FableCut video editor: ensure the editor web server is running (auto-starts it), and get the editor URL, project summary and media library. Call this first in a session.

Return the FableCut project schema documentation: clips, tracks, props, keyframe animation, transitions, and editing recipes. Read this before editing. TOKEN TIP: pass section to fetch only the '## …' section(s) you need (substring match, e.g. "props", "Recipes", "Remake") instead of the whole manual.

Get the FableCut project (the timeline document). TOKEN TIP: pass compact:true for a one-line-per-clip summary (ids, tracks, timings, non-default props) — usually all you need to plan an edit; fetch the full JSON only when you must inspect exact keyframes.

Apply targeted edits to the FableCut project WITHOUT round-tripping the whole document — PREFER THIS over get+set for every edit (it is ~10-100x cheaper in tokens and merge-safe by design: it re-reads the latest document from disk, applies your ops in order, bumps revision once, saves atomically). Ops: {op:'addClip', clip:{…}} (id auto-generated if omitted) · {op:'updateClip', id, set:{…}} · {op:'removeClip', id} · {op:'addMedia', media:{…}} · {op:'removeMedia', id} · {op:'setProject', set:{name|width|height|fps|background|markers|disabledTracks|lockedTracks|untargetedTracks|encodeProfile|master}} (markers = the full list [{t, label?, color?}], color: gold|red|orange|green|cyan|blue|purple|pink; master = {gain}, the master fader in dB) · {op:'setTrack', id:'A1', set:{gain?, pan?, out?}} (audio-track fader in dB −60…+12, pan −1…1, out = a submix bus id or 'master'; null or 0 resets) · {op:'setBus', id:'B1', set:{name?, gain?, pan?, mute?}} (submix bus, created if missing; route tracks into it with setTrack out) · {op:'removeBus', id} · {op:'setFx', target:'clip'|'track'|'bus'|'master', id?, preset?:'podcast'|… OR fx:[{type,…params}], append?:true} (audio effects — validated; presets: clean-voice, podcast, radio, deep-voice, telephone, cinematic, wide, muffled; fx:null clears; on a clip it applies to its linked stems too) · {op:'setFxKeys', target, id?, index?|type?, param, keys:[{t, v, ease?}]|null} (automate one effect parameter: t is clip-local for a clip's effects, timeline seconds otherwise; see the 'Audio mix' docs section). TIMELINE EDITS — the editor's own split / ripple / trim code, so linked stems, track targeting (untargetedTracks) and locks behave exactly as in the UI; times in seconds: {op:'split', at, ids?} (no ids: every targeted track) · {op:'rippleDelete', ids} (later clips close the hole) · {op:'closeGap', at} · {op:'lift'|'extract', from?, to?} (remove a range; extract closes it; default = project inPoint/outPoint, which then clear) · {op:'insert'|'overwrite', mediaId, at, in?, duration?} (three-point edit: insert pushes later clips right, overwrite replaces what is there; a video brings one audio stem per channel) · {op:'rippleTrim'|'roll', id, side:'in'|'out', delta} · {op:'slip'|'slide', id, delta} (clamped to the media; the note says what was applied) · {op:'crossfade', ids? | at, duration?} (constant-power audio crossfade, borrowing handles from both sides). Any of these takes tracks:[…] to target lanes for that op only. setProject also takes inPoint / outPoint. updateClip merge rules: top-level keys are replaced (keyframes/transitionIn/transitionOut wholesale), props merges key-by-key, and setting any key to null deletes it. LOCKS: the user can lock clips (locked:true) and tracks (lockedTracks); updateClip / removeClip on a locked clip — or on a clip linked to one — and addClip onto a locked track are refused. Leave locked material alone; only if the user asked you to change it, pass force:true on that op (or unlock first: updateClip set:{locked:null}, which is always allowed). All-or-nothing: an invalid op aborts the whole patch unsaved.

