# Bech32 validate

`bech32-validate` · version 1.0.0 · Encoding & checksums · free, no key needed

Check Bech32 or Bech32m text and return a reason, without throwing when the checksum fails.

**Use when you need to: check whether bech32 text has a valid checksum · check whether bech32m text has a valid checksum · report a reason when bech32 text is rejected.**

## Decide before calling

Read the [versioned contract](/v1/tools/bech32-validate/versions/1.0.0) and the supported scope below. Reuse `bech32-validate@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 `bech32-validate@1.0.0` for check whether bech32 text has a valid checksum. 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

- check whether bech32 text has a valid checksum
- check whether bech32m text has a valid checksum
- report a reason when bech32 text is rejected
- detect mixed case without decoding symbols
- bech32 validation of separator and hrp
- bech32m validation of the 2bc830a3 constant
- say if a checksummed string is empty or too short
- validate bech32 text and keep going on a bad checksum

## Not supported

- return the 5-bit symbol array
- repair an invalid checksum
- decide bech32 versus bech32m from a witness version
- convert between 8-bit bytes and 5-bit symbols

## Behavior

- Well-typed text that fails the format returns {valid:false, reason}. It throws only for a non-object, unknown or missing fields, a non-string, NaN, Infinity, a lone surrogate, or more than 90 characters.
- reason is ok, empty, mixed_case, no_separator, empty_hrp, hrp_character, data_character, short_checksum, or bad_checksum. Checks run in that order after the length limit.
- A valid string reports the lowercase HRP, data_length (checksum excluded), and variant. Polymod residue 1 is bech32 (BIP 173). Residue 0x2bc830a3 is bech32m (BIP 350).
- All-uppercase is allowed and is not mixed case. An uppercase HRP whose checksum was computed without lowercasing fails as bad_checksum, matching BIP 173 vector A1G7SGD8.
- Segwit program length, witness version, and padding of the converted program are not checked.
- Disclaimer: format transform only; provides no confidentiality, integrity, or authenticity.

## Input

- `text` (string, required): min length 0; max length 90

## Output

- `valid` (boolean, required)
- `reason` (one of "ok", "empty", "mixed_case", "no_separator", "empty_hrp", "hrp_character", "data_character", "short_checksum", "bad_checksum", required)
- `variant` (one of "bech32", "bech32m", null, required)
- `hrp` (string, required): min length 0; max length 83; pattern `^[\x21-\x40\x5b-\x7e]*$`
- `data_length` (integer, required): min 0; max 82

## Limits

- max text chars: 90

## Example

Request input:

```json
{
  "text": "a12uel5l"
}
```

Response:

```json
{
  "result": {
    "valid": true,
    "reason": "ok",
    "variant": "bech32",
    "hrp": "a",
    "data_length": 0
  }
}
```

## How to call it

### MCP

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

```json
{
  "id": "bech32-validate",
  "version": "1.0.0",
  "input": {
    "text": "a12uel5l"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/bech32-validate/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"text":"a12uel5l"}'
```

The machine-readable contract is at [/v1/tools/bech32-validate/versions/1.0.0](/v1/tools/bech32-validate/versions/1.0.0).

### CLI

```sh
node cli.mjs run bech32-validate 1.0.0 --input input.json --base-url https://computefirst.net
```

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

## Related tools

- [Bech32 decode](/tools/bech32-decode): Decode Bech32 or Bech32m text into a lowercase HRP, 5-bit data, and the checksum variant.
- [Bech32 encode](/tools/bech32-encode): Encode lowercase HRP and 5-bit data as Bech32 or Bech32m text using that checksum.
- [Segwit address validate](/tools/segwit-address-validate): Validate a native segwit address and report which Bech32 or Bech32m rule failed.
- [Bech32 convert bits](/tools/bech32-convert-bits): Regroup integers between bit widths using BIP 173 rules, rejecting bad leftover padding.
- [Pem envelope validate](/tools/pem-envelope-validate): Check one RFC 7468 PEM envelope for labels, whitespace, and strict base64.
- [Ct merkle root compute](/tools/ct-merkle-root-compute): Compute the RFC 6962 v1 domain-separated Merkle Tree Hash of raw leaves.