feat(project): wire dev handler

Author: tejaskash

package.json

@@ -7,6 +7,9 @@
     "agentcore": "./dist/index.js"
   },
   "main": "./dist/index.js",
+  "engines": {
+    "node": ">=20.12.0"
+  },
   "files": [
     "dist"
   ],

src/assets/templates/shared/env.local.template

@@ -1,7 +1,7 @@
 # Environment variables for local development.
-# `agentcore dev` loads this file into your agent's process. Values here
-# override anything the CLI injects. This file is gitignored — keep secrets
-# out of version control, but they are safe here.
+# `agentcore project dev` loads this file into your agent's process. Values here
+# override injected values except PORT, FASTMCP_PORT, and LOCAL_DEV, which the
+# CLI owns. This file is gitignored — keep secrets out of version control.
 #
 # Example:
 # MY_API_KEY=...

src/core/dev/container.test.ts

@@ -61,6 +61,8 @@ function harness(
   config: {
     available?: (tool: string, probeArgs?: string[]) => Promise<boolean>;
     stream?: StreamBehavior;
+    awsDirectory?: string;
+    processEnv?: NodeJS.ProcessEnv;
   } = {},
 ) {
   const calls: ProcessCall[] = [];
@@ -77,6 +79,11 @@ function harness(
         (async (tool) => {
           return tool === "docker";
         }),
+      awsDirectory: config.awsDirectory ?? join(tmpdir(), "agentcore-container-no-aws"),
+      processEnv: config.processEnv ?? {
+        AWS_ACCESS_KEY_ID: "test-access-key",
+        AWS_SECRET_ACCESS_KEY: "test-secret-key",
+      },
     }),
   };
 }
@@ -189,6 +196,10 @@ describe("ContainerDevRunner", () => {
       "-p",
       `127.0.0.1:3000:${containerPort}`,
       "-e",
+      "AWS_ACCESS_KEY_ID=test-access-key",
+      "-e",
+      "AWS_SECRET_ACCESS_KEY=test-secret-key",
+      "-e",
       "API_KEY=super-secret",
       "-e",
       `PORT=${containerPort}`,
@@ -202,6 +213,35 @@ describe("ContainerDevRunner", () => {
     expect(run.options.redactedCommand?.join(" ")).not.toContain("super-secret");
   });
 
+  test("uses a shared AWS config and rejects missing credentials", async () => {
+    const projectRuntime = runtime();
+    const root = await projectRoot(projectRuntime);
+    const awsDirectory = join(root, ".aws");
+    await mkdir(awsDirectory);
+    await writeFile(join(awsDirectory, "config"), "[profile sandbox]\nregion=us-east-1\n");
+    const { calls, runner } = harness({
+      awsDirectory,
+      processEnv: { AWS_PROFILE: "sandbox", AWS_REGION: "us-east-1" },
+    });
+
+    await collect(runner.run(input(root, projectRuntime)));
+
+    const run = commandCall(calls, "run");
+    expect(run.command).toContain(`${awsDirectory}:/aws-config:ro`);
+    expect(run.command).toContain("AWS_PROFILE=sandbox");
+    expect(run.command).toContain("AWS_CONFIG_FILE=/aws-config/config");
+    expect(run.options.redactedCommand?.join(" ")).not.toContain("sandbox");
+
+    const missing = harness({
+      awsDirectory: join(root, "missing-aws"),
+      processEnv: {},
+    });
+    await expect(collect(missing.runner.run(input(root, projectRuntime)))).rejects.toThrow(
+      "Unable to resolve AWS credentials for the container",
+    );
+    expect(missing.calls).toHaveLength(0);
+  });
+
   test("preserves an existing build context .dockerignore", async () => {
     const projectRuntime = runtime({ buildContextPath: "." });
     const root = await projectRoot(projectRuntime);

src/core/dev/container.ts

@@ -1,5 +1,6 @@
 import { createHash } from "node:crypto";
 import { existsSync, statSync, writeFileSync } from "node:fs";
+import { homedir } from "node:os";
 import { join, resolve } from "node:path";
 import { InputValidationError, InvalidEnvironmentError } from "../../errors";
 import type { DevEvent, DevRunner, DevServerInput } from "../../handlers/project/dev/types";
@@ -10,8 +11,17 @@ import {
   type ProcessStreamer,
   type StreamProcessOptions,
 } from "../../io";
+import { DEV_PORTS } from "./port";
 
