Skip to content

feat(newtab): Add hnt-backend-investigation skill - #32

Open
mmiermans wants to merge 51 commits into
mozilla:mainfrom
mmiermans:add-hnt-backend-investigation-skill
Open

feat(newtab): Add hnt-backend-investigation skill#32
mmiermans wants to merge 51 commits into
mozilla:mainfrom
mmiermans:add-hnt-backend-investigation-skill

Conversation

@mmiermans

@mmiermans mmiermans commented Jul 30, 2026

Copy link
Copy Markdown

Adds hnt-backend-investigation to the newtab plugin: a diagnostic workflow for Home New Tab backend incidents, covering content recommendations, Picture of the Day and the daily crossword. It produces an evidence-backed FINDINGS.md carrying a root cause, quantified impact and the change that would resolve it, alongside a HYPOTHESES.md working list.

references/data-sources.md holds per-system access and the data traps that silently return wrong answers. Its table shapes, project ids, endpoints, API auth and database accounts were checked against the live systems rather than written from memory. Docs only, no code changes.

Installing it before this merges

This repo is itself a plugin marketplace, so installing from the branch is two sequential steps: register the branch as a marketplace, then install the newtab plugin from it. The path you register is the repo root, the directory holding .claude-plugin/marketplace.json, not the skill folder.

1. Clone the branch:

cd ~
git clone -b add-hnt-backend-investigation-skill \
  https://github.com/mmiermans/firefox-aidev-plugins.git hnt-skill-review

2. Start Claude Code from that same directory, then run both commands:

/plugin marketplace add ./hnt-skill-review
/plugin install newtab@firefox-aidev-plugins

/plugin install opens a details view where you pick an install scope to confirm. If the summary says Run /reload-plugins to activate., run that. Then check it landed: /skills should list newtab:backend-investigation, and you can invoke it directly with /newtab:backend-investigation.

To undo: /plugin marketplace remove firefox-aidev-plugins. If you already have that marketplace from mozilla/firefox-aidev-plugins, remove it first, since both share the name.

What to look at

  • Invoke it with something like "newtab DE sections look empty, investigate"
  • It asks once where you keep investigations, then remembers it. That is its only persistent side effect outside the investigation directory, so it is worth confirming what it recorded
  • It should confirm the symptom against live data before theorizing, and raise a User action: task for anything it cannot reach, such as corpus MySQL needing the AWS Client VPN, rather than stopping to wait
  • Every number in FINDINGS.md should be reproducible from the queries saved beside it

@mmiermans
mmiermans force-pushed the add-hnt-backend-investigation-skill branch from 3dd3157 to d0e16f9 Compare July 30, 2026 17:49
mmiermans added 27 commits July 30, 2026 13:54
@mmiermans
mmiermans marked this pull request as ready for review August 10, 2026 21:50
Copilot AI lite review requested due to automatic review settings August 10, 2026 21:50

Copilot AI left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview

Adds a new backend-investigation skill to the newtab plugin, providing a structured diagnostic workflow for Firefox Home/New Tab backend incidents and a companion reference of data sources, access paths, and “silent wrong answer” traps.

Changes:

  • Add plugins/newtab/skills/backend-investigation/SKILL.md defining the investigation workflow and required outputs (FINDINGS.md, HYPOTHESES.md).
  • Add plugins/newtab/skills/backend-investigation/references/data-sources.md documenting systems to query, access constraints, and common pitfalls.
  • Document the new skill in plugins/newtab/README.md.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File Description
plugins/newtab/skills/backend-investigation/SKILL.md New skill write-up defining the end-to-end investigation workflow and report templates.
plugins/newtab/skills/backend-investigation/references/data-sources.md New reference guide for where/how to collect evidence across HNT backend systems.
plugins/newtab/README.md Adds user-facing documentation entry for the new backend-investigation skill.
Suppressed comments (1)

plugins/newtab/skills/backend-investigation/SKILL.md:254

  • In the FINDINGS.md template, the Timeline header row is missing the Markdown table separator line, so the timeline won’t format as a table.
## Timeline (UTC)
| Time | Observation | Source |


💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

| No `mcp__sentry__` tools at all | `claude mcp add --scope user --transport http sentry https://mcp.sentry.dev/mcp`, then `/mcp` in the restarted session to authenticate |
| Sentry connected but unauthenticated or scoped too narrowly | `/mcp`, and authenticate for the `mozilla` org |
| Corpus MySQL hangs rather than erroring, and they have the VPN client | Connect to the AWS Client VPN, then say so; if it still hangs, the login path itself is stale |
| Corpus MySQL hangs and there is no VPN client installed | Install the AWS VPN Client from https://aws.amazon.com/vpn/client-vpn-download/, then download the client configuration from the endpoint page — https://us-east-1.console.aws.amazon.com/vpcconsole/home?region=us-east-1#ClientVPNEndpointDetails:clientVpnEndpointId=cvpn-endpoint-0d3c4e4a0121a5763 — load that profile into the client, connect, and say so |
Comment on lines +180 to +182
```markdown
| # | Hypothesis | What would kill it | Probe | Result | Status |
```
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants