From babe3c68ca3f47c01592a6ff211f586541b952f4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A0=20Arrufat?= <adria.arrufat@gmail.com>
Date: Wed, 8 Apr 2026 13:01:21 +0200
Subject: [PATCH] tools: add getEnv tool to read environment variables

---
 src/browser/tools.zig | 12 ++++++++++++
 src/mcp/tools.zig     | 13 +++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/src/browser/tools.zig b/src/browser/tools.zig
index 18c6b2c6..ad1213cb 100644
--- a/src/browser/tools.zig
+++ b/src/browser/tools.zig
@@ -55,6 +55,7 @@ const Action = enum {
     selectOption,
     setChecked,
     findElement,
+    getEnv,
 };
 
 const action_map = std.StaticStringMap(Action).initComptime(.{
@@ -78,6 +79,7 @@ const action_map = std.StaticStringMap(Action).initComptime(.{
     .{ "selectOption", .selectOption },
     .{ "setChecked", .setChecked },
     .{ "findElement", .findElement },
+    .{ "getEnv", .getEnv },
 });
 
 /// Execute a tool by name. Returns the result text.
@@ -113,6 +115,7 @@ pub fn call(
         .selectOption => execSelectOption(session, registry, arena, arguments),
         .setChecked => execSetChecked(session, registry, arena, arguments),
         .findElement => execFindElement(session, registry, arena, arguments),
+        .getEnv => execGetEnv(arena, arguments),
     };
 }
 
@@ -497,6 +500,15 @@ fn execFindElement(session: *lp.Session, registry: *CDPNode.Registry, arena: std
     return aw.written();
 }
 
+fn execGetEnv(arena: std.mem.Allocator, arguments: ?std.json.Value) ToolError![]const u8 {
+    const Params = struct { name: []const u8 };
+    const args = parseArgsOrErr(Params, arena, arguments) orelse return ToolError.InvalidParams;
+    const name_z = arena.dupeZ(u8, args.name) catch return ToolError.InternalError;
+    const value = std.posix.getenv(name_z) orelse
+        return std.fmt.allocPrint(arena, "Environment variable '{s}' is not set", .{args.name}) catch ToolError.InternalError;
+    return value;
+}
+
 // --- Shared helpers ---
 
 fn ensurePage(session: *lp.Session, registry: *CDPNode.Registry, url: ?[:0]const u8, timeout: ?u32, waitUntil: ?lp.Config.WaitUntil) ToolError!*lp.Page {
diff --git a/src/mcp/tools.zig b/src/mcp/tools.zig
index e5160cdb..a824f6d3 100644
--- a/src/mcp/tools.zig
+++ b/src/mcp/tools.zig
@@ -241,6 +241,19 @@ pub const tool_list = [_]protocol.Tool{
             \\}
         ),
     },
+    .{
+        .name = "getEnv",
+        .description = "Read the value of an environment variable. Useful for retrieving credentials or configuration without hardcoding them.",
+        .inputSchema = protocol.minify(
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "name": { "type": "string", "description": "The environment variable name to read." }
+            \\  },
+            \\  "required": ["name"]
+            \\}
+        ),
+    },
 };
 
 pub fn handleList(server: *Server, arena: std.mem.Allocator, req: protocol.Request) !void {