Add show_dsc_schema() MCP function

Cargo.toml

@@ -201,7 +201,7 @@ regex = { version = "1.12.3" }
 # registry, dsc-lib, dsc-lib-registry, dsctest
 registry = { version = "1.3" }
 # dsc
-rmcp = { version = "1.5.0" }
+rmcp = { version = "1.7.0" }
 # dsc_lib
 rt-format = { version = "0.3" }
 # dsc, dsc-lib, dsc-bicep-ext, dscecho, registry, dsc-lib-registry, runcommandonset, sshdconfig

dsc/src/args.rs

@@ -7,6 +7,7 @@ use dsc_lib::dscresources::command_resource::TraceLevel;
 use dsc_lib::progress::ProgressFormat;
 use dsc_lib::types::{FullyQualifiedTypeName, ResourceVersionReq, TypeNameFilter};
 use rust_i18n::t;
+use schemars::JsonSchema;
 use serde::Deserialize;
 
 #[derive(Debug, Clone, PartialEq, Eq, ValueEnum)]
@@ -296,9 +297,11 @@ pub enum ResourceSubCommand {
     },
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, ValueEnum)]
+#[derive(Debug, Deserialize, Clone, Copy, JsonSchema, PartialEq, Eq, ValueEnum)]
 pub enum SchemaType {
+    AdaptedDscResourceManifest,
     Configuration,
+    ConfigurationExportResult,
     ConfigurationGetResult,
     ConfigurationSetResult,
     ConfigurationTestResult,
@@ -311,6 +314,9 @@ pub enum SchemaType {
     ManifestList,
     ResolveResult,
     Resource,
+    ResourceGetResult,
+    ResourceSetResult,
+    ResourceTestResult,
     ResourceManifest,
     RestartRequired,
     SetResult,

dsc/src/mcp/mcp_server.rs

@@ -26,6 +26,7 @@ impl McpServer {
                 + Self::list_dsc_functions_router()
                 + Self::list_dsc_resources_router()
                 + Self::show_dsc_resource_router()
+                + Self::show_dsc_schema_router()
         }
     }
 }

dsc/src/mcp/mod.rs

@@ -15,6 +15,7 @@ pub mod list_dsc_functions;
 pub mod list_dsc_resources;
 pub mod mcp_server;
 pub mod show_dsc_resource;
+pub mod show_dsc_schema;
 
 /// This function initializes and starts the MCP server, handling any errors that may occur.
 ///

dsc/src/mcp/show_dsc_resource.rs

@@ -12,11 +12,15 @@ use dsc_lib::{
 };
 use rmcp::{ErrorData as McpError, Json, tool, tool_router, handler::server::wrapper::Parameters};
 use rust_i18n::t;
-use schemars::JsonSchema;
+use schemars::{JsonSchema, json_schema};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use tokio::task;
 
+fn nullable_json_object_schema(_: &mut schemars::SchemaGenerator) -> schemars::Schema {
+    json_schema!({"oneOf": [{"type": "null"}, {"type": "object"}]})
+}
+
 #[derive(Serialize, JsonSchema)]
 pub struct DscResource {
     /// The namespaced name of the resource.
@@ -35,6 +39,7 @@ pub struct DscResource {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub author: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    #[schemars(schema_with = "nullable_json_object_schema")]
     pub schema: Option<Value>,
 }
 

