# SpyFu Keyword Expansions API

> SpyFu Keyword Expansions API is a paid API for AI agents from spyfu.x402.paysponge.com, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Returns related and expanded keyword suggestions for a given seed keyword using SpyFu's keyword database

## Facts

- Endpoint: GET https://spyfu.x402.paysponge.com/apis/keyword_api/v2/related/getKeywordExpansions
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 1
- Tags: x402
- Canonical page: https://www.zero.xyz/c/spyfu-0e77cbba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_N5CWilIzQjrYvqRvombyr

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 spyfu-0e77cbba
```

Example prompt: Can you pull up related keyword expansions for 'project management software' from SpyFu so I can build out my SEO keyword list?

## When to prefer this

Choose this endpoint when you need to expand a seed keyword into a broader set of related search terms for SEO or PPC planning, especially when SpyFu's proprietary keyword database is preferred over generic keyword tools. Ideal for building keyword clusters or discovering long-tail variants.

## Known failure modes

- Missing required keyword parameter returns 400 error
- Empty or unrecognized keyword returns empty results set
- Rate limiting or payment failure returns 402 or 429
- SpyFu database has no data for niche/obscure keywords
- Network timeout from upstream SpyFu API

## How this service works

GET /apis/keyword_api/v2/related/getKeywordExpansions

## Output

A list of related and expanded keywords derived from the seed keyword, likely including search volume, competition data, and semantic variations as returned by SpyFu's keyword expansion database.

## 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
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   },
   "additionalProperties": false
  }
 },
 "additionalProperties": false
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/spyfu-0e77cbba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from spyfu.x402.paysponge.com](https://www.zero.xyz/host/spyfu.x402.paysponge.com/llms.txt)