Anvil › Docs › /v1/uuid

UUID generator API: random v4 and time-ordered v7 UUIDs

A UUID is a 128-bit identifier written as 36 characters, like 019a4b1e-7c2f-7d10-9f3a-2b6c1e8d4a51. You can create one anywhere without asking a central database, and the chance of two ever clashing is so small it can be ignored. This endpoint hands you fresh ones in either of the two versions people actually use today.

Parameters

Example

Request:

GET https://api.oddlathe.com/v1/uuid?version=7&count=3

Response (generated by the real code when these docs were last built; random or time-based values will differ for you):

{
 "version": 7,
 "uuids": [
  "01a1cd58-085e-7232-bab6-22485c6d7a39",
  "01a1cd58-085e-7c2e-985d-fb5f1d45e599",
  "01a1cd58-085e-784d-b344-0d1678bbe3ad"
 ]
}

Code examples

curl 'https://api.oddlathe.com/v1/uuid?version=7&count=3'

const params = new URLSearchParams({
  version: "7",
  count: "3"
});
const res = await fetch(`https://api.oddlathe.com/v1/uuid?${params}`);
if (!res.ok) throw new Error((await res.json()).error.message);
const data = await res.json();
console.log(data);

import json, urllib.parse, urllib.request

params = urllib.parse.urlencode({"version": "7", "count": "3"})
url = "https://api.oddlathe.com/v1/uuid?" + params
# Send a User-Agent: the edge network refuses Python's default one.
req = urllib.request.Request(url, headers={"User-Agent": "my-script/1.0"})
with urllib.request.urlopen(req, timeout=10) as r:
    data = json.load(r)
print(data)

When it's useful

• Primary keys for database rows created by many machines at once
• Idempotency keys for payment or webhook retries
• Test fixtures and seed data in a shell script or spreadsheet
• Correlation IDs that follow one request through several services

Good to know

• Version 4 is 122 random bits. It reveals nothing, which is good for public IDs, but the values are scattered, so B-tree indexes split pages and grow faster.
• Version 7 (RFC 9562) starts with a 48-bit Unix timestamp in milliseconds, then random bits. New IDs sort after old ones, so inserts stay at the end of the index. The trade-off: anyone holding the ID can read roughly when it was made.
• Both versions use the operating system's cryptographic random source. Responses are marked no-store so no cache hands the same ID to two callers.

v7 UUIDs put a millisecond timestamp in the first 48 bits, so they sort by creation time and index well in databases. v4 is 122 random bits.

Errors

Errors are JSON like {"error": {"code": "…", "message": "…"}}. The ones this endpoint can return:

• bad_param (400): a value is the wrong type or out of range (the message says which)
• rate_limited (429): over 60 requests a minute; wait for Retry-After seconds

Questions

Related endpoints

• /v1/ulidULIDs: sortable, 26-character IDs
• /v1/nanoidShort URL-safe random IDs (21 chars, 126 bits)

Prefer a page to an API?

• UUID & password generator (in your browser) on Tooltern: same job, nothing leaves your browser.

Published 3 November 2026 · OpenAPI 3.1 spec · Limits and privacy