MCP Server

Cyphrex is available as a remote MCP server, listed in the official MCP registry. Any agent running in Claude, Cursor, or any MCP-compatible tool can connect directly.

Connect

Add this to your Claude Desktop or Cursor config:

{
  "mcpServers": {
    "cyphrex": {
      "url": "https://mcp.cyphrex.io/mcp",
      "headers": {
        "Authorization": "Bearer cprx_live_..."
      }
    }
  }
}

Available Tools

  • register_agent(name, type, description) - Register a new agent and get a Cyphrex agent ID
  • check_action(agentId, action) - Check if an action is allowed against the agent behavior profile
  • log_action(agentId, action, metadata) - Log an action to the audit trail
  • get_audit_log(agentId, limit) - Retrieve recent actions for an agent
  • set_behavior_profile(agentId, profile) - Define what the agent is and is not allowed to do
  • verify_agent(agentId) - Look up an agent identity and blockchain SSN status
  • scan_mcp_tools_list(agentId, serverUrl, tools) - Scans all tools exposed by an MCP server for threats before use
  • proxy_mcp_request(agentId, upstreamUrl, message) - Proxies an MCP request through Cyphrex threat enforcement

Authenticate with Authorization: Bearer cprx_live_... on the MCP session. Do not pass apiKey in tool arguments; that parameter is deprecated because many MCP clients persist tool arguments in conversation history.

MCP Threat Scanner

Cyphrex scans every MCP tool call in real time and enforces policy at the point of action. When your agent connects to an MCP server through Cyphrex, the gateway checks:

  • Tool description scanning detects prompt injection attempts embedded in tool descriptions and names. Poisoned tool lists are not returned to the agent when severity meets the agent gateway_block_severity (default high).
  • Tool poisoning detection diffs tool schemas against stored snapshots. A changed definition at or above the block threshold is withheld from the caller.
  • Server URL validation checks MCP server URLs against your agent behavior profile allowed domains. Unauthorized servers are blocked before tools/call is forwarded, and logged.
  • Tool result scanning is post execution detection of PII patterns, prompt injection in response content, and unexpected data volumes. It cannot prevent the upstream call; findings are logged as detection, not as a block.

Per agent settings on the behavior profile: gateway_block_severity (default high) and gateway_fail_mode (default closed; a scanner error blocks rather than forwarding).

To use the gateway, route MCP tool calls through:

POST https://mcp.cyphrex.io/mcp/gateway
{
  agentId: your-agent-id,
  upstreamUrl: https://your-mcp-server.com/mcp,
  message: { jsonrpc: "2.0", id: 1, method: "tools/list", params: {} }
}

The response includes outcome: "blocked" or "forwarded". Blocked requests have upstream: null. Threats are logged in the dashboard under Security → MCP Threats with severity levels, tool names, and server URLs.

MCP Gateway

Route an agent's MCP tools/call and tools/list traffic through Cyphrex so policy is enforced at the point of action. On tools/call the order is:

  1. Policy check via the Cyphrex check endpoint, using action type tool_use
  2. Upstream server validation
  3. Forward, only if both pass
  4. Result scan (post execution detection, not prevention)

A block returns a JSON-RPC error with upstream: null. The upstream request is never made. The response includes blockSource: policy when the check endpoint denied the action, or threat when server validation or tool poisoning stopped it.

Two settings on the agent behavior profile control gateway behavior:

  • gateway_block_severity defaults to high. Threats at this severity and above are blocked.
  • gateway_fail_mode defaults to closed. Fail closed means a scanner error blocks rather than forwarding. A scanner that cannot run is not evidence that the request is safe. Set open only if you want a scanner error to forward with a warning.

Coverage: routing through tool_use means the gateway evaluates off limits actions, rate limits, freeze, and prompt injection, but not allowed_apis or blocked_apis, which apply only to http_call, nor data_scopes, which apply only to data_access. MCP server URL policy is enforced separately by server validation.

Registry

Listed in the official MCP registry as io.github.getcyphrex/cyphrex-mcp

Source: github.com/getcyphrex/cyphrex-mcp

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