# proofcut

<!-- mcp-name: io.github.tydude001/proofcut -->

**An AI video editor that proves its cuts.** Your recordings in, a finished,
mastered film out: cut by transcript, with b-roll, cards, music and captions,
and every step an agent can call. proofcut renders on your own machine, then
transcribes the render and checks that it says what the edit says.

https://github.com/user-attachments/assets/4153d180-3d7c-4c70-af5f-54d63d0a8bd5

Above: an agent cutting a demo video, unattended. The two runs it was cut
from, uncut (silent: the recorder took frames only, and the voice is in the
film the agent cut): [the workspace](https://github.com/tydude001/proofcut/releases/download/v0.23.0/proofcut-v0.23.0-uncut-workspace-run.mp4)
(2:26) and [Claude Code with the proofcut plugin](https://github.com/tydude001/proofcut/releases/download/v0.23.0/proofcut-v0.23.0-uncut-claude-code-run.mp4)
(3:09).

That is not a staged run. [TRIAL.md](https://github.com/tydude001/proofcut/blob/main/docs/TRIAL.md) scores three unattended
ones, each handed a goal and no steps, and each passed every one of its checks.
- **The demo cut**, the one above.
- **Real footage:** 96 seconds of narration with its fluffed takes left in,
  plus four clips of film footage. The agent cut it to 45 seconds, chose
  footage by what each line was about, burned captions, and checked its own
  render: all 123 expected words heard back.
- **A whole film:** the demo material plus a score, briefed as a finished film
  ready to upload. In 192 seconds and $2.27 the agent cut it, laid the music
  under the voice, ended on a card, mastered it to −16 LUFS, and checked it.
  The score, the level and the end card were each measured in the delivered
  file, not taken from the project.

> **Have a Mac or a Windows PC and half an hour?** Nobody has run proofcut on
> a Mac yet, and on Windows only its author has. One script runs the whole
> test and removes what it installed:
> [§ Help wanted](#help-wanted-a-mac-or-a-windows-run).

## Try it

Check your machine first, before cloning anything. `proofcut doctor` probes
every tool proofcut uses and prints the fix for anything missing
([§ Requirements](#requirements) has the list). With
[uv](https://docs.astral.sh/uv/) installed:

```sh
uvx proofcut doctor
```

The first run downloads Python 3.13 if uv has none, plus proofcut's
dependencies, about 230 MB together.

On Linux, `proofcut setup` installs whatever doctor marked ✗, for you alone
and with no sudo, and `proofcut setup --uninstall` removes exactly what it
added. It says what it will download and asks first; whisper is about 1.9 GB
of it. On a Mac or a Windows PC, follow the fix doctor prints under each ✗.

```sh
uvx proofcut setup
```

The demo and your own recordings run from a checkout:

```sh
git clone https://github.com/tydude001/proofcut && cd proofcut
uv sync
```

### The two-minute demo

No footage needed. [docs/DEMO.md](https://github.com/tydude001/proofcut/blob/main/docs/DEMO.md) generates a voiceover with a
real retake, b-roll and a score, then walks a whole small film: cut the retake
by naming its words, hang b-roll off a phrase, lay the score under the voice,
render and master it, end on a card, and check the render against the
timeline.

```sh
uv run python scripts/make_demo.py ~/proofcut-demo
```

### In Claude Code

The plugin registers proofcut's MCP server, so all 93 tools are available
with no setup of your own:

```
/plugin marketplace add tydude001/proofcut
/plugin install proofcut@proofcut
```

The first start downloads about 175 MB of Python dependencies, and Claude
Code gives a server 30 seconds to connect. On a slow connection, start that
first session as `MCP_TIMEOUT=300000 claude`, or reconnect proofcut in `/mcp`
once the download has finished.

