Marketplace · API · x402

api.form5500data.com/search

Find U.S. retirement plans (401(k), 403(b), pension and others) in public DOL Form 5500 filings, plan years 2021 onward, for prospecting, benchmarking and research: by company name (fuzzy, including former and DBA names), EIN, state, assets, participants, recordkeeper (any brand, matched to today's firm) or plan type. Each result: EIN and plan number, plan and sponsor name, assets, participants, current recordkeeper. Small plans (about 9 in 10) file no Schedule C, so no recordkeeper.

Use it

Call it (an x402 client pays automatically)

curl -i https://api.form5500data.com/search
# 402 reply -> sign PAYMENT-REQUIRED with an x402 client (e.g. @x402/fetch) -> retry with PAYMENT-SIGNATURE

This listing as JSON

curl https://aipaygen.com/v1/catalog/api/x402-5a183ac5d0e00c82

Search the whole marketplace from your agent (MCP)

{
  "mcpServers": {
    "aipaygen": {
      "url": "https://aipaygen.com/mcp"
    }
  }
}