ThreadTidy is a native macOS app that turns a noisy Gmail "Print all" PDF into a clean, court-ready threaded PDF. Drag the dirty PDF onto the drop zone and ThreadTidy rebuilds the conversation as a tidy document: a title page with a numbered Index of Communications, then one clean entry per message — each on its own page with a clickable navigation strip (1 2 [3] 4 5) so a reviewer can jump straight to any message and back to the index. It preserves every word the senders wrote — To, Cc, Bcc, timestamps, signatures, attachment listings, and inline styling (bold, italic, underline, hyperlinks). It strips only print chrome: page headers and footers, the Gmail logo, [Quoted text hidden] markers, and the duplicated forwarded/re-quoted message blocks that Gmail repeats inside every reply. ThreadTidy runs fully offline — no network access, no telemetry, nothing leaves your Mac.

Gmail's "Print all" export is unusable for court filings. A conversation that is really a 14-page exchange balloons to 19 pages of header banners, repeated quoted text, and Gmail UI chrome. Reviewers then have to wade through duplicated forwards and [Quoted text hidden] placeholders to follow who said what, when.

ThreadTidy produces a tidy version of the same thread — a clear title, a date range, a numbered timeline, and one clean entry per message — without altering a single word of the underlying email content. The result reads like the conversation actually happened, in order, once.

The pages below are a synthetic illustration — fictional names and content, not a screenshot and not a real email. They show the two kinds of page ThreadTidy produces: a title page with a numbered Index of Communications, and one page per message. In the produced PDF every ordinal is a live link — click a number to jump to that message, click Index to jump back — so a court reader can navigate a long thread without scrolling.

Page 1 — Index of Communications (one numbered row per message):

┌──────────────────────────────────────────────────────────────────────┐
│                                                                        │
│                  Re: Project Falcon — kickoff schedule                 │
│                    Apr 28, 2026  –  Apr 30, 2026                        │
│                                                                        │
│   Index of Communications                                              │
│     1.  Apr 28, 2026  8:12 AM   Jane Doe    → John Smith   Re: Falcon… │
│     2.  Apr 29, 2026  9:03 AM   John Smith  → Jane Doe     Re: Falcon… │
│     3.  Apr 30, 2026  8:38 AM   Jane Doe    → John Smith   Re: Falcon… │
│     4.  Apr 30, 2026 10:15 AM   John Smith  → Jane Doe     Re: Falcon… │
│     5.  Apr 30, 2026  4:47 PM   Jane Doe    → John Smith   Re: Falcon… │
│                                                                        │
│           (each row number links to that message's page)               │
│                                                                        │
└──────────────────────────────────────────────────────────────────────┘

A message page — note the navigation strip across the top: every ordinal 1 2 3 4 5 is listed, the current one bold and bracketed, with a jump-back link to the Index:

┌──────────────────────────────────────────────────────────────────────┐
│  ↩ Index      1   2  [3]  4   5              Message 3 of 5             │
│  ────────────────────────────────────────────────────────────────────│
│   3.                                                                   │
│   From:     Jane Doe <[email protected]>                            │
│   To:       John Smith <[email protected]>                        │
│   Cc:       Team List <[email protected]>                               │
│   Date:     Wed, Apr 30, 2026 at 8:38 AM                               │
│   Subject:  Re: Project Falcon — kickoff schedule                      │
│                                                                        │
│   Hi John,                                                             │
│                                                                        │
│   Confirming the kickoff for next Tuesday. The agenda is attached —    │
│   please review the **budget section** before we meet. The vendor      │
│   quote is _provisional_ and the signed SOW is at                      │
│   https://example.com/sow.                                             │
│                                                                        │
│   Thanks,                                                              │
│   Jane                                                                 │
│                                                                        │
│   Attachments:                                                         │
│     • Falcon-Agenda.pdf      (84 KB)                                   │
│     • Budget-Q2.xlsx         (212 KB)                                  │
└──────────────────────────────────────────────────────────────────────┘

In the real output **budget section** renders as actual bold text, _provisional_ as italic, and the URL as a live hyperlink — the ASCII markers above only stand in for styling the page here cannot show. Each message keeps its full stacked header (Cc and Bcc rows appear only when present), and the 1 2 [3] 4 5 strip plus every Index row number are clickable cross-references in the produced PDF.

