fix: add edge runtime compatibility for Cloudflare Workers

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mcpcat",
-  "version": "0.1.8",
+  "version": "0.1.9",
   "description": "Analytics tool for MCP (Model Context Protocol) servers - tracks tool usage patterns and provides insights",
   "type": "module",
   "main": "dist/index.js",
@@ -54,7 +54,7 @@
   "packageManager": "pnpm@10.11.0",
   "devDependencies": {
     "@changesets/cli": "^2.29.4",
-    "@modelcontextprotocol/sdk": "1.11",
+    "@modelcontextprotocol/sdk": "~1.23.0",
     "@types/node": "^22.15.21",
     "@typescript-eslint/eslint-plugin": "^8.32.1",
     "@typescript-eslint/parser": "^8.32.1",
@@ -73,9 +73,9 @@
   },
   "dependencies": {
     "@opentelemetry/otlp-transformer": "^0.203.0",
-    "mcpcat-api": "0.1.3",
+    "mcpcat-api": "0.1.6",
     "redact-pii": "3.4.0",
-    "zod": "3.25.30"
+    "zod": "^3.25 || ^4.0"
   },
   "lint-staged": {
     "*.{ts,js}": [

src/modules/context-parameters.ts

@@ -1,26 +1,12 @@
 import { RegisteredTool } from "../types";
 import { z } from "zod";
 import { DEFAULT_CONTEXT_PARAMETER_DESCRIPTION } from "./constants";
-
-// Detect if something is a Zod schema (has _def and parse methods)
-function isZodSchema(schema: any): boolean {
-  return (
-    schema &&
-    typeof schema === "object" &&
-    "_def" in schema &&
-    typeof schema.parse === "function"
-  );
-}
-
-// Detect if it's shorthand Zod syntax (object with z.* values)
-function isShorthandZodSyntax(schema: any): boolean {
-  if (!schema || typeof schema !== "object" || Array.isArray(schema)) {
-    return false;
-  }
-
-  // Check if any value is a Zod schema
-  return Object.values(schema).some((value) => isZodSchema(value));
-}
+import {
+  isZodSchema,
+  isShorthandZodSyntax,
+  schemaHasProperty,
+  extendObjectSchema,
+} from "./zod-compat";
 
 export function addContextParameterToTool(
   tool: RegisteredTool,
@@ -43,36 +29,25 @@ export function addContextParameterToTool(
     return modifiedTool;
   }
 
-  // Handle Zod z.object() schemas
+  const contextDescription =
+    customContextDescription || DEFAULT_CONTEXT_PARAMETER_DESCRIPTION;
+
+  // Handle Zod z.object() schemas (both v3 and v4)
   if (isZodSchema(modifiedTool.inputSchema)) {
     // Check if context already exists in Zod schema shape
-    if (
-      modifiedTool.inputSchema.shape &&
-      "context" in modifiedTool.inputSchema.shape
-    ) {
+    if (schemaHasProperty(modifiedTool.inputSchema, "context")) {
       return modifiedTool;
     }
-    // It's a Zod schema, augment it with context
-    const contextSchema = z.object({
-      context: z
-        .string()
-        .describe(
-          customContextDescription || DEFAULT_CONTEXT_PARAMETER_DESCRIPTION,
-        ),
-    });
-
-    // Use extend to add context to the schema
-    if (typeof modifiedTool.inputSchema.extend === "function") {
-      modifiedTool.inputSchema = modifiedTool.inputSchema.extend(
-        contextSchema.shape,
-      );
-    } else if (typeof modifiedTool.inputSchema.augment === "function") {
-      modifiedTool.inputSchema =
-        modifiedTool.inputSchema.augment(contextSchema);
-    } else {
-      // Fallback: merge with new z.object
-      modifiedTool.inputSchema = contextSchema.merge(modifiedTool.inputSchema);
-    }
+
+    // Extend the schema with context using our compat layer
+    const contextShape = {
+      context: z.string().describe(contextDescription),
+    };
+
+    modifiedTool.inputSchema = extendObjectSchema(
+      modifiedTool.inputSchema,
+      contextShape,
+    );
 
     return modifiedTool;
   }
@@ -84,18 +59,15 @@ export function addContextParameterToTool(
       return modifiedTool;
     }
 
