Your agent licenses the script. And calls it. On its own.

step 0 · install

Add the server

One entry in your MCP client's config. The server runs locally, holds no keys of its own, and signs with the wallet you point it at — the same wallet that will hold the licences it buys.

{
  "mcpServers": {
    "loxley": {
      "command": "npx",
      "args": ["-y", "@loxleymarkets/mcp"],
      "env": {
        "LOXLEY_CHAIN": "robinhood-4663",
        "LOXLEY_WALLET": "${LOXLEY_WALLET_PRIVATE_KEY}"
      }
    }
  }
}

the loop

Discover, license, call

Three tools, in the order an agent uses them. Each one is a normal MCP tool call; nothing here needs a browser, a form, or you.

1. 1

   Discover

   The agent searches the shelf the way a buyer would — by what the script does, what it scores, and what it costs. Every field it filters on is computed from the onchain record, so there is nothing here for a publisher to inflate.

   loxley_search

   live · simulated datacopy

   // the agent asks the shelf a question
   {
     "tool": "loxley_search",
     "arguments": {
       "class": "POLICY",
       "min_score": 1.4,
       "max_price_usd": 100,
       "limit": 3
     }
   }
   
   // → what comes back
   {
     "results": [
       {
         "id": "lox:0xd0e5",
         "name": "DrawdownSentry",
         "summary": "Blocks the orders that would deepen a drawdown past your limit.",
         "score": 1.76,
         "dsr": 0.99,
         "price_usd": 79,
         "owners": 3100,
         "licensed": false
       }
     ]
   }

2. 2

   License

   One call, one price, once. The agent sets its own ceiling; the server refuses anything above it. The licence is an ERC-1155 that lands in the wallet and stays there — there is no renewal to miss and no subscription to cancel.

   loxley_license

   live · simulatedcopy

   // one price, once, with a ceiling the agent sets itself
   {
     "tool": "loxley_license",
     "arguments": {
       "artifact": "lox:0xd0e5",
       "max_price_usd": 100
     }
   }
   
   // → the licence is in the wallet, and stays there
   {
     "licence": "erc1155:0x8f21…/17",
     "paid_usd": 79,
     "tx": "0x4c1a…",
     "renews": false,
     "callable": true
   }

3. 3

   Call

   From here the script is a tool like any other in the agent's belt. The licence is checked onchain, the run is attested, and the attestation comes back with the answer so the agent can prove what it called and what it got.

   loxley_call

   live · simulatedcopy

   // the script is now just another tool in the belt
   {
     "tool": "loxley_call",
     "arguments": {
       "artifact": "lox:0xd0e5",
       "input": { "order": { "…": "…" }, "portfolio": { "…": "…" } }
     }
   }
   
   // → verdict, reason, attestation, and a bill of zero
   {
     "verdict": "resize",
     "output": { "qty": 150, "reason": "drawdown 6.4% against an 8.0% limit" },
     "attestation": { "run_hash": "0x9f31…", "epoch": 47 },
     "billing": { "model": "one_time_licence", "charged_usd": 0 }
   }

the wire

What a call looks like, and what comes back

One example, end to end: an agent about to send an order asks DrawdownSentry whether it may. The response carries the verdict, the reason in words the agent can log, the attestation that proves the declared code ran — and a billing block that reads zero, because the licence was already paid for once.

{
  "tool": "loxley_call",
  "arguments": {
    "artifact": "lox:0xd0e5",
    "input": {
      "order": {
        "symbol": "AAPL",
        "side": "buy",
        "qty": 400,
        "limit_usd": 228.10
      },
      "portfolio": {
        "nav_usd": 250000,
        "drawdown_pct": 6.4,
        "drawdown_limit_pct": 8.0
      }
    }
  }
}

{
  "verdict": "resize",
  "output": {
    "qty": 150,
    "reason": "drawdown 6.4% against an 8.0% limit; size cut to keep the floor intact"
  },
  "attestation": {
    "code_hash": "keccak256(wasm_module)",
    "run_hash": "0x9f31…",
    "runtime": "wasm-1.2",
    "epoch": 47,
    "latency_ms": 12
  },
  "billing": {
    "model": "one_time_licence",
    "charged_usd": 0
  }
}

Two fields are worth stopping on. `attestation.run_hash` is what makes a challenge possible: anyone can replay the module against the same input and slash the publisher's bond if the hash differs. `billing.charged_usd` is zero on every call after the first purchase — that is the whole point of a one-time licence, stated where an agent can assert on it.

what you need

Before it can buy anything

A wallet on chain 4663

Robinhood Chain, an Arbitrum L2. The server signs with it; you fund it. Nothing else on this site touches it.

USDC for the licences

Prices are quoted in dollars and settled in USDC. A script costs its tag price once — budget for the shelf, not for a meter.

An MCP client

Claude Code, Claude Desktop, Cursor, or your own agent loop over the MCP SDK. The server is a stdio process; it needs no inbound network.

A spend ceiling

Set max_price_usd on every licence call and the server will refuse anything dearer, so an agent left running cannot spend the wallet on a shelf full of scripts.