@tryagent/mcp-proxy

Human-in-the-loop governance for any MCP-speaking agent — no code changes, one config file. The proxy is an MCP server that fronts your upstream MCP servers and re-exports every tool; mapped tools escalate to TryAgent before they execute.

// tryagent-mcp.json
{
  "upstreams": [
    { "name": "stripe", "command": "npx -y @stripe/mcp" }
  ],
  "policies": {
    "stripe:create_refund": "payments.refund"
  },
  "default": "passthrough"
}

Point your MCP client at the proxy instead of the upstreams:

{
  "mcpServers": {
    "governed": {
      "command": "npx",
      "args": ["-y", "@tryagent/mcp-proxy", "--config", "tryagent-mcp.json"],
      "env": { "TRYAGENT_API_KEY": "ain_live_…" }
    }
  }
}

Behavior

• Tools are re-exported as <upstream>__<tool> (MCP tool names disallow :); the config's policies keys keep the readable upstream:tool form. Governed tools get a [TryAgent: requires approval under "<policy>"] note appended to their description so the model knows.
• On a governed tools/call the proxy creates a TryAgent escalation (the tool args become structured evidence — rubric conditions like args.amount > 100 evaluate against them) and honors the platform's mode ladder: a required rubric blocks until a human decides; reviewed / sampled / autonomous come back system-decided immediately, so the call passes through while the decision is logged.
• Unknown policy keys and agentIds auto-register on first escalate — no dashboard prework.
• Fail closed: a denial returns an MCP error result and the upstream is never called; if the TryAgent API is unreachable, mapped tools error instead of executing. Set "default": "block" for allowlist-style deployments where unmapped tools are refused too.

Config reference

| Field | Meaning | | --- | --- | | upstreams[].name | Namespace prefix ([A-Za-z0-9_-], no __) | | upstreams[].command | Command to spawn; inline args OK, or use args | | upstreams[].env | Extra env for the upstream process | | policies | "upstream:tool" → TryAgent policy key | | default | passthrough (default) or block | | apiKey / baseUrl | Override TRYAGENT_API_KEY / API base | | waitIntervalMs / waitTimeoutMs | Decision polling knobs |

Requires Node.js >= 20.17.