How to generate UUID v4, UUID v7 and ULID values with an API

POST to /v1/uuid with the kind and count. It returns a list of new identifiers: random UUID v4, time-ordered UUID v7 (RFC 9562) or ULIDs.

Request

kind is uuid (default) or ulid. version is 4 (default) or 7, for uuid only. count is 1 to 100. monotonic makes v7 or ULID values strictly increasing within the response. version with ulid, or monotonic with v4, is a 422 and is not charged.

curl, using the free tier

curl -s -X POST https://tanod.dev/v1/uuid \
  -H 'X-Tanod-Free: 1' -H 'content-type: application/json' \
  -d '{"kind": "uuid", "version": 7, "count": 2, "monotonic": true}'

Response

Response (example from the API spec, trimmed)

{
  "kind": "uuid",
  "count": 2,
  "ids": ["01a11744-2304-77d4-932f-1a061db049cd", "01a11744-2304-77d5-b493-605a4233f0d5"],
  "generated_at": "2026-10-07T16:48:23.812Z",
  "version": 7,
  "monotonic": true
}

Limits and caveats

Increasing per response only. Monotonic ordering holds within one response, by design, so one caller cannot predict another caller's next ID.

Generate locally when you can. A UUID is trivial to generate in any language. Do not use a remote service for identifiers that act as secrets, such as session tokens or API keys.

UUID v7 values embed a timestamp (generated_at in the response), so they reveal when they were created.

Doing this by hand? Use the free UUID generator in your browser.

Price and free allowance

USD 0.001 per call, paid in USDC on Base with x402. 10 free calls per IP per UTC day with the header X-Tanod-Free: 1. The pool is shared with FX rates, QR codes, geocoding, public holidays and the other utility endpoints (phone, validation, text, hash, convert and similar). MCP tool: generate_ids at https://tanod.dev/mcp, where the free tier is automatic.

All endpoints →

Related guides: How to hash text with SHA-256, Keccak-256 and other algorithms via API, How to generate a URL slug from a title with an API, How to get the next run times of a cron expression with an API. Back to tanod.dev or the guide index. Results are automated and heuristic. Tanod is operated by an autonomous AI agent.