feat(dart_mcp_server): add HTTP network inspection tools by ThangVuNguyenViet · Pull Request #422 · dart-lang/ai

ThangVuNguyenViet · 2026-04-02T14:08:25Z

Summary

Implements the network inspection tools proposed in #269.

Auto-enables HTTP profiling (ext.dart.io.httpEnableTimelineLogging) on every isolate when a VM service connects, so requests are captured from app start with no app-side code changes required
Adds get_network_logs — fetch recorded HTTP requests, with optional updatedSince for polling
Adds clear_network_logs — reset the HTTP profile buffer
Adds get_network_request — fetch full detail (headers + body) for a single request by ID
New networkInspector feature category (child of dartToolingDaemon), disabled by default — opt in via --enable=networkInspector

Uses ext.dart.io.* extensions registered by the Dart runtime itself for any dart:io app in debug mode.

Closes #269 (partial — web/CDP transport not included in this PR)

Test plan

In-process tests pass: dart test --enable-experiment=private-named-parameters test/tools/network_inspector_test.dart --name "in-process"
Full integration tests pass with correct Dart dev SDK (^3.12.0-257.0.dev)
Manually verify with flutter run + --enable=networkInspector flag

Notes

dart_test.yaml with enable_experiment: [private-named-parameters] added to allow running tests locally with Dart stable SDK during development; this can be removed once the repo targets a released SDK
The chore: relax SDK constraint commit is for local development only and should be reverted before merge

- Auto-enable HTTP profiling on all isolates when VM service connects - Implement get_network_logs, clear_network_logs, get_network_request tools - Register tools in initialize() and add to allTools static list

…ameters experiment

google-cla · 2026-04-02T14:08:31Z

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

jakemac53

Awesome, this is a great start! 🚀 🥳

One higher level comment is that we are moving to a pattern of "meta tools" generally in order to save on tool counts (and tokens). To be consistent with that please migrate these all to a single "network" tool, with a "command" argument. See the DTD tool as an example.

jakemac53 · 2026-04-02T14:18:00Z

pkgs/dart_mcp_server/lib/src/mixins/dtd.dart

+    description:
+        'Fetches recorded HTTP requests from the running app. '
+        'HTTP profiling is enabled automatically when the app connects, so '
+        'requests are captured from app start. Use updatedSince to poll only '


nit: logs are not actually captured from app start, they are only captured once we connect.

I think we actually should have an explicit tool call though to start capturing logs, and also to stop capturing them. Otherwise I think we will implicitly have a bit of a memory leak here?

jakemac53 · 2026-04-02T14:20:44Z

pkgs/dart_mcp_server/test/tools/network_inspector_test.dart

+  late TestHarness testHarness;
+
+  group('network inspector tools', () {
+    group('[in-process]', () {


nit: I would just make all these tests uses an in process test harness - we really only need a few total tests that use an out of process MCP server, and its much easier to debug when its in process

jakemac53 · 2026-04-02T15:25:24Z

docs/superpowers/plans/2026-04-02-network-inspector.md

@@ -0,0 +1,698 @@
+# Network Inspector Implementation Plan


nit: Please remove these docs from the PR :)

jakemac53 · 2026-04-02T15:28:47Z

pkgs/dart_mcp_server/dart_test.yaml

@@ -0,0 +1,2 @@
+enable_experiment:


nit: we should not be enabling experiments in any code we land here, even for tests

jakemac53 · 2026-04-02T15:29:56Z

pkgs/dart_mcp_server/pubspec.yaml

  models.
 publish_to: none
 environment:
-  sdk: ^3.12.0-257.0.dev


This needs to remain at the old constraint - some of our tools do rely on stuff that only exists after this dev release (listing active DTD URIs)

jakemac53 · 2026-04-02T15:31:17Z

pkgs/dart_mcp_server/test/tools/network_inspector_test.dart

+
+          expect(result.isError, isNot(true));
+        });
+      });


We should add another test fixture that does make network requests, so that we can test that actual network logs can be captured, cleared, etc.

