"npx adk web" fails for agents targeting ADK for TypeScript 1.0.0

[cp-689]

agent1.0.0.zip

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Describe the bug
After upgrading an ADK agent from 0.5.0 to 1.0.0, "npx adk web" failed with the following error:

`

npx adk web
node:internal/modules/package_json_reader:301
throw new ERR_MODULE_NOT_FOUND(packageName, fileURLToPath(base), null);
^

Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'yaml' imported from C:\source\projects\agent1.0.0\node_modules@google\adk-devtools\dist\cli_entrypoint.mjs
at Object.getPackageJSONURL (node:internal/modules/package_json_reader:301:9)
at packageResolve (node:internal/modules/esm/resolve:768:81)
at moduleResolve (node:internal/modules/esm/resolve:859:18)
at defaultResolve (node:internal/modules/esm/resolve:991:11)
at #cachedDefaultResolve (node:internal/modules/esm/loader:719:20)
at #resolveAndMaybeBlockOnLoaderThread (node:internal/modules/esm/loader:736:38)
at ModuleLoader.resolveSync (node:internal/modules/esm/loader:765:52)
at #resolve (node:internal/modules/esm/loader:701:17)
at ModuleLoader.getOrCreateModuleJob (node:internal/modules/esm/loader:621:35)
at ModuleJob.syncLink (node:internal/modules/esm/module_job:160:33) {
code: 'ERR_MODULE_NOT_FOUND'
}
`

Rolling back to 0.5.0 resolved the issue.

So, I created a new agent from scratch using the steps outlined here: https://adk.dev/get-started/typescript/

I again received the error message above when using "npx adk web"

My project (node_modules excluded) is attached as a zip file.

To Reproduce
Steps to reproduce the behavior:

1. Unzip the attached agent project
2. Enter the base directory - where agent.ts resides
3. Run "npm install"
4. Run "npx adk web"
5. This error occurs:

`

npx adk web
node:internal/modules/package_json_reader:301
throw new ERR_MODULE_NOT_FOUND(packageName, fileURLToPath(base), null);
^

Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'yaml' imported from C:\source\projects\agent1.0.0\node_modules@google\adk-devtools\dist\cli_entrypoint.mjs
at Object.getPackageJSONURL (node:internal/modules/package_json_reader:301:9)
at packageResolve (node:internal/modules/esm/resolve:768:81)
at moduleResolve (node:internal/modules/esm/resolve:859:18)
at defaultResolve (node:internal/modules/esm/resolve:991:11)
at #cachedDefaultResolve (node:internal/modules/esm/loader:719:20)
at #resolveAndMaybeBlockOnLoaderThread (node:internal/modules/esm/loader:736:38)
at ModuleLoader.resolveSync (node:internal/modules/esm/loader:765:52)
at #resolve (node:internal/modules/esm/loader:701:17)
at ModuleLoader.getOrCreateModuleJob (node:internal/modules/esm/loader:621:35)
at ModuleJob.syncLink (node:internal/modules/esm/module_job:160:33) {
code: 'ERR_MODULE_NOT_FOUND'
}
`

Expected behavior
The web server should start on port 8000.

Desktop (please complete the following information):

• OS: Windows 11
• TS version/environment:

npx --version
11.9.0

node --version
v24.14.0

npm --version
11.9.0

• ADK version(see maven dependency): 1.0.0

[eduardoRoth]

YAML issue seems to be related to this file: yaml_test_loader.ts in line 12

import {parse} from 'yaml';

As in the package json (dev/package.json) the dependency that is installed is js-yaml

"js-yaml": "^4.1.1",

[eduardoRoth]

Created a PR for this fix

• fix(): uses js-yaml instead of yaml for parsing #293