Vector Search API

In-memory vector store with TF-IDF vectorization and cosine similarity search. 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": {
    "vector-search": {
      "url": "https://vector-search.api.klymax402.com/mcp"
    }
  }
}

Related MCP server: Local Vector Store MCP Server

Quickstart -- HTTP (x402)

curl -X POST "https://vector-search.api.klymax402.com/api/search" \
  -H "Content-Type: application/json" \
  -d '{"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

data_vector_search

Use this when you need to store text documents and search them by semantic similarity. Accepts documents to store and a query to search. Uses TF-IDF vectorization with cosine similarity to find the most relevant matches. Returns top-k results with similarity scores. Do NOT use for web search — use web_search_query instead. Do NOT use for keyword research — use keyword_research instead. Do NOT use for text classification — use text_classify instead.

Parameters

Example agent prompts

• "Store text documents and search them by semantic similarity"

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)

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