Change Python package resolution to use the PyPA simple api on PyPI

packages/worker-bundler/package.json

@@ -36,6 +36,7 @@
     "@typescript/vfs": "^1.6.4",
     "es-module-lexer": "^2.2.0",
     "esbuild-wasm": "0.28.1",
+    "fflate": "^0.8.2",
     "resolve.exports": "^2.0.3",
     "semver": "^7.8.5",
     "smol-toml": "^1.7.0",

packages/worker-bundler/src/index.ts

@@ -8,7 +8,7 @@ import { bundleWithEsbuild, bundlerOnlyOptionsWarning } from "./bundler";
 import { hasNodejsCompat, parseWranglerConfig } from "./config";
 import { hasDependencies, installDependencies } from "./installer";
 import { transformAndResolve } from "./transformer";
-import type { CreateWorkerOptions, CreateWorkerResult } from "./types";
+import type { CreateWorkerOptions, CreateWorkerResult, Modules } from "./types";
 import {
   DEFAULT_ENTRY_POINTS,
   detectEntryPoint,
@@ -117,7 +117,7 @@ export async function createWorker(
   const wranglerConfig = parseWranglerConfig(fileSystem);
   const nodejsCompat = hasNodejsCompat(wranglerConfig);
 
-  // Auto-install dependencies if package.json has dependencies
+  // Auto-install dependencies if package.json or pyproject.toml has dependencies
   const installWarnings: string[] = [];
   if (hasDependencies(fileSystem)) {
     const installResult = await installDependencies(
@@ -143,6 +143,29 @@ export async function createWorker(
     );
   }
 
+  if (entryPoint.endsWith(".py")) {
+    const modules: Modules = {};
+    for (const path of fileSystem.list()) {
+      if (path === "pyproject.toml") {
+        continue;
+      }
+      const content = fileSystem.read(path);
+      if (content !== null) {
+        modules[path] = content;
+      }
+    }
+
+    return {
+      mainModule: entryPoint,
+      modules,
+      wranglerConfig: {
+        compatibilityDate: wranglerConfig?.compatibilityDate ?? "2026-07-02",
+        compatibilityFlags: wranglerConfig?.compatibilityFlags ?? []
+      },
+      warnings: installWarnings
+    };
+  }
+
   if (bundle) {
     // Try bundling with esbuild-wasm
     const result = await bundleWithEsbuild({
@@ -171,7 +194,6 @@ export async function createWorker(
     if (installWarnings.length > 0) {
       result.warnings = [...(result.warnings ?? []), ...installWarnings];
     }
-
     return result;
   } else {
     // No bundling - transform files and resolve dependencies.