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DeltaDeck
Free, open source, local only

DeltaDeck

Every change, stacked for review.

A local viewer that shows what changed in your docs and code since you last looked, rendered properly, and lets you hand feedback straight back to your AI agent.

Install View on GitHub
DeltaDeck showing a markdown file with an edited paragraph highlighted in amber and two added list items in green, the copy and add buttons on a change, and the review basket with two items, one of them "Line 5-6 · Parser > parse (edited)".

How it works

Your agent edited twelve files. You want to read what changed, not the whole repository.

  1. Step 1

    The deck

    Every change since you last looked, across the folder. What's new lists them, newest first. Files you have not seen get a dot.

  2. Step 2

    Flip through

    Open a file and the changes are highlighted in place. n and p jump to the next and previous change.

  3. Step 3

    Pick cards

    b puts a change in the review basket, with a note if you like. c copies just that one change.

  4. Step 4

    Deal back

    Copy for AI builds one prompt with a diff and your note per change. Paste it into your agent.

What lands in your agent

One markdown prompt. Each item has its location, whether it was added, edited or removed, a diff of the old and new text, and your note.

Paths are relative to the git repository, so an agent running at the repo root finds the files. Code items carry the line range and the enclosing symbol.

Copied prompt
Review feedback on recent changes. For each item, revise as noted. ## src/parser.ts ### 1. Line 5-6 · Parser > parse (edited) ```diff-    const files = this.walk(root);-    return files.map((f) => this.read(f));+    const files = this.walk(root, { cache: true });+    return this.readAll(files);``` Note: keep the old read() for single files.

Built for reviewing AI work

For tech leads and developers who spend the day checking what agents wrote. PMs reading the docs are welcome too.

  • Changes in the rendered view

    Edited blocks in amber, new ones in green, removals as a dashed line. In rendered markdown and .docx, and line by line in code and text.

  • What's new, folder-wide

    A feed of every file that changed since you last opened it, with what changed in each. The history stays in the app's data dir, never in your folder.

  • Review basket and Copy for AI

    Pick changes, add a note to each, copy one prompt: diffs, repo-relative paths, line ranges and symbols. Session only, nothing saved.

  • Git, read-only

    See what changed since the last commit with the same highlights, an Uncommitted list with +/- counts, and blame. Nothing is written to the repo.

  • Search and autocomplete

    Project-wide full-text search with folder and type filters. With editing on, the editor completes names from the whole folder.

  • Hidden files, handled

    Git-ignored files are hidden by default and one toggle away. Secrets like .env stay locked and open read-only after a confirm.

  • Local only

    Nothing leaves your machine. No AI calls, no account, no telemetry. --read-only turns off editing.

  • Opens what agents touch

    Markdown with mermaid, Word .docx, source code with an outline, JSON, CSV and xlsx tables, images, PDFs and large logs. Markdown and .docx export to PDF.

Install

Desktop builds are for Mac (Apple Silicon and Intel) and Linux x86_64. On other Linux machines, run it with uvx. Windows is not supported; use WSL.

Install the Mac app

curl -fsSL https://raw.githubusercontent.com/dharmen8980/deltadeck/main/install.sh | bash
  • Installs DeltaDeck.app to ~/Applications. Apple Silicon and Intel are both built.
  • The script downloads the app itself, so macOS does not quarantine it and there is no Gatekeeper prompt on first launch.
  • Read the script first if you like: install.sh.

FAQ

Is my code sent anywhere?
No. A small server on 127.0.0.1 reads the folder and your browser or the desktop app shows it. Nothing goes over the network.
Does it call an AI?
No. Copy for AI puts a prompt on your clipboard. You paste it into the agent you already use.
Does it edit my files?
Only when you do. Editing is on by default: an editor and file management with version history and undo. Start it with --read-only, or turn off Allow editing in the desktop app's menu, to make it view-only.
Why is the Mac app unsigned?
It is an early project without an Apple Developer account yet. The install script downloads the app with curl, so macOS shows no prompt. For a browser download, see Direct download above.
Which files does it show?
Markdown, .mmd diagrams, Word .docx, source code, plain text and logs, JSON, CSV, xlsx, images and PDFs. Change highlights cover markdown, .docx, code and text.