n8n + PostAxis

Automate social media with n8n

Plug PostAxis into an n8n AI Agent and posting becomes just another step in your workflow: RSS to posts, form to announcement, CRM to case study.

MCP Client Tool node, Streamable HTTP
API key in a Bearer header
Post from any trigger

Connect n8n Start for $0

Set up n8n with PostAxis

Plug PostAxis into n8n once, then talk to it like you would to whoever runs your accounts. Every click is in the full guide below.

Plug in about 5 minutes

Step 1 of 2

Add PostAxis to an n8n AI Agent

Attach an MCP Client Tool to your AI Agent node, point it at PostAxis and authenticate with a Bearer API key (needs the API add-on).

PostAxis account
A connected social account
n8n installed
API add-on

MCP endpoint

https://postaxis.io/api/mcp

Talk

Step 2 of 2

Then tell n8n what you need

n8n picks the PostAxis tools it needs. Scheduled posts go out on time whether or not the chat is still open.

Try asking

Publish a weekly summary to Telegram every Friday
Save a draft when a form is submitted
List failed posts every morning

New blog post in the RSS feed: write posts for X and LinkedIn and schedule them for 9:00 tomorrow.

Scheduled 2 posts for 9:00 tomorrow: X (243 characters) and LinkedIn, both linking to the new article.

via PostAxis

Example answer · lands in your PostAxis calendar

Full setup guide for n8n

Every step from a new PostAxis account to your first scheduled post. Takes about 5 minutes once your accounts are connected. Want ready-made workflows? Read the full n8n guide

1
Create your PostAxis account
Sign up at app.postaxis.io. Every plan starts with a 7-day free trial and includes MCP access with OAuth sign-in. Create an account
2
Connect your social accounts
Open Accounts in PostAxis and connect the networks you want to post to: Instagram, TikTok, YouTube, X, LinkedIn, Facebook, Threads or Telegram. Your agent can only post to accounts connected here, and it never sees your social media passwords. Open Accounts
3
Create an API key
In PostAxis open Settings → API keys and click Create API key. Copy it; it is shown only once. This needs the API add-on.
4
Add an AI Agent node
In your workflow add an AI Agent node after your trigger (RSS, form, schedule, webhook…) and connect a chat model to it.
5
Attach the MCP Client Tool
On the agent’s Tool input add MCP Client Tool. Set the endpoint to the URL below and the transport to HTTP Streamable.
Copy this
```
https://postaxis.io/api/mcp
```
6
Set authentication
Choose Bearer Auth, create a new credential and paste your PostAxis API key. Leave “Tools to include” on All.
7
Tell the agent what to do
In the agent’s prompt, describe the job, for example “write posts for X and LinkedIn from this article and schedule them for 9:00 tomorrow”. Run the workflow once to test.

What can n8n do with PostAxis?

Everything PostAxis does in the dashboard that makes sense to do by asking: writing, scheduling, editing, publishing and checking your queue.

Sentences in, posts out

Describe the post in your own words. n8n turns it into posts and PostAxis handles the scheduling.

Every network you run

Instagram, TikTok, YouTube, X, LinkedIn, Facebook, Threads and Telegram, from a single message.

Checked before it’s saved

Caption length, media count, video length and format are checked for every network before anything is saved.

Weeks ahead in one go

Ask for a week or a month. n8n can dry-run up to 50 posts at once, show you the plan, then schedule it.

Your images and video

Attach images and videos from a link, or get a one-time upload link for files on your computer.

A key you can revoke

n8n uses an API key you create and can revoke at any time. It only reaches accounts connected in your PostAxis workspace.

What is n8n?

n8n is a workflow automation tool. Its AI Agent node can use MCP servers through the MCP Client Tool, alongside hundreds of app integrations.

With PostAxis, posting becomes one step in any workflow: a trigger fires, the agent writes the post and PostAxis schedules it.

What can you ask n8n to post?

Brief it like a person: what it’s about, where it goes, when. Four requests that work well with n8n:

Trigger
New article, new posts
When a new article appears in the RSS feed, write posts for X and LinkedIn and schedule them for 9:00 the next morning.
To n8n
Schedule
A weekly roundup
Every Friday at 16:00, publish a roundup of this week’s articles to our Telegram channel.
To n8n
Review first
Drafts for approval
When a form is submitted, write a LinkedIn and Facebook announcement and save it as a draft for review.
To n8n
Report
Review the week
Tell me which posts published this week and which failed, and reschedule the failed ones for tomorrow.
To n8n

How does n8n talk to PostAxis?

