Fix MCP tool availability and shell escaping in tag mode

Pass MCP config and allowed tools through claude_args to ensure tools like
mcp__github_comment__update_claude_comment are properly available to Claude CLI.

Key changes:
- Tag mode outputs claude_args with MCP config (as JSON string) and allowed tools
- Fixed shell escaping vulnerability when JSON contains single quotes
- Agent mode passes through user-provided claude_args unchanged
- Re-added mcp_config input for users to provide custom MCP servers
- Cleaned up misleading comments and unused file operations
- Clarified test workflow is for fork testing

Security fix: Properly escape single quotes in MCP config JSON to prevent
shell injection vulnerabilities.

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/claude-test.yml

@@ -0,0 +1,38 @@
+# Test workflow for km-anthropic fork (v1-dev branch)
+# This tests the fork implementation, not the main repo
+name: Claude Code (Fork Test)
+
+on:
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  issues:
+    types: [opened, assigned]
+  pull_request_review:
+    types: [submitted]
+
+jobs:
+  claude:
+    if: |
+      (github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review' && contains(github.event.review.body, '@claude')) ||
+      (github.event_name == 'issues' && (
+        contains(github.event.issue.body, '@claude') || 
+        contains(github.event.issue.title, '@claude')
+      ))
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+      issues: write
+      id-token: write  # Required for OIDC token exchange
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        
+      - name: Run Claude Code
+        uses: km-anthropic/claude-code-action@v1-dev
+        with:
+          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}

action.yml

@@ -65,6 +65,10 @@ inputs:
     description: "Additional arguments to pass directly to Claude CLI"
     required: false
     default: ""
+  mcp_config:
+    description: "Additional MCP configuration (JSON string) that merges with built-in GitHub MCP servers"
+    required: false
+    default: ""
   additional_permissions:
     description: "Additional GitHub permissions to request (e.g., 'actions: read')"
     required: false
@@ -124,6 +128,8 @@ runs:
         DEFAULT_WORKFLOW_TOKEN: ${{ github.token }}
         USE_COMMIT_SIGNING: ${{ inputs.use_commit_signing }}
         ADDITIONAL_PERMISSIONS: ${{ inputs.additional_permissions }}
+        CLAUDE_ARGS: ${{ inputs.claude_args }}
+        MCP_CONFIG: ${{ inputs.mcp_config }}
 
     - name: Install Base Action Dependencies
       if: steps.prepare.outputs.contains_trigger == 'true'
@@ -160,7 +166,7 @@ runs:
         INPUT_PROMPT_FILE: ${{ runner.temp }}/claude-prompts/claude-prompt.txt
         INPUT_SETTINGS: ${{ inputs.settings }}
         INPUT_TIMEOUT_MINUTES: ${{ inputs.timeout_minutes }}
-        INPUT_CLAUDE_ARGS: ${{ steps.prepare.outputs.mcp_config_file && format('--mcp-config {0} {1}', steps.prepare.outputs.mcp_config_file, inputs.claude_args) || inputs.claude_args }}
+        INPUT_CLAUDE_ARGS: ${{ steps.prepare.outputs.claude_args }}
         INPUT_EXPERIMENTAL_SLASH_COMMANDS_DIR: ${{ github.action_path }}/slash-commands
 
         # Model configuration

src/entrypoints/prepare.ts

@@ -6,7 +6,6 @@
  */
 
 import * as core from "@actions/core";
-import { writeFile } from "fs/promises";
 import { setupGitHubToken } from "../github/token";
 import { checkWritePermissions } from "../github/validation/permissions";
 import { createOctokit } from "../github/api/client";
@@ -58,11 +57,7 @@ async function run() {
       githubToken,
     });
 
-    // Write MCP config to a file and set the file path as output
+    // MCP config is handled by individual modes (tag/agent) and included in their claude_args output
-    const mcpConfigPath = `${process.env.RUNNER_TEMP}/claude-mcp-config.json`;
-    await writeFile(mcpConfigPath, result.mcpConfig);
-    core.setOutput("mcp_config", result.mcpConfig);
-    core.setOutput("mcp_config_file", mcpConfigPath);
 
     // Step 6: Get system prompt from mode if available
     if (mode.getSystemPrompt) {

src/modes/agent/index.ts

@@ -79,7 +79,9 @@ export const agentMode: Mode = {
       }
     }
 
-    core.setOutput("mcp_config", JSON.stringify(mcpConfig));
+    // Agent mode: pass through user's claude_args without modification
+    const userClaudeArgs = process.env.CLAUDE_ARGS || "";
+    core.setOutput("claude_args", userClaudeArgs);
 
     return {
       commentId: undefined,

src/modes/tag/index.ts

@@ -114,7 +114,53 @@ export const tagMode: Mode = {
       context,
     });
 
-    core.setOutput("mcp_config", mcpConfig);
+    // Don't output mcp_config separately anymore - include in claude_args
+    
+    // Build claude_args for tag mode with required tools
+    // Tag mode REQUIRES these tools to function properly
+    const tagModeTools = [
+      "Edit",
+      "MultiEdit", 
+      "Glob",
+      "Grep",
+      "LS",
+      "Read",
+      "Write",
+      "mcp__github_comment__update_claude_comment",
+    ];
+    
+    // Add git commands when not using commit signing
+    if (!context.inputs.useCommitSigning) {
+      tagModeTools.push(
+        "Bash(git add:*)",
+        "Bash(git commit:*)",
+        "Bash(git push:*)",
+        "Bash(git status:*)",
+        "Bash(git diff:*)",
+        "Bash(git log:*)",
+        "Bash(git rm:*)"
+      );
+    } else {
+      // When using commit signing, use MCP file ops tools
+      tagModeTools.push(
+        "mcp__github_file_ops__commit_files",
+        "mcp__github_file_ops__delete_files"
+      );
+    }
+    
+    const userClaudeArgs = process.env.CLAUDE_ARGS || "";
+    
+    // Build complete claude_args with MCP config (as JSON string), tools, and user args
+    // Note: Once Claude supports multiple --mcp-config flags, we can pass as file path
+    // Escape single quotes in JSON to prevent shell injection
+    const escapedMcpConfig = mcpConfig.replace(/'/g, "'\\''");
+    let claudeArgs = `--mcp-config '${escapedMcpConfig}' `;
+    claudeArgs += `--allowedTools "${tagModeTools.join(',')}" `;
+    if (userClaudeArgs) {
+      claudeArgs += userClaudeArgs;
+    }
+    
+    core.setOutput("claude_args", claudeArgs.trim());
 
     return {
       commentId,