Post to Listmonk from Codex

Codex can send email campaigns through Listmonk using Postiz. Install the Postiz skill or add the Postiz MCP server to Codex, connect your Listmonk instance in Postiz, then describe the newsletter. Codex writes the body, sets the subject and preview text, picks the list and template, and schedules the send.

Setup Guide GitHub

Please make sure there is always a human in the loop.

Last updated: September 2026

How do I post to Listmonk from Codex?

Set up Codex once with the Postiz skill or the Postiz MCP server, connect Listmonk in Postiz, then ask. The whole setup takes a few minutes.

Setup, then just ask

# One-time setup, option A: Postiz skill + CLI
npx skills add gitroomhq/postiz-agent
export POSTIZ_API_KEY=your_api_key   # or: postiz auth:login

# One-time setup, option B: Postiz MCP server (OAuth, no key)
codex mcp add postiz --url https://mcp.postiz.com/mcp-oauth-dynamic
codex mcp login postiz

# Then just ask Codex:
> Send the monthly newsletter to the
  Customers list tomorrow at 9am

Codex: Done! Your Listmonk post is scheduled.

Listmonk-Specific Features

📧

Email Campaigns

Create and send email campaigns to your subscriber lists with rich HTML content, subject lines, and preview text.

📋

Mailing Lists

Target specific subscriber lists by ID. Send campaigns to the right audience segment every time.

🎨

Template Support

Use pre-built email templates by specifying a template ID. Maintain consistent branding across all campaigns.

👁

Preview Text

Set preview text that appears in email clients before the recipient opens the message. Boost open rates with compelling previews.

📰

Newsletter Automation

Automate recurring newsletters with scheduled sends. Let AI agents craft and deliver content on a regular cadence.

📅

Scheduled Delivery

Schedule email campaigns for optimal delivery times. Use ISO timestamps to send at exactly the right moment.

How does Codex post to Listmonk?

You describe what you want in plain language and Codex handles the Postiz calls for you. Here is how a typical conversation goes.

Find Your Listmonk Integration

Ask Codex whether your Listmonk account is connected. It also checks which options the platform supports.

Example conversation

> Is my Listmonk account connected to Postiz?

Codex: Yes — your Listmonk account is connected
  and ready. Want me to post something?

Compose Your Email

Write your email body in plain text or HTML. Tell Codex the subject line and preview text and it sets them.

Example conversation

> Draft a Listmonk post about our new
  feature launch

Codex: Here's a draft for Listmonk:
  "We just shipped something big..."
  Want me to add media and schedule it?

Schedule and Send

Schedule your email campaign for a specific time or send immediately. Target a specific list and optionally apply a template for consistent formatting.

Example conversation

> Yes — add screenshot.png and schedule
  it for tomorrow at 9am

Codex: Done! Scheduled on Listmonk for
  tomorrow at 9:00 AM.

Listmonk Settings Reference

Mention any of these in plain language and Codex sets them for you. These are the options every Listmonk campaign can carry.

Field	Type	Required	Description
`__type`	string	Yes	Must be "listmonk" to identify the platform
`subject`	string	Yes	Email subject line (min 1 character)
`preview`	string	Yes	Preview text shown in email clients before opening
`list`	string	Yes	List ID to send the campaign to
`template`	string	No	Template ID to use for the email layout

Common Configurations

Ask Codex for any of these common Listmonk campaign scenarios and it applies the matching settings.

Weekly Newsletter

Just ask

> Post it with: Weekly Newsletter

Codex: Got it. Applying:
  subject: Weekly Newsletter - March Edition
  preview: This week: new features, tips, and community highlights
  list: list-1
  template: newsletter-tmpl

Product Announcement

Just ask

> Post it with: Product Announcement

Codex: Got it. Applying:
  subject: Introducing Our New Feature
  preview: We've been working on something big...
  list: list-2

Promotional Campaign with Template

Just ask

> Post it with: Promotional Campaign with Template

Codex: Got it. Applying:
  subject: Flash Sale - 48 Hours Only
  preview: Up to 50% off everything in store
  list: list-3
  template: promo-template

Plain Text Update

Just ask

> Post it with: Plain Text Update

Codex: Got it. Applying:
  subject: A quick note from the team
  preview: Important updates about your account
  list: list-1

What is Codex?

