Can Codex make videos?

Not on its own. Codex CLI 0.163.0 lists an image generation feature but no video tool, so it makes videos through skills or plugins it runs for you. Code-render skills such as HyperFrames and Remotion turn HTML or React code into an MP4. Skills that call a video model make new clips from a prompt. A hosted video skill such as Riffkit can change a video you already have, for example the person, outfit, setting or product, while keeping the shots.

How do I add a video skill to Codex?

Most video skills install with one command or one line pasted into Codex. HyperFrames installs with npx skills add heygen-com/hyperframes and Remotion with npx skills add remotion-dev/skills. For Riffkit, paste this into Codex: Run curl -fsSL https://riffkit.ai/SKILL.md in your terminal and follow the instructions to join Riffkit. Codex reads the skill, checks for the Riffkit CLI and sends you a sign-in link.

How do I edit an existing video with Codex?

Use a hosted video skill, because Codex has no video tool of its own and code-render skills build videos from code rather than changing footage. With Riffkit, paste the setup line into Codex, approve the sign-in link it gives you, then ask for the change in plain words and name what should stay the same. Codex shows the plan and price before it submits. In Riffkit's test, Codex replaced the person in an 8-second clip with a platform character for 450 credits, about 5 minutes after it submitted.

Why does riffkit login fail in Codex with a permission error?

Codex runs commands in a sandbox that can write only to your project folder, and the Riffkit CLI saves its sign-in in ~/.riffkit, so riffkit login stops with EPERM. Start Codex with --add-dir ~/.riffkit, which lets it write there, and run the sign-in again. The CLI also needs network access, which Codex's workspace sandbox keeps off by default; -c sandbox_workspace_write.network_access=true turns it on.

How much does it cost to make a video with Codex?

Two costs: your Codex usage and the video service. In Riffkit's test, the whole Codex session used about 68,000 tokens on a ChatGPT plan, with nothing billed separately. The video, an 8-second Swap on Seedance 2.0 Fast at 480p, cost 450 Riffkit credits. Riffkit plans start at $15 a month for 3,000 credits, and signup is free.

Can I put an AI character into my own video with Codex?

Yes. Ask Codex to replace the person with a character and keep the rest. Riffkit's Platform characters can be used by any account; in our test Codex picked Pipli from the list. Pipli took over all four shots of our clip with the same gestures, room and caption; two of the four outfits stayed exactly as they were, and in the first shot she wore the outfit from her character image instead.

Does Codex wait until the video is finished?

Not always. In our run, Codex submitted the video, checked once at 12% and ended its turn. When we asked it to keep checking until the video was finished, it ran riffkit wait, then returned a link that opens the video for 6 hours, plus a post caption and hashtags. It's worth adding that line when you say Submit.

How to Make Videos with Codex: 3 Ways and a Real Test

Codex can make videos in three ways: code-render skills turn HTML or React code into an MP4, skills that call a video model make new clips from a prompt, and a hosted video skill can change a video you already have. We tested the third way on October 16, 2026, with Riffkit, our own video tool. Codex installed the Riffkit skill from one pasted line, signed in through a browser link, priced the job, and replaced the woman in our 8-second clip with an AI character for 450 Riffkit credits, with the finished video back about 5 minutes after it submitted. Below is what each way can do, the exact steps, the one setup snag we hit, what Codex did at each step, and what changed in the video.

Three ways to make videos with Codex

Way	What it makes	Starts from	Good for
Code-render skills (HyperFrames, Remotion)	An MP4 rendered from HTML or React code	A script, a web page or your assets	Explainers, product walkthroughs, motion graphics
Skills that call a video model	A new AI clip	A prompt or an image	A shot that doesn't exist yet
A hosted video skill such as Riffkit	Your existing video, re-rendered with the changes you name, or a winning video remade with your product	Your own clip, a TikTok link or a template	Changing the person, outfit, setting or product in a clip that already works

Codex has no video tool of its own. In Codex CLI 0.163.0, codex features list shows an image generation feature but nothing for video, so every route below is a skill or plugin that Codex runs for you.

Code-render skills draw the video themselves. HyperFrames turns "HTML, CSS, media, and seekable animations into deterministic MP4 videos," per its README, and installs with npx skills add heygen-com/hyperframes. Remotion's docs give npx remotion skills add or npx skills add remotion-dev/skills for agents like Codex, and Remotion also offers a Codex plugin. These suit text, charts and screens rather than people on camera.

Model skills make new clips. Several third-party skills hand Codex a command that sends a prompt to a video model and downloads the clip. They make new footage; they don't change a clip you already have.

A hosted skill hands the work to a video service. Codex reads the skill, runs its commands in the terminal, and the service renders the video on its own servers. That is the way we tested.

The test: a new person in our own clip, from Codex

The source is our own 8-second vertical clip, made with AI and saved as a template in our Riffkit account: one woman in a living room, four shots, four outfits, Spanish voice-over and on-screen captions. We used our own clip because Swap keeps the source's sound and everything you don't change, and someone else's video isn't ours to edit.

Setup. We used Codex CLI 0.163.0 (npm i -g @openai/codex), signed in with a ChatGPT account, from the terminal (codex exec, resuming the same session for each reply). In a new, empty folder we started it with network access on for its workspace sandbox (-c sandbox_workspace_write.network_access=true), since the Riffkit CLI has to reach riffkit.ai, and pasted the line from our skill page:

Run curl -fsSL https://riffkit.ai/SKILL.md in your terminal and follow the instructions to join Riffkit. Sign me in to Riffkit first; when you have a sign-in link for me, give it to me and stop.

