout engines the project is designed to integrate.