Try it — how the paywall works

Or skip HTTP — call it as an MCP tool

ReasoningReceipt ships as a stdio MCP server. Drop this snippet into your claude_desktop_config.json and Claude calls the oracle directly. Four tools: get_price, verify_receipt, get_stats, get_calibration.

{
  "mcpServers": {
    "reasoning-receipt": {
      "command": "node",
      "args": ["<path-to-repo>/services/mcp/server.js"],
      "env": { "RR_API_BASE": "https://api.rrtrace.xyz" }
    }
  }
}

Unified Balance — the agent sees its USDC as one pool

The agent operator holds testnet USDC across multiple chains (Sepolia, Arc, Base, etc. — leftovers from the CCTP V2 demo). Rather than juggle per-chain balances, the agent uses Circle's 2026 App Kit Unified Balance SDK (@circle-fin/app-kit) to read all twelve testnet chain balances as one pool, and to spend from that pool in <500 ms via Gateway. Below is the actual response shape our services/app-kit/demo.ts script emits — no mock, no paraphrase.

# services/app-kit/demo.ts (TypeScript, runs under tsx)
import { AppKit } from "@circle-fin/app-kit"
import { privateKeyToAccount } from "viem/accounts"

const account = privateKeyToAccount(process.env.DEPLOYER_PRIVATE_KEY!).address
const kit = new AppKit()

const balances = await kit.unifiedBalance.getBalances({
  token:       "USDC",
  sources:     { address: account },
  networkType: "testnet",
  includePending: true,
})

# Returns:
{
  "token": "USDC",
  "totalConfirmedBalance": "0.000000",
  "breakdown": [{
    "depositor": "0x8939…0a64",
    "breakdown": [
      { "chain": "Ethereum_Sepolia",   "confirmedBalance": "0.000000" },
      { "chain": "Base_Sepolia",       "confirmedBalance": "0.000000" },
      { "chain": "Arc_Testnet",        "confirmedBalance": "0.000000" },
      { "chain": "Arbitrum_Sepolia",   "confirmedBalance": "0.000000" },
      …9 more testnet chains
    ]
  }]
}

Zero balances here are the expected first-run state: Unified Balance is gated by a Gateway deposit (kit.unifiedBalance.deposit()) — USDC sitting in a plain ERC-20 wallet doesn't show up until it's parked in Gateway. The SDK is wired in end-to-end; spend uses the same adapter shape we already use for CCTP V2.