Add headers field to McpTool spec

agentschema-emitter/lib/model/tools/mcp.tsp

@@ -31,6 +31,10 @@ model McpTool extends Tool {
   @doc("List of allowed operations or resources for the MCP tool")
   @sample(#{ allowedTools: #["operation1", "operation2"] })
   allowedTools?: string[];
+
+  @doc("Custom HTTP headers to include in requests to the MCP server, useful for authentication or routing")
+  @sample(#{ headers: #{ Authorization: "Bearer token" } })
+  headers?: Record<string>;
 }
 
 alias mcpApprovalMode = "always" | "never" | "specify";

agentschema-emitter/src/ast.ts

@@ -442,7 +442,7 @@ export const resolveModelProperty = (program: Program, property: ModelProperty,
     prop.isCollection = false;
 
     prop.typeName = getModelType(model, rootNamespace, rootAlias);
-    if (prop.typeName.name === "Record<unknown>") {
+    if (prop.typeName.name === "Record<unknown>" || prop.typeName.name === "Record<string>") {
       prop.isScalar = true;
       prop.isDict = true;
       prop.typeName = {

docs/src/content/docs/reference/McpTool.md

@@ -33,6 +33,7 @@ classDiagram
         +string serverDescription
         +McpServerApprovalMode approvalMode
         +string[] allowedTools
+        +dictionary headers
     }
     class McpServerApprovalMode {
         +string kind
@@ -53,6 +54,8 @@ approvalMode:
 allowedTools:
   - operation1
   - operation2
+headers:
+  Authorization: Bearer token
 ```
 
 ## Properties
@@ -65,6 +68,7 @@ allowedTools:
 | serverDescription | string | The description of the MCP tool |
 | approvalMode | [McpServerApprovalMode](../mcpserverapprovalmode/) | The approval mode for the MCP tool, either 'auto' or 'manual'(Related Types: [McpServerToolAlwaysRequireApprovalMode](../mcpservertoolalwaysrequireapprovalmode/), [McpServerToolNeverRequireApprovalMode](../mcpservertoolneverrequireapprovalmode/), [McpServerToolSpecifyApprovalMode](../mcpservertoolspecifyapprovalmode/)) |
 | allowedTools | string[] | List of allowed operations or resources for the MCP tool |
+| headers | dictionary | Custom HTTP headers to include in requests to the MCP server, useful for authentication or routing |
 
 ## Composed Types
 

docs/src/content/docs/reference/README.md

@@ -187,6 +187,7 @@ classDiagram
         +string serverDescription
         +McpServerApprovalMode approvalMode
         +string[] allowedTools
+        +dictionary headers
     }
     class OpenApiTool {
 

docs/src/content/docs/reference/Record<string>.md

@@ -0,0 +1,24 @@
+---
+title: "Record<string>"
+description: "Documentation for the Record<string> type."
+slug: "reference/record<string>"
+---
+
+
+
+## Class Diagram
+
+```mermaid
+---
+title: Record<string>
+config:
+  look: handDrawn
+  theme: colorful
+  class:
+    hideEmptyMembersBox: true
+---
+classDiagram
+    class Record<string> {
+
+    }
+```

docs/src/content/docs/reference/Tool.md

@@ -60,6 +60,7 @@ classDiagram
         +string serverDescription
         +McpServerApprovalMode approvalMode
         +string[] allowedTools
+        +dictionary headers
     }
     Tool <|-- McpTool
     class OpenApiTool {

runtime/csharp/AgentSchema.Tests/McpToolConversionTests.cs

@@ -22,6 +22,8 @@ public void LoadYamlInput()
 allowedTools:
   - operation1
   - operation2
+headers:
+  Authorization: Bearer token
 
 """;
 
@@ -50,7 +52,10 @@ public void LoadJsonInput()
   "allowedTools": [
     "operation1",
     "operation2"
-  ]
+  ],
+  "headers": {
+    "Authorization": "Bearer token"
+  }
 }
 """;
 
@@ -79,7 +84,10 @@ public void RoundtripJson()
   "allowedTools": [
     "operation1",
     "operation2"
-  ]
+  ],
+  "headers": {
+    "Authorization": "Bearer token"
+  }
 }
 """;
 
@@ -111,6 +119,8 @@ public void RoundtripYaml()
 allowedTools:
   - operation1
   - operation2
+headers:
+  Authorization: Bearer token
 
 """;
 
@@ -144,7 +154,10 @@ public void ToJsonProducesValidJson()
   "allowedTools": [
     "operation1",
     "operation2"
-  ]
+  ],
+  "headers": {
+    "Authorization": "Bearer token"
+  }
 }
 """;
 
@@ -170,6 +183,8 @@ public void ToYamlProducesValidYaml()
 allowedTools:
   - operation1
   - operation2
+headers:
+  Authorization: Bearer token
 
 """;
 

runtime/csharp/AgentSchema/McpTool.cs

@@ -55,6 +55,11 @@ public McpTool()
     /// </summary>
     public IList<string>? AllowedTools { get; set; }
 
+    /// <summary>
+    /// Custom HTTP headers to include in requests to the MCP server, useful for authentication or routing
+    /// </summary>
+    public IDictionary<string, object>? Headers { get; set; }
+
 
     #region Load Methods
 
@@ -106,6 +111,11 @@ public McpTool()
             instance.AllowedTools = (allowedToolsValue as IEnumerable<object>)?.Select(x => x?.ToString()!).ToList() ?? [];
         }
 
+        if (data.TryGetValue("headers", out var headersValue) && headersValue is not null)
+        {
+            instance.Headers = headersValue.GetDictionary()!;
+        }
+
         if (context is not null)
         {
             instance = context.ProcessOutput(instance);
@@ -167,6 +177,11 @@ public McpTool()
             result["allowedTools"] = obj.AllowedTools;
         }
 
+        if (obj.Headers is not null)
+        {
+            result["headers"] = obj.Headers;
+        }
+
 
         return result;
     }