Through MCP, the Model Context Protocol: an open standard for giving AI apps tools. PostAxis runs an MCP server; n8n connects to it and gets 11 tools that work on your account, nothing more. Full MCP reference

From your message to a scheduled post

What happens between you hitting enter and the post showing up in your calendar.

You write one message: what, where, when
n8n looks up your accounts and the limits of each network you named
It drafts a version per network and sends them to PostAxis
PostAxis checks every version and saves it as scheduled, a draft or live
The post sits in your calendar, editable until it goes out

n8n + PostAxis

Server: https://postaxis.io/api/mcp
Transport: Streamable HTTP
Sign-in: API key (Bearer)

Tools n8n discovers

list_workspacesYour PostAxis workspaces
list_accountsConnected social accounts per workspace
get_platform_rulesCaption limits and media rules per network
upload_media_from_urlPull an image or video into your media library
create_upload_linkOne-time link for uploading a local file
create_postDraft, schedule or publish one post
create_posts_bulkSchedule up to 50 posts in one call
list_postsPosts by status or date range
get_postOne post with its per-network status
update_postEdit text, media or time before it goes out
delete_postRemove a draft or scheduled post

MCP Client Tool or HTTP Request node?

Use the MCP Client Tool when an AI Agent decides what to post. For fixed workflows (same post, same time) the PostAxis REST API with an HTTP Request node is simpler.

Can n8n save drafts for approval?

Yes. Tell the agent to save posts as drafts. They appear in PostAxis under Drafts, where someone can edit and schedule them.

How does n8n sign in to PostAxis?

n8n signs in to PostAxis, never to your social networks. Your Instagram, X or LinkedIn accounts stay connected to PostAxis, and you can revoke n8n’s access at any time.

API add-on✓ Used by n8n

API key

Create a key under Settings → API keys
Send it as Authorization: Bearer KEY, or in the URL for clients that only take a URL
Revoke the key any time and access stops at once

Best for servers and automations with no browser: n8n, Grok, Manus, headless agents

Every plan

OAuth sign-in

n8n opens the PostAxis sign-in in your browser
You log in and click Approve
It gets access to your account only, until you revoke it

Best for apps you use yourself: ChatGPT, Claude, Cursor, Codex and most others

If something doesn’t work

The most common problems when connecting n8n, and how to fix them.

The agent says no accounts are connected

Connect at least one social account under Accounts in PostAxis. If you use several workspaces, tell the agent which one, for example “use my Acme workspace”.

401 Unauthorized or “sign in again”

The sign-in expired or was revoked. Reconnect from your agent (it opens the PostAxis sign-in again). With an API key, check the key is still active under Settings → API keys.

A post was rejected before saving

PostAxis checks each network’s rules first: caption length, media count, video length and format. The error says what to change; ask the agent to fix it and try again.

Posts are scheduled at the wrong time

Say the timezone in your request, for example “9:00 Europe/Berlin”. Without one, the agent uses the timezone it was told or UTC.

I want to stop an agent from posting

Open Settings → API keys in PostAxis. Revoke the agent under Connected agents, or revoke its API key. It loses access immediately.

n8n and PostAxis: questions

Can I use the REST API instead?

Yes. For fixed workflows the PostAxis REST API with an HTTP Request node is simpler; the MCP Client Tool is best when an AI Agent decides what to post.

What is the PostAxis MCP server?

It’s a remote Model Context Protocol server at https://postaxis.io/api/mcp that gives AI agents 11 tools to list your accounts, upload media and create, schedule, edit and delete posts in PostAxis.

Which social networks are supported?

Instagram (posts, Reels, carousels), TikTok (videos and photo posts), YouTube Shorts, X, LinkedIn, Facebook Pages, Threads and Telegram channels.

How much does it cost?

MCP access with OAuth is included in every PostAxis plan, and every plan starts with a 7-day free trial. API keys need the API add-on.

What stops an agent from posting something wrong?

PostAxis checks every post against each network’s rules before saving, the agent can preview bulk plans without saving them, everything shows up in your calendar, and you can revoke an agent at any time in Settings → API keys.