video-extend

A command that adds new footage to the end of an existing MP4 video using a written instruction and Grok Imagine.

In plain words
What is it for?
Use it with a publicly reachable video URL to describe the next camera movement or scene and choose an extension of two to ten seconds.
Why use it?
It continues a clip without asking you to generate a separate video from scratch.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/moore-developers/grok-cli/video-extend
Clone the repo
git clone --depth 1 https://github.com/Moore-developers/grok-cli
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 558 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00558
Opus 5 $0.00000 $0.00279
Sonnet 5 $0.00000 $0.00112
Haiku 4.5 $0.00000 $0.00056

Measured 2d ago against content hash 2a4f20723d79, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

video-extend scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

docs/commands/video-extend.md · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

grok-cli video-extend

Purpose

Extend an existing video with Grok Imagine.

This command is separate from video and video-edit. video generates new video, video-edit edits an existing video, and video-extend appends new footage to the end of an existing MP4 video.

Note: video-extend only supports a remote video URL. It does not expose local video paths because real validation showed that local MP4 files were encoded and sent to the upstream service, but the final xAI extension job returned an internal error. To extend a local video, upload it first and then pass the remote URL with --video-url.

Common Usage

grok-cli video-extend --video-url https://example.com/source.mp4 --prompt "The camera pans left" --duration 6

Script or skill usage:

grok-cli video-extend --json --video-url https://example.com/source.mp4 --prompt "Continue the camera move"

Parameters

  • PROMPT: positional extension prompt.
  • --prompt <PROMPT>: explicit script-friendly prompt.
  • --video-url <URL>: source video URL to extend.
  • --duration <SECONDS>: extension length, default 6, clamped to 2..=10.
  • --json: use the standard JSON envelope.
  • --auth-file <PATH>: override the OAuth state file path.
  • --model <MODEL>: override the model for this video extension request only.
  • --timeout <SECONDS>: total video polling timeout, default 600; individual HTTP requests still stay within the media request ceiling.

Behavior

  • Default model is grok-imagine-video.
  • The command calls POST /videos/extensions and sends video: {"url": ...} plus the normalized duration.
  • --video-url is required; local video paths are not part of the public capability surface.
  • aspect_ratio and resolution are not sent; the extension inherits the input video properties.
  • The command reads request_id from the create response and polls GET /videos/{request_id} until completion.
  • Successful calls are written to the local usage SQLite database under video usage.

Read the full file on GitHub · 61 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 61 lines · 0 tokens per session scan A 2a4f20723d79

Subscribe to this mod's changes

video-extend is a command published in the GitHub repository Moore-developers/grok-cli (52 stars, last pushed 20d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 558 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.