Replace the FableCut project JSON. Pass the COMPLETE document (read with fablecut_get_project, modify, send back whole). Revision is auto-bumped; the open editor UI hot-reloads instantly so the user sees the edit live. CONFLICT-SAFE: if the project changed on disk since your last fablecut_get_project (e.g. the user tweaked something in the UI), the call errors instead of overwriting — re-read, re-apply your edit on top of the latest document, and retry.

Analyze a reference video into an EDIT BLUEPRINT so a similar edit can be rebuilt with different footage over the same music. Returns: shot boundaries (cuts) with per-shot audio energy, music beats + BPM, a loudness curve, the detected drop, and extracts the reference's music track into media/ (registered in the project, ready to place on A1). Remake recipe: copy the reference's width/height/fps to the project, write beats into project markers, lay the extracted music on A1, then place one clip per blueprint shot at the same start/duration — pick calm footage for low-energy shots and action for high-energy ones, and make the biggest moment land on drop. See the 'Remake a reference video' section of fablecut_docs.

Import a media file into FableCut's media library and register it in the project. Pass a local absolute path (copied, including .svg) or an https:// URL (downloaded into ./media/; video/audio/image only — remote SVG is refused). The URL is never kept as the playback src — CORS would break export. Returns the created media entry (use its id in clips).

List ffmpeg encoding profiles for Fast export (from encoding-profiles.json). Each profile is a raw ffmpeg argument list plus jpegQuality, extension, and optional color (output matrix/range — default BT.709 tv). Use to pick a profile id for project.encodeProfile. Edit encoding-profiles.json on disk to add custom profiles — anything the local ffmpeg supports works, and the server hot-reloads the file. Profiles are dry-run against ffmpeg when an export starts, so a bad argument is rejected before rendering.

Loudness-normalize clips: measures each clip's source audio (ITU-R BS.1770 integrated LUFS, or sample peak) after its channel routing and sets props.gain (clip gain, dB) so it lands on the target — the same measurement as the editor's Normalize button. Linked stems (a video's per-channel audio clips) are measured together and get one shared gain, so a stereo pair stays balanced; passing a video clip normalizes its stems. Volume keyframes / fades are untouched (they ride on top). Typical targets: -14 LUFS streaming/social, -16 LUFS podcast/dialogue, -23 LUFS broadcast, or mode 'peak' at -1 dBFS. Needs ffmpeg + ffprobe on PATH. Refuses locked clips unless force:true.

Duck music under dialogue: finds where the voice tracks have sound (RMS above threshold, short gaps bridged so the music doesn't pump between words) and writes duck keyframes (dB) on the given music clips — a dip of amount dB ramping down attack s before speech and back up release s after. The duck multiplies the clip's volume, so its own level, volume keyframes and fades are untouched, and re-running replaces the previous dips (amount 0 clears them). Voice = every audio clip on under tracks (default: all audio tracks the music isn't on). Linked stems of a music clip get the same keys. The same pipeline as the editor's Auto-duck. Needs ffmpeg + ffprobe on PATH. Refuses locked clips unless force:true.

Reduce background noise (hiss, hum, room tone) on audio clips: ffmpeg's FFT denoiser renders a cleaned FLAC of each clip's whole source file into media/, and the clip — with its linked stems — switches to it (the picture keeps its own file, so links and timing stay intact). The same as the inspector's Noise control. amount 'off' switches back to the original. Re-running reuses a file already rendered. Needs ffmpeg + ffprobe on PATH. Refuses locked clips unless force:true.

Render the timeline to a video file in exports/ — the editor's own Fast export (same compositor, audio mix and encoding profile as the Export button), so the file matches what the user sees. It runs in a browser: an open editor tab takes the job (the user sees the progress bar), or with no tab open the server starts headless Chrome / Edge (set FABLECUT_CHROME to pick one) and closes it afterwards. Waits for the file by default and returns its path. Range: the project's inPoint→outPoint when set, else the whole timeline (or pass range). Needs ffmpeg on PATH. One export at a time. Long edits: pass wait:false, then poll with {job}; {cancel:job} stops one.