How do I run Merge PDF Files with Codex MCP?

Codex can use medux_merge_pdf through Medux MCP to merge multiple PDF files into one ordered PDF. The workflow identifies the exact inputs, reviews the tool arguments, monitors processing, and verifies the returned result.

Codex MCP tutorial · document

How to merge PDF files with Codex MCP and Medux

Q: Which MCP tool does this tutorial use?

This workflow uses medux_merge_pdf . Review its arguments before approval and consult the API reference for the current contract.

Use Codex and Medux through MCP to merge multiple PDF files into one ordered PDF. This guide covers input preparation, the approval gate, task monitoring, and a concrete output check.

POST/api/app/v1/process/asset/merge_pdf

Merge multiple PDF files into a single PDF output.

Open the Merge PDF API reference →

Codex-specific workflow

Run Merge PDF Files as a Codex MCP task

Use the active workspace as the source of truth. Ask Codex to identify the PDF file IDs in the intended merge order, select medux_merge_pdf, 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_merge_pdf through Medux MCP to merge PDF files.
First inspect and identify the PDF file IDs in the intended merge order.
Show me the exact tool arguments before execution.
After the task completes, return the merged PDF and verify that all source PDFs are present once and the final page order is correct.

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 merged PDF. The final check is explicit: confirm that all source PDFs are present once and the final page order is correct.

What this tutorial does

Medux operation

Merge multiple PDF files into a single PDF output.

Agent workflow

Codex selects medux_merge_pdf, presents the arguments for review, calls Medux, and reports the response.

Before you start

Authentication

Authentication is required via Authorization header.

Preconditions

Upload each source file and create file references 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.

Merge multiple PDF files into a single PDF output.

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
`input_file_ids`	array<string>	Required	Input PDF file id list.
`model_id`	string	Optional	Merge PDF model id. Default: merge-pdf-default.
`title`	string	Optional	Optional task title.

Step-by-step workflow

Connect Medux MCP to Codex

Add the Medux remote MCP endpoint to Codex, provide an authorized credential, and confirm that the medux_merge_pdf tool is available.

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.

Ask Codex to run Merge PDF

Use one direct instruction with the intended values. Codex should select the Medux tool and show the proposed arguments before execution.

Review and approve the tool call

Check that the tool is medux_merge_pdf and that each file ID, task ID, option, and output setting matches your request before approving it.

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_merge_pdf
  ↓
Review inputs and approve the tool call
  ↓
Medux runs Merge PDF
  ↓
Codex reports the response and output

Frequently asked questions

Can Codex use the Medux Merge PDF API through MCP?

Codex can call the medux_merge_pdf Medux MCP tool to merge multiple PDF files into a single PDF output. 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_merge_pdf. Review its arguments before approval and consult the API reference for the current contract.