ailuc_mcp_proxy

# Gravitee.io MCP Proxy Policy This policy for [Gravitee.io API Gateway](https://gravitee.io) enables proxying and forwarding of various data streams, including Server-Sent Events (SSE) and HTTP streams with multiple operating modes. ## Features - **SSE to SSE Forwarding**: Proxy SSE events from a remote SSE server to clients - **STDIO to SSE Forwarding**: Convert local process output to SSE events for clients - **SSE to STDIO Forwarding**: Forward received SSE events to a local process - **HTTP Stream Proxying**: Direct HTTP stream forwarding with minimal transformation ## Build ```bash $ mvn clean install ``` ## Deploy Copy the generated JAR file from the `target` directory to the Gravitee.io plugins directory: ```bash $ cp target/mcp-proxy-policy-1.0.0-SNAPSHOT.zip /path/to/gravitee/plugins/ ``` ## Configuration ### SSE to SSE Mode ```json { "mcp-proxy": { "proxyMode": "SSE_TO_SSE", "remoteHost": "events.example.com", "remotePort": 443, "secureConnection": true, "headers": [ { "name": "Authorization", "value": "Bearer TOKEN" } ], "keepAliveSeconds": 30 } } ``` ### STDIO to SSE Mode ```json { "mcp-proxy": { "proxyMode": "STDIO_TO_SSE", "command": "python generate_events.py", "environmentVars": [ { "name": "EVENT_INTERVAL", "value": "1000" }, { "name": "MAX_EVENTS", "value": "100" } ], "keepAliveSeconds": 30 } } ``` ### SSE to STDIO Mode ```json { "mcp-proxy": { "proxyMode": "SSE_TO_STDIO", "command": "node process_events.js", "environmentVars": [ { "name": "LOG_LEVEL", "value": "info" }, { "name": "OUTPUT_DIR", "value": "/tmp/events" } ] } } ``` ### HTTP Stream Mode ```json { "mcp-proxy": { "proxyMode": "HTTP_STREAM", "remoteHost": "stream.example.com", "remotePort": 8080, "secureConnection": false, "headers": [ { "name": "X-API-Key", "value": "your-api-key" } ] } } ``` ## Configuration Properties | Property | Description | Type | Default | Required | |----------|-------------|------|---------|----------| | proxyMode | Proxy mode (SSE_TO_SSE, STDIO_TO_SSE, SSE_TO_STDIO, HTTP_STREAM) | enum | SSE_TO_SSE | Yes | | remoteHost | Remote server hostname | string | - | Yes (for SSE_TO_SSE and HTTP_STREAM) | | remotePort | Remote server port | integer | 8080 | No | | command | Local command to execute | string | - | Yes (for STDIO modes) | | headers | Custom HTTP headers | array | [] | No | | environmentVars | Environment variables for local process | array | [] | No | | keepAliveSeconds | Keep-alive timeout in seconds | integer | 15 | No | | secureConnection | Use HTTPS | boolean | false | No | ## How It Works ### SSE to SSE Mode The policy forwards requests to a remote SSE server and proxies the SSE events back to the client. It maintains proper SSE formatting and sends keep-alive messages when configured. ### STDIO to SSE Mode The policy executes a local process, captures its stdout, and converts each line to an SSE event that is sent to the client. This allows any command-line tool to become an SSE source. ### SSE to STDIO Mode The policy receives SSE events from clients, extracts the data, and forwards it to a local process via stdin. The process can then process the events as needed. ### HTTP Stream Mode The policy directly forwards HTTP streams between client and remote server with minimal transformation. This is useful for streaming APIs that don't follow the SSE format. ## Limitations - The SSE modes require proper SSE events in the standard format - Local process execution requires appropriate permissions on the gateway host - Large volumes of events may impact gateway performance ## Troubleshooting For troubleshooting, check the Gravitee Gateway logs. The policy uses the following logger names: - `io.gravitee.policy.sse.MCPProxyPolicy` - `io.gravitee.policy.sse.handlers.SSEToSSEHandler` - `io.gravitee.policy.sse.handlers.StdioToSSEHandler` - `io.gravitee.policy.sse.handlers.SSEToStdioHandler` - `io.gravitee.policy.sse.handlers.HttpStreamHandler` - `io.gravitee.policy.sse.utils.MCPUtils` ## Contributing Contributions are welcome! Please feel free to submit a Pull Request.