edit_video's own description lists speed-change as one of the things it does alongside stitching, trimming, captioning and mixing — it's an agent-driven EDL render, so instead of dragging a speed keyframe on a timeline, you describe the change in plain English and the agent builds the edit list for you.
This is useful for comedic slow-motion reveals, time-lapse-style speed-ups, or a speed ramp on a specific section while the rest of the clip plays normally.
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Agent-driven EDL render via the Versely editor pipeline (POST /features/editor-render). Stitch, trim, speed-change, caption, overlay, and mix user media (workspace/generation HTTPS URLs) into ONE final video. Prefer this over chaining cut_video + attach_audio + add_*_captions when the user wants a multi-clip assembly in a single step. Billing: preview:true is free 480p (per-user cooldown); final export (preview:false, default) charges the normal single editor_export price. Prefer preview:true while the user is iterating; only final-render after confirmation. Clips must be HTTPS URLs (file:// and other schemes rejected). Returns { video_url, credits_charged, preview_notes } or a 402-style insufficient-credits error.
What to tell the agent
Versely's agent maps this plain-English request directly onto edit_video. You don't need to know the parameter names — just describe what you want.
“Play the first 3 seconds of this video at half speed for a slow-motion reveal, then normal speed for the rest.”
How it works
1. Describe which section changes speed
Tell the agent the time range and whether it should speed up or slow down.
2. Specify the factor
Half speed, double speed, 4x time-lapse — describe it in plain terms; the agent maps it into the render.
3. Preview for free
Use preview:true to sanity-check the pacing at 480p before spending credits on the full render.
4. Export
Confirm the final, full-resolution render once the speed change reads correctly.
What it costs
Free 480p preview (preview:true, per-user cooldown), then the standard editor_export price for the final render.
The formula behind that number: What does editing a video cost if I keep changing it? — charges per finished export, so iteration is free and the count is the whole bill.
Limits & things to know
- This is a natural-language instruction to an agent-driven render, not a frame-by-frame speed-curve editor — very fine-grained speed ramping is better checked via preview first.
- Audio pitch behavior during a speed change should be specified explicitly if it matters to you (e.g. 'keep the pitch normal' vs. letting it shift with the speed).
Who uses this
- Slow-motion reveals and comedic beats
- Time-lapse-style speed-ups of a long process shot
- Speed ramps into a hook moment
Frequently asked questions
Can I speed up just part of the video, not all of it?+
Yes — describe the specific time range and speed factor to the agent; the rest of the clip can stay at normal speed.
Is there a dedicated 'speed' parameter I set manually?+
edit_video is an agent-driven EDL render — you describe the speed change in plain English rather than setting a numeric field yourself, and the agent constructs the underlying edit.
Related Versely tools
Related editing jobs
Change a Video's Playback Speed inside Versely
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