Any other MCP client runs the same server, from a checkout or with no
checkout at all:

```sh
uv run --project /path/to/proofcut proofcut mcp
uvx proofcut mcp
```

### On your own recording

```sh
uv run proofcut init myproject
uv run proofcut -C myproject import VO.wav --clip-id vo
uv run proofcut -C myproject transcribe vo                  # whisper, word-timed
uv run proofcut -C myproject seed vo                        # auto-editor strips silences
uv run proofcut -C myproject transcript vo --search "here's the thing"
uv run proofcut -C myproject cut vo 111:114 --plan          # what do those indices say?
uv run proofcut -C myproject cut vo 111:114 --pad 0.1       # inclusive word range
uv run proofcut -C myproject export final.mp4 --render      # or a .kdenlive to finish in an NLE
uv run proofcut -C myproject verify final.mp4               # did the render say what you edited?
```

To watch the edit instead, open the workspace. It plays the source through
the edit, so seeing a cut costs no render:

```sh
uv run proofcut -C myproject open        # server plus an app window
uv run proofcut -C myproject web --open  # the same page in a browser tab
```

## From recordings to a finished film

One project, and proofcut's own commands from the first import to the
delivered file. No NLE finishes the film, and nothing else touches the render.
Each stage is one command, and each row links the section of the
[manual](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md) that
walks it.

| Stage | Command |
|---|---|
| [Bring in the voiceover and footage, and transcribe](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#the-core-loop) | `import`, `transcribe` |
| [Cut retakes and asides by naming their words](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#word-indices-and-locate) | `cut vo 111:114` |
| [Hang b-roll and cards off the lines they belong to](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#cards-cues-and-tails) | `cue add`, `card new` |
| [Open cold on a scene](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#a-cold-open), [end on a card](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#cards-cues-and-tails) | `head`, `tail` |
| [Play the footage's own lines in a gap, or under the narration](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#holds-the-films-own-lines) | `hold add`, `hold under` |
| [Score it: placed passages, crossfaded, levelled under the voice](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#the-music-bed) | `music` |
| [Pull breaths down without cutting them](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#attenuation) | `attenuate` |
| [Render](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#renders-presets-undo-migration) and [master to a loudness target](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#the-master) | `export --render --loudness -16` |
| [Burn in captions](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#captions) | `captions --burn` |
| [Check the render says what the edit says](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#verifying-a-render) | `verify`, [`frames`](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#frames-film-check-black-spots), [`hold check`](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md#holds-the-films-own-lines) |

Two video essays of five to six minutes have been rebuilt this way and
measured against their originals, which had been finished outside proofcut.
One came out the same length to the frame. The other matched its original's
63 voiceover ranges to the millisecond, with the voice aligned to the sample,
starting from a retake pass made in Kdenlive. Both master at the original's
−16 LUFS (HISTORY.md § The Lambs/Longlegs native rebuild, § The Scream native
rebuild).

proofcut makes no footage and writes no script. It takes what you recorded to
a film, and proves the film matches the edit.

Beyond the stages above, one line each:

- **The workspace.** Edit (transcript, preview, drag-trim and razor), Frame
  (review every crop in place) and Finish (presets, verify, and the finished
  file). The truth strip warns while you edit if the film would ship wrong.
- **An agent that can look.** `shot-sheet` draws the whole picture track as
  one labelled grid, and `footage-sheet` browses a clip you haven't cut yet.
  Both return the image itself over MCP.
- **Transcript self-checks.** Retake seams, invented words, swallowed repeats
  and suspect durations are reported when a transcript is attached, and
  `unspoken` lets the render itself testify to words nobody said.
- **B-roll by description.** `describe` writes what is on screen in each
  ~10-second window of footage, so an agent can choose a clip by what a line
  is about.
- **Reframing.** Per-shot crop windows for aspect changes, face-aware
  proposals (`reframe-detect`), a review sheet, and stacked splits for two
  speakers. Cards are redrawn at the new frame size, never stretched.
- **Derived reels.** `reel` cuts part of the film into a new project, such as
  a vertical teaser. It reports every picture it dropped and pins the ones it
  kept.
- **NLE round-trip.** Export to Kdenlive or OTIO, finish elsewhere, and
  `import-edit` the trim back.

