YTJ Lookup bronze

ytj.23signs.org

“Read-only lookup of Finnish companies from PRH YTJ open data. Full Trade Register refreshed daily, with register notices, Vero corporate tax data, LEI group relationships and daily statistics; no authentication, HATEOAS _links in every response. Also an MCP server at /mcp.

a2a https://ytj.23signs.org talk to it https://ytj.23signs.org/.well-known/agent-card.json its card

Checked 4d ago pushNotifications, stateTransitionHistory, streaming

we checked this the operator says this

Community rating 0 0 up · 0 down — sign in to vote

Verified by agenttru.st

Everything here is a check agenttru.st performed itself. Assurance, protocol, hosting and freshness are in the card above and are not repeated.

Certificate: Issued by Google Trust Services domain-validated
Valid until 3 Jan 2027 as of our check on 9 Nov 2026. A wildcard certificate: its other hosts are invisible here, because CT logs the wildcard, not them.

Control of the hostname was checked; nothing about who operates it.

Key ECDSA P-256, signed ECDSA-SHA256, issued via WE1 under GTS Root R4 — classical, as every publicly trusted certificate is today.

Names on this certificate (3)

23signs.org, ytj.23signs.org, *.ytj.23signs.org.
Connection: TLS 1.3 · X25519MLKEM768 — post-quantum hybrid key exchange, agreed with our checker on 9 Nov 2026. What this means
DANE / TLSA: Not verified (TLSA query returned RCodeNameError)
Discovery: Well-known document
This host also publishes an ARD catalog (/.well-known/ai-catalog.json) declaring 4 resources. The catalog's entries are the publisher's claims, not something agenttru.st verified.
AI use policy: Search: yesAI input: yesAI training: yes

What this site's robots.txt says about how AI may use its content. Recorded as the operator wrote it, not enforced — these are preferences about use, not access, and agenttru.st only reads the agent's own discovery documents.
AI-facing documents: Publishes /llms.txt — “YTJ Lookup API” a curated map of the site's content for language models

Fetched from this host during verification. Neither document is how this agent was discovered.
First seen: 5 Oct 2026

View verification details

Assurance: bronze Bronze — agent card fetched over HTTPS with a valid certificate
Protocols: A2A verified by handshake or card fetch, not merely advertised
Hosted in: ? Unknown · Cloudflare, Inc. (AS13335)
The address did not geolocate — usually anycast hosting, where one address answers from many places at once.
Last checked: 4d ago

What this agent says it can do

Declared in the agent's own card. agenttru.st has not tested whether it completes any of these tasks — the operator of ytj.23signs.org controls every word below.

Search Finnish companies

Search by company name (substring) or exact business ID. GET /api/v1/companies?name=|businessId=

finlandcompany-registryytjprhy-tunnus

Examples it gives

what is the business ID of Nokia
find Finnish companies with Elisa in the name

Look up one Finnish company

Fetch one company by exact business ID, with VAT/employer registers, former names, insolvency situations, register notices since 2014, Vero tax by year, LEI group relationships and similar companies. GET /api/v1/companies/{businessId}

finlandcompany-registryytjprhy-tunnus

Examples it gives

look up Finnish company 0112038-9
is Y-tunnus 1463611-4 active

Finnish company statistics

Births and deaths of Finnish companies over time, company forms, industries and their growth, municipalities, age, seasonality. GET /api/v1/stats

finlandstatisticscompany-demographyytjprh

Examples it gives

how many companies were founded in Finland this year
companies per 1000 residents in Tampere

What its catalog declares

From the ARD catalog this host publishes at /.well-known/ai-catalog.json. The operator controls every entry; agenttru.st verified that the catalog exists and parses, and nothing about what the entries say.

YTJ Lookup API

vnd.oai.openapi+yaml

OpenAPI 3.1 description of the five endpoints (four free, one paid batch): search by name or business ID (paged), single lookup by business ID with enrichment, statistics, and dataset status. Plain HTTP GET, JSON responses with HATEOAS _links, RFC 9457 errors.

https://ytj.23signs.org/openapi.yaml

YTJ Lookup skill

ai-skill+md

Agent skill with when-to-use guidance, parameters, response and error shapes, known limitations (toiminimi, daily snapshot) and worked examples.

https://ytj.23signs.org/SKILL.md

YTJ Lookup agent card

a2a-agent-card

A2A agent card: REST interface, no authentication, three read-only skills.

https://ytj.23signs.org/.well-known/agent-card.json

YTJ Lookup tool card

mcp-server-card

MCP server card for the hosted MCP server at /mcp (Streamable HTTP, stateless, no auth): three tools with JSON Schema inputs (search, lookup with enrichment, statistics). The same tools are registered in the browser via WebMCP.

https://ytj.23signs.org/.well-known/mcp/server-card.json

Technical agent card

Copied from the agent's card. The operator controls these values; agenttru.st has not verified them.

Provider: 23signs.org — what this agent says about itself; other agents claiming the same provider are not thereby related
Protocol: a2a
Version: 0.3.0
Card completeness: complete all eight fields required by a2a.proto v1.0

View all card details

Capabilities: pushNotifications stateTransitionHistory streaming
Agent card: https://ytj.23signs.org/.well-known/agent-card.json

Operate this agent and would rather not be listed? Request removal.