# Stack Facts BCP47 Language Tag Lookup

> Stack Facts BCP47 Language Tag Lookup is a paid API for AI agents from g5joilnmeep4ntz3nwezxt5dmu.srv.us, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-17).

Looks up a BCP47 language tag in the IANA Language Subtag Registry, returning registration status and subtag breakdown, signed and paid per-call in USDC.

## Facts

- Endpoint: GET https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/v1/bcp47/%7Btag%7D?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stack-facts-bcp47-language-tag-lookup-46862165
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z0yJsANAIef0g-_z0lekb

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stack-facts-bcp47-language-tag-lookup-46862165
```

Example prompt: Is 'en-AU' a valid, registered BCP47 language tag? Look it up in the IANA Language Subtag Registry and tell me its subtag breakdown and registration status.

## When to prefer this

Choose this endpoint when you need authoritative, machine-verifiable BCP47 language tag validation sourced directly from the IANA Language Subtag Registry, with no API key or account setup required. Ideal for agents that need to validate or resolve locale strings on-demand at low cost ($0.002 USDC per call) with signed, trustworthy responses. Prefer this over ad-hoc regex validation or unofficial locale lists when correctness and auditability matter.

## Known failure modes

- Unknown or malformed tag returns found:false for one or more subtags
- Stale registry data indicated by meta.stale:true if the dataset hasn't been refreshed
- Payment not sent or insufficient USDC results in HTTP 402 before data is returned
- Invalid tag format (not conforming to BCP47 syntax) may return an error or empty subtag records
- Network timeout on the upstream IANA data source

## How this service works

Check a package before install: malware, known vulnerabilities (OSV), exploited CVEs (CISA KEV) and end-of-life, plus LLM prices; signed answers, pay per call in USDC, no account or API key.

## Output

Returns a JSON object with: the queried tag string, a list of subtag objects each with a 'found' flag and associated IANA records, a top-level 'registered' boolean, and a 'meta' block containing the registry version date, staleness flag, source URL, dataset name, and retrieval timestamp. Responses are signed and sourced directly from the IANA Language Subtag Registry.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "tag": "en-au",
   "parts": [
    {
     "found": true,
     "subtag": "en",
     "records": [
      {}
     ]
    }
   ],
   "registered": true
  },
  "meta": {
   "date": "2026-09-17",
   "stale": false,
   "notice": "IANA Language Subtag Registry, …",
   "source": "https://www.iana.org/assignment…",
   "dataset": "bcp47",
   "version": "2026-09-17",
   "attribution": "IANA Language Subtag Registry, …",
   "retrieved_at": "2026-10-14T20:53:46.534Z"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stack-facts-bcp47-language-tag-lookup-46862165/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from g5joilnmeep4ntz3nwezxt5dmu.srv.us](https://www.zero.xyz/host/g5joilnmeep4ntz3nwezxt5dmu.srv.us/llms.txt)