@aspect-warden/mcp-server

MCP (Model Context Protocol) server that gives AI agents policy-enforced wallet capabilities on Sepolia. Works with Claude Desktop, OpenClaw, and any MCP-compatible client.

Install

npm install @aspect-warden/mcp-server

Or run directly:

npx @aspect-warden/mcp-server

Setup with Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "warden": {
      "command": "npx",
      "args": ["@aspect-warden/mcp-server"],
      "env": {
        "RPC_URL": "https://eth-sepolia.g.alchemy.com/v2/YOUR_KEY",
        "SEPOLIA_USDT_ADDRESS": "0x7169D38820dfd117C3FA1f22a697dBA58d90BA06"
      }
    }
  }
}

Restart Claude Desktop. The agent now has access to all Warden wallet tools.

Setup with OpenClaw

Add the same config to your OpenClaw MCP settings, or install the warden-wallet skill:

npx skills add tetherto/wdk-agent-skills

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | RPC_URL | No | https://rpc.sepolia.org | Sepolia RPC endpoint | | POLICY_DELEGATE_ADDRESS | No | — | Deployed PolicyDelegate contract for EIP-7702 | | SEPOLIA_USDT_ADDRESS | No | 0x7169...BA06 | USDT token address on Sepolia | | ERC8004_IDENTITY_REGISTRY | No | — | ERC-8004 identity registry address | | WARDEN_STORAGE_KEY | No | machine-scoped | Passphrase for encrypting persisted wallet state |

MCP Tools

Once connected, the agent can call these tools:

Wallet Management

| Tool | Description | |------|-------------| | warden_create_wallet | Create a new agent wallet with policy enforcement | | warden_get_balance | Check ETH and token balances | | warden_transfer | Send ERC-20 tokens (validated against policy) | | warden_get_audit_log | Fetch transaction decision history |

Policy Management

| Tool | Description | |------|-------------| | warden_setup_policy | Configure spending policy from natural language | | warden_get_policy_status | View current spending status and limits | | warden_update_policy | Modify policy at runtime |

On-Chain Enforcement (EIP-7702)

| Tool | Description | |------|-------------| | warden_delegate_to_policy | Delegate EOA to PolicyDelegate contract | | warden_create_session_key | Create scoped sub-agent permissions | | warden_revoke_session_key | Revoke sub-agent access |

Safety Controls

| Tool | Description | |------|-------------| | warden_freeze | Emergency halt all operations | | warden_unfreeze | Resume after freeze | | warden_register_identity | Register agent on ERC-8004 identity registry |

Permissions (ERC-7715)

| Tool | Description | |------|-------------| | warden_grant_permissions | Grant permissions to an agent | | warden_revoke_permissions | Revoke agent permissions | | warden_get_permissions | View agent permission grants |

Example Conversation

User: Create a conservative wallet. Max $50/day, USDT only.

Agent: [calls warden_create_wallet with maxPerTx=10, dailyLimit=50]
       Created wallet 0xABC...123 with conservative policy.
       - Max per transaction: 10 USDT
       - Daily limit: 50 USDT
       - Anomaly detection: enabled

User: Send 5 USDT to 0xDEF...456

Agent: [calls warden_transfer with amount=5, recipient=0xDEF...456]
       Transfer approved and sent.
       - Risk score: 12/100
       - Daily remaining: 45 USDT
       - Tx hash: 0x789...

User: Send 200 USDT to 0xDEF...456

Agent: [calls warden_transfer — PolicyEngine blocks it]
       Transfer blocked: exceeds daily limit of 50 USDT.
       Current daily spend: 5 USDT.

Wallet Persistence

Wallet private keys and policy configuration are automatically saved to ~/.warden/wallet-state.enc using AES-256-CBC encryption. When the MCP server restarts (e.g., Claude Desktop relaunch), it restores the previous wallet — no need to call warden_create_wallet again.

• Storage: ~/.warden/wallet-state.enc (encrypted, file permissions 0600)
• Encryption: AES-256-CBC with key derived from WARDEN_STORAGE_KEY env var (or machine-scoped default)
• What's persisted: private key, agent ID, policy configuration, spending tracker, audit log, frozen state, session keys, permission grants
• Full state recovery: everything survives restarts — works seamlessly with OpenClaw and other MCP clients that may restart the server between calls

To use a different wallet, simply call warden_create_wallet again — it overwrites the saved state.

Architecture

AI Agent (Claude / OpenClaw)
    ↓ MCP Protocol (stdio)
@aspect-warden/mcp-server
    ↓ evaluates every tx
@aspect-warden/policy-engine (19 rules + anomaly detection)
    ↓ on-chain enforcement
PolicyDelegate.sol (EIP-7702 / Sepolia)

License

MIT