Visual Studio Code is a code editor that supports editing, navigating, understanding, debugging, and extending software projects. Developers use it for the edit-build-debug cycle, and the catalogue add-ons provide skills, instructions, and agents for working within the editor.
Borrowing it
Nothing to install: this file belongs to microsoft/vscode. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/microsoft/vscode/main/.github/skills/sessions/SKILL.mdgit clone --depth 1 https://github.com/microsoft/vscodeWrote 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.
[](https://agentmods.dev/skills/microsoft/vscode/sessions)<a href="https://agentmods.dev/skills/microsoft/vscode/sessions"><img src="https://agentmods.dev/badge/skills/microsoft/vscode/sessions/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.
<a href="https://agentmods.dev/skills/microsoft/vscode/sessions"><img src="https://agentmods.dev/badge/skills/microsoft/vscode/sessions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Rogue Agent · line 91 Skill modifies its own code, configuration, or behavior at runtime. Self-modification enables an agent to escalate privileges, disable safety constraints, or install persistent backdoors.Fix: Prevent the skill from modifying its own code, SKILL.md, or configuration files. Treat skill files as read-only at runtime.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00020 | $0.01301 |
| Opus 5.5 | $0.00008 | $0.00520 |
| Sonnet 5.5 | $0.00004 | $0.00260 |
| Haiku 4.5 | $0.00002 | $0.00130 |
Grade A, and why
sessions scanned grade A with 0 findings 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 1mo 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agents Window development
Use this skill for implementation, review, or design work under src/vs/sessions/**.
1. Apply the core principles
- Preserve the layer direction:
vs/sessionsmay importvs/workbenchand lower layers;vs/workbenchmust never importvs/sessions. - Keep shared Sessions code provider-neutral. Non-provider contributions must not import provider implementations.
- Model mutable session and chat state with observables. Use events for notifications, not as a parallel state model or for control flow.
- Register Sessions menu IDs in
browser/menus.tsand consumeMenus.*. - Import contributions from the appropriate
sessions.*.main.tsentry point. - Prefer Sessions-owned adaptations over shared workbench changes unless the capability is genuinely shared.
- Put stable architecture in the owning specification and concrete behavior in tests. Do not preserve implementation chronology as development guidance.
2. Identify the owning area
Start with src/vs/sessions/README.md, then read only the specifications relevant to the change:
| Area | Specification |
|---|---|
| Layering, folder ownership, cross-module imports | src/vs/sessions/LAYERS.md |
| Session/chat model, services, provider contract, core data flow | src/vs/sessions/SESSIONS.md |
| Automations ownership, routing, migration, persistence, and run lifecycle | src/vs/sessions/AUTOMATIONS.md |
| Workbench parts, grid, title bar, editor presentation | src/vs/sessions/LAYOUT.md |
| Session-aware layout state and restoration | src/vs/sessions/LAYOUT_CONTROLLER.md |
| Single-pane behavior and expected compositions | src/vs/sessions/SINGLE_PANE_SCENARIOS.md |
| Sessions sidebar list, grouping, filtering, and persistence | src/vs/sessions/SESSIONS_LIST.md |
| Phone layout and mobile components | src/vs/sessions/MOBILE.md |
| AI customizations | src/vs/sessions/AI_CUSTOMIZATIONS.md |
| Copilot customizations | src/vs/sessions/copilot-customizations-spec.md |
| Copilot Chat provider | src/vs/sessions/contrib/providers/copilotChatSessions/COPILOT_CHAT_SESSIONS_PROVIDER.md |
| Agent Host provider | src/vs/sessions/contrib/providers/agentHost/AGENT_HOST_SESSIONS_PROVIDER.md |
| Remote Agent Host provider | src/vs/sessions/contrib/providers/remoteAgentHost/REMOTE_AGENT_HOST_SESSIONS_PROVIDER.md |
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.
- 1mo ago Changed · +1 lines 6ad1a0611780
- 1mo ago First seen · 93 lines · 20 tokens per session scan A e14fb404a519
sessions is a skill published in the GitHub repository microsoft/vscode (194,219 stars, last pushed today), licensed MIT. It adds 20 tokens to every session and 1,301 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
planned-task-runtime
Handles system follow-up turns: planned-task-follow-up (synthesize, replan, build-workflow, checkpoint), background-task-completed, running-tasks context, and workflowbuildercreatetasks silence rules. Load whenever any of these tags appear or after calling workflowbuildercreatetasks.
output-eval-error-analysis
Systematically review workflow traces to identify failure modes before building evaluators. Use when starting an eval project, after significant pipeline changes, or when production quality drops.
output-dev-folder-structure
Workflow folder structure conventions for Output SDK. Use when creating new workflows, organizing workflow files, or understanding the standard project layout.
output-dev-code-style
Code style conventions for Output SDK workflow projects. Use when writing or reviewing any TypeScript/JavaScript code. Discovers the project's own linting rules first; falls back to Output SDK conventions when no linter is configured.
output-dev-workflow-cost
Calculate and display the cost of an Output SDK workflow execution run. Use when checking LLM token costs, API service costs, or total spend for a specific workflow run.
output-dev-llm-streaming
Implement LLM text streaming in Output workflow steps with generateTextWithStreaming, Agent.generateWithStreaming, streamText, or Agent.stream. Use when adding token progress, onChunk callbacks, or handling streamText onEnd/onError with Temporal retries.