A GitHub Copilot canvas extension that wraps the Spec Kit bug extension — the three-stage bug triage pipeline (assess → fix → test) that takes a bug report from triage to a verified fix.

The canvas gives that pipeline a side-panel UI: it lists every bug under .specify/bugs/<slug>/, shows which stages are done, previews each Markdown artifact, and drives the pipeline by invoking the generated speckit-bug-* skills through the agent.

• Pipeline overview — a live count of how many bugs have reached each stage, plus a tally of verified / partial / failed verification results.
• Per-bug cards — title, slug, the assessment severity and verification result badges, a pill per stage (done / next / pending), and a one-click Run <next stage> button.
• Rerun from any stage — every available stage pill stays enabled. Clicking one opens its run dialog, where the current artifact can also be previewed. Rerun explicitly authorizes overwrite, uses the existing artifact as context, preserves still-valid content, and marks later artifacts stale until rerun.
• Stage-aware inputs — assess requires a bug report (pasted text or a URL); fix requires a current assessment.md; test requires a current assessment.md and fix.md. Optional stage guidance is passed through. An invalid assessment ends the pipeline — the card shows "no fix needed" instead of pushing a fix.
• Rendered artifact preview — view completed Markdown artifacts (assessment.md, fix.md, test.md) as formatted headings, lists, code, blockquotes, and tables in a dedicated full-width canvas view with a Back to dashboard control.
• Targeted clarification — [NEEDS CLARIFICATION: …] items in the assessment's Reproduction and Open Questions sections render a Clarify action. The canvas requires an answer in a confirmation dialog before it sends a validated assess rerun and overwrite request to the agent.
• New bug → assess — paste a bug report (or URL), optionally set a slug, and kick off speckit-bug-assess.
• Guided prerequisite setup — when Spec Kit or the bug extension is missing, the canvas makes setup the first step and sends the required setup work to the agent instead of forwarding an unavailable bug command.
• Live updates — the panel refreshes automatically (SSE) as the bug commands write new artifacts.

The canvas is read-only against the filesystem; it never writes bug files. All changes happen through the bug commands themselves, so the extension's safety guardrails still apply (only speckit-bug-fix ever edits source code).

This is a canvas extension, so it renders in the GitHub Copilot app side panel — not in the plain terminal CLI. Installing the plugin only registers the canvas; nothing opens automatically.

To open it, ask Copilot in chat, e.g. "Open the Bug Fix Pipeline" (or "open the bug fix dashboard"). The agent matches your request to this canvas (id: bugfix-canvas, displayName "Bug Fix Pipeline") and opens it in a side panel. There is no slash command or menu entry — discovery is the agent matching the canvas name/description.

Once it is open you can drive it two ways:

• Click the panel — the New bug → assess form and each card's Run/Rerun and Clarify buttons.
• Ask the agent — the canvas also exposes agent-callable actions (list_bugs, setup_bug, run_stage, clarify_item), so "run assess on this stack trace in the bug pipeline" works too.

If the project isn't set up for Spec Kit or the bug extension isn't installed, the canvas shows a setup step first.

Buttons in the canvas POST to a loopback HTTP endpoint, which calls session.send({ prompt: "/skill:speckit-bug-<stage> slug=<slug>" }). The skill runs in your normal chat session — watch the transcript for the agent's work and any prompts (e.g. slug confirmation, URL-fetch approval).

Each open canvas gets a random capability token. The loopback server requires that token and its canonical Host/Origin on UI, API, and event-stream requests.

Commands are restricted to the three speckit-bug-* skills and slugs are normalized to [a-z0-9-], so the canvas can only trigger bug stages.

• list_bugs — returns all bugs with per-stage progress, assessment verdict/severity, fix status, and verification result.
• setup_bug — asks the agent to initialize Spec Kit and install bug.
• clarify_item — validates a clarification by artifact/index/question, captures the user's answer, and reruns the assess stage.
• run_stage — runs or reruns a stage ({ slug, stage, report?, instructions?, overwrite? }) by sending the matching command. Existing artifacts require overwrite: true.

Via marketplace (recommended):

copilot plugin marketplace add OWNER/spec-kit-copilot
copilot plugin install spec-kit-copilot-bugfix@spec-kit-marketplace

The plugin manifest lives at plugins/spec-kit-copilot-bugfix/plugin.json and declares this directory through its extensions/ component path.

Anywhere else (gist): share it as a private gist ("Share extension as gist…" in the command palette, or the share_extension tool), then install with "Install extension from gist…" into ~/.copilot/extensions/ so it follows you across projects. The bundled copilot-extension.json manifest is what makes the gist install flow recognize it.

The canvas detects whether the project is initialized and whether bug is installed. If either prerequisite is missing, it presents a setup action before the new-bug form. Bugs are written under .specify/bugs/<slug>/.