# OpenVerbs SEO Keyword Variations API

> OpenVerbs SEO Keyword Variations API is a paid API for AI agents from seo.openverbs.com, paid per call via x402, $0.04/call, status unknown (last checked 2026-10-29).

Expands a seed keyword phrase into related keyword variations containing that phrase, each with Google monthly search volume, CPC, competition, keyword difficulty, and search intent.

## Facts

- Endpoint: POST https://seo.openverbs.com/v1/keyword-variations?utm_source=zero.xyz
- Price: $0.04/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openverbs-seo-keyword-variations-api-7ec4d758
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OoYHQSLtvNFH7WqPyzAZ3

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 openverbs-seo-keyword-variations-api-7ec4d758 -d '<json body>'
```

Example prompt: Can you expand 'running shoes' into keyword variations — I want up to 50 results for the US market in English, including each one's monthly search volume, CPC, keyword difficulty, and search intent?

## When to prefer this

Use this endpoint when you need to discover keyword variations that literally contain a specific seed phrase, especially when you want rich per-keyword metrics (volume, CPC, competition, difficulty, intent) in a single call. Prefer this over the Related Keywords endpoint when you specifically want phrase-match expansions rather than semantically related terms. Ideal for building phrase-match ad groups, content clusters around a core topic, or long-tail keyword lists anchored to a specific phrase.

## Known failure modes

- No keyword variations found for the seed phrase returns empty results
- Invalid or unsupported language code returns an error
- Unsupported location code returns an error or empty results
- Seed phrase exceeds 80-character maximum returns a validation error
- Limit parameter outside 1-100 range returns a validation error
- Payment failure or insufficient USDC balance prevents the call from completing

## How this service works

Keyword variations API: expand a seed phrase into keywords containing that phrase, such as 'running shoes' into 'running shoes for women'. Each includes Google monthly search volume, CPC, competition, keyword difficulty and search intent. No matches returns empty results.

## Output

A list of keyword variation strings that each contain the seed phrase, annotated with Google monthly search volume, cost-per-click (CPC), competition level, keyword difficulty score (0-100), and search intent classification. Returns an empty result set if no matching variations are found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer",
   "maximum": 100,
   "minimum": 1,
   "description": "Maximum suggestions to return. Defaults to 20."
  },
  "keyword": {
   "type": "string",
   "maxLength": 80,
   "minLength": 1,
   "description": "Seed phrase; suggestions contain this phrase."
  },
  "languageCode": {
   "type": "string",
   "pattern": "^[A-Za-z]{2}$",
   "description": "Language code (2-letter). Defaults to en."
  },
  "locationCode": {
   "type": "integer",
   "description": "DataForSEO location code. Defaults to 2840 (United States)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/openverbs-seo-keyword-variations-api-7ec4d758/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from seo.openverbs.com](https://www.zero.xyz/host/seo.openverbs.com/llms.txt)