-    // Create a new Zod schema with context
-    const contextField = z
-      .string()
-      .describe(
-        customContextDescription || DEFAULT_CONTEXT_PARAMETER_DESCRIPTION,
-      );
+    // Extend using our compat layer (handles both v3 and v4)
+    const contextShape = {
+      context: z.string().describe(contextDescription),
+    };
 
-    // Create new z.object with context and all original fields
-    modifiedTool.inputSchema = z.object({
-      context: contextField,
-      ...modifiedTool.inputSchema,
-    });
+    modifiedTool.inputSchema = extendObjectSchema(
+      modifiedTool.inputSchema,
+      contextShape,
+    );
 
     return modifiedTool;
   }
@@ -115,8 +87,7 @@ export function addContextParameterToTool(
 
     modifiedTool.inputSchema.properties.context = {
       type: "string",
-      description:
-        customContextDescription || DEFAULT_CONTEXT_PARAMETER_DESCRIPTION,
+      description: contextDescription,
     };
 
     // Add context to required array if it exists

src/modules/eventQueue.ts

@@ -189,9 +189,18 @@ class EventQueue {
 }
 
 export const eventQueue = new EventQueue();
-process.once("SIGINT", () => eventQueue.destroy());
-process.once("SIGTERM", () => eventQueue.destroy());
-process.once("beforeExit", () => eventQueue.destroy());
+
+// Register graceful shutdown handlers if available (Node.js only)
+// Edge environments (Cloudflare Workers, etc.) don't have process signals
+try {
+  if (typeof process !== "undefined" && typeof process.once === "function") {
+    process.once("SIGINT", () => eventQueue.destroy());
+    process.once("SIGTERM", () => eventQueue.destroy());
+    process.once("beforeExit", () => eventQueue.destroy());
+  }
+} catch {
+  // process.once not available in this environment - graceful shutdown handlers not registered
+}
 
 export function setTelemetryManager(telemetryManager: TelemetryManager): void {
   eventQueue.setTelemetryManager(telemetryManager);

src/modules/exceptions.ts

@@ -1,5 +1,21 @@
 import { ErrorData, StackFrame, ChainedErrorData } from "../types.js";
-import { readFileSync } from "fs";
+
+// Lazy-loaded fs module for context_line extraction (Node.js only)
+// Edge environments don't have filesystem access
+let fsModule: typeof import("fs") | null = null;
+let fsInitAttempted = false;
+
+function getFsSync(): typeof import("fs") | null {
+  if (!fsInitAttempted) {
+    fsInitAttempted = true;
+    try {
+      fsModule = require("fs");
+    } catch {
+      fsModule = null;
+    }
+  }
+  return fsModule;
+}
 
 // Maximum number of exceptions to capture in a cause chain
 const MAX_EXCEPTION_CHAIN_DEPTH = 10;
@@ -120,8 +136,14 @@ function addContextToFrame(frame: StackFrame): StackFrame {
     return frame;
   }
 
+  // Get fs module lazily - returns null in edge environments
+  const fs = getFsSync();
+  if (!fs) {
+    return frame; // File reading not available in this environment
+  }
+
   try {
-    const source = readFileSync(frame.abs_path, "utf8");
+    const source = fs.readFileSync(frame.abs_path, "utf8");
     const lines = source.split("\n");
     const lineIndex = frame.lineno - 1; // Convert to 0-based index
 
@@ -635,9 +657,18 @@ function makeRelativePath(filename: string): string {
   // Step 7: Strip deployment-specific paths
   result = stripDeploymentPaths(result);
 
-  // Step 8: Strip current working directory
-  const cwd = process.cwd();
-  if (result.startsWith(cwd)) {
+  // Step 8: Strip current working directory (if available)
+  // process.cwd() may not be available in edge environments
+  let cwd: string | null = null;
+  try {
+    if (typeof process !== "undefined" && typeof process.cwd === "function") {
+      cwd = process.cwd();
+    }
+  } catch {
+    // process.cwd() not available in this environment
+  }
+
+  if (cwd && result.startsWith(cwd)) {
     result = result.substring(cwd.length + 1); // +1 to remove leading /
   }