pstack for GitHub Copilot

This repository is a GitHub Copilot plugin for the Copilot app and Copilot CLI. The repo root is the plugin.

It packages the Copilot parent from open-pstack. Skills stay shared. Copilot-only agents live in agents/ as *.agent.md files. Claude agents/*.md files are not here. Copilot loads every *.md and *.agent.md in the plugin agents directory.

Do not copy skills/ into ~/.agents/skills/ or ~/.copilot/skills/. Copilot loads plugin skills last. A home skill with the same name: silently wins, and the plugin copy is dropped.

Install

The Copilot app and Copilot CLI share ~/.copilot/settings.json. Install once.

copilot plugin marketplace add balazstasi/pstack-copilot
copilot plugin install pstack@pstack-copilot

That writes extraKnownMarketplaces.pstack-copilot and enabledPlugins["pstack@pstack-copilot"].

In the Copilot app: Customize → Plugins, add marketplace balazstasi/pstack-copilot, then install pstack.

From a local clone instead:

copilot plugin marketplace add "$(pwd)"
copilot plugin install pstack@pstack-copilot

If an older pstack@open-pstack marketplace is still enabled, disable or uninstall it so two pstacks do not load:

copilot plugin uninstall pstack@open-pstack
copilot plugin marketplace remove open-pstack

Confirm the loaded path:

copilot plugin list

The enabled plugin must load from this repo, not from ~/Projects/open-pstack.

Home-skill collisions

Copilot skill order is first-found-wins. Plugin skills lose to ~/.agents/skills/ and ~/.copilot/skills/. If /how or /poteto-mode still looks like Cursor (composer models, disable-model-invocation), a home copy is winning.

Move colliding names out of the way. Keep the backup so Cursor or Grok can still use them:

mkdir -p ~/.agents/skills.bak-pstack-copilot
# example; move every name that also exists in this repo's skills/
mv ~/.agents/skills/poteto-mode ~/.agents/skills.bak-pstack-copilot/

Then copilot skill list. pstack names should come from the plugin, not Custom skills.

Run with the pstack agent

Pick poteto-agent in the Copilot app agent picker (or type /agent). That file is sticky for the session. It loads poteto-mode before any work. There is no extra CLI latch.

Copilot CLI uses the plugin id:

copilot --agent pstack:poteto-agent

pstack-terra and the other pstack-<stem> files are spawn lanes for task(). Do not pick them as the session agent.

A sessionStart hook submits /poteto-mode on a new default-agent session and injects a short mandate as additionalContext (resume and -p included). Copilot may ask you to trust that hook. The prompt hook does not fire on resume or -p. The same hook links every agents/*.agent.md into ~/.copilot/agents/ so the Copilot app picker and task() see file stems. It does not replace a regular file of the same name.

Fan-out limits

Before a panel, set these in ~/.copilot/settings.json so concurrency is at least the configured panel size (3 by default):

{
  "subagents": {
    "maxConcurrency": 3,
    "maxDepth": 2
  }
}

Values below the panel size collapse arena, architect, and interrogate.

Configure models

In Copilot CLI or the Copilot app:

/setup-pstack

Setup writes ~/.copilot/pstack-models.md and a bounded <!-- pstack:models:begin --> block at the end of ~/.copilot/copilot-instructions.md. It does not fold pstack into a repo-gated section of that file.

Copilot first-run defaults:

• feature / refactoring / how explorer → copilot:gpt-5.6-luna@xhigh
• swarm workers → copilot:gpt-6-astra@low
• judgment and prose → copilot:grok-4.6@high
• hardest / how explainer → copilot:gpt-5.6-terra@high
• bug-fix / perf / hillclimb → copilot:gpt-5.6-sol@medium
• panels → terra, sol, kimi (2 or 3 distinct families; /setup-pstack sets the list)
• why / reflect → inherit-parent

copilot:gpt-5.6-sol@medium is Copilot Sol. codex:gpt-5.6-sol still means the Codex CLI. copilot:grok-4.6@high is Copilot Grok (pstack-grok). grok:grok-4.6 still means the Grok CLI. Setup never maps Fable to Terra or Grok CLI to Copilot Grok.

Layout

.
├── .github/plugin/marketplace.json   # marketplace name pstack-copilot, source ./
├── .github/plugin/plugin.json        # plugin name pstack, agents/, skills/, hooks/
├── agents/                           # Copilot-only *.agent.md
├── hooks/                            # sessionStart: /poteto-mode, mandate, agent links
└── skills/                           # shared pstack skills, including setup-pstack and poteto-mode

Tests

cd skills/poteto-mode/scripts
bun test --parallel bootstrap orch watch-pr runner check-plan

From the repo root:

bun test hooks/session-start.test.ts

License

MIT. See NOTICE.md, LICENSE, and LICENSE-cursor-team-kit.