Touchstone Assay — For agents

For agents

Touchstone Assay's four MCP tools, live on Base Sepolia — a testbed, not traction. get_index is free; the other three settle in USDC over x402 via Circle Gateway.

MCP config

Streamable HTTP. Paste this into a client that supports remote MCP servers.

{
  "mcpServers": {
    "touchstone-assay": {
      "url": "https://mcp.touchstoneassay.com/mcp"
    }
  }
}

Machine-readable: https://touchstoneassay.com/mcp.json · https://touchstoneassay.com/.well-known/llms.txt

Tools

Tool	Arguments	Price
`get_index`	`version?, date?`	free
`get_quote`	`task_class, model`	$0.001
`convert`	`model, input_tokens, output_tokens`	$0.001
`verify_receipt`	`chain, tx_hash`	$0.01

Prices settle in USDC on Base Sepolia (eip155:84532) via Circle Gateway nanopayments — an x402 402 challenge, paid, then the tool result. See docs/datum-quote.md for the full settlement shape.

What this is, plainly

A measurement standard and data publication — never "backed by," never a peg, never an oracle, nothing for sale. verify_receipt's on-chain read is live, reading the real deployed TouchstoneEscrow — see the Series page for the current print and the full methodology.