![Frame mode: a shot list beside the selected shot's windows — each crop
drawn as a rect on three of the source's own frames, over a filmstrip of the
whole shot with the sampled instants ticked on it, the window's rect quoted
in source pixels, Approve/Re-frame beside it, and coverage chips for stale
framing and unexplained steps](https://raw.githubusercontent.com/tydude001/proofcut/main/docs/img/frame-mode.png)

proofcut is 0.x software. A project from an older version is refused rather
than guessed at, and `proofcut migrate` brings it forward.

## Why proofcut

- **It checks its own work.** `verify` transcribes the finished file and
  diffs it word by word against the timeline, so a retake left in the film is
  caught before anyone watches it. Frame counts and the picture are measured
  too, because ffmpeg, melt and auto-editor all exit 0 on some failures.
- **Cuts stay addressable.** Every word in a recording keeps a fixed index
  that never renumbers, so `cut vo 111:114` names the same words however many
  cuts came before it. `--plan` prints what a range says before anything
  changes, and `restore` and `undo` walk it back.
- **Built for agents.** 93 MCP tools with typed inputs and structured
  returns, so Claude Code, Codex or your own agent can drive it. Tools like
  `shot-sheet` return an image of the edit, not a file path the agent can't
  open.
- **One engine, three ways in.** The MCP server, the `proofcut` command line
  and a browser workspace all call the same operations. Every tool has a
  matching command (the test suite enforces it), so anything an agent does,
  you can script or re-run by hand.
- **Local-first.** Commercial AI editors are apps around a metered cloud
  service. proofcut transcribes, edits and renders on your machine, and calls
  no cloud service of its own: no account, no per-minute billing. The only
  thing that talks to a model provider is the agent you choose to run (the
  optional footage-description and voice models download once, on first use).
- **No lock-in.** The timeline is OpenTimelineIO. Export a `.kdenlive` or
  OTIO file, finish in Resolve, Premiere or Kdenlive, and bring your trim back
  with `import-edit`.

![The proofcut workspace on the demo project: the transcript with a retake struck
through, the preview drawing the shot under the playhead with its captions, the
side rail on its agent tab reporting a finished render against the timeline,
and the layered timeline below — picture, waveform and captions as three
projections of one edit](https://raw.githubusercontent.com/tydude001/proofcut/main/docs/img/edit-mode.png)

## Help wanted: a Mac or a Windows run

GitHub's macOS and Windows runners take the demo to a checked render, but a
runner never reads the instructions. No person has run proofcut on a Mac. On
Windows, the author's own Windows 11 laptop has, twice, and nobody else's PC;
Windows 10 and ARM64 PCs have not been tried at all. If you have one of these
machines and half an hour, one script installs what proofcut needs, makes a
short test video, has proofcut cut, score, master and check it, and puts a
report on your Desktop. It asks before it starts, records what it added, and
removes exactly that on request, nothing you already had. A run that stops at
the first step is just as useful, because where it stops is the finding.

On a Mac:

```sh
git clone https://github.com/tydude001/proofcut
bash proofcut/scripts/mac_trial.sh
```

It installs `uv`, `ffmpeg-full`, `espeak-ng` and `auto-editor` with Homebrew
(and Homebrew itself if you have none), plus the Shotcut app for its renderer
and whisper. `bash proofcut/scripts/mac_trial.sh --uninstall` removes them.
Then [file the report](https://github.com/tydude001/proofcut/issues/new?template=mac-test.yml).

On Windows, from PowerShell:

```powershell
git clone https://github.com/tydude001/proofcut
powershell -ExecutionPolicy Bypass -File proofcut\scripts\windows_trial.ps1
```

It downloads `uv`, `ffmpeg`, `auto-editor`, `espeak-ng`, Shotcut's renderer
and whisper into one folder under `%LOCALAPPDATA%`. Nothing is installed
system-wide and it needs no administrator rights. The same command with
`-Uninstall` deletes that folder. It puts `proofcut-windows-report.zip` on
your Desktop with your home folder's name taken out; [file the report](https://github.com/tydude001/proofcut/issues/new?template=windows-test.yml).

