Add support for MCP Inspector and update README (#23)

Author: pubmodmatt

README.md

@@ -12,13 +12,54 @@ First, build the repo with:
 cargo build
 ```
 
-Next, start the Apollo Router:
+Next, run the graph in the Apollo Router:
 
 ```sh
 rover dev --supergraph-config ./graphql/weather/supergraph.yaml
 ```
 
-Then, register the MCP Server with your AI agent.
+## MCP Inspector
+
+You can run the MCP Server with [MCP Inspector](https://modelcontextprotocol.io/docs/tools/inspector).
+
+### Stdio Transport
+
+You can run the MCP inspector with the stdio transport as follows:
+
+```sh
+npx @modelcontextprotocol/inspector \
+  target/debug/mcp-apollo-server \
+  --directory <absolute path to this git repo> \
+  -s graphql/weather/api.graphql \
+  -o graphql/weather/operations/forecast.graphql graphql/weather/operations/alerts.graphql graphql/weather/operations/all.graphql
+```
+
+Press "Connect" in the MCP Inspector and "List Tools" to see the list of available tools.
+
+### HTTP+SSE Transport
+
+To use the SSE transport with MCP Inspector, first start the MCP server in SEE mode:
+
+```sh
+target/debug/mcp-apollo-server \
+  --directory <absolute path to this git repo> \
+  --sse-port 5000 -s graphql/weather/api.graphql \
+  -o graphql/weather/operations/forecast.graphql graphql/weather/operations/alerts.graphql graphql/weather/operations/all.graphql
+```
+
+Now start the MCP Inspector:
+
+```sh
+npx @modelcontextprotocol/inspector
+```
+
+Set the transport to SSE in the inspector and the URL to `http://localhost:5000/sse`, then press "Connect" in MCP Inspector.
+
+## MCP Client
+
+You can use the MCP Server with your favorite MCP client.
+
+### Client Configuration
 
 For Claude Desktop, the configuration file is in the following location on MacOS:
 
@@ -28,7 +69,9 @@ For Claude Desktop, the configuration file is in the following location on MacOS
 
 For Cursor, you can find the file by opening the MCP tab in Settings.
 
-Add the following to this file, using the absolute path to this Git repo:
+#### Stdio Transport
+
+To use the stdio transport, add the following to the MCP configuration file for you client, using the absolute path to this Git repo:
 
 ```json
 {
@@ -50,15 +93,38 @@ Add the following to this file, using the absolute path to this Git repo:
 }
 ```
 
+#### HTTP+SEE Transport
+
+To use the HTTP+SSE transport, first start the MCP server as described above for MCP Inspector.
+
+Set the following in the MCP configuration file for your client:
+
+```json
+{
+  "mcpServers": {
+    "weather": {
+        "command": "npx",
+        "args": [
+            "mcp-remote",
+            "http://127.0.0.1:5000/sse"
+        ]
+    }
+  }
+}
+```
+
+### Usage
+
 Restart your AI agent. You should now see the tools successfully registered. For example, in Claude Desktop, you should see a small hammer icon with the number of tools next to it.
 
 You can now issue prompts related to weather forecasts and alerts, which will call out to the tools and invoke the GraphQL operations.
 
 **Note** that due to current limitations of Apollo Connectors, the schema is using a hard-coded weather forecast link, so the forecast will be for a fixed location.
 
+
 # Running Your Own Graph
 
-You can easily run the server with your own GraphQL schema and operations in the AI agent configuration file:
+You can easily run the server with your own GraphQL schema and operations. For example with the stdio transport:
 
 ```json
 {
@@ -84,4 +150,17 @@ The operation files are just `.graphql` files, with each file containing a singl
 
 Run your schema in Apollo Router at the endpoint given in your configuration file.
 
-In Claude Desktop, click the hammer icon to see the description generated for your tools.
+Use MCP Inspector, or in Claude Desktop, click the hammer icon to see the description generated for your tools.
+
+# Introspection
+
+You can optionally enable support for allowing the AI model to introspect the schema and formulate its own queries. It is recommended that this only be done with a Contract variant schema, so you can control what parts of your schema are exposed to the model.
+
+To enable this mode, add `--introspect` to the MCP server command line.
+
+Two new tools will be exposed by the server:
+
+* `schema` - returns the GraphQL schema
+* `execute` - executes an operation on the GraphQL endpoint
+
+The MCP client can then use these tools to provide schema information to the model, and allow the model to execute GraphQL operations based on that schema.

crates/mcp-apollo-server/src/server.rs

@@ -8,7 +8,7 @@ use buildstructor::buildstructor;
 use reqwest::header::{CONTENT_TYPE, HeaderMap, HeaderName, HeaderValue};
 use rmcp::model::{
     CallToolRequestParam, CallToolResult, Content, ErrorCode, ListToolsResult,
-    PaginatedRequestParam,
+    PaginatedRequestParam, ServerCapabilities, ServerInfo,
 };
 use rmcp::serde_json::Value;
 use rmcp::service::RequestContext;
@@ -161,6 +161,13 @@ impl ServerHandler for Server {
                 .collect(),
         })
     }
+
+    fn get_info(&self) -> ServerInfo {
+        ServerInfo {
+            capabilities: ServerCapabilities::builder().enable_tools().build(),
+            ..Default::default()
+        }
+    }
 }
 
 fn tool_not_found(name: &str) -> McpError {