# Soundex Phonetic Code & Name Comparison

> Soundex Phonetic Code & Name Comparison is a paid API for AI agents from text-similarity.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Computes the American Soundex code for a name and optionally compares two names to determine whether they sound alike.

## Facts

- Endpoint: GET https://text-similarity.x402tookit.com/soundex?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/soundex-phonetic-code-name-comparison-5c58d6da
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UeLOBe7kL3p99zm7oCGjF

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability soundex-phonetic-code-name-comparison-5c58d6da
```

Example prompt: What's the American Soundex code for 'Robertson', and does it match the code for 'Roberson'?

## When to prefer this

Use this endpoint when you need classical American Soundex encoding, especially for genealogical research, historical record linkage, or legacy database phonetic matching that specifically uses the Soundex standard. Prefer it over Metaphone or Jaro-Winkler sibling endpoints when the target system or index is Soundex-based, or when you need the simple variant (H and W treated as separators). Use the optional second-name comparison parameter when you want a direct same-code verdict rather than computing two codes separately.

## Known failure modes

- Name contains no usable letters (all digits or symbols) — returns null code
- Name exceeds 200 characters — request rejected or truncated
- Invalid variant value — falls back to american default or returns error
- Network timeout — no response returned
- Non-ASCII characters present — accents stripped before processing, may alter expected code

## How this service works

American Soundex code of a name (R163 for Robert), with an optional second name to test whether they sound alike.

## Output

Returns the Soundex code string for the input name (e.g. R163 for Robert), the variant used, and — if a second name was provided — the Soundex code of that name, a boolean indicating whether the two codes match, a verdict string, a summary explanation, and a list of reasons supporting the verdict.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "name"
     ],
     "properties": {
      "name": {
       "type": "string",
       "description": "A name or word, up to 200 characters (letters only are used; accents are stripped)"
      },
      "other": {
       "type": "string",
       "description": "Optional second name to compare codes"
      },
      "variant": {
       "enum": [
        "american",
        "simple"
       ],
       "type": "string",
       "description": "american (default; H and W are transparent) or simple (H and W separate like vowels)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "code": {
       "type": [
        "null",
        "string"
       ]
      },
      "name": {
       "type": [
        "null",
        "string"
       ]
      },
      "other": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "letters": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "variant": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "sameCode": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "otherCode": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notC
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/soundex-phonetic-code-name-comparison-5c58d6da/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from text-similarity.x402tookit.com](https://www.zero.xyz/host/text-similarity.x402tookit.com/llms.txt)