MCP Ingress Protocol & Dual Transport

MCP Ingress Protocol & Dual Transport 🔌

FaradAiWire’s Proxy Ingress listener operates on Port 8090, implementing standard Model Context Protocol (MCP) transport specifications.

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Ingress Endpoints (Port 8090)

Endpoint	HTTP Method	Purpose
/sse	GET	Establishes persistent Server-Sent Events (SSE) session with the AI agent.
/message	POST	Ingests JSON-RPC 2.0 frames associated with an SSE session or standalone request.
/mcp	POST	Single-shot JSON-RPC 2.0 execution endpoint (convenient for curl/scripts).

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1. Server-Sent Events (SSE) Handshake

When an agent like Claude Code or Cursor connects to FaradAiWire via SSE:

1. Client Request:

   GET /sse HTTP/1.1
   Host: 127.0.0.1:8090
   Authorization: Bearer dev-local-key
   Accept: text/event-stream

2. FaradAiWire Handshake Response:

   HTTP/1.1 200 OK
   Content-Type: text/event-stream
   Cache-Control: no-cache
   Connection: keep-alive
   
   event: endpoint
   data: /message?sessionId=sess_8f91c0e3b

3. Subsequent Tool Invocations: The agent posts its JSON-RPC frames to /message?sessionId=sess_8f91c0e3b.

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2. Direct HTTP JSON-RPC POST (/message or /mcp)

For automated test runners, bash scripts, or simple agents:

curl -X POST http://127.0.0.1:8090/message \
  -H "Authorization: Bearer dev-local-key" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": "call-1",
    "method": "tools/call",
    "params": {
      "name": "calculate_hash",
      "arguments": { "algorithm": "sha256", "text": "FaradAi" }
    }
  }'

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3. Dual Upstream Transports

FaradAiWire acts as a protocol bridge, supporting two distinct upstream tool transports:

Local Subprocesses (stdio)

• Spawns local tools (e.g. npx -y @modelcontextprotocol/server-postgres) directly as OS subprocesses.
• Process Isolation: Runs subprocesses in dedicated process groups (syscall.Setpgid), preventing rogue tool processes from surviving gateway shutdown.
• Sanitized Environment: Passes filtered environment variables to prevent leaking master API keys to subprocesses.

Remote MCP Servers (http/sse)

• Connects to remote MCP microservices over HTTP or persistent SSE streams.
• SSRF Guard: Inspects IP targets to block private RFC 1918 subnets and cloud metadata endpoints (169.254.169.254).