@dcprotocol/mcp

@dcprotocol/mcp

MCP server for DCP Vault. Use this to connect AI agents (Claude, Cursor, OpenClaw, etc.) to a local DCP vault without exposing private keys.

This package is for local MCP usage. If your agent runs on another machine, use the relay flow (@dcprotocol/client or DCP proxy) instead of trying to point a remote agent directly at local MCP.

Install

npm install @dcprotocol/mcp

Run

npx -y @dcprotocol/mcp

The MCP server talks to the local vault. It does not expose a public network service by itself.

Tools

Available tools:

• vault_list_scopes
• vault_get_address
• vault_budget_check
• vault_read
• vault_sign_tx
• vault_sign_message
• vault_sign_typed_data
• vault_sign_x402
• vault_write
• vault_unlock
• vault_lock

Input/Output Highlights

vault_read

• Input: { scope, fields? }
• fields (optional) lets the agent request a subset of keys.

vault_sign_tx

• Input: { chain, unsigned_tx, description?, amount?, currency?, destination?, idempotency_key? }
• Budget enforcement uses amount + currency if provided.

vault_sign_message

• Input: { chain, message, encoding?, description? }

vault_sign_typed_data

• Input: { chain, typed_data, description? }

vault_sign_x402

• Input: { network, payload, amount?, currency?, recipient?, purpose?, typed_data? }

vault_write

• Input: { scope, data }

vault_budget_check

• Input: { amount, currency, chain? }
  (chain is required for USDC/USDT)
• Output: { allowed, remaining, limits, requires_approval }

Unlock Flow

MCP is a separate process and must be unlocked before reads/signing:

vault_unlock({ "passphrase": "..." })

To avoid typing your passphrase in chat, use the local UI:

• Start REST server: npx -y @dcprotocol/server
• Open http://127.0.0.1:8420
• Click Unlock MCP (uses OS keychain; no passphrase is written to disk)

Consent Flow

First access requires approval. You can approve via:

• CLI: dcp approve <consent_id> --session
• UI: http://127.0.0.1:8420

By default MCP runs in non‑TTY mode: it creates a pending consent and waits until you approve via UI/CLI. To enable interactive terminal prompts, set DCP_MCP_ALLOW_TTY=1.

For stable sessions across restarts, set a fixed agent name:

MCP_AGENT_NAME=claude-desktop

Sessions and Limits

• Session timeout: 30 min idle, 4 hours max
• Rate limit: 5 operations/minute per session

Environment Variables

Variable	Purpose	Default
VAULT_DIR	Vault storage directory	~/.dcp
DCP_MCP_ALLOW_TTY	Enable terminal consent prompts	0
MCP_AGENT_NAME	Stable agent name for session reuse	MCP Agent
DCP_MCP_SESSION_MINUTES	Auto‑unlock window after UI unlock	30

Claude Desktop Example

{
  "mcpServers": {
    "dcp": {
      "command": "npx",
      "args": ["@dcprotocol/mcp"]
    }
  }
}

Docs: see the root README for full usage and architecture.