pstack for GitHub Copilot

Run pstack in the VS Code agents window with GitHub Copilot.

pstack is Lauren Tan's (poteto) set of agent workflows. Tell it a goal and it picks the right one: root-cause a bug before fixing it, sketch a design before coding it, race several attempts and keep the best, review a diff with more than one model. Then it proves the result works. This repo makes all 54 of its skills work on Copilot.

Why · Install · Use it · Agents window setup · What you get · How it works · Security · Credits

Why this exists

pstack ships for Cursor, and pstack-claude ports it to Claude Code. VS Code's new agents window can load Claude Code plugins too, so it looks like pstack-claude should just work there. On the Copilot target it doesn't, and nothing tells you:

What you'd expect	What actually happens on Copilot
pstack switches on at the start of every session	Copilot ignores the plain text the startup hook prints, so pstack never switches on
The skills load as pstack:poteto-mode, pstack:tdd, ...	Copilot answers "Skill not found" to the pstack: prefix
Skills call Agent, Skill, AskUserQuestion, TodoWrite	Copilot's tools are named task, skill, ask_user, update_todo
pstack:poteto-agent handles delegated work	VS Code rejects every dispatch to it, and its agents window lists each plugin agent twice

This port fixes all four and leaves pstack's own content untouched. Each fix is checked against the real Copilot runtime, both the Copilot CLI and the copy bundled inside VS Code. The plugin as pstack-claude ships it, unchanged, fails three of those checks.

Install

VS Code

1. Open Preferences: Open User Settings (JSON) and add:

   "chat.plugins.enabled": true,
   "chat.plugins.marketplaces": ["hackernotfound/pstack-vscode"]

2. In the Extensions view, search @agentPlugins, install pstack-copilot, and accept the trust prompt.

3. Open the agents window and pick Copilot in the session target picker.

That's it. Under Customizations, pstack-copilot now shows up in Plugins, its hook in Hooks, and poteto-mode in Skills.

Want to see your subagents while they run? Follow the one-time agents window setup. It adds a live list of running subagents, side-by-side subagent panes, and chat tabs, close to T3 Code.

Copilot CLI

copilot plugin marketplace add hackernotfound/pstack-vscode
copilot plugin install pstack-copilot@pstack-vscode

VS Code also lists plugins you install this way.

Installed 1.1.1 or earlier? The plugin was called pstack then. Run copilot plugin uninstall pstack, then install pstack-copilot as above. In VS Code, uninstall pstack and install pstack-copilot. A chat.pluginLocations path to plugins/pstack keeps working as it is.

Using the Claude target too? The Claude target loads your Claude Code plugins from ~/.claude. Keep pstack-claude for that target, and use this port for Copilot.

Use it

Just work as usual. A change that touches more than one file, a design question, or a bug with an unknown cause switches pstack into poteto-mode on its own, and it picks the matching playbook from there.

To start a workflow yourself, ask for it by name:

use poteto-mode to add rate limiting to the API client
run tdd on the date parser bug
architect the new sync engine before writing code
how does auth work in this repo?

First read in a session. pstack keeps its playbooks inside the plugin folder, outside your workspace. The first time a session reads one, VS Code asks Allow reading file outside of workspace? and shows the plugin path. Choose Allow in this Session. Reads of pstack's other files in that session then go through without asking.

Options: turn off the startup hook, pick models, pin a version

• Turn off the startup hook. Add session hook: off to ~/.copilot/pstack-models.md. pstack then runs only when you ask for it.
• Pick models. By default Copilot chooses each subagent's model, because which models you can use depends on your plan. To pin models per role, run setup-pstack. It writes ~/.copilot/pstack-models.md with model names your account accepts, such as claude-opus-5.5.
• Pin a version. Marketplace installs follow main. To stay on one release, clone this repo, check out its tag (for example v1.0.0), and in VS Code set "chat.pluginLocations": { "/absolute/path/to/pstack-vscode/plugins/pstack": true } instead of the marketplace line.

What you get

Skill	What it does
poteto-mode	The entry point. Picks a playbook for your task and holds the work to pstack's principles.
tdd	Reproduces a bug with a failing test, then fixes it.
architect	Sketches types and module shape before any code.
arena	Races several attempts at a task, then keeps and combines the best parts.
interrogate	Reviews a diff with an adversarial panel of reviewers.
how / why	Explains how code works, or why it was built that way.
unslop / deslop	Cuts filler from prose and from code.
principle-*	23 short engineering principles the workflows cite as they work.

Every skill is in plugins/pstack/skills/.

How it works

flowchart LR
  A["pstack-claude<br/>(pinned commit)"] --> B["tools/build.mjs"]
  O["overlay/<br/>Copilot fixes"] --> B
  B --> P["plugins/pstack"]
  P --> V["VS Code agents window<br/>(Copilot target)"]
  P --> C["Copilot CLI"]

Loading

tools/build.mjs copies pstack-claude at the commit pinned in upstream.json, adds the Copilot fixes from overlay/, and writes the plugin to plugins/pstack/. The fixes are:

• A startup hook that Copilot reads. It prints the poteto-mode instructions as JSON with an additionalContext field, the only hook output Copilot injects.
• A Copilot tool map. copilot-tools.md translates every Claude tool and model name the skills use. poteto-mode points Copilot at it.
• Bare skill names in the startup instructions, such as poteto-mode rather than pstack:poteto-mode.
• No plugin agents. Copilot dispatches its built-in general-purpose agent and has it load poteto-mode first, which is all pstack:poteto-agent does. Shipping no agents also keeps VS Code's agent picker free of duplicates.
• An Agent Plugins 1.0 manifest. The startup hook lives under com.github.copilot/, where Copilot looks for it in that format. The port ships no .claude-plugin/ folder, because VS Code treats any plugin with one as a Claude plugin.

Tested on VS Code 1.140.0 and its bundled Copilot runtime, and on Copilot CLI 1.0.91. Updating to a newer pstack, the generated files, and the live tests are covered in docs/maintaining.md.

Security

• No server, no telemetry. Whatever the skills ask your agent to read goes only to your model provider.
• One thing runs by itself. That's the startup hook. It prints a fixed file from the plugin and reads nothing from your workspace.
• Scripts run only when your agent runs them. The helper scripts in skills/poteto-mode/scripts/ use your git and gh login. Keep tool approvals on, and leave chat.tools.autoApprove off in VS Code.
• Everything is pinned. The upstream source is a full commit SHA, the script dependencies install from a lockfile with integrity hashes, and CI actions are pinned to commit SHAs. CI fails if anything floats.

Found a vulnerability? See SECURITY.md.

Credits

• pstack by Lauren Tan (poteto). The workflows, skills, and principles are hers.
• pstack-claude by Michael Denyer. The Claude Code port this one is built from.
• cursor-team-kit skills by Cursor.

MIT licensed. Upstream license and notice files are in licenses/, and NOTICE.md lists what this port adds.