• macOS 14 (Sonoma) or newer
• Xcode 15+ command-line tools (Swift toolchain) for building from source
• Apple Silicon recommended — the experimental MLX path is Metal-based
• Network access on the first build only, so SwiftPM can fetch the ML packages (a few hundred MB); subsequent builds are offline

There is one canonical build command:

./script/build-app.sh

This produces a ready-to-run ThreadTidy.app. The convenience symlink build/ThreadTidy.app always points at the most recent build, which lives in its own versioned folder under build/builds/ (e.g. build/builds/v0.1.0-7/ThreadTidy.app) so older builds stick around for side-by-side comparison.

What the script does, in order:

1. Bumps the monotonic build number in build/version/BUILD_NUMBER and stamps it into Info.plist as CFBundleVersion.
2. Builds the ThreadTidy SwiftPM product in Release.
3. Compiles mlx.metallib from MLX's vendored Metal kernels.
4. Assembles a .app bundle (Contents/MacOS, Contents/Resources, Contents/Frameworks), bundling libpdfium.dylib and the metallib, patching @rpath so the bundled dylib resolves.
5. Ad-hoc signs the app so it launches on the local Mac.

Flags:

• --no-bump — build without incrementing the build number.
• --print — print the current build number and exit.
• --regen-icon — regenerate AppIcon.icns.
• --dist — also produce a distributable ThreadTidy.zip (strips the quarantine attribute; recipients still right-click → Open since it is not notarized).
• --notarize — sign with a Developer ID, submit to Apple's notary service, staple the ticket, and produce a signed zip that launches cleanly on any Mac (implies --dist).

First build: SwiftPM fetches mlx-swift, mlx-swift-examples, and swift-transformers over the network (a few hundred MB). TPPDF and libpdfium are already vendored in the repo, so only the ML packages are downloaded, and only once.

1. Launch ThreadTidy.app (e.g. open build/ThreadTidy.app).
2. Drag a Gmail "Print all" PDF onto the dashed drop zone.
3. ThreadTidy cleans the thread and saves the result to ~/Downloads.
4. You can also drag the cleaned PDF straight out of the window into Finder, Mail, or any drop target.

A cleaned copy is also kept in $TMPDIR while the app is running, so you can drag it out repeatedly without re-processing.

The Gmail "Print all" pipeline is the fully-working, supported path. Beyond it, the repo contains scaffolding for broader format coverage:

• Heuristic parsers for other clients — Outlook and Apple Mail parsers are partially implemented. Outlook's print layout differs structurally from Gmail (only the most recent message has a stacked header; older messages are inlined as On … wrote: / From: / Sent: / To: / Subject: blocks), and the dispatcher detects format per PDF.
• On-device MLX universal fallback — a local, instruction-tuned LLM intended to parse any email PDF when no heuristic matches. The orchestration, prompt, JSON contract, Thread mapping, settings surface, and a differential-validation harness (heuristic vs. MLX) are in place, but the actual model inference call is currently a stub and there is no working MLX path in production yet.

This is honest, in-progress work — treat it as a roadmap, not a feature. For the full design and a precise status breakdown, see:

• docs/MULTI_FORMAT_AND_MLX.md — the multi-format + MLX design spec.
• docs/MLX_STATUS.md — what is built vs. what remains.

• It does not summarize, redact, or otherwise alter email body text. Every word the senders wrote is preserved verbatim.
• It does not extract inline body images. In v1 they appear as [image] placeholders (attachment images included); full image round-tripping is on the roadmap.
• It does not phone home or require any network access at runtime. (Only the first source build touches the network, to fetch dependencies.)

To sign and notarize a build for distribution to other Macs, run ./script/build-app.sh --notarize; tagged releases are built and signed automatically via GitHub Actions. See docs/SIGNING_AND_NOTARIZATION.md for credential setup.

ThreadTidy/
├── README.md                       # this file
├── LICENSE                         # Polyform Noncommercial 1.0.0
├── docs/
│   ├── MULTI_FORMAT_AND_MLX.md     # multi-format + MLX design spec
│   ├── MLX_STATUS.md               # MLX implementation status
│   └── SIGNING_AND_NOTARIZATION.md # signing / notarization setup
├── src/
│   ├── ThreadTidy/                 # Swift sources (App, Parser, Renderer, Resources)
│   └── libs/
│       ├── TPPDF/                  # vendored PDF rendering library
│       └── pdfium-mac/             # vendored libpdfium
├── script/
│   └── build-app.sh                # canonical build script
└── build/
    └── version/
        └── BUILD_NUMBER            # monotonic build counter (tracked in git)

ThreadTidy is licensed under the Polyform Noncommercial License 1.0.0 — free to use, modify, and share for any noncommercial purpose. See the LICENSE file for the full terms. ThreadTidy ships as part of the soundsuite package.