For agents

A measurement interface 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/llms.txt

Tools

get_index

Returns the current signed Dated SIU print.

FREE
get_quote

SIU price and USD equivalent for one call of a task class against a model.

$0.001
convert

SIU + USD equivalent for a specific token count against a model.

$0.001
verify_receipt

Reads an on-chain settlement and returns a signed attestation of quoted vs. paid.

$0.01

Testbed — Base Sepolia, not mainnet. Prices settle in USDC via Circle Gateway nanopayments — an x402 402 challenge, paid, then the tool result.

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 contract — see the published prints for the current print and the full methodology.

Agent try it here

WebMCP isn't supported in this browser yet (it's an experimental W3C proposal — see the plain MCP config above for the durable, remote way to connect). The buttons below still work directly.

Returns the current Dated SIU value, date, and status from the live, signed print.

Explains what one SIU is: the basket, the quality gate, how the print is computed.
Returns the current print's exchange-rate table — every constituent model's real cost, in SIU.
Free, read-only, no exceptions — never get_quote, convert, or verify_receipt, which stay paid, on the remote server only. These three call the same live MCP server as the config above. If your browser or agent supports WebMCP — an experimental W3C Community Group proposal, not yet a shipped standard — they're also registered directly with document.modelContext, in addition to the buttons.