# Synapse Dictionary & Thesaurus API

> Synapse Dictionary & Thesaurus API is a paid API for AI agents from anibalb.duckdns.org, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Returns synonyms, related words, and thesaurus results for a given query word or phrase via a pay-per-call API using USDC on Base.

## Facts

- Endpoint: GET https://anibalb.duckdns.org/x402/dictionary-thesaurus?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-dictionary-thesaurus-api-3308f224
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-lVw0FhjCDYM3FbP1Qwwg

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 synapse-dictionary-thesaurus-api-3308f224
```

Example prompt: Can you look up words that mean something similar to 'blockchain' and give me a ranked list of related terms?

## When to prefer this

Choose this endpoint when you need fast, pay-per-call thesaurus or synonym lookups without account registration or API keys. It is ideal for agents that need occasional vocabulary enrichment, synonym expansion, or word similarity scoring without committing to a subscription. Prefer this over traditional thesaurus APIs when operating in a crypto-native, x402-payment environment on Base.

## Known failure modes

- Missing required 'word' or query parameter returns an error or empty results
- Invalid operation type may return unexpected results
- Network or DNS issues with duckdns.org dynamic host could cause timeouts
- Payment failure (insufficient USDC balance) results in HTTP 402 response
- Very obscure or misspelled words may return empty results array

## How this service works

Public data and utility APIs paid per call in USDC on Base (x402). No accounts, no API keys. 174 routes: crypto/equity data, onchain reads, DNS/email/security intel, geo/weather, x402 payment diagnostics, dev utilities and more.

## Output

Returns a JSON array of word objects, each containing a 'word' field (the related term) and a 'score' field (numeric relevance/similarity score). Results are ranked by score descending. The response also echoes the operation type ('op') and original query.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "op": "ml",
  "query": "blockchain",
  "results": [
   {
    "word": "disdain",
    "score": 105035
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-dictionary-thesaurus-api-3308f224/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from anibalb.duckdns.org](https://www.zero.xyz/host/anibalb.duckdns.org/llms.txt)