DiffPrism

Review GitHub PRs with AI superpowers. Paste a PR URL, see the diff in your browser, and use Claude Code or Cursor to interrogate every line, file, and change. Your AI gets full codebase context from your local clone — not just the diff hunks.

How It Works

1. Open a PR — diffprism review https://github.com/owner/repo/pull/123
2. See the diff — Browser opens with syntax-highlighted diffs, file browser, and analysis briefing
3. Ask your AI — In Claude Code or Cursor, ask questions about the changes. Your AI calls MCP tools to get context and posts findings inline on the diff.

$ cd ~/dev/my-project
$ diffprism review https://github.com/owner/repo/pull/123
  Fetching PR #123 from owner/repo...
  Add retry logic to API client
  4 files changed
  Local repo: /Users/you/dev/my-project

  Review open in browser. Use Claude Code to ask questions about this PR.

Then in Claude Code:

> What does this PR change?
  → calls get_pr_context → high-level overview

> Is the retry logic in client.ts correct?
  → calls get_file_diff + get_file_context → full file from your local clone

> Flag line 47 as a concern
  → calls add_review_comment → annotation appears on the diff in your browser

Setup

npm install -g diffprism
diffprism setup          # Register MCP server with Claude Code

Run the server from within your local clone so the AI gets full file context:

cd ~/dev/my-project
diffprism server         # Or let it auto-start on first review

PR Review

diffprism review https://github.com/owner/repo/pull/123   # Full GitHub URL
diffprism review owner/repo#123                            # Shorthand format

The server auto-detects your local clone by matching git remote -v against the PR's repo. Your AI can then read full files via git show — not just diff hunks.

MCP Tools

DiffPrism exposes 14 MCP tools to your AI:

PR Review

Tool	Purpose
get_pr_context	High-level PR overview: metadata, briefing, file list, local repo status
get_file_diff	Diff hunks for a specific file with triage category
get_file_context	Full file content from local repo via git show
add_review_comment	Post a comment that appears inline on the diff in real-time
get_review_comments	Read all comments and annotations on the session
get_user_focus	What file/line the user is currently viewing in the browser

Review Lifecycle

Tool	Purpose
open_review	Open browser review UI for local changes or a GitHub PR
get_review_result	Fetch result from a previous review
update_review_context	Push updated reasoning/description to a running session

Analysis

Tool	Purpose
analyze_diff	Returns analysis JSON (patterns, complexity, test gaps)
get_diff	Returns structured diff JSON (file-level and hunk-level changes)

Annotation

Tool	Purpose
add_annotation	Post a structured finding on a specific line
flag_for_attention	Mark files for human attention
get_review_state	Get current state of a session including all annotations

Local Agent Review

DiffPrism also works for reviewing local agent-generated changes:

diffprism review                    # Review all changes (staged + unstaged)
diffprism review --staged           # Staged changes only
diffprism review HEAD~3             # Last 3 commits
diffprism review main..feature      # Branch diff

Running multiple Claude Code sessions? All reviews appear in one browser dashboard with status badges, branch info, and desktop notifications.

Features

• AI-powered PR review — Your AI gets full codebase context via 14 MCP tools
• Live annotations — AI findings appear inline on the diff in real-time
• Local repo context — Full file content from your clone, not just diff hunks
• No vendor lock-in — Works with Claude Code, Cursor, or any MCP client
• Syntax-highlighted diffs — Unified or split view with refractor
• Multi-session dashboard — Review multiple agents from one browser tab
• Review briefing — Complexity scores, test coverage gaps, pattern flags
• Auto-detect local repo — Matches git remote -v against the PR's repo
• Keyboard shortcuts — j/k files, n/p hunks, s status, ? help
• Dark/light mode — Toggle with persistence

CLI Reference

diffprism review <ref>              # Open a review (PR URL, git ref, or flags)
diffprism setup                     # Configure Claude Code integration
diffprism setup --global            # Global setup (no git repo needed)
diffprism server                    # Start the background server
diffprism server status             # Check server status
diffprism server stop               # Stop the server
diffprism teardown                  # Remove configuration

Development

git clone https://github.com/CodeJonesW/diffprism.git
cd diffprism
pnpm install
pnpm test
pnpm run build
pnpm cli review --staged            # Run CLI from source

Project Structure

packages/core       — Server, types, server-client utilities
packages/git        — Git diff extraction + parser
packages/analysis   — Deterministic review briefing
packages/ui         — React 19 + Vite 6 + Tailwind + Zustand
packages/mcp-server — MCP tool server (14 tools)
packages/github     — GitHub PR fetching + review submission
cli/                — Commander CLI

Requirements

• Node.js >= 20
• Git

Documentation

• Claude Code Setup Guide — detailed configuration and troubleshooting
• Dev Testing Guide — running from source