MCP工具：Governance代理

Action Dependency Chains

Declare prerequisite actions in policy. The proxy tracks completed actions per session and blocks anything where prerequisites aren't met.

rules:
  - match:
      tool: 'process_refund'
    requires: ['orders.lookup', 'customer.verify']

1. Install

npx @gethelio/proxy init

This single package includes the built-in dashboard UI bundle.

Quick Start (5 minutes)

Examples

Ready-made configurations for common patterns:

• Basic: Deny destructive operations, allow everything else
• Slack Approvals: Route destructive actions to Slack
• Spend Limits: Govern payment tool usage

2. Configure

npx @gethelio/proxy init already created a helio.yaml in your project root. Open it and point upstream.url at your existing MCP server. Helio v0.1 proxies a single upstream MCP server. A fuller example with policies, audit, and a dashboard secret:

version: '1'

upstream:
  url: 'http://localhost:8080/mcp' # Your existing MCP server
  transport: streamable-http # streamable-http (default), sse, or stdio

listen:
  port: 3000 # Helio listens here

policies:
  default: allow

  rules:
    # Block destructive operations
    - match:
        tool: 'delete_*'
      action: deny
      feedback:
        message: 'Destructive operations are disabled'

    # Rate limit expensive API calls
    - match:
        tool: 'search_*'
      action: rate_limit
      limits:
        max_calls: 100
        window: 1h
        key: tool

    # Spend limit on payment tools
    - match:
        tool: 'create_payment'
      action: spend_limit
      limits:
        max_spend:
          field: '$.amount'
          limit: 5000
          currency: 'GBP'
          window: 24h

audit:
  storage: sqlite
  retention: 90d
  include_responses: true

dashboard:
  enabled: true
  port: 3100
  api_secret: '${HELIO_DASHBOARD_SECRET}'

If your upstream requires a static credential (for example Authorization: Bearer … on a hosted MCP server), set upstream.headers — values support ${VAR} interpolation so secrets stay out of the file.

About dashboard.api_secret:

• If you ran npx @gethelio/proxy init, your helio.yaml already contains a generated api_secret (a literal 32-byte hex value, also printed when you ran init). It's set — skip this step.
• If you authored helio.yaml by hand using the ${HELIO_DASHBOARD_SECRET} placeholder shown above, set the variable before start:

  export HELIO_DASHBOARD_SECRET="$(openssl rand -hex 32)"
  

Optional SDK enrichment

from helio import HelioContext

Approval Workflows

Route sensitive actions to Slack, webhook, or the Helio dashboard. Configurable timeout and escalation, plus a dashboard-only break-glass override (REST API and dashboard UI; not exposed as a Slack button).

How Helio Compares

\* Per-tool and per-session spend limits ship in v0.1. Cross-tool spend aggregation is planned for v0.2.