## Requirements

proofcut is developed on Linux (a Fedora-based desktop). On macOS and
Windows the test suite passes on CI and GitHub's runners take the demo to a
checked render. On Windows one person's PC has too, the author's; no person
has run it on a Mac yet. Where each OS stands is in
[docs/plans/PORTABILITY.md](https://github.com/tydude001/proofcut/blob/main/docs/plans/PORTABILITY.md).

Every hard part of an editor already exists as mature open source, and
proofcut is the layer that lets an agent drive those tools and check what
they produced. Run `uv run proofcut doctor` to check everything below at
once. On Linux, `uv run proofcut setup` installs any of the last four that
doctor marks ✗: a static ffmpeg, whisper, auto-editor's release binary and
Shotcut's portable melt, which renders with no display at all
([docs/plans/INSTALL.md](https://github.com/tydude001/proofcut/blob/main/docs/plans/INSTALL.md)).

| You need | For | Notes |
|---|---|---|
| **Python 3.13** and [uv](https://docs.astral.sh/uv/) | everything | `uv sync` installs the Python side. The only runtime dependencies are `mcp` and OpenTimelineIO, which holds the timeline and exports it to other editors. |
| **ffmpeg / ffprobe** built with `libx264`, freetype and libass | cutting, concatenating, captions, rendering | Fedora's default `ffmpeg-free` has no `libx264`: use RPM Fusion's `ffmpeg`. On a Mac, Homebrew's `ffmpeg` lacks freetype and libass: install `ffmpeg-full` and put `$(brew --prefix ffmpeg-full)/bin` first on `PATH` (it is keg-only). |
| **[auto-editor](https://github.com/WyattBlue/auto-editor) 31+** | silence and bad-take removal, single-source renders | Install the upstream binary. The PyPI package is a stale 29.x. |
| **whisper** | word-timed transcription (30+ languages), render verification | Any `openai-whisper` install. `uv tool install --python 3.12 openai-whisper` is the short route (3.12 because torch's Intel-Mac builds stop there); add `--torch-backend cpu` without an NVIDIA GPU (1.9 GB instead of 5.5 GB). Found via `PROOFCUT_WHISPER`, then `PATH`. The CPU build transcribed the demo's 19-second voiceover in 33 seconds. |
| **MLT (`melt`)** | layered renders (b-roll, cards, music) | Your distribution's MLT package (`mlt` on Fedora, whose `melt` package is an unrelated compression tool), or Kdenlive, whose flatpak copy is found automatically. `PROOFCUT_MELT` overrides both. |

Optional. Each unlocks one feature, `proofcut doctor` reports whether it is
available, and everything else works without it:

| Optional | Unlocks | Notes |
|---|---|---|
| **ImageMagick 7** (`magick`) | title and end cards, rendered from SVG templates | ImageMagick 6's `convert` is not used, so distributions that still ship 6 (Ubuntu 24.04) need ImageMagick's own build. |
| **[Claude Code](https://docs.claude.com/en/docs/claude-code)** (`claude`, logged in) | the agent pane in the workspace | `proofcut mcp` works with any MCP client; only the pane runs `claude` itself. |
| **`PROOFCUT_VLM`** | `describe` (b-roll search by what's on screen) | The python of a venv with torch, transformers, bitsandbytes and Pillow, on a CUDA GPU. The Qwen2.5-VL model downloads on first use. |
| **`PROOFCUT_FACE`** | `reframe-detect` (face-aware crops) | The python of a venv with insightface, onnxruntime and opencv-python. |
| **`PROOFCUT_TTS`**, **`PROOFCUT_TTS_MODEL`**, **`PROOFCUT_TTS_VOICE`** | `vo-synth` (a line in a cloned voice) | A python with qwen-tts and a CUDA torch, a local Qwen3-TTS snapshot, and a directory holding a reference clip of the voice. There is no default voice, on purpose. |

## Working on proofcut

Whether you're a person or a coding agent, start with
[CLAUDE.md](https://github.com/tydude001/proofcut/blob/main/CLAUDE.md). It holds the rules and the traps this repo has
already hit, and Claude Code loads it automatically.
[CONTRIBUTING.md](https://github.com/tydude001/proofcut/blob/main/CONTRIBUTING.md) is the short version a pull request is
checked against, and [SECURITY.md](https://github.com/tydude001/proofcut/blob/main/SECURITY.md) says how to report a
vulnerability.