 const CONTAINER_TOOLS = ["docker", "podman", "finch"] as const;
+const AWS_ENV_KEYS = [
+  "AWS_ACCESS_KEY_ID",
+  "AWS_SECRET_ACCESS_KEY",
+  "AWS_SESSION_TOKEN",
+  "AWS_REGION",
+  "AWS_DEFAULT_REGION",
+  "AWS_PROFILE",
+] as const;
 const CLEANUP_TIMEOUT_MS = 2_000;
 const DOCKERFILE_NAME = "Dockerfile";
 const CONTAINER_RUNTIME_INSTALL_HINT =
@@ -44,15 +54,21 @@ type ToolAvailable = typeof toolAvailable;
 type ContainerDevRunnerConfig = {
   streamProcess?: ProcessStreamer;
   toolAvailable?: ToolAvailable;
+  awsDirectory?: string;
+  processEnv?: NodeJS.ProcessEnv;
 };
 
 export class ContainerDevRunner implements DevRunner {
   private readonly streamProcess: ProcessStreamer;
   private readonly toolAvailable: ToolAvailable;
+  private readonly awsDirectory: string;
+  private readonly processEnv: NodeJS.ProcessEnv;
 
   constructor(config: ContainerDevRunnerConfig = {}) {
     this.streamProcess = config.streamProcess ?? streamProcess;
     this.toolAvailable = config.toolAvailable ?? toolAvailable;
+    this.awsDirectory = config.awsDirectory ?? join(homedir(), ".aws");
+    this.processEnv = config.processEnv ?? process.env;
   }
 
   public async *run(input: DevServerInput): AsyncGenerator<DevEvent, void> {
@@ -71,6 +87,18 @@ export class ContainerDevRunner implements DevRunner {
       throw new InputValidationError(`container Dockerfile not found: ${dockerfilePath}`);
     }
 
+    const hasAwsCredentials = Boolean(
+      (input.env?.AWS_ACCESS_KEY_ID ?? this.processEnv.AWS_ACCESS_KEY_ID) &&
+      (input.env?.AWS_SECRET_ACCESS_KEY ?? this.processEnv.AWS_SECRET_ACCESS_KEY),
+    );
+    const hasAwsConfig = existsSync(this.awsDirectory);
+    if (!hasAwsCredentials && !hasAwsConfig) {
+      throw new InputValidationError(
+        "Unable to resolve AWS credentials for the container. Configure AWS credentials " +
+          "or set AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, then retry.",
+      );
+    }
+
     const tool = await this.resolveContainerTool(input.signal);
     input.signal.throwIfAborted();
     if (input.runtime.buildContextPath) {
@@ -116,15 +144,23 @@ export class ContainerDevRunner implements DevRunner {
     yield { type: "status", message: `Building image with ${tool}` };
     yield* this.streamProcess(buildCommand, buildOptions);
 
-    const containerPort = portForProtocol(input.runtime.protocol);
-    const forwardedEnv: Record<string, string> = {
-      ...input.env,
+    const containerPort = DEV_PORTS[input.runtime.protocol ?? "HTTP"];
+    const forwardedEnv: Record<string, string> = {};
+    for (const key of AWS_ENV_KEYS) {
+      if (this.processEnv[key]) forwardedEnv[key] = this.processEnv[key];
+    }
+    Object.assign(forwardedEnv, input.env, {
       PORT: String(containerPort),
       LOCAL_DEV: "1",
-    };
+    });
     if (input.runtime.protocol === "MCP") {
       forwardedEnv.FASTMCP_PORT = String(containerPort);
     }
+    const awsMount = hasAwsConfig ? ["-v", `${this.awsDirectory}:/aws-config:ro`] : [];
+    if (awsMount.length) {
+      forwardedEnv.AWS_CONFIG_FILE = "/aws-config/config";
+      forwardedEnv.AWS_SHARED_CREDENTIALS_FILE = "/aws-config/credentials";
+    }
     const envFlags = Object.entries(forwardedEnv).flatMap(([key, value]) => [
       "-e",
       `${key}=${value}`,
@@ -141,6 +177,7 @@ export class ContainerDevRunner implements DevRunner {
       containerName,
       "-p",
       `127.0.0.1:${input.port}:${containerPort}`,
+      ...awsMount,
       ...envFlags,
       imageTag,
     ];
@@ -158,6 +195,7 @@ export class ContainerDevRunner implements DevRunner {
           containerName,
           "-p",
           `127.0.0.1:${input.port}:${containerPort}`,
+          ...awsMount,
           ...redactedEnvFlags,
           imageTag,
         ],
@@ -204,12 +242,6 @@ export class ContainerDevRunner implements DevRunner {
   }
 }
 
