diffdump

Any pull request. One clean review.

diffdump opens GitHub pull requests, commits, and comparisons in a fast, focused review view — no account, no repository access granted to Diffdump. Raw unified git diffs can also be shared as unlisted, expiring review links. It is hosted at diffdump.com.

Capabilities

Review a GitHub diff

• For any supported GitHub URL, replace github.com with diffdump.com:

  https://github.com/freckle-io/next/pull/744
  https://diffdump.com/freckle-io/next/pull/744
  

• Or paste a public GitHub pull request, commit, or comparison URL into the form on the home page.

• GitHub reviews are client-only: the diff is fetched straight from GitHub and rendered in the browser without creating a share or storing anything on Diffdump.

• Collapsed context expands like on GitHub: the arrows on each hunk separator reveal the unchanged lines around a change, fetched on demand from api.github.com at the exact revisions the diff compares.

• Pull requests can be reviewed inline: select diff lines to draft comments, browse existing GitHub comment threads, and publish all drafts together as one GitHub review — Comment, Approve, or Request changes. Reviews are published by the browser directly to api.github.com; unsent drafts persist in browser localStorage, keyed to the pull request's head commit.

• Private repositories and review publishing use an optional personal access token: preferably a fine-grained PAT with Pull requests read/write and Contents read permissions, or a classic PAT carrying the repo scope. Either token can publish the reviews you submit. The token is saved only in browser localStorage and sent only to api.github.com; it is never submitted to Diffdump.

Create a share link

• Paste a unified git diff on the home page and get a link immediately, or pipe one straight from your terminal:

  git diff | curl -T- https://diffdump.com/d

  The response body is the share URL — append | xargs open to jump straight into the review view.

• Links are unlisted by design: 96-bit, base64url-encoded random slugs served with noindex, nofollow. There is no public listing.

• Shares accept diffs up to 2 MiB and expire after 24 hours.

Review view

• Multi-file, syntax-highlighted patch rendering via @pierre/diffs, with unified and split layouts and optional line wrapping.
• A searchable file tree (@pierre/trees) with per-file git status for jumping between changed files.
• Files are automatically categorized as Source, Tests, Docs, or Other — the view can be filtered by category and ordered by patch order or by category, with file and addition/deletion counts per group.
• Files can be marked as Viewed and collapsed, with progress saved locally for each GitHub diff or shared-view link.
• On pull-request routes, inline review comments in unified and split layouts: draft on selected lines, inspect drafts and published GitHub threads in a Comments sidebar (including outdated comments, linked back to GitHub), and submit everything as one review.
• Light and dark themes, one-click share-link copy, and a live countdown to link expiry.

Architecture

• TanStack Start runs on Cloudflare Workers.
• GitHub reviews are client-only: the browser fetches the diff and existing review comments directly from GitHub and publishes pull-request reviews straight to api.github.com. Neither the token, the diff, nor any review content passes through Diffdump.
• Unsent review drafts (and an interrupted submission's pending review id) live only in browser localStorage, scoped to the pull request and its head commit.
• Shared unified diffs are stored as private objects in Cloudflare R2.
• Share links expire after 24 hours.
• Share URLs use 96-bit, base64url-encoded random slugs.

How it works

The direct GitHub routes read the optional token after client hydration and request GitHub's diff media type directly from api.github.com. On pull requests they also list existing review comments and publish new reviews with the same direct browser calls. Every response renders without creating a Diffdump share, and review drafts stay in the browser until they are published to GitHub.

Shared diffs take the server path:

1. A user pastes a unified git diff on / or uploads one with curl -T-; both clients send the raw patch with PUT /d.
2. The Worker rate-limits anonymous creation and validates the patch and its 2 MiB size limit.
3. The Worker generates a 16-character cryptographic slug and conditionally writes diffs/<slug> to R2 so an existing share is never overwritten.
4. The app navigates to /view/<slug>, loads the private object through the Worker, and renders it in the browser until its 24-hour expiry.

Anonymous creation rate limit

Diff creation is limited to 10 requests per 60 seconds for each CF-Connecting-IP in a Cloudflare location. The limit and period are configured under ratelimits in wrangler.jsonc. If the period changes, keep the Retry-After value in src/server/diff-upload.ts aligned with it.

Requests over the limit receive 429 Too Many Requests with a plain-text message and a Retry-After header, so both browsers and shell clients can recover without authentication. Rate-limiter failures fail closed with 503 and do not write to R2.

Cloudflare's rate-limit counters are local to each Cloudflare location, permissive, and eventually consistent; this is abuse protection rather than an exact usage quota. Rejections emit a diff_creation_rate_limited event to Workers Logs with the Cloudflare location only. Diff contents, share slugs, and client IPs are not included in the custom log entry.

Local development

Requirements: Node.js 22 or newer and a Cloudflare account for deployment.

pnpm install
pnpm run cf-typegen
pnpm run dev

The Cloudflare Vite plugin provides a locally persisted R2 binding during development.

Validation

pnpm test
pnpm run build

Deploy

Authenticate Wrangler, create the production bucket once, then deploy:

pnpm exec wrangler login
pnpm exec wrangler r2 bucket create diffdump-diffs
pnpm exec wrangler r2 bucket lifecycle add diffdump-diffs expire-diffs-after-one-day diffs/ --expire-days 1
pnpm run deploy

The R2 bucket is private and is only available to the Worker through the DIFFS binding in wrangler.jsonc. The application enforces the 24-hour expiry when a link is read; the lifecycle rule removes expired objects from R2.