Yault AESP

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 (claude_desktop_config.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 YAULT_API_KEY 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:

Backend Requirements

The MCP server is a thin API client. It expects a Yault backend providing:

• GET /api/vault/balance/:address
• GET /api/vault/balances/:address
• GET /api/vault/agent-authorization
• POST /api/vault/deposit -- { address, amount }
• POST /api/vault/redeem -- { address, shares }
• POST /api/vault/transfer -- { from_address, to_address, amount, currency? }

Authentication: Authorization: Bearer sk-yault-* via YAULT_API_KEY env variable.

Security Model

AESP is built around "bounded autonomy":

• Agent API keys should be policy-bound before spend execution.
• Spending controls should include per-tx and rolling limits (daily/weekly/monthly).
• Destination constraints should be allowlist-driven where applicable.
• Sensitive operations should stay outside broad agent key scopes.
• Human escalation remains the fallback for policy violations.

For vulnerability reporting, see SECURITY.md.

Related Packages

Development

Run tests:

npm test

Build TypeScript:

npm run build:ts

Build with WASM (requires acegf-wallet as a sibling repo, or set ACEGF_ROOT):

npm run build:wasm
npm run build:ts

See CONTRIBUTING.md for the full development guide.

License

This project is licensed under the Apache License 2.0. See LICENSE for the full text.