-function portForProtocol(protocol: DevServerInput["runtime"]["protocol"]): number {
-  if (protocol === "MCP") return 8000;
-  if (protocol === "A2A") return 9000;
-  return 8080;
-}
-
 function isDirectory(path: string): boolean {
   try {
     return statSync(path).isDirectory();

src/core/dev/port.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, test } from "bun:test";
+import type { PortChecker } from "../../io";
+import { resolveDevPort } from "./port";
+
+const signal = new AbortController().signal;
+
+describe("resolveDevPort", () => {
+  test.each([
+    ["HTTP", 8080],
+    ["AGUI", 8080],
+    ["MCP", 8000],
+    ["A2A", 9000],
+  ] as const)("uses the %s default", async (protocol, port) => {
+    expect(await resolveDevPort(protocol, undefined, async () => true, signal)).toEqual({
+      port,
+      requestedPort: port,
+    });
+  });
+
+  test("walks up from occupied defaults", async () => {
+    const checked: number[] = [];
+    const check: PortChecker = async (port) => {
+      checked.push(port);
+      return port === 8002;
+    };
+
+    expect(await resolveDevPort("MCP", undefined, check, signal)).toEqual({
+      port: 8002,
+      requestedPort: 8000,
+    });
+    expect(checked).toEqual([8000, 8001, 8002]);
+  });
+
+  test("accepts a free explicit port and rejects an occupied one", async () => {
+    expect(await resolveDevPort("A2A", 4567, async () => true, signal)).toEqual({
+      port: 4567,
+      requestedPort: 4567,
+    });
+    await expect(resolveDevPort("A2A", 4567, async () => false, signal)).rejects.toThrow(
+      "lsof -i :4567",
+    );
+  });
+
+  test("bounds the default search", async () => {
+    await expect(resolveDevPort("HTTP", undefined, async () => false, signal)).rejects.toThrow(
+      "No free port found in range 8080-8179",
+    );
+  });
+});

src/core/dev/port.ts

@@ -0,0 +1,45 @@
+import { InputValidationError } from "../../errors";
+import type { ProjectRuntime } from "../project/schema";
+import type { PortChecker } from "../../io";
+
+const MAX_PORT_ATTEMPTS = 100;
+export const DEV_PORTS = { HTTP: 8080, AGUI: 8080, MCP: 8000, A2A: 9000 } as const;
+
+export type DevPort = {
+  port: number;
+  requestedPort: number;
+};
+
+function portInUse(port: number, suffix = ""): InputValidationError {
+  return new InputValidationError(
+    `Port ${port} is already in use. Find the process with ` +
+      `'lsof -i :${port}' (macOS/Linux) or 'netstat -ano | findstr :${port}' (Windows), ` +
+      `then stop it${suffix}.`,
+  );
+}
+
+export async function resolveDevPort(
+  protocol: ProjectRuntime["protocol"],
+  explicitPort: number | undefined,
+  checkPort: PortChecker,
+  signal: AbortSignal,
+): Promise<DevPort> {
+  const defaultPort = DEV_PORTS[protocol ?? "HTTP"];
+  const requestedPort = explicitPort ?? defaultPort;
+
+  if (await checkPort(requestedPort, signal)) {
+    return { port: requestedPort, requestedPort };
+  }
+
+  if (explicitPort !== undefined) {
+    throw portInUse(requestedPort, " or choose a different --port");
+  }
+
+  for (let port = requestedPort + 1; port < requestedPort + MAX_PORT_ATTEMPTS; port++) {
+    if (await checkPort(port, signal)) return { port, requestedPort };
+  }
+
+  throw new InputValidationError(
+    `No free port found in range ${requestedPort}-${requestedPort + MAX_PORT_ATTEMPTS - 1}.`,
+  );
+}

src/errors/errors.tsx

@@ -135,7 +135,7 @@ export class EmbeddedAssetNotFoundError extends AgentCoreCLIError {
   }
 }
 
-export class RuntimeInvokeInterruptedError extends AgentCoreCLIError {
+export class CommandInterruptedError extends AgentCoreCLIError {
   readonly reported: boolean;
 
   constructor(cause?: unknown, reported = false) {

src/errors/index.tsx

@@ -1,5 +1,6 @@
 export {
   AgentCoreCLIError,
+  CommandInterruptedError,
   DeserializationError,
   EmbeddedAssetNotFoundError,
   FileWriteError,
@@ -10,7 +11,6 @@ export {
   NotImplementedError,
   ProjectFileExistsError,
   ResultTruncationError,
-  RuntimeInvokeInterruptedError,
   RuntimeInvokeResponseError,
   SourceResolutionError,
   type AgentCoreCLIErrorOptions,