Add X-MCP-Toolsets header support for remote GitHub MCP configuration (#2015)

Author: Copilot

.changeset/patch-add-mcp-toolsets-header.md

@@ -682,16 +682,24 @@ func (e *ClaudeEngine) renderGitHubClaudeMCPConfig(yaml *strings.Builder, github
 
 		// Use effective token with precedence: custom > top-level > default
 		effectiveToken := getEffectiveGitHubToken(customGitHubToken, workflowData.GitHubToken)
-		yaml.WriteString(fmt.Sprintf("                  \"Authorization\": \"Bearer %s\"", effectiveToken))
+
+		// Collect headers in a map
+		headers := make(map[string]string)
+		headers["Authorization"] = fmt.Sprintf("Bearer %s", effectiveToken)
 
 		// Add X-MCP-Readonly header if read-only mode is enabled
 		if readOnly {
-			yaml.WriteString(",\n")
-			yaml.WriteString("                  \"X-MCP-Readonly\": \"true\"\n")
-		} else {
-			yaml.WriteString("\n")
+			headers["X-MCP-Readonly"] = "true"
+		}
+
+		// Add X-MCP-Toolsets header if toolsets are configured
+		if toolsets != "" {
+			headers["X-MCP-Toolsets"] = toolsets
 		}
 
+		// Write headers using helper
+		writeHeadersToYAML(yaml, headers, "                  ")
+
 		yaml.WriteString("                }\n")
 	} else {
 		// Local mode - use Docker-based GitHub MCP server (default)

.github/workflows/github-mcp-tools-report.lock.yml

@@ -278,14 +278,24 @@ func (e *CopilotEngine) renderGitHubCopilotMCPConfig(yaml *strings.Builder, gith
 		yaml.WriteString("                \"type\": \"http\",\n")
 		yaml.WriteString("                \"url\": \"https://api.githubcopilot.com/mcp/\",\n")
 		yaml.WriteString("                \"headers\": {\n")
-		yaml.WriteString("                  \"Authorization\": \"Bearer \\${GITHUB_PERSONAL_ACCESS_TOKEN}\"\n")
+
+		// Collect headers in a map
+		headers := make(map[string]string)
+		headers["Authorization"] = "Bearer \\${GITHUB_PERSONAL_ACCESS_TOKEN}"
 
 		// Add X-MCP-Readonly header if read-only mode is enabled
 		if readOnly {
-			yaml.WriteString(",\n")
-			yaml.WriteString("                  \"X-MCP-Readonly\": \"true\"\n")
+			headers["X-MCP-Readonly"] = "true"
 		}
 
+		// Add X-MCP-Toolsets header if toolsets are configured
+		if toolsets != "" {
+			headers["X-MCP-Toolsets"] = toolsets
+		}
+
+		// Write headers using helper
+		writeHeadersToYAML(yaml, headers, "                  ")
+
 		yaml.WriteString("                },\n")
 
 		// Populate tools field with allowed tools or "*" if none specified

pkg/workflow/claude_engine.go

@@ -0,0 +1,34 @@
+package workflow
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// writeHeadersToYAML writes a map of headers to YAML format with proper comma placement
+// indent is the indentation string to use for each header line (e.g., "                  ")
+func writeHeadersToYAML(yaml *strings.Builder, headers map[string]string, indent string) {
+	if len(headers) == 0 {
+		return
+	}
+
+	// Sort keys for deterministic output
+	keys := make([]string, 0, len(headers))
+	for key := range headers {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+
+	// Write each header with proper comma placement
+	for i, key := range keys {
+		value := headers[key]
+		if i < len(keys)-1 {
+			// Not the last header, add comma
+			fmt.Fprintf(yaml, "%s\"%s\": \"%s\",\n", indent, key, value)
+		} else {
+			// Last header, no comma
+			fmt.Fprintf(yaml, "%s\"%s\": \"%s\"\n", indent, key, value)
+		}
+	}
+}

pkg/workflow/copilot_engine.go

@@ -202,10 +202,167 @@ This workflow tests remote mode with array toolsets.
 
 	yamlStr := string(yamlContent)
 
