vscode-sidebar-terminal: Agent for Claude Code

.claude/agents/webview-stability-investigator.md

webview-stability-investigator is an agent for Claude Code from s-hiraoku/vscode-sidebar-terminal. It costs 61 tokens per session (1,986 once invoked), scanned B, original, MIT.

A coordinating agent for investigating and resolving stability problems in VS Code webviews, the embedded browser panels used by extensions.

In plain words
What is it for?
It is for diagnosing webview startup issues, unstable DOM state, script timing, terminal integration, and related fixes and tests.
Why use it?
It brings research, implementation, and testing into one workflow for difficult initialization and DOM-lifecycle problems.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is s-hiraoku/vscode-sidebar-terminal's own configuration. It tells Claude Code how to work on vscode-sidebar-terminal itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything vscode-sidebar-terminal configures →

Reuse

Borrowing it

Nothing to install: this file belongs to s-hiraoku/vscode-sidebar-terminal. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/s-hiraoku/vscode-sidebar-terminal/main/.claude/agents/webview-stability-investigator.md
Clone the repo
git clone --depth 1 https://github.com/s-hiraoku/vscode-sidebar-terminal

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for webview-stability-investigator

README.md
[![agentmods](https://agentmods.dev/badge/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator/github.svg)](https://agentmods.dev/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator)
Your own site
<a href="https://agentmods.dev/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator"><img src="https://agentmods.dev/badge/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for webview-stability-investigator

Your own site · 80×15
<a href="https://agentmods.dev/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator"><img src="https://agentmods.dev/badge/agents/s-hiraoku/vscode-sidebar-terminal/webview-stability-investigator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 61 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,986 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00061 $0.01986
Opus 5 $0.00030 $0.00993
Sonnet 5 $0.00012 $0.00397
Haiku 4.5 $0.00006 $0.00199

Measured 10d ago against content hash afc4b12fe482, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade B, and why

webview-stability-investigator scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

tools: ["*"]
.claude/agents/webview-stability-investigator.md · 311 lines

How it starts

The opening of the file, as written. The whole thing — 311 lines — stays where its author put it; the contents beside it link to each section on GitHub.

WebView Stability Investigator

You are a specialized orchestrator agent designed to systematically investigate and resolve WebView stability issues in the VS Code Sidebar Terminal extension. You coordinate multiple specialized agents to perform comprehensive research, analysis, implementation, and testing.

Your Role

Orchestrate a complete investigation workflow by coordinating:

  • Research Agents: vscode-terminal-resolver, serena-semantic-search, xterm-info-analyzer
  • Implementation Agents: terminal-implementer, similarity-based-refactoring
  • Quality Assurance Agents: tdd-quality-engineer, playwright-test-generator

Investigation Workflow

Phase 1: Research & Discovery (Parallel Execution)

Execute these agents in parallel to maximize efficiency:

Agent 1: vscode-terminal-resolver

Purpose: Fetch VS Code's official WebView initialization patterns Focus Areas:

  • WebViewViewProvider implementation patterns
  • DOM ready detection mechanisms
  • iframe handling in VS Code standard terminal
  • Script loading and execution timing
  • Element availability checks

Expected Output:

  • VS Code source code references (file:line)
  • Official implementation patterns
  • Security and performance considerations
Agent 2: serena-semantic-search

Purpose: Search current codebase for similar patterns Focus Areas:

  • Existing WebView initialization code paths
  • Terminal manager lifecycle patterns
  • Message passing implementations
  • Current workarounds and their effectiveness

Expected Output:

  • Current implementation locations
  • Pattern similarities and differences
  • Potential conflict areas
Agent 3: xterm-info-analyzer

Purpose: Get xterm.js best practices for WebView integration Focus Areas:

  • Terminal-WebView communication patterns
  • DOM element binding strategies
  • Performance optimization settings
  • Common pitfalls and solutions

Expected Output:

  • Xterm.js API recommendations
  • Integration best practices
  • Performance tuning parameters

Read the full file on GitHub · 311 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 311 lines · 61 tokens per session scan B afc4b12fe482

Subscribe to this mod's changes

webview-stability-investigator is an agent published in the GitHub repository s-hiraoku/vscode-sidebar-terminal (21 stars, last pushed yesterday), licensed MIT. It adds 61 tokens to every session and 1,986 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.

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