Codex is OpenAI's coding agent. It runs as the Codex CLI in your terminal (npm install -g @openai/codex), as an IDE extension, and in the cloud, and it can run shell commands and call MCP servers, which is how it drives Postiz. Codex is not ChatGPT: ChatGPT is the chat assistant on chatgpt.com and connects to Postiz differently (see the ChatGPT guide). For the full setup, start at the Codex + Postiz hub.

💻

Terminal & IDE Native

Codex runs in your terminal or IDE. You type what you want in plain English and it handles Postiz for you — no extra configuration needed.

🔧

Autonomous Execution

Codex runs commands inside a sandbox with approval rules you control, and works through multi-step tasks like discovering channels, uploading media, and scheduling Listmonk posts.

⚡

Parallel Tasks

Run multiple Codex tasks simultaneously. Schedule posts to different platforms in parallel while Codex handles other coding work.

How Postiz Works with Codex

Codex discovers Postiz two ways: the postiz skill, which it loads from .agents/skills or ~/.agents/skills and which you can invoke with $postiz, or the Postiz MCP server added with codex mcp add. Either way it learns the available tools and chains them for Listmonk workflows.

✓Install the Postiz skill with npx skills add, or add the Postiz MCP server with codex mcp add
✓Codex loads skills from .agents/skills and reads SKILL.md to learn the Postiz CLI
✓Authenticate with POSTIZ_API_KEY or postiz auth:login; the MCP route uses OAuth instead
✓Codex runs commands in its sandbox and asks for approval based on your permission settings
✓Works alongside your coding tasks in parallel

Install Postiz

# Install the Postiz skill
npx skills add gitroomhq/postiz-agent

# Set your API key
export POSTIZ_API_KEY=your_api_key

# Or add the Postiz MCP server instead (OAuth, no API key)
codex mcp add postiz --url https://mcp.postiz.com/mcp-oauth-dynamic
codex mcp login postiz

# Then ask, interactively or headless
codex "list my social media integrations"
codex exec "post today's changelog to Listmonk"

Listmonk Campaigns with Codex

Tell Codex what to post from your terminal or IDE — it discovers your integrations via Postiz and handles the entire publishing workflow.

💻

Just Ask Codex

Terminal and IDE integration

Tell Codex what to post from your terminal or IDE — it discovers your integrations via Postiz and handles the entire publishing workflow.

Codex CLI

$ codex "Post to Listmonk about our
  new feature launch, schedule for
  tomorrow at 9am"

Codex: I'll handle that.
  Found your Listmonk integration.
  Composing and scheduling the post.

  Done! Your post is scheduled.
  Post ID: abc-123

💻

Parallel Tasks

Multiple tasks at once

Codex can handle multiple tasks in parallel. Schedule posts to different platforms while it works on other coding tasks simultaneously.

Codex Parallel Tasks

# Run multiple posting tasks in parallel
$ codex "Schedule a post about our
  launch to X for tomorrow 9am" &

$ codex "Write a LinkedIn article
  about our new feature and schedule
  for tomorrow noon" &

$ codex "Fix the bug in auth.ts"

# All three tasks run simultaneously

Why Codex + Postiz for Listmonk

Codex's autonomous execution makes Postiz a natural fit. The agent reads the SKILL.md to understand every available command, then autonomously chains them together for Listmonk email workflows.

✓Runs in your terminal or IDE — just type what you want
✓Autonomous execution in sandboxed environments
✓Parallel task support — post while coding
✓Template selection applied automatically based on campaign type
✓Cross-post email content to Listmonk + social platforms in a single conversation
✓Powered by OpenAI's most capable models

SKILL.md (loaded by Codex from .agents/skills)

---
name: postiz
description: Social media automation
  CLI for scheduling posts across
  30+ platforms including Listmonk
homepage: https://docs.postiz.com/public-api/introduction
---

# Loaded by Codex from .agents/skills
# Invoke explicitly with $postiz

# Available Commands
- postiz integrations:list
- postiz integrations:settings <id>
- postiz posts:create
- postiz upload <file>
- postiz analytics:platform <id>

# Listmonk Settings
subject, preview, list, template

Also Works with Claude Code

Postiz works with any AI agent that can run commands or call MCP tools — you ask, the agent does the work. That includes Anthropic's Claude Code: see the Claude Code Listmonk guide, or the Postiz Agent page for any other agent.

