camkit

The missing CLI and MCP server for Camtasia.

Programmatic Camtasia editing toolkit. A Camtasia .cmproj bundle's timeline is plain JSON (project.tscproj); camkit reads and rewrites it directly — no ffmpeg re-encoding, Camtasia stays the final renderer.

Platform: the core timeline and media commands are cross-platform; the Camtasia app-control commands (status, open, close, docs) drive the macOS app via AppleScript and are macOS-only.

Extracted from a working rough-cut workflow: record long takes → transcribe with word-level Whisper timestamps → pick the best takes → camkit rebuild rewrites the timeline to keep only the good segments.

Packages

• @camkit/core — pure cross-platform logic: tscproj load/mutate, editRate time math (705600000 units/s at the project level), clips/sources listing, rebuild planning (per-(src,track) template dedup keeps two-track screen+camera recordings in sync), transcript + silence parsing. Functions return structured data; no console output, no platform calls.
• @camkit/darwin — macOS Camtasia app control via AppleScript: open documents list, status, open, close-with-save. Camtasia never re-reads project.tscproj while a document is open, so the edit cycle is close (saves) → edit JSON → open (reloads). Throws on other platforms.
• @camkit/cli — the camkit binary: info, clips, sources, rebuild, export-audio, export-video, captions, silences, transcribe, status, close, open, docs. Rebuild always backs up to .bak and refuses to run with a ~project.tscproj lock or an existing backup unless --force. Always --dry-run first. export-audio flat-mixes the timeline's audio to one file (m4a/wav/flac/…) for cleanup in Audacity/Auphonic — pure ffmpeg, honours track mute and per-clip gain (--raw to bypass). captions injects an animated Dynamic Caption track straight into the project from a transcript (same backup/lock safety as rebuild). export-video renders the current timeline to a ProRes 422 .mov by driving Camtasia's GUI export (Camtasia stays the renderer — effects, transitions, Dynamic Captions and .trec video streams need its engine, no ffmpeg re-encode). macOS-only; needs Accessibility permission. Brittle: it drives Camtasia's export menus via UI scripting, verified only on Camtasia 2026.1.3 — menu renames or a Welcome window can break it. Prefer a short smoke export after Camtasia updates.
• @camkit/mcp — placeholder; will wrap core later.

Prerequisites

• Bun ≥ 1.x
• ffmpeg on PATH — required by camkit export-audio, silences, and transcribe (brew install ffmpeg)
• A transcription engine — required by camkit transcribe only; see Transcription engines. OPENAI_API_KEY (cloud), REPLICATE_API_TOKEN (hosted), or whisper-cpp (local, brew install whisper-cpp).
• macOS + Camtasia — required by status/close/open/docs and export-video; everything else is cross-platform
• Accessibility permission — required by camkit export-video only. It drives Camtasia's export GUI via System Events, so grant your terminal under System Settings ▸ Privacy & Security ▸ Accessibility.

Docs

• Transcription engines — engine precedence (OpenAI, Replicate, local whisper.cpp), model overrides.
• Captions in the Camtasia UI — higher-quality captions, Dynamic Caption presets, SRT import.
• Why export-video drives the GUI — why rendering can't be done from JSON, the export approaches tried, and why UI scripting is the only working path.

Use

bun install
bun test             # unit tests (time math, rebuild planning, silence parsing)
bun run typecheck
bun run build        # standalone executable → packages/cli/dist/camkit
bun packages/cli/src/camkit.ts info --project path/to/foo.cmproj

# or put the bin on your PATH (it's the TS source, run by bun via shebang):
ln -sf "$PWD/packages/cli/src/camkit.ts" ~/.bun/bin/camkit
camkit --help

See packages/cli/README.md for full command documentation; every command also has camkit <command> --help.

Gotchas carried over from the reference workflow

• .trec recordings are QuickTime containers: ffmpeg reads the audio and h264 streams but cannot decode the tscc2 screen stream.
• Whisper folds pauses into stretched word timestamps — always cross-check kept ranges with camkit silences before finalizing a cut.
• After a rebuild the project is already cut and .bak holds the original; to recut, restore the .bak first or you'll back up the cut file.