Keyword Research API

SEO keyword research -- Google Suggest, intent classification, long-tail discovery, related queries. Content planning. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "keyword-research": {
      "url": "https://keyword-research.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl "https://keyword-research.api.klymax402.com/api/keywords?query=..."
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

Tool	Method	Path	Price	Description
seo_research_keywords	GET	/api/keywords	$0.02	Research keywords with Google autocomplete suggestions, related queries, and intent classification
seo_research_keywords	POST	/api/keywords	$0.02	Research keywords with Google autocomplete suggestions, related queries, and intent classification (POST variant)

seo_research_keywords

Use this when you need keyword ideas, SEO research, or content planning data for a topic. Returns keyword suggestions and intent data in JSON.

Parameters

Name	Type	Required	Description
query	string	yes	The seed keyword or phrase to research (e.g. 'bitcoin trading', 'best crm software')

Example response:

{"query":"bitcoin trading","suggestions":["bitcoin trading platform","bitcoin trading bot","bitcoin trading for beginners"],"relatedQueries":{"vs":["bitcoin trading vs investing"],"howTo":["how to start bitcoin trading"]},"longTailKeywords":["best bitcoin trading app 2026","bitcoin trading strategy for beginners"],"searchIntent":"commercial","totalKeywords":47}

When to use: writing blog posts, FOR SEO content strategy, topic cluster planning, content gap analysis, and competitive keyword research.

Not for: page SEO audit (use seo_audit_page), content extraction (use web_scrape_to_markdown), domain intelligence (use domain_lookup_intelligence).

seo_research_keywords

Use this when you need keyword ideas, SEO research, or content planning data for a topic. Returns keyword suggestions and intent data in JSON. POST variant of seo_research_keywords -- same params passed as JSON body instead of query string.

Parameters

Name	Type	Required	Description
query	string	yes	The seed keyword or phrase to research (e.g. 'bitcoin trading', 'best crm software')

Example response:

{"query":"bitcoin trading","suggestions":["bitcoin trading platform","bitcoin trading bot","bitcoin trading for beginners"],"relatedQueries":{"vs":["bitcoin trading vs investing"],"howTo":["how to start bitcoin trading"]},"longTailKeywords":["best bitcoin trading app 2026","bitcoin trading strategy for beginners"],"searchIntent":"commercial","totalKeywords":47}

When to use: writing blog posts, FOR SEO content strategy, topic cluster planning, content gap analysis, and competitive keyword research.

Not for: page SEO audit (use seo_audit_page), content extraction (use web_scrape_to_markdown), domain intelligence (use domain_lookup_intelligence).

Example agent prompts

• "Keyword ideas, SEO research, or content planning data for a topic"
• "Keyword ideas, SEO research, or content planning data for a topic"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
• Network: Base L2 (eip155:8453)
• Asset: USDC
• Facilitator: Coinbase CDP (primary), PayAI (fallback)
• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt
• Full API reference: https://klymax402.com/llms-full.txt
• Live stats: https://klymax402.com/stats

License

MIT