# Uuid format

`uuid-format` · version 1.0.0 · Identifiers & check digits · free, no key needed

Format exactly 16 octets as an RFC 9562 UUID string.

**Use when you need to: format uuid bytes · encode 16 octets as uuid · render uppercase braced uuid.**

## Decide before calling

Read the [versioned contract](/v1/tools/uuid-format/versions/1.0.0) and the supported scope below. Reuse `uuid-format@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation.

## Explain the choice

"I can use `uuid-format@1.0.0` for format uuid bytes. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

## Supported

- format uuid bytes
- encode 16 octets as uuid
- render uppercase braced uuid
- uuid text from 16 bytes
- network order octets to uuid text
- format uuid with braces

## Not supported

- parsing UUID text
- UUID generation

## Behavior

- Bytes remain in network order; no integer or host-endian reinterpretation occurs.
- uppercase and braces independently default to false; output ordering is fixed.
- Disclaimer: format transform only; provides no confidentiality, integrity, or authenticity.

## Input

- `bytes` (array of integer, required): min items 16; max items 16; each min 0; each max 255
- `uppercase` (boolean, optional): default `false`
- `braces` (boolean, optional): default `false`

## Output

- `uuid` (string, required): min length 36; max length 38

## Limits

- byte count: 16

## Example

Request input:

```json
{
  "bytes": [
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0,
    0
  ]
}
```

Response:

```json
{
  "result": {
    "uuid": "00000000-0000-0000-0000-000000000000"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "uuid-format",
  "version": "1.0.0",
  "input": {
    "bytes": [
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0
    ]
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/uuid-format/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"bytes":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}'
```

The machine-readable contract is at [/v1/tools/uuid-format/versions/1.0.0](/v1/tools/uuid-format/versions/1.0.0).

### CLI

```sh
node cli.mjs run uuid-format 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

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- [Ulid format](/tools/ulid-format): Format an explicit 48-bit timestamp and ten random bytes as one canonical uppercase ULID.
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- [Eu vat id validate](/tools/eu-vat-id-validate): Detect the country from an EU/XI VAT id prefix and validate its format and, where defined, national checksum.
- [Iban compute from bban](/tools/iban-compute-from-bban): Compute the MOD 97-10 check digits and full IBAN for a country code and BBAN, using the pinned IBAN registry.