# 2s.io Related Word Lookup

> 2s.io Related Word Lookup is a paid API for AI agents from 2s.io, paid per call via x402, $0.0012/call, status unknown (last checked 2026-09-14).

Returns ranked related words for a seed word given a specified linguistic relation (rhymes, synonyms, antonyms, homophones, etc.) with relevance scores and grammatical tags.

## Facts

- Endpoint: GET https://2s.io/api/word/related
- Price: $0.0012/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/2s-io-a78b8982
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4RfMtgfMHT0IG15DcUCT3

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 2s-io-a78b8982
```

Example prompt: Can you find me the top 10 words that rhyme with 'moon'? I need ranked candidates with their syllable counts for a poem I'm writing.

## When to prefer this

Use this endpoint when you need linguistically structured word relationships (rhymes, synonyms, antonyms, homophones, phonetic neighbors, collocations) with ranked scores and syllable metadata — ideal for poetry generation, naming tasks, vocabulary expansion, or autocomplete suggestions. Prefer over generic LLM word suggestions when you need scored, canonically ranked candidates backed by a lexical database.

## Known failure modes

- Missing required 'word' parameter returns validation error
- Missing required 'relation' parameter returns validation error
- Invalid 'relation' enum value returns error
- No matching words found returns empty result list
- Limit out of range (0 or >100) returns validation error
- Payment failure (x402) returns 402 with payment details

## How this service works

Related-word lookup via Datamuse. Supply a seed word and a relation kind: rhymes, near-rhymes, synonyms, antonyms, means (semantic match), triggers (associated by usage), homophones, sounds-like (phonetic neighbour), spelled-like (typo / wildcard), follows-from (words that come after), preceded-by (words that come before). Returns ranked candidates with relevance score, syllable count, and grammatical tags. Useful for content generation, rhyme/poetry, vocabulary expansion, and naming agents.

## Output

A ranked list of candidate words matching the specified relation to the seed word, each with a relevance score, syllable count, and grammatical part-of-speech tags. Results are sorted by relevance descending, up to the requested limit (default 25, max 100).

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "word": "moon",
   "limit": 10,
   "relation": "rhymes"
  }
 }
}
```

## 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",
    "queryParams"
   ],
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "const": "GET"
    },
    "queryParams": {
     "required": [
      "word",
      "relation"
     ],
     "properties": {
      "word": {
       "type": "string"
      },
      "limit": {
       "type": "integer",
       "default": 25,
       "maximum": 100,
       "minimum": 1
      },
      "relation": {
       "enum": [
        "rhymes",
        "near-rhymes",
        "synonyms",
        "antonyms",
        "means",
        "triggers",
        "homophones",
        "sounds-like",
        "spelled-like",
        "follows-from",
        "preceded-by"
       ],
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/2s-io-a78b8982/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)