From 6ba443c1ea8d9e99b6e895024e867d13a0193528 Mon Sep 17 00:00:00 2001
From: MarcAButler <marc.a.butler.1999@gmail.com>
Date: Sat, 16 May 2026 21:08:18 -0400
Subject: [PATCH] Feature: Add ability to get loaded scripts

---
 CHANGELOG.md            |  5 +++++
 README.md               |  1 +
 src/debugMCPServer.ts   | 12 ++++++++++++
 src/debuggingHandler.ts | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 52 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d824033..e05096d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to DebugMCP will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/), and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [Unreleased]
+
+### Added
+- **`get_loaded_scripts` tool** — returns all scripts currently loaded in the active debug session via the DAP `loadedSources` request. Works on a running session without requiring execution to be paused. Each entry contains `name`, `path` (null for dynamically generated scripts), and `sourceReference` (non-zero when there is no on-disk path). Gracefully returns an error object if there is no active session or if the debug adapter does not support `loadedSources`.
+
 ## [1.0.8] - 2025-03-14
 
 ### Added
diff --git a/README.md b/README.md
index a16ed39..7ec816c 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,7 @@ DebugMCP is an MCP server that gives AI coding agents full control over the VS C
 | **remove_breakpoint** | Remove a breakpoint from a specific line | `fileFullPath` (required)<br>`line` (required) |
 | **clear_all_breakpoints** | Remove all breakpoints at once | None |
 | **list_breakpoints** | List all active breakpoints | None |
+| **get_loaded_scripts** | Returns all scripts currently loaded in the active debug session (name, path, sourceReference). Works on a running session without pausing execution. Useful for discovering exact file paths before calling `add_breakpoint`. | None |
 | **get_variables_values** | Get variables and their values at current execution point | `scope` (optional: 'local', 'global', 'all') |
 | **evaluate_expression** | Evaluate an expression in debug context | `expression` (required) |
 
diff --git a/src/debugMCPServer.ts b/src/debugMCPServer.ts
index 40e33f8..4ea41d1 100644
--- a/src/debugMCPServer.ts
+++ b/src/debugMCPServer.ts
@@ -183,6 +183,18 @@ export class DebugMCPServer {
             return { content: [{ type: 'text' as const, text: result }] };
         });
 
+        // Get loaded scripts tool
+        this.mcpServer!.registerTool('get_loaded_scripts', {
+            description: 'Returns all scripts currently loaded in the active debug session. ' +
+                'Does not require the session to be paused — it can be called at any point while a debug session is running. ' +
+                'Each entry includes the script name, its file path on disk (or null for dynamically generated scripts), ' +
+                'and a sourceReference (non-zero for scripts with no on-disk path). ' +
+                'Use this to discover exact file paths before calling add_breakpoint, ' +
+                'which avoids unbound breakpoints caused by guessed or incorrect paths.',
+        }, async () => {
+            const result = await this.debuggingHandler.handleGetLoadedScripts();
+            return { content: [{ type: 'text' as const, text: result }] };
+        });
         // Get variables tool
         this.mcpServer!.registerTool('get_variables_values', {
             description: 'Inspect all variable values at the current execution point. This is your window into program state - see what data looks like at runtime, verify assumptions, identify unexpected values, and understand why code behaves as it does.',
diff --git a/src/debuggingHandler.ts b/src/debuggingHandler.ts
index dd87bde..e0ff2ab 100644
--- a/src/debuggingHandler.ts
+++ b/src/debuggingHandler.ts
@@ -23,6 +23,7 @@ export interface IDebuggingHandler {
     handleListBreakpoints(): Promise<string>;
     handleGetVariables(args: { scope?: 'local' | 'global' | 'all' }): Promise<string>;
     handleEvaluateExpression(args: { expression: string }): Promise<string>;
+    handleGetLoadedScripts(): Promise<string>;
 }
 
 /**
@@ -380,6 +381,39 @@ export class DebuggingHandler implements IDebuggingHandler {
         }
     }
 
+    /**
+     * Return all scripts currently loaded in the active debug session via the DAP loadedSources request
+     */
+    public async handleGetLoadedScripts(): Promise<string> {
+        try {
+            const session = vscode.debug.activeDebugSession;
+
+            if (!session) {
+                return JSON.stringify({ error: 'No active debug session. Start a debug session first.' });
+            }
+
+            let response: { sources: Array<{ name: string; path?: string; sourceReference?: number }> };
+            try {
+                response = await session.customRequest('loadedSources', {});
+            } catch (err) {
+                return JSON.stringify({
+                    error: 'The active debug adapter does not support loadedSources.',
+                    hint: 'This capability is supported by Node.js, Electron, and Chrome-based debug adapters.',
+                });
+            }
+
+            const sources = (response.sources ?? []).map(s => ({
+                name: s.name,
+                path: s.path ?? null,
+                sourceReference: s.sourceReference ?? 0,
+            }));
+
+            return JSON.stringify(sources, null, 2);
+        } catch (error) {
+            throw new Error(`Error getting loaded scripts: ${error}`);
+        }
+    }
+
     /**
      * Evaluate an expression in current debug context
      */