Where things live:

| Path | What it is |
|---|---|
| `src/proofcut/ops.py` | Every operation. The MCP tools, the CLI and the web UI all call these. |
| `src/proofcut/server.py` | The MCP server. Register tools with `@_tool()`, never `@mcp.tool()`. |
| `src/proofcut/cli.py` | The `proofcut` command: one subcommand per tool, printing JSON. |
| `src/proofcut/webui.py`, `src/proofcut/web/` | The workspace. It posts to `ops` and renders what comes back; it never decides anything itself. |
| `src/proofcut/project.py`, `timeline.py` | The project manifest (`proofcut.json`) and the OTIO timeline. |
| `tests/` | `test_server_stdio.py` drives a real `proofcut mcp` subprocess; `test_webui_http.py` a real socket. |
| `scripts/` | The demo maker, the Mac and Windows trial kits, screenshot capture. |
| `docs/` | The manual, the demo, and the design record (below). |

Run the checks:

```sh
uv sync
uv run ruff check .      # never `ruff format`; see CONTRIBUTING.md
uv run pytest
```

The suite talks to a real `proofcut mcp` subprocess, so it is slower than a
pure unit suite. Tests that need whisper, auto-editor, melt or ImageMagick
skip when the tool is missing. Tests that render through `melt` also need a
display: on a headless machine use `QT_QPA_PLATFORM=offscreen` or `xvfb-run
-a` (`proofcut doctor` tells you which your MLT needs). Without one they fail
with "no display for MLT's Qt module to open", which is the environment, not a
regression.

The documentation:

- [docs/MANUAL.md](https://github.com/tydude001/proofcut/blob/main/docs/MANUAL.md): every command, with the reasoning.
- [docs/DEMO.md](https://github.com/tydude001/proofcut/blob/main/docs/DEMO.md): the whole loop in two minutes.

proofcut's reasoning is part of what it ships, so the design record is public:

- [PLAN.md](https://github.com/tydude001/proofcut/blob/main/docs/PLAN.md): architecture, stack decisions, open questions.
- [HISTORY.md](https://github.com/tydude001/proofcut/blob/main/docs/HISTORY.md): the dated record of what shipped and what the
  evidence said.
- [PRIOR-ART.md](https://github.com/tydude001/proofcut/blob/main/docs/PRIOR-ART.md): what else exists in this space, and what
  proofcut does that they don't.
- [NEXT.md](https://github.com/tydude001/proofcut/blob/main/docs/NEXT.md): the directions after the queues closed, ranked.
- [TRIAL.md](https://github.com/tydude001/proofcut/blob/main/docs/TRIAL.md): an agent cutting a video end to end, unattended
  and scored.
- [docs/plans/](https://github.com/tydude001/proofcut/tree/main/docs/plans): the plans, in progress and finished. A step
  that landed says "Shipped" and names its HISTORY.md section.

## License

[PolyForm Shield 1.0.0](https://github.com/tydude001/proofcut/blob/main/LICENSE). proofcut is source-available, not open
source: you can read, run, change and redistribute it for any purpose except
building a product that competes with it. Cutting your own videos, running it
for clients, building on it and forking it to fix a bug are all fine. For a
commercial licence, ask.

The bundled typefaces are not proofcut's to relicense. The caption face in
`src/proofcut/fonts/` and the three browser faces in `src/proofcut/web/` are
OFL-1.1, each with its licence text beside it and its source in that
directory's `FONTS.md`.

## Say thanks

If proofcut cut a video for you, you can [buy me a coffee on Ko-fi](https://ko-fi.com/tydude001).