Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/jokull/icelandic-datanpx agentmods add skills/jokull/icelandic-data/skatturinnWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/jokull/icelandic-data/skatturinn)<a href="https://agentmods.dev/skills/jokull/icelandic-data/skatturinn"><img src="https://agentmods.dev/badge/skills/jokull/icelandic-data/skatturinn/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/jokull/icelandic-data/skatturinn"><img src="https://agentmods.dev/badge/skills/jokull/icelandic-data/skatturinn.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 24 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00027 | $0.03269 |
| Opus 5 | $0.00014 | $0.01635 |
| Sonnet 5 | $0.00005 | $0.00654 |
| Haiku 4.5 | $0.00003 | $0.00327 |
Grade A, and why
skatturinn scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 355 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skatturinn (Iceland Tax Authority)
Company registry and annual reports (ársreikningar) from the Icelandic tax authority.
Overview
Skatturinn operates the Company Registry (Fyrirtækjaskrá) and Annual Reports Registry (Ársreikningaskrá). Annual reports are free of charge since January 1, 2021. Downloading goes through a server-side shopping cart, but no browser is required — the cart is cookie/viewstate state that httpx handles directly. See "Access Method" below.
Use case: Map company ownership chains by extracting beneficial owners from annual reports, then recursively looking up parent company reports.
URLs
| Resource | URL Pattern |
|---|---|
| Company lookup | https://www.skatturinn.is/fyrirtaekjaskra/leit/kennitala/{kennitala} |
| Search by name | https://www.skatturinn.is/fyrirtaekjaskra/leit?nafn={company_name} |
| Search page | https://www.skatturinn.is/fyrirtaekjaskra/leit |
| Annual reports info | https://www.skatturinn.is/fyrirtaekjaskra/arsreikningaskra/ |
| API Portal | https://api.skatturinn.is/ (requires registration, limited endpoints) |
Finding a Company's Kennitala
To find a company's kennitala by name, use WebFetch on the search URL:
https://www.skatturinn.is/fyrirtaekjaskra/leit?nafn={company_name}
Example: ?nafn=dansport returns the company page with kennitala 4807032350.
This is more reliable than Google searches. The page shows matching companies with their kennitala prominently displayed.
Data Available
Company Lookup Page
Each company page at /fyrirtaekjaskra/leit/kennitala/{kt} shows:
- Basic info: Name, kennitala, address, registration date, legal form
- Management: Directors, beneficial owners with ownership percentages
- Beneficial owners (Raunverulegir eigendur): Name, birth year/month, % and holding type (Beint/Óbeint). Beneficial owners are by definition natural persons — the page shows no kennitala for them, only birth year/month. Listed companies (kauphallarfélög) render no owner block at all.
- Shareholders (Hluthafar): Section on some pages; may carry kennitalas
- Activity: ÍSAT codes (business classification)
- Annual reports table: List of submitted reports with:
- Operating year (Rek. ár)
- Submission date (Skiladagsetning)
- Report number (Nr. ársreiknings)
- Report type (Tegund ársreiknings)
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 355 lines · 27 tokens per session scan A 15ee0ba2ae31
skatturinn is a skill published in the GitHub repository jokull/icelandic-data (52 stars, last pushed yesterday), licensed MIT. It adds 27 tokens to every session and 3,269 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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