Posts

A plain post becomes a text post. Media in mediaItems selects an image, video or document post.

Fields in platformSpecificData on the LinkedIn entry add polls, reposts, a first comment and organization targeting.

Text post

Up to 3,000 characters. LinkedIn collapses the rest behind a "see more" fold, so put the hook first.

import Zernio from '@zernio/node';

const zernio = new Zernio();

const { data: published } = await zernio.posts.createPost({
  body: {
    content: 'I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code.',
    platforms: [
      { platform: 'linkedin', accountId: '66b2e19d8c3f5a7e9d0b1c2d' }
    ],
    publishNow: true
  }
});

console.log(published.post.platforms[0].platformPostUrl);

Response (201):

{
  "post": {
    "_id": "65f1c0a9e2b5af0012ab34cd",
    "status": "published",
    "platforms": [
      {
        "platform": "linkedin",
        "status": "published",
        "platformPostUrl": "https://www.linkedin.com/feed/update/urn:li:share:..."
      }
    ]
  }
}

Every sample below changes only the mediaItems or the platforms entry of this request.

Image post

One image, recommended 1200 x 627 px (landscape), or up to 20 images in one post. Images cannot share a post with a video or a document:

"mediaItems": [
  { "type": "image", "url": "https://cdn.example.com/photo1.jpg" },
  { "type": "image", "url": "https://cdn.example.com/photo2.jpg" },
  { "type": "image", "url": "https://cdn.example.com/photo3.jpg" }
]

Video post

One video per post. Personal profiles accept up to 10 minutes, organization pages up to 30 minutes, in MP4, MOV or AVI:

"mediaItems": [
  { "type": "video", "url": "https://cdn.example.com/demo.mp4" }
]

Document post

A PDF, PPT, PPTX, DOC or DOCX displays as a swipeable carousel. At most 100 MB and 300 pages, one per post, with no images or videos alongside it.

LinkedIn requires a title. Set documentTitle, or Zernio falls back to the media item title, then the filename:

"mediaItems": [
  { "type": "document", "url": "https://cdn.example.com/report.pdf" }
],
"platforms": [
  {
    "platform": "linkedin",
    "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
    "platformSpecificData": { "documentTitle": "2027 Industry Report" }
  }
]

The first page is the cover. Password-protected PDFs do not work.

Poll

poll creates a LinkedIn poll:

• A question of 1 to 140 characters.
• 2 to 4 options of 1 to 30 characters each.
• A duration of ONE_DAY, THREE_DAYS, SEVEN_DAYS (default) or FOURTEEN_DAYS.

A poll cannot be combined with mediaItems or reshareUrl, and cannot be edited after publishing.

API-created polls are non-sponsored only (they cannot be promoted as ads):

{
  "platform": "linkedin",
  "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
  "platformSpecificData": {
    "poll": {
      "question": "Which feature should we build next?",
      "options": ["API keys", "Webhooks", "SDKs"],
      "duration": "SEVEN_DAYS"
    }
  }
}

Repost

reshareUrl reposts an existing LinkedIn post. It takes the post's link (its "Copy link to post" action) or a urn:li:share, urn:li:ugcPost or urn:li:groupPost URN.

The published post is always a reshare authored by your account, with the original embedded underneath:

• With content or customContent, your text is the commentary ("repost with your thoughts").
• With no text, it publishes as a text-free reshare.

LinkedIn's API cannot create the one-click "Repost" feed treatment where the original author stays the author.

reshareUrl is mutually exclusive with mediaItems, and works on personal profiles and organization pages:

{
  "platform": "linkedin",
  "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
  "platformSpecificData": {
    "reshareUrl": "https://www.linkedin.com/posts/someone_some-post-id"
  }
}

First comment

firstComment posts a comment right after publishing. Put external links there, because LinkedIn suppresses posts with a URL in the caption:

{
  "platform": "linkedin",
  "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
  "platformSpecificData": {
    "firstComment": "Read the full guide here: https://example.com/api-guide"
  }
}

Link preview

A text post with a URL and no media gets an automatic preview card. disableLinkPreview: true suppresses it:

{
  "platform": "linkedin",
  "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
  "platformSpecificData": { "disableLinkPreview": true }
}

Post to several organizations

One connected account can post to every organization page the member administers. List them with LinkedIn organizations:

curl "https://zernio.com/api/v1/accounts/66b2e19d8c3f5a7e9d0b1c2d/linkedin-organizations" \
  -H "Authorization: Bearer $ZERNIO_API_KEY"

Response (200):

{
  "organizations": [
    { "id": "111111111", "name": "Example Corp", "vanityName": "example-corp", "localizedName": "Example Corp" },
    { "id": "222222222", "name": "Example Labs", "vanityName": "example-labs", "localizedName": "Example Labs" }
  ]
}

Then repeat the platforms entry with the same accountId and a different organizationUrn (urn:li:organization: followed by the organization id).

Omit it to post to the account's default organization or personal profile:

"platforms": [
  {
    "platform": "linkedin",
    "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
    "platformSpecificData": { "organizationUrn": "urn:li:organization:111111111" }
  },
  {
    "platform": "linkedin",
    "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
    "platformSpecificData": { "organizationUrn": "urn:li:organization:222222222" }
  }
]

Geo-restriction

geoRestriction.countries limits who sees the post: only followers in the listed countries.

Organization pages only. LinkedIn rejects the post unless the targeted audience exceeds 300 followers:

{
  "platform": "linkedin",
  "accountId": "66b2e19d8c3f5a7e9d0b1c2d",
  "platformSpecificData": {
    "geoRestriction": { "countries": ["US", "ES"] }
  }
}

countries takes up to 25 uppercase ISO 3166-1 alpha-2 codes.

Zernio resolves them to LinkedIn geo URNs. 45 countries are mapped, and unsupported codes are skipped silently.

Edit a published post

Edit post replaces the text of a LinkedIn post that is already published, on member profiles and organization pages alike.

• Edits are text-only and capped at the same 3,000 characters as publishing.
• There is no time window and no limit on the number of edits.
• The post keeps its id, and LinkedIn shows an "edited" marker on it.
• Mentions and hashtags in the new text are preserved.
• Media, polls, articles and reshare targets cannot be changed.

const { data: edited } = await zernio.posts.editPost({
  path: { postId: '65f1c0a9e2b5af0012ab34cd' },
  body: {
    platform: 'linkedin',
    content: 'Updated post text with corrected information',
    accountId: '66b2e19d8c3f5a7e9d0b1c2d'
  }
});

console.log(edited.url);

Response (200):

{
  "success": true,
  "id": "urn:li:share:7200000000000000000",
  "url": "https://www.linkedin.com/feed/update/urn:li:share:7200000000000000000"
}

accountId picks which copy to edit when the post went to several LinkedIn accounts. Without it, the first linkedin entry on the post is edited.