Claude Code

by Anthropic

Claude reads the Postiz skill so it knows what it can do, then autonomously discovers your Listmonk integration, composes your email campaign with subject, preview text, and list targeting, and sends it on schedule.

Claude Code

> Send a newsletter to list-1 about our
  new feature launch, schedule for Monday

Claude: Done! Scheduled on Listmonk for
  tomorrow at 9:00 AM.

Can Codex post to Listmonk and other platforms at once?

Send an email campaign and post to social media simultaneously. Each platform gets its own settings.

Example

> Post "Excited to announce our new feature!" to
  Listmonk and LinkedIn tomorrow at 9am, then schedule
  a daily tip on Listmonk every weekday at 10am

Codex: Done! Scheduled:
  - Listmonk + LinkedIn: tomorrow 9:00 AM
  - Daily tips on Listmonk: Mon-Fri 10:00 AM

What can I ask Codex to post on Listmonk?

Codex takes plain-English prompts in an interactive session, as a one-off codex exec command, or through the $postiz skill. These are the kinds of prompts people type for Listmonk.

Prompts for Listmonk

> Send the monthly newsletter to the Customers list tomorrow 9am,
  subject "September updates", build the body from CHANGELOG.md

$ codex exec "Create a Listmonk campaign for the Beta list announcing the new
  API, preview text 'Two new endpoints', use the Product template"

> $postiz Which Listmonk lists and templates are available?
  Draft a welcome campaign for the newest list

What Listmonk rules should Codex follow?

These are the Listmonk limits and required settings Postiz enforces. Codex reads them from postiz integrations:settings, and you can mention any of them in your prompt.

✓subject, preview, and list are all required.
✓template is optional; list and template ids come from postiz integrations:settings.
✓The body of your prompt or file becomes the email content.
✓Email cannot be recalled after sending, so schedule ahead and review before the send time.

Codex and Listmonk FAQ

How do I post to Listmonk from Codex?

Install the Postiz skill with npx skills add gitroomhq/postiz-agent, or add the Postiz MCP server with codex mcp add postiz --url https://mcp.postiz.com/mcp-oauth-dynamic. Connect Listmonk in Postiz once, then ask Codex in plain English what to post and when. Codex resolves the Listmonk settings, uploads any media, and schedules the post.

What does Codex need to send a Listmonk campaign?

Three required fields: subject line, preview text shown in inboxes, and the list id to send to. Template is optional. Codex reads your lists and templates through postiz integrations:settings and matches the names you mention, so "send to the Customers list with the Product template" is enough to get started.

Can I review a Listmonk email before Codex sends it?

Yes. Ask Codex to schedule the campaign for a later time and review the draft it prints, or have it create a Postiz draft instead of scheduling. Because email cannot be recalled after delivery, keep a human in the loop and consider sending to a small test list first.

Can Codex post to Listmonk on a schedule without me watching?

Yes. Postiz stores scheduled Listmonk posts and publishes them at the chosen time, so Codex does not need to stay open. For unattended runs, call codex exec with your prompt from a script or cron job. Keep a human reviewing the output, since Codex will publish exactly what it is told to publish.

Do I need a Postiz API key to post to Listmonk from Codex?

Not with the MCP route. Run codex mcp login postiz and Codex signs in to your Postiz account over OAuth, so it only reaches channels you already connected, including Listmonk. The CLI skill route needs either postiz auth:login or a POSTIZ_API_KEY environment variable. Your Listmonk login itself never leaves Postiz.

Is posting to Listmonk from Codex the same as posting from ChatGPT?

No. Codex is OpenAI's coding agent for your terminal and IDE, and it reaches Postiz through the Postiz skill or MCP server. ChatGPT is the chat assistant on chatgpt.com, which connects to Postiz as an app or custom MCP connector. Both can publish to Listmonk; see the ChatGPT guide for that setup.