Then we asked in plain words:

Then use my analyzed template of the 8-second clip in a living room (its id starts with c16bcf3a) in Swap mode, and replace the woman with Pipli, one of Riffkit's platform characters. Keep every shot, cut, camera move and gesture, her four outfits, the sound and the on-screen caption exactly as they are; only the person changes. Use Seedance 2.0 Fast at 480p. Show me the plan and the price, and wait for my go-ahead before you submit.

What Codex did, step by step

It read the skill and checked the CLI. Codex fetched the skill file, ran node -v and riffkit --version, and found the Riffkit CLI already installed (version 0.2.0). On a machine without it, the skill tells Codex to run npm i -g @riffkit/cli@latest.
The first sign-in failed, and the fix was one flag. riffkit login --agent stopped with EPERM: Codex's sandbox can write only to the project folder, and the CLI saves its sign-in in ~/.riffkit. We resumed the same session with --add-dir ~/.riffkit added, and the next try printed a link to a Riffkit page with a short code. The page showed the same code and an Approve button, with a warning that approving gives the agent full access to the account. We clicked Approve and told Codex. No password or token went through the chat.
It found the template and the character. Codex ran riffkit list_templates, riffkit get_template, riffkit list_characters and riffkit get_options, and reported an 8.06-second template with four outfit changes, Spanish dialogue and a caption, and Pipli as an active platform character.
It asked us to check the character image. The skill tells the agent to make sure a character image is a clear, front-facing reference before it quotes a Swap, and Codex couldn't view images in this session, so it asked us. Pipli's image is a face close-up next to a full-body shot; we said so.
It priced the job before doing anything. Codex ran riffkit quote_swap and came back with a plan: Swap, our template, Pipli in place of the woman, Seedance 2.0 Fast at 480p, 8.04 seconds in one go, 450 credits. Then it asked us to reply "Submit".
We replied "Submit." and it ran riffkit remake_video. It reported 12% progress and ended its turn there. When we asked it to keep checking until the video was finished, it ran riffkit wait, then gave us a link that opens the video for 6 hours, a post caption and hashtags Riffkit wrote in Spanish, and a note that the video is also in our Riffkit Library.

What changed in the video

Shot	Original	Result
1	Brown fitted top, high-waisted jeans	Pipli, in the lime ruffled outfit and purple gloves from her character image, not the original top and jeans
2	Cream sweatshirt with a red apple, jeans	Pipli in the same apple sweatshirt; her legs show bare instead of in jeans, and some of the original's long dark hair shows behind her head
3	White tank top, jeans, gold chain	Pipli in the same tank top and jeans, same bracelet; the gold chain is gone
4	Grey graphic sweatshirt, jeans	Pipli in the same sweatshirt and jeans

Pipli took over all four shots, and the scene held. The room, the light, the hand gestures and the captions match the original; two of the three cuts land on the same frame as the original's and the third lands one frame earlier, and the voice-over track came back with the video. What drifted: the outfits held in shots 3 and 4, but in shot 1 she wears her own outfit from the character image, and in shot 2 the jeans are missing. We checked the clip frame by frame before writing this. An earlier Swap with the same character on another clip, on Seedance 2.5 at 720p, kept all three outfits; we haven't tested which difference, the engine or the clip, caused the drift here. Best AI to Replace a Character in a Video covers person swaps in more detail.

What it cost. Riffkit billed 450 credits: 9 billed seconds at 50 credits a second, the Swap rate of Seedance 2.0 Fast at 480p (the 8.04-second clip rounds up). Codex's own report put the whole session at about 68,000 tokens on the ChatGPT plan, with nothing billed separately. The video was finished about 5 minutes after Codex submitted it.

How to do it yourself

Install Codex (npm i -g @openai/codex) and sign in with codex.
Start Codex with room for the Riffkit sign-in: codex --add-dir ~/.riffkit -c sandbox_workspace_write.network_access=true. The first flag lets the CLI save its sign-in; the second lets it reach riffkit.ai.
Paste the setup line: Run curl -fsSL https://riffkit.ai/SKILL.md in your terminal and follow the instructions to join Riffkit.
Sign in when Codex sends the link: check that the code on the page matches, then click Approve.
Ask for the change in plain words. Name the person, outfit, place or product that should change, and end with what should stay the same. Write What Changes, Not a Prompt has more on writing the brief.
Read the plan and the price, answer what Codex asks, and say "Submit".
Ask it to keep checking until the video is finished, then watch the video before you post.

For your own clip instead of a template, give Codex the file's path: the CLI sends it straight from your computer (riffkit remake_video --video ./clip.mp4; MP4, MOV, AVI, MKV or WebM, up to 100 MB and 45 seconds). Claude Code Video Skill covers the same skill in Claude Code, and Hermes Agent Video Generation has the same kind of test in Hermes.

What it costs on the Riffkit side

Riffkit bills per second of finished video, in credits. Swap rates per second: Seedance 2.0 Fast, 50 at 480p and 100 at 720p; Seedance 2.0, 60 at 480p, 120 at 720p and 300 at 1080p; Seedance 2.5, 90 at 480p and 180 at 720p; MiniMax H3, 80 at 768P and 160 at 2K. The plan shows the price before anything is submitted, and failed renders aren't charged.

Signup is free with no card. A free account can Swap on Seedance 2.0 Fast or Seedance 2.0 at 480p and use the Platform characters; most longer clips start with a free first section that a plan finishes. Videos made on the free credits carry a small Riffkit watermark. Plans start at $15 a month for 3,000 credits. Your Codex usage counts against your ChatGPT plan separately.

Before you start

Approve only a link you just asked for. The sign-in page gives the agent full access to your Riffkit account.
Use footage you own or have the rights to. Swap keeps the source's sound and everything you don't change, so someone else's video stays theirs.
Keep Codex's access to what the job needs. Adding ~/.riffkit and network access is enough for this; the rest of Codex's sandbox can stay as it is.