PROTOCOL · LAYER 1 · MCP

MCP is how the model
talks to the wallet.

Model Context Protocol is the lingua franca between LLM agents and external systems. AgentWallet exposes one MCP endpoint per agent — every spend, refund, mandate and inbox capability surfaces as a typed MCP tool. Drop the URL into Claude Desktop, Cursor or your own runtime and the agent can move money in the next turn.

Why MCP

Tool calls, not webhooks.

Typed tools

Each capability has a JSON-Schema input + output. The model knows exactly what to send and what comes back.

Streaming-safe

Long-running tools (a SEPA payout, a multi-sig approval) stream progress events back to the model.

Vendor-neutral

Anthropic, OpenAI, Cursor, Devin, Replit, LangChain — every modern runtime speaks MCP. One URL, every framework.

Tool definition

An AgentWallet MCP tool, fully typed.

{
  "name": "card.charge",
  "description": "Authorize a charge on the agent's virtual card.",
  "inputSchema": {
    "type": "object",
    "required": ["amount_minor", "currency", "merchant", "idempotency_key"],
    "properties": {
      "amount_minor":     { "type": "integer", "minimum": 1 },
      "currency":         { "type": "string",  "pattern": "^[A-Z]{3}$" },
      "merchant":         { "type": "string"  },
      "merchant_mcc":     { "type": "string",  "pattern": "^[0-9]{4}$" },
      "idempotency_key":  { "type": "string"  },
      "mandate_id":       { "type": "string"  }
    }
  },
  "outputSchema": {
    "type": "object",
    "properties": {
      "status":     { "enum": ["authorized","declined","needs_approval"] },
      "trace_id":   { "type": "string" },
      "ledger_row": { "type": "string" },
      "decline_reason": { "type": "string" }
    }
  }
}
Tool-call lifecycle

From prompt to settlement.

01

Tool call

Model emits card.charge with idempotency_key + mandate_id.

02

Policy check

Cap, MCC, geofence, anomaly evaluator runs in <50ms.

03

Mandate verify

Server verifies the AP2 mandate against the principal's WebAuthn key.

04

Settle + trace

Charge authorized; ledger row written; trace ID returned to the model.

Plug your model in.

Free MCP endpoint with every agent.