ci: verify harness runtime in Cloudflare Workers

.changeset/harness-worker-edge-smoke.md

@@ -0,0 +1,5 @@
+---
+"@ai-sdk-tool/harness": patch
+---
+
+Verify the runtime subpath in a real Cloudflare Worker bundle and keep optional Node-only MCP and skills modules out of edge bundles unless those features are configured.

.github/workflows/ci.yml

@@ -117,3 +117,29 @@ jobs:
 
       - name: Test
         run: SKIP_E2E=1 pnpm run test
+
+  edge-safe:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10.32.1
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Check Cloudflare Worker runtime compatibility
+        run: pnpm run test:edge-safe

package.json

@@ -12,6 +12,7 @@
     "typecheck:root": "pnpm -F @ai-sdk-tool/harness exec tsc --noEmit -p ../../tsconfig.root.json",
     "check": "pnpm exec ultracite check .",
     "lint": "pnpm exec ultracite fix .",
+    "test:edge-safe": "pnpm -F @ai-sdk-tool/harness build && node scripts/cloudflare-worker-edge-smoke/run.mjs",
     "test:headless-edit": "node --import tsx scripts/test-headless-edit-ops.ts",
     "test:headless-edit-edge": "node --import tsx scripts/test-headless-edit-edge-cases.ts",
     "changeset": "changeset",
@@ -45,6 +46,7 @@
     "tsx": "^4.21.0",
     "turbo": "^2.9.6",
     "ultracite": "^7.6.0",
-    "vitest": "^4.1.5"
+    "vitest": "^4.1.5",
+    "wrangler": "^4.85.0"
   }
 }

packages/harness/edge-smoke/worker.mjs

@@ -0,0 +1,39 @@
+import { createAgentRuntime, defineAgent } from "@ai-sdk-tool/harness/runtime";
+
+export default {
+  async fetch() {
+    if ("process" in globalThis) {
+      return json({ ok: false, error: "process global is present" }, 500);
+    }
+
+    const runtime = await createAgentRuntime({
+      name: "cf-worker-edge-smoke",
+      cwd: "/",
+      agents: [
+        defineAgent({
+          name: "bot",
+          agent: { model: {}, instructions: "edge smoke" },
+        }),
+      ],
+    });
+
+    try {
+      const session = await runtime.openSession({
+        sessionId: "cf-worker-edge-smoke-session",
+      });
+      return json({
+        ok: session.sessionId === "cf-worker-edge-smoke-session",
+        sessionId: session.sessionId,
+      });
+    } finally {
+      await runtime.close();
+    }
+  },
+};
+
+function json(body, status = 200) {
+  return new Response(JSON.stringify(body), {
+    headers: { "content-type": "application/json" },
+    status,
+  });
+}

packages/harness/edge-smoke/wrangler.jsonc

@@ -0,0 +1,7 @@
+{
+  "$schema": "../../../node_modules/wrangler/config-schema.json",
+  "name": "plugsuits-harness-runtime-edge-smoke",
+  "main": "./worker.mjs",
+  "compatibility_date": "2026-04-27",
+  "workers_dev": true
+}

packages/harness/src/agent.ts

@@ -25,6 +25,8 @@ export interface StopConditionInput {
 }
 export type StopCondition = (input: StopConditionInput) => boolean;
 
+const MCP_INIT_MODULE = "./mcp-init.js";
+
 const toToolSet = async (toolSources: ToolSource[] | undefined) => {
   if (!toolSources || toolSources.length === 0) {
     return {};
@@ -235,7 +237,9 @@ export async function createAgent(config: AgentConfig): Promise<Agent> {
   };
 
   if (config.mcp !== undefined) {
-    const { resolveMCPOption } = await import("./mcp-init");
+    const { resolveMCPOption }: typeof import("./mcp-init") = await import(
+      MCP_INIT_MODULE
+    );
     const resolved = await resolveMCPOption(config.mcp, mergedTools);
     mergedTools = resolved.tools;
     const previousClose = closeFn;

packages/harness/src/runtime/create-runtime.ts

@@ -14,6 +14,8 @@ import type {
   DefinedAgent,
 } from "./types";
 
+const SKILLS_MODULE = "../skills.js";
+
 const getDefaultCwd = (): string => {
   if (typeof process === "undefined") {
     return "/";
@@ -29,7 +31,9 @@ const getDefaultCwd = (): string => {
 const loadConfiguredSkills = async (
   config: AgentSkillsConfig
 ): Promise<SkillInfo[]> => {
-  const { SkillsEngine } = await import("../skills");
+  const { SkillsEngine }: typeof import("../skills") = await import(
+    SKILLS_MODULE
+  );
   return await new SkillsEngine(config).loadAllSkills();
 };