Yault AESP MCP server

AESP - Agent Economic Sovereignty Protocol

Defining how AI agents operate economically under human sovereignty.

Website | npm

What Is AESP

AESP is a TypeScript SDK and MCP integration layer for agent payments under explicit human control. It is designed so that agents can execute economic actions while humans retain full economic sovereignty.

Core principles:

• Policy-gated execution -- every spend action is bounded by configurable policy rules (per-tx limits, daily/weekly/monthly budgets, address allowlists, time windows).
• Human override path -- risky actions are escalated to a review queue instead of being auto-approved.
• Verifiable commitments -- execution context can be tied to EIP-712 signed intent, enabling on-chain settlement guarantees.
• Practical integration -- MCP tools expose vault operations to AI agent frameworks; subpath exports let you import only what you need.

Install

npm install @yault/aesp

Requires Node.js >= 18.

Quick Start

Add to Claude Desktop

Add the following to your Claude Desktop config (claudedesktopconfig.json):

{
  "mcpServers": {
    "yault": {
      "command": "npx",
      "args": ["-y", "@yault/aesp"],
      "env": {
        "YAULT_API_KEY": "sk-yault-..."
      }
    }
  }
}

Add to Claude Code

claude mcp add yault -- npx -y @yault/aesp

Then set the environment variable YAULTAPIKEY in your shell or .claude/settings.json.

Run standalone

export YAULT_API_KEY="sk-yault-..."
yault-mcp                  # if installed globally
npx @yault/aesp            # via npx

Get your API key

Go to yault.xyz to create an account and obtain your API key (sk-yault-*). The key is tied to your vault — each user manages their own key. Agent developers do not need a key unless they are also vault users; it is the end-user who configures their own key in the MCP client.

Use SDK modules

import { PolicyEngine } from '@yault/aesp/policy';
import { getAllMCPTools } from '@yault/aesp/mcp';
import { NegotiationStateMachine } from '@yault/aesp/negotiation';

const engine = new PolicyEngine(storageAdapter);
await engine.load();

const tools = getAllMCPTools(); // 6 MCP tool definitions

Modules

AESP is organized into subpath exports so you can import only what you need:

MCP Tools

The stdio server exposes 6 backend-connected tools:

Shortened. The full README is on GitHub.