-	// In remote mode, toolsets are not currently supported via environment variables
-	// The remote server might have different configuration mechanism
-	// For now, we verify the workflow compiles successfully
+	// In remote mode, toolsets should be passed via X-MCP-Toolsets header
 	if !strings.Contains(yamlStr, "https://api.githubcopilot.com/mcp/") {
 		t.Errorf("Expected remote mode URL in YAML")
 	}
+
+	// Check for X-MCP-Toolsets header with the configured toolsets
+	if !strings.Contains(yamlStr, `"X-MCP-Toolsets": "repos,issues"`) {
+		t.Errorf("Expected X-MCP-Toolsets header with 'repos,issues' in remote mode, but didn't find it.\nGenerated YAML:\n%s", yamlStr)
+	}
+}
+
+func TestGitHubToolsetRemoteModeMultipleEngines(t *testing.T) {
+	tests := []struct {
+		name           string
+		workflowMD     string
+		expectedHeader string
+		engineType     string
+	}{
+		{
+			name: "Claude remote mode with toolsets",
+			workflowMD: `---
+on: push
+engine: claude
+tools:
+  github:
+    mode: remote
+    toolset: [repos, issues, pull_requests]
+---
+
+# Test Workflow
+
+Claude remote mode with toolsets.
+`,
+			expectedHeader: `"X-MCP-Toolsets": "repos,issues,pull_requests"`,
+			engineType:     "claude",
+		},
+		{
+			name: "Copilot remote mode with toolsets",
+			workflowMD: `---
+on: push
+engine: copilot
+tools:
+  github:
+    mode: remote
+    toolset: [actions, discussions]
+---
+
+# Test Workflow
+
+Copilot remote mode with toolsets.
+`,
+			expectedHeader: `"X-MCP-Toolsets": "actions,discussions"`,
+			engineType:     "copilot",
+		},
+		{
+			name: "Remote mode with all toolsets",
+			workflowMD: `---
+on: push
+engine: claude
+tools:
+  github:
+    mode: remote
+    toolset: [all]
+---
+
+# Test Workflow
+
+Remote mode with all toolsets.
+`,
+			expectedHeader: `"X-MCP-Toolsets": "all"`,
+			engineType:     "claude",
+		},
+		{
+			name: "Remote mode without toolsets",
+			workflowMD: `---
+on: push
+engine: claude
+tools:
+  github:
+    mode: remote
+---
+
+# Test Workflow
+
+Remote mode without toolsets.
+`,
+			expectedHeader: "", // No header should be added
+			engineType:     "claude",
+		},
+		{
+			name: "Remote mode with toolsets and read-only",
+			workflowMD: `---
+on: push
+engine: copilot
+tools:
+  github:
+    mode: remote
+    toolset: [repos, issues]
+    read-only: true
+---
+
+# Test Workflow
+
+Remote mode with toolsets and read-only.
+`,
+			expectedHeader: `"X-MCP-Toolsets": "repos,issues"`,
+			engineType:     "copilot",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create temporary directory for test
+			tempDir := t.TempDir()
+			mdPath := filepath.Join(tempDir, "test-workflow.md")
+
+			// Write workflow file
+			err := os.WriteFile(mdPath, []byte(tt.workflowMD), 0644)
+			if err != nil {
+				t.Fatalf("Failed to write test workflow: %v", err)
+			}
+
+			// Compile the workflow
+			compiler := NewCompiler(false, "", "test")
+			compileErr := compiler.CompileWorkflow(mdPath)
+			if compileErr != nil {
+				t.Fatalf("Failed to compile workflow: %v", compileErr)
+			}
+
+			// Read the generated YAML
+			yamlPath := strings.TrimSuffix(mdPath, ".md") + ".lock.yml"
+			yamlContent, readErr := os.ReadFile(yamlPath)
+			if readErr != nil {
+				t.Fatalf("Failed to read generated YAML: %v", readErr)
+			}
+
+			yamlStr := string(yamlContent)
+
+			// Verify remote mode URL
+			if !strings.Contains(yamlStr, "https://api.githubcopilot.com/mcp/") {
+				t.Errorf("Expected remote mode URL in YAML")
+			}
+
+			// Check for expected header
+			if tt.expectedHeader != "" {
+				if !strings.Contains(yamlStr, tt.expectedHeader) {
+					t.Errorf("Expected header %q in YAML but didn't find it.\nGenerated YAML:\n%s", tt.expectedHeader, yamlStr)
+				}
+			} else {
+				// Verify no X-MCP-Toolsets header is present
+				if strings.Contains(yamlStr, "X-MCP-Toolsets") {
+					t.Errorf("Expected no X-MCP-Toolsets header in YAML but found one.\nGenerated YAML:\n%s", yamlStr)
+				}
+			}
+
+			// If read-only is in the test name, also verify X-MCP-Readonly header
+			if strings.Contains(tt.name, "read-only") {
+				if !strings.Contains(yamlStr, `"X-MCP-Readonly": "true"`) {
+					t.Errorf("Expected X-MCP-Readonly header in YAML but didn't find it.\nGenerated YAML:\n%s", yamlStr)
+				}
+			}
+		})
+	}
 }