Rendering PR Diffs as Interactive Cursor Canvases with the PR Review Canvas Plugin

The PR Review Canvas plugin transforms GitHub pull request diffs into structured, interactive Cursor Canvases that prioritize core logic changes while grouping ancillary modifications by reviewer relevance.

The cursor/plugins repository hosts the PR Review Canvas plugin, a Cursor extension that reimagines code review by converting static GitHub diffs into dynamic, navigable Canvas views. By analyzing pull request content and applying intelligent categorization, the plugin surfaces critical architectural changes first and de-emphasizes mechanical boilerplate, reducing cognitive load for reviewers.

Architecture and Skill Declaration

The plugin is declared to the Cursor runtime through pr-review-canvas/.cursor-plugin/plugin.json, which defines the entry point and metadata. The core logic resides in pr-review-canvas/skills/pr-review-canvas/SKILL.md, a declarative skill definition that encodes the review workflow.

The SKILL.md file contains YAML front matter (delimited by ---) that instructs the Cursor engine how to invoke the skill, followed by procedural instructions for Canvas generation. The skill strictly requires a GitHub PR URL or gh pr diff reference and aborts if no valid PR link is provided, refusing to fall back to generic git diff output.

Diff Gathering and Change Grouping

Upon invocation, the skill executes gh pr diff <pr> to collect file paths, additions, deletions, and hunks. It then partitions the changes into three ordered sections:

1. Core logic – New behavior, algorithmic changes, and API surface modifications receive full diff views with complete context.
2. Wiring & integration – Route registration, dependency injection, and configuration plumbing appear in condensed views.
3. Boilerplate & mechanical – Import updates, renames, and generated code are summarized in collapsed lists.

For dense core changes, the skill enhances the Canvas with pseudocode summaries, concrete example traces showing before/after execution on small inputs, and visual callouts (tags like Subtle, Breaking, or Perf) to flag risky hunks.

Canvas Rendering with SDK

The plugin leverages the Cursor Canvas SDK (referenced in the parent cursor-team-kit repository) to render visual components. The SDK selects appropriate layouts based on change type: state diagrams for refactors, tables for schema migrations, and syntax-highlighted diff blocks for code changes. This structured rendering transforms textual patches into interactive visualizations that reviewers can expand, collapse, and navigate directly within the Cursor UI.

User Interaction and Invocation

Reviewers can trigger the plugin using natural language commands such as "PR review canvas" or "review this PR on a canvas" followed by a PR URL. Once activated, the Canvas appears as a native Cursor UI element, allowing interactive exploration of sections, inline diff inspection, and following of embedded example traces.

Code Examples

Triggering via natural language in the Cursor UI:

User: review this PR on a canvas https://github.com/owner/repo/pull/42

Programmatic invocation using the Cursor SDK:

import { launchCanvas } from '@cursor/sdk';

async function openReviewCanvas(prUrl: string) {
  // The skill validates the URL and runs `gh pr diff`.
  await launchCanvas('pr-review-canvas', { pr: prUrl });
}

// Example usage
openReviewCanvas('https://github.com/owner/repo/pull/42');

Simplified JSON representation of the Canvas layout:

{
  "title": "PR #42 Review Canvas",
  "sections": [
    {
      "title": "Core Logic",
      "type": "diff",
      "files": ["src/core/engine.ts"]
    },
    {
      "title": "Wiring & Integration",
      "type": "condensed",
      "files": ["src/config/routes.ts"]
    },
    {
      "title": "Boilerplate",
      "type": "summary",
      "files": ["src/utils/helpers.ts"]
    }
  ],
  "callouts": [
    { "file": "src/core/engine.ts", "line": 128, "tag": "Breaking", "note": "Removed retry path" }
  ]
}

Key Implementation Files

The plugin source code is organized under the pr-review-canvas/ directory in the cursor/plugins repository:

File	Purpose
pr-review-canvas/.cursor-plugin/plugin.json	Declares plugin metadata, version, and entry point to the Cursor runtime
pr-review-canvas/skills/pr-review-canvas/SKILL.md	Defines skill prerequisites, diff gathering logic, and grouping algorithms
pr-review-canvas/README.md	Documents usage triggers, requirements, and integration notes
pr-review-canvas/CHANGELOG.md	Tracks feature additions and version history

These files demonstrate how the PR Review Canvas integrates with the Cursor platform to provide a structured, reviewer-centric diff experience.

Summary

• The PR Review Canvas plugin converts GitHub PR diffs into interactive Cursor Canvases through the declarative skill system in cursor/plugins.
• Changes are automatically categorized into core logic, wiring & integration, and boilerplate sections to prioritize reviewer attention.
• The skill requires a valid GitHub PR URL and executes gh pr diff to gather change data, refusing to process generic git diffs.
• Visual callouts, pseudocode summaries, and execution traces enhance dense code changes with contextual metadata.
• Integration occurs via natural language triggers or the launchCanvas SDK method, rendering structured layouts through the Cursor Canvas SDK.

Frequently Asked Questions

How does the PR Review Canvas plugin prioritize which changes to show first?

The plugin analyzes the diff content and assigns changes to one of three priority tiers. Core logic changes—including new algorithms and API modifications—receive full visibility with expanded diff views. Wiring & integration changes appear in condensed format, while boilerplate modifications are collapsed into summary lists. This grouping ensures reviewers encounter high-impact changes before mechanical updates.

Can the plugin work with local git diffs or does it require a GitHub PR?

The skill strictly requires a GitHub PR URL or gh pr diff reference. According to the skill definition in SKILL.md, the plugin aborts execution and prompts the user for a valid PR link if one is not provided. It does not support generic git diff output or local-only repositories.

What types of visual enhancements can appear on the Canvas?

For complex changes, the Canvas may display pseudocode blocks that summarize algorithmic logic in plain language, concrete example traces showing side-by-side execution comparisons, and callout tags such as Breaking, Subtle, or Perf that flag specific lines requiring careful review. These annotations are generated automatically based on the density and nature of the diff content.

How do I trigger the PR Review Canvas from within Cursor?

You can invoke the plugin using natural language commands like "PR review canvas" or "review this PR on a canvas" followed by the GitHub URL. Alternatively, developers can programmatically launch the Canvas using the Cursor SDK's launchCanvas('pr-review-canvas', { pr: url }) method, as implemented in the cursor-team-kit reference implementation.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}