How to post to LinkedIn from n8n

Step by step

1. Create a free PostWire account

   Open postwire.io/dashboard.html, type your email and press Create my free account. PostWire emails you a link to confirm the address; connecting accounts and publishing unlock once it is confirmed. No password and no card (free plan: 1 business, 20 posts a month, 5 AI drafts a day (about 20 a month), 2 networks per post, 3 scheduled posts at a time — every network connects free, no card).

2. Connect LinkedIn

   In the dashboard open Accounts, press Connect on LinkedIn and then Continue to LinkedIn. You sign in on LinkedIn itself and approve posting on your behalf; PostWire never sees your password. Posts go out on your own profile, under your name.

3. Copy your API key

   In the dashboard, open API & MCP and press Copy key on the API key card. It is sent as Authorization: Bearer pw_live_… (the X-API-Key header also works). Keep it server-side.

4. Install the node (self-hosted n8n)

   In n8n: Settings → Community nodes → Install, enter n8n-nodes-postwire, and add a PostWire API credential with the key. The node is not verified by n8n yet, so it installs on self-hosted n8n; on n8n Cloud use the HTTP Request in step 7.

5. Configure Post → Publish

   Networks: LinkedIn. Content: Smart Distribute: Write a Native Post per Network, with the Idea from the previous node (e.g. {{ $json.title }} — {{ $json.contentSnippet }}). Media: None for a text post, or URL / Binary File for one image. The LinkedIn draft is written in the first person, with the hook inside the first 210 characters (what the feed shows before "see more"), one idea per short block and three hashtags at the end. Under Options, Dry Run checks everything without publishing and Brand Voice sets the tone.

6. Put the link in the first comment

   Add the URL to the Idea and the words "link in the comments": the LinkedIn draft comes back with a first_comment that carries the link, and the node publishes it as your own comment right under the post. To write both yourself, set Content to Drafts From a Previous Step and pass an object (the comment takes up to 1,250 characters):

   {
     "linkedin": {
       "text": "We cut our build time from 14 minutes to 3.\n\nHere is the one change that did most of it…",
       "first_comment": "Full write-up: https://example.com/blog/faster-builds"
     }
   }

7. On n8n Cloud, or for several images or a PDF: one HTTP Request node

   POST to the REST API with header Authorization: Bearer pw_live_…. media takes up to 20 images, each with optional alt text, or one PDF, PowerPoint or Word document that LinkedIn shows as a swipeable carousel:

   POST https://postwire.io/api/post
   Authorization: Bearer pw_live_…
   Content-Type: application/json
   
   // Text, three images and the link in the first comment
   {
     "platforms": ["linkedin"],
     "per_platform": { "linkedin": { "text": "{{ $json.post }}", "first_comment": "Details: {{ $json.url }}" } },
     "media": [
       { "url": "https://…/chart-1.png", "type": "image", "alt": "Build time per week, falling from 14 to 3 minutes" },
       { "url": "https://…/chart-2.png", "type": "image" },
       { "url": "https://…/chart-3.png", "type": "image" }
     ],
     "idempotency_key": "{{ $json.id }}"
   }
   
   // A document carousel
   {
     "platforms": ["linkedin"],
     "text": "Our Q3 report in 9 slides.",
     "media": [{ "url": "https://…/q3-report.pdf", "type": "document", "title": "Q3 report" }]
   }

8. Read the result, or schedule it

   The node returns the post's id and its link, https://www.linkedin.com/feed/update/…, and first_comment.ok tells you the comment went out. To publish later, use Post → Schedule with When: At a Specific Time or In the Next Free Queue Slot. To react when a post lands, start a second workflow with the PostWire Trigger node (Post Published, Post Failed).

A retry with the same Idempotency Key is refused for 24 hours, so a re-run never posts twice; with Smart Distribute the node sets one per execution. LinkedIn sign-ins last about 60 days: Connection → Check Health in a weekly workflow, or the trigger's Connection Needs Sign-In event, tells you before a scheduled post is due.