dsc/src/mcp/show_dsc_schema.rs

@@ -0,0 +1,47 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use crate::{args::SchemaType, mcp::mcp_server::McpServer, util};
+use rmcp::{ErrorData as McpError, Json, tool, tool_router, handler::server::wrapper::Parameters};
+use schemars::{JsonSchema, json_schema};
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use tokio::task;
+
+fn json_object_schema(_: &mut schemars::SchemaGenerator) -> schemars::Schema {
+    json_schema!({"type": "object"})
+}
+
+#[derive(Deserialize, JsonSchema)]
+pub struct ShowSchemaRequest {
+    #[schemars(description = "The schema type to retrieve the JSON schema for.")]
+    pub r#type: SchemaType,
+}
+
+#[derive(Serialize, JsonSchema)]
+pub struct ShowSchemaResponse {
+    #[schemars(schema_with = "json_object_schema")]
+    pub schema: Value,
+}
+
+#[tool_router(router = show_dsc_schema_router, vis = "pub")]
+impl McpServer {
+    #[tool(
+        description = "Get the JSON schema for a specific part of using DSC, such as a configuration or output from an operation.",
+        annotations(
+            title = "Get the JSON schema for a specific part of using DSC",
+            read_only_hint = true,
+            destructive_hint = false,
+            idempotent_hint = true,
+            open_world_hint = true,
+        )
+    )]
+    pub async fn show_dsc_schema(&self, Parameters(ShowSchemaRequest { r#type }): Parameters<ShowSchemaRequest>) -> Result<Json<ShowSchemaResponse>, McpError> {
+        let result = task::spawn_blocking(move || {
+            let schema = util::get_schema(r#type);
+            Ok(ShowSchemaResponse { schema: schema.as_value().clone() })
+        }).await.map_err(|e| McpError::internal_error(e.to_string(), None))??;
+
+        Ok(Json(result))
+    }
+}

dsc/src/util.rs

@@ -3,6 +3,8 @@
 
 use crate::args::{SchemaType, OutputFormat, TraceFormat};
 use crate::resolve::Include;
+use dsc_lib::configure::config_result::{ConfigurationExportResult, ResourceGetResult, ResourceSetResult};
+use dsc_lib::dscresources::adapted_resource_manifest::AdaptedDscResourceManifest;
 use dsc_lib::{
     configure::{
         config_doc::{
@@ -161,9 +163,15 @@ pub fn add_fields_to_json(json: &str, fields_to_add: &HashMap<String, String>) -
 #[must_use]
 pub fn get_schema(schema: SchemaType) -> Schema {
     match schema {
+        SchemaType::AdaptedDscResourceManifest => {
+            schema_for!(AdaptedDscResourceManifest)
+        },
         SchemaType::Configuration => {
             schema_for!(Configuration)
         },
+        SchemaType::ConfigurationExportResult => {
+            schema_for!(ConfigurationExportResult)
+        },
         SchemaType::ConfigurationGetResult => {
             schema_for!(ConfigurationGetResult)
         },
@@ -200,6 +208,15 @@ pub fn get_schema(schema: SchemaType) -> Schema {
         SchemaType::Resource => {
             schema_for!(Resource)
         },
+        SchemaType::ResourceGetResult => {
+            schema_for!(ResourceGetResult)
+        },
+        SchemaType::ResourceSetResult => {
+            schema_for!(ResourceSetResult)
+        },
+        SchemaType::ResourceTestResult => {
+            schema_for!(ResourceTestResult)
+        },
         SchemaType::ResourceManifest => {
             schema_for!(ResourceManifest)
         },

dsc/tests/dsc_mcp.tests.ps1

@@ -76,6 +76,7 @@ Describe 'Tests for MCP server' {
             'list_dsc_functions'  = $false
             'list_dsc_resources'  = $false
             'show_dsc_resource'   = $false
+            'show_dsc_schema'     = $false
         }
 
         $response = Send-McpRequest -request $mcpRequest
@@ -611,4 +612,26 @@ greeting: Hello from YAML parameters
         $response.error.code | Should -Be -32600
         $response.error.message | Should -Match 'Invalid parameters'
     }
+
+    It 'Calling show_dsc_schema works' {
+        $mcpRequest = @{
+            jsonrpc = "2.0"
+            id      = 19
+            method  = "tools/call"
+            params  = @{
+                name      = "show_dsc_schema"
+                arguments = @{
+                    type = "AdaptedDscResourceManifest"
+                }
+            }
+        }
+
+        $response = Send-McpRequest -request $mcpRequest
+        $response.id | Should -Be 19
+        $response.result.structuredContent | Should -Not -BeNullOrEmpty
+        $response.result.structuredContent.schema | Should -Not -BeNullOrEmpty
+        $schema = dsc schema --type adapted-dsc-resource-manifest | ConvertFrom-Json -Depth 20
+        $response.result.structuredContent.schema.'$schema' | Should -Be $schema.'$schema' -Because ($response.result.structuredContent | ConvertTo-Json -Depth 20 | Out-String)
+        $response.result.structuredContent.schema.title | Should -BeExactly $schema.title -Because ($response.result.structuredContent | ConvertTo-Json -Depth 20 | Out-String)
+    }
 }