Paperasse
romainsimon/paperasseSix French-language skills for accounting, tax, notary, audit and co-ownership paperwork, with reference data and test cases.
With caveats
Check first Depth 5/5
shinkoku (Japanese tax filing) Claude skills
A Japanese-language plugin of 24 skills that walks sole proprietors and employees through kakutei shinkoku: bookkeeping, tax calculation and e-Tax entry.
Our verdict Recommended with caveats
Thorough and carefully gated for its niche, but it handles My Number and financial records and installs a CLI whose code is outside the skills.
What shinkoku (Japanese tax filing) does
shinkoku is a plugin for Japan's annual income-tax and consumption-tax filing (kakutei shinkoku). In a working folder it creates shinkoku.config.yaml and a local database, then guides the user through skills for deciding whether filing is required, collecting documents, importing CSVs, receipts, invoices and withholding slips into double-entry journals, income tax, consumption tax (including the 20% special rule and simplified method), furusato nozei, housing-loan and medical deductions, a settlement step and a submission checklist. Separate reading skills extract data from receipts, invoices, payment statements and deduction certificates. The e-tax skill is the largest at 66 KB: it uses browser automation to fill the government's filing site, pauses for the user to authenticate with the My Number card, and states the agent must never click the final send button. A Python CLI, installed with uv from the GitHub repo, does calculations and storage. The README covers tax years 2025 and 2026 and lists unsupported cases such as stock and FX trading, real-estate income and white-form filing. All instructions are in Japanese.
Good for
- Sole proprietors, side-business earners and employees in Japan filing with the blue-form method
- Japanese readers who want an agent to handle bookkeeping and e-Tax entry with a human sending the return
Not for
- Anyone outside Japan or non-Japanese readers
- Stock, FX, real-estate, retirement or non-resident cases, which the README says are unsupported
What's inside depth 3/5
24 skills averaging 12 KB (e-tax 66 KB, income-tax 39 KB) with references in many, but the calculation CLI lives outside the skill files and there are no evals.
- Skills
- 24
- Reference docs
- 68
- Scripts
- 1
- Tests / evals
- 0
- Templates
- 0
- Avg SKILL.md
- 12.1 KB
Counted from the repository file tree. How we score depth.
Dependencies and costs
- Python 3.11+ and uv for the shinkoku CLI
- Browser automation for e-Tax: Claude in Chrome, Antigravity browser sub-agent or Playwright CLI
- A My Number card with a smartphone or IC reader for e-Tax authentication
Security review
Review before installingA Japanese tax-filing plugin: a local Python CLI with a SQLite ledger and a YAML profile (including My Number, address and bank account for refunds), plus skills that read your receipts and statements and drive the NTA e-Tax web form through a browser automation tool. It makes no network calls itself, but the e-tax skill ships a script that spoofs the browser's OS and bot-detection signals on the government site, and it tells the agent to stop before the electronic signature and submit step so you do that yourself.
Worth knowing
- Runs remote code at an unpinned versionThe e-tax skill runs
npx @playwright/mcp@latest --init-script skills/e-tax/scripts/etax-stealth.js, and README installs@playwright/cli@latest, both unpinned.skills/e-tax/scripts/etax-stealth.js:8 - Relies on a CLI or package we could not reviewBrowser automation for e-Tax relies on Playwright CLI/MCP, Claude in Chrome or the Antigravity browser sub-agent, and the CLI needs uv and the PyPI packages pydantic, pdfplumber and pyyaml; none of that code is in the repository.README.md:136
- Installs packages or toolsInstalls @playwright/cli globally with npm, runs
playwright-cli install --skillsandnpx playwright install chromium.README.md:136
What we checked
The repository (208 files) on Oct 29, 2026. Not a full review: we read 12 of 58 code files; it relies on code outside the repository: Playwright CLI / @playwright/mcp (npm) and Claude in Chrome used for e-Tax browser automation; src/shinkoku/tools/*.py, models.py, tax_constants.py, master_accounts.py, duplicate_detection.py, most CLI modules and the tests were searched for network and process use but not read in full.
NVIDIA SkillSpector static scan: 29 pattern hits (Agent Snooping 17, MCP Rug Pull 8, Supply Chain 3, Dangerous Code Execution 1). SkillSpector's 29 hits are 'skill enumeration' notes on CLAUDE.md/plan file paths, unpinned npx playwright/skills mentions in docs, and known-advisory dependency pins (pytest 9.0.2 and lxml 6.0.2 in pyproject) that apply to dev/test environments. The e-tax stealth script was not flagged by the scanner but is described in the flags above.
A review, not a certification. Skills change after we check them — read the files before installing.
License
MIT — commercial use allowed. The README disclaims liability and tells users to verify results or consult a tax accountant.
Can it run unattended?
Not really. The workflow depends on user answers, document uploads and a physical My Number authentication step, and forbids the agent from submitting.
Alternatives to shinkoku (Japanese tax filing)
OpenAccountants
openaccountants/openaccountantsA large open library of tax skills (2,000+ across 250+ jurisdictions) with figures cited to the law, also served through a hosted MCP connector.
With caveats
Broad access Depth 2/5
BrowserAct Skills
browser-act/skillsA browser-automation CLI skill with stealth browsers, CAPTCHA solving and handoff to a human, plus about 100 ready-made scraper skills for shops and lead sources.
With caveats
Broad access Depth 3/5
FAQ
What is shinkoku?
An AI-agent plugin for Japanese tax filing that covers bookkeeping, income tax and consumption tax calculation, and entry of the return into the e-Tax filing site, for sole proprietors and salaried workers.
How do I install shinkoku?
In Claude Code run /plugin marketplace add kazukinagata/shinkoku then /plugin install shinkoku@shinkoku, or install only the skills with npx skills add kazukinagata/shinkoku. The CLI needs Python 3.11+ and uv, and /setup installs it for you.
Does shinkoku submit my tax return automatically?
No. The e-tax skill pauses for your My Number card authentication and says the agent must never press the send button; you submit manually.
Is it safe to give shinkoku my My Number?
It stores it in a local config file that the README says is gitignored, and tells the agent not to log it. Keep the working folder out of any remote repository and review the CLI source, which is not part of the skill files.
Sources: GitHub repository (stars, license, file tree, last push Sep 9, 2026). Review based on the README and SKILL.md files as published.