ISIN Validation
Validates an ISIN (ISO 6166): country code, national identifier and the letter-aware check digit.
POST /v1/finance/isin · 1 credit · deterministic
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/v1/finance/isin
{
"isin": "US0378331005"
}
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Why this exists
Built for hostile input
A Turkish address arrives as "Cd." or "Cad." or "Caddesi", with the flat number glued to the building number. Generic parsers drop half of it silently. This one tells you what it could not place.
Every number carries its provenance
Each archived point stores the source URL and a content hash of the page it came from, and the archive is committed to a Merkle root anchored in Bitcoin. Every commitment — with its cutoff, leaf count and anchors — is published at /proof, so you can check for yourself how current the latest one is. The bulletins themselves are public and anyone can read them; what this adds is that a number you quote can be shown to be the number we held on that date, and that it has not been edited since.
You only pay for work
Repeated inputs come from cache and cost zero credits. If a response ever fails its own schema, the call is refunded automatically.
Endpointsexpand any row to see the parameters and call it live
Validation1
/v1/finance/isin
ISIN Validation
deterministic
1 credit
Validates an ISIN (ISO 6166): country code, national identifier and the letter-aware check digit.
Portfolio imports and corporate-action files fail on a single mistyped ISIN. The check digit is a Luhn variant that first expands letters to two digits (A=10…Z=35), so a swapped letter is caught, not just a swapped digit. XS (international), EU and other reserved prefixes are accepted as country codes even though they are not ISO 3166 territories. A valid ISIN is self-consistent. It is not proof the security exists, is listed, or is the one you meant.
Parameters
| isin* | string | ISIN, 12 characters, e.g. US0378331005. |
/v1/finance/isin
{
"isin": "US0378331005"
}
Press Run to call the live API from your browser.
Pricingone key covers every endpoint
Credits are consumed per call and cache hits are free. Requests without a key run on a narrow per-IP demo quota so you can evaluate before signing up.
The API key is e-mailed the moment payment clears. Upgrades keep the same key, so your integration is never broken.
Want to finish the integration before paying?
Use it from an AI assistantthe same catalogue, exposed as MCP tools
Every endpoint is also published over the Model Context Protocol, so Claude, ChatGPT or your own agent can call it directly — no glue code, no wrapper functions. The assistant sees the same input schemas and the same metering.
Currently 25 tools. New endpoints appear automatically; nothing to update on your side.
claude_desktop_config.json
{
"mcpServers": {
"temsor": {
"url": "https://api.temsor.com/mcp",
"headers": { "x-api-key": "fk_live_…" }
}
}
}
Quickstart
Official client: npm install temsor-api · npmjs.com/package/temsor-api
Node.js
import Client from "temsor-api";
const api = new Client({ apiKey: KEY });
const r = await api.${(() => {
const first = apis[0];
return first.slug.split(/[/-]/).map((p, i) => (i === 0 ? p : p[0].toUpperCase() + p.slice(1))).join('');
})()}(${esc(JSON.stringify(apis[0].examples[0]?.input ?? {}))});
console.log(r, r.$meta);cURL
curl -s https://api.temsor.com/v1/finance/isin \
-H "content-type: application/json" \
-H "x-api-key: fk_live_…" \
-d '{"isin":"US0378331005"}'JavaScript
const res = await fetch("https://api.temsor.com/v1/finance/isin", {
method: "POST",
headers: { "content-type": "application/json", "x-api-key": KEY },
body: JSON.stringify({"isin":"US0378331005"})
});
const { data } = await res.json();Python
import httpx
r = httpx.post("https://api.temsor.com/v1/finance/isin",
headers={"x-api-key": KEY},
json={"isin":"US0378331005"})
data = r.json()["data"]