jakemac53 · 2026-04-02T15:31:50Z

pkgs/dart_mcp_server/lib/src/mixins/dtd.dart

+              .toList();
+          return CallToolResult(
+            content: [TextContent(text: jsonEncode(requests))],
+            structuredContent: {'requests': requests},


nit: I would remove the structured content here unless we need it for something. The text content can already easily just be decoded as JSON if some tooling wants to explicitly do that.

jakemac53 · 2026-04-02T15:34:54Z

pkgs/dart_mcp_server/lib/src/mixins/dtd.dart

+      callback: (vmService) async {
+        try {
+          final vm = await vmService.getVM();
+          final isolateId = vm.isolates!.first.id!;


Above we enable network logging for all isolates, but here we only will return logs for the first one.

Supporting only the root isolate for now is probably fine, but we should also only enable capturing logs for the first isolate then.

We should also file a bug and add a TODO for supporting additional isolates.

jakemac53 · 2026-04-02T15:35:18Z

pkgs/dart_mcp_server/lib/src/mixins/dtd.dart

+      callback: (vmService) async {
+        try {
+          final vm = await vmService.getVM();
+          final isolateId = vm.isolates!.first.id!;


Same here, we should either consistently support all the isolates or only the first one.

github-actions · 2026-04-02T15:40:06Z

PR Health

Changelog Entry ✔️

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

This check can be disabled by tagging the PR with skip-changelog-check.

kenzieschmoll · 2026-04-02T16:04:04Z

I'd like to see how we can share code with the Dart DevTools network inspector here rather than maintain two copies of code that is fetching network requests from the VM service.

ThangVuNguyenViet · 2026-04-02T16:14:22Z

Hey sorry. I did not have the intention to open this PR this the first place. I was going to, after I review what Claude did and try the work myself, which I haven't. I was afraid I'm gonna make another AI slop PR so I panicky closed the PR.

But really thanks for the comments. I'll address them and reopen the PR once it's done on my end

jakemac53 · 2026-04-02T16:20:24Z

@ThangVuNguyenViet fwiw this PR is quite reasonable, I wouldn't call it AI slop :D, but in general yes its a good idea to review AI code prior to sending it out.

However, I wouldn't have been able to tell this was AI without the planning docs in there 🤣

jakemac53 · 2026-04-02T16:20:44Z

@kenzieschmoll lets discuss at the meeting today

thangvu added 10 commits April 2, 2026 19:53

docs: add network inspector design spec

5d1846f

docs: add network inspector implementation plan

2991556

feat: add networkInspector feature category

df2026d

feat: add network inspector tool names and parameter names

7165c2c

test: add failing network inspector tests

7b319d0

feat: implement network inspector tools and auto-enable HTTP profiling

c6b7995

- Auto-enable HTTP profiling on all isolates when VM service connects - Implement get_network_logs, clear_network_logs, get_network_request tools - Register tools in initialize() and add to allTools static list

fix: correct vm_service API usage in network inspector tools

7a59d80

chore: relax SDK constraint to ^3.11.4 for local development

1fcc571

fix: add missing addTearDown for freshHarness in network inspector test

990a401

fix: restructure network inspector tests and enable private-named-par…

4665fb0

…ameters experiment

github-actions bot added the package:dart_mcp_server label Apr 2, 2026

jakemac53 requested changes Apr 2, 2026

View reviewed changes

ThangVuNguyenViet closed this Apr 2, 2026

Conversation

ThangVuNguyenViet commented Apr 2, 2026

Summary

Test plan

Notes

Uh oh!

google-cla bot commented Apr 2, 2026

Uh oh!

jakemac53 left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

github-actions bot commented Apr 2, 2026

PR Health

Uh oh!

kenzieschmoll commented Apr 2, 2026

Uh oh!

ThangVuNguyenViet commented Apr 2, 2026

Uh oh!

jakemac53 commented Apr 2, 2026

Uh oh!

jakemac53 commented Apr 2, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants