01
Connect Medux MCP to Codex
Add the Medux remote MCP endpoint to Codex, provide an authorized credential, and confirm that the medux_add_audio_to_video tool is available.
Codex MCP tutorial · media
How to add or replace audio in a video with Codex MCP and Medux
Use Codex and Medux through MCP to add a new audio track to a video or replace its existing audio. This guide covers input preparation, the approval gate, task monitoring, and a concrete output check.
POST/api/app/v1/process/video/add_audio_to_video
Replace or add an audio track to a video.
Open the Add Audio to Video API reference →Codex-specific workflow
Run Add or Replace Audio in Video as a Codex MCP task
Use the active workspace as the source of truth. Ask Codex to identify the source video, audio file, and timing requirements, select medux_add_audio_to_video, and keep the Medux task ID and returned output with the rest of the project. Naming the input roles and the expected result prevents an agent from guessing which file should be used where.
Codex prompt pattern
In this workspace, use medux_add_audio_to_video through Medux MCP to add or replace audio in a video.
First inspect and identify the source video, audio file, and timing requirements.
Show me the exact tool arguments before execution.
After the task completes, return the updated video and verify that the new audio is present at the intended time and the full video plays correctly.Approval gate
Before approving the call, compare the selected tool, file or asset IDs, ordering, timing, and output settings with the request. If a local filename was mapped to an uploaded Medux file ID, keep that mapping visible so it can be audited later.
Result verification
Let Codex monitor an asynchronous task until it reaches a terminal state, then save or report the updated video. The final check is explicit: confirm that the new audio is present at the intended time and the full video plays correctly.
What this tutorial does
Medux operation
Replace or add an audio track to a video.
Agent workflow
Codex selects medux_add_audio_to_video, presents the arguments for review, calls Medux, and reports the response.
Before you start
Authentication
- Authentication is required via Authorization header.
Preconditions
- Upload the source file and create a file reference before calling this endpoint.
- Successful requests return a Medux task record immediately. Use the task query or sync endpoints to track completion.
- All file inputs must be uploaded and persisted as file references before submission.
Prompt Codex
Start with a clear instruction that names the Medux operation and the intended inputs.
Replace or add an audio track to a video.Request fields to review
Confirm these values before approving the MCP tool call. The linked API page remains the source of truth for current limits and response semantics.
| Field | Type | Requirement | Purpose |
|---|---|---|---|
video_file_id | string | Required | Input video file id. |
audio_file_id | string | Required | Input audio file id. |
model_id | string | Optional | Model Default: add-audio-to-video-default. |
title | string | Optional | Optional task title. |
Step-by-step workflow
02
Prepare the required inputs
Prepare the source files, asset IDs, text, or settings required by the operation. Upload local media first when the tool requests file IDs.
03
Ask Codex to run Add Audio to Video
Use one direct instruction with the intended values. Codex should select the Medux tool and show the proposed arguments before execution.
04
Review and approve the tool call
Check that the tool is medux_add_audio_to_video and that each file ID, task ID, option, and output setting matches your request before approving it.
05
Check the Medux response
If Medux returns an asynchronous task, let the agent monitor it until completion; otherwise review the immediate response and save any result identifiers or output URLs.
Workflow recap
User goal
↓
Codex selects medux_add_audio_to_video
↓
Review inputs and approve the tool call
↓
Medux runs Add Audio to Video
↓
Codex reports the response and outputFrequently asked questions
Can Codex use the Medux Add Audio to Video API through MCP?
Codex can call the medux_add_audio_to_video Medux MCP tool to replace or add an audio track to a video. This guide covers the required inputs, approval flow, result handling, and the matching API reference.
Which MCP tool does this tutorial use?
This workflow uses medux_add_audio_to_video. Review its arguments before approval and consult the API reference for the current contract.