LinkedIn

Publish text, images, videos, documents and polls to LinkedIn with POST /v1/posts and platform: "linkedin". One connected account posts as a personal profile or as any organization page the member administers, and the same account serves analytics and comments.

Quick reference

Before you start

LinkedIn connects personal profiles and organization pages through the same account. Organization pages get full analytics, 30-minute videos and the comments API; personal profiles get limited analytics and 10-minute videos. A post carries one media type: images, one video or one document, never mixed.

Connect

Call GET /v1/connect/linkedin with profileId on Get OAuth connect URL. After OAuth the user picks a personal profile or one of the organizations they administer, in standard or headless mode; see platforms requiring secondary selection. The connecting accounts guide covers the flow and scopes in general; Account health reports what a connected account can do with the scopes the user granted.

To switch an existing account between personal and organization posting without a second OAuth, call Switch LinkedIn account type.

OAuth scopes

LinkedIn connections request the widest scope set of any platform because one token covers personal posting, organization pages and ads.

Sign-in and profile:

Personal posting and analytics:

Organization pages, usable only when the member is an admin of an organization:

Ads, used by LinkedIn Ads:

Publish

A plain post becomes a text post. Media in mediaItems selects an image, video or document post, and 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, and a duration of ONE_DAY, THREE_DAYS, SEVEN_DAYS (default) or FOURTEEN_DAYS. A poll cannot be combined with mediaItems or reshareUrl, cannot be edited after publishing, and 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 from its link (the post's "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"), and 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, and 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.

Platform fields

All fields go in platformSpecificData on the LinkedIn entry.

Media requirements

Images

Videos

Recommended: 1920 x 1080 px, 16:9 or 1:1, 30 fps, H.264 with AAC audio at 192 kbps, 10 to 30 Mbps.

Documents

Media URLs

A media URL must be publicly accessible with no authentication, return the media bytes with the correct Content-Type header, not redirect to an HTML page, and sit on a fast host. Google Drive, Dropbox, OneDrive and iCloud links return an HTML page instead of the file and fail; test a URL in an incognito window, or upload through the media endpoint. Zernio proxies Supabase storage URLs automatically.

Analytics

Call GET /v1/analytics?platform=linkedin (Analytics API). Personal accounts get metrics only for posts published through Zernio, because LinkedIn returns metrics only for posts authored by the authenticated member.

const { data: analytics } = await zernio.analytics.getAnalytics({
  query: { platform: 'linkedin', fromDate: '2026-08-01', toDate: '2026-08-31' }
});

console.log(analytics.posts);

Response (200), one entry per post:

{
  "posts": [
    {
      "_id": "65f1c0a9e2b5af0012ab34cd",
      "platform": "linkedin",
      "status": "published",
      "publishedAt": "2026-08-14T10:00:05Z",
      "platformPostUrl": "https://www.linkedin.com/feed/update/urn:li:share:7200000000000000000",
      "analytics": {
        "impressions": 8420,
        "reach": 6210,
        "likes": 131,
        "comments": 17,
        "shares": 9,
        "clicks": 240,
        "engagementRate": 1.86
      }
    }
  ]
}

Four LinkedIn-only endpoints go deeper:

• Personal aggregate analytics: totals or a daily series across a personal account's posts, covering impressions, reach, reactions, comments, shares, saves and sends.
• Organization aggregate analytics: impressions, clicks, reactions, engagement rate, follower gains (organic and paid) and page-view metrics for organization pages. The member must be an ADMINISTRATOR of the organization and the account must hold r_organization_social, r_organization_followers and r_organization_admin.
• Post analytics: per-post metrics by URN for personal and organization accounts; saves and sends are personal-only, organizations return 0.
• Post reactions: individual reactions with reactor profiles, organization accounts only.

Inbox

LinkedIn supports comments on organization pages and reactions from either account type; its messaging API is closed to third-party apps, so there are no DMs.

Like comment takes the composite comment URN the comments endpoints return as commentId, and an optional reactionType picks the reaction instead of the default LIKE. An account connected before Zernio requested the social-feed scopes gets a 403 with code linkedin_reconnect_required: reconnect it. Like post reacts to a post from any connected account, so an executive account can react to the brand's post; it takes the same reactionType and the same scopes. You can also read a post's reactions with Post reactions on organization accounts.

What you cannot do

LinkedIn's API does not expose:

• Long-form articles (linkedin.com/article/new/)
• Events
• InMail and DMs
• Newsletters
• Following hashtags or tagging connections
• Mixed media in one post (images with a video, or images with a document)
• The one-click "Repost" feed treatment (reposts are always authored by your account)

Common errors

A publishNow: true post that LinkedIn rejects returns 207 with post.status: "failed" and the message in platforms[].errorMessage:

{
  "message": "Post created but publishing failed",
  "error": "All platforms failed",
  "post": {
    "_id": "65f1c0a9e2b5af0012ab34cd",
    "status": "failed",
    "platforms": [
      {
        "platform": "linkedin",
        "status": "failed",
        "errorMessage": "Content is a duplicate of urn:li:share:7200000000000000000"
      }
    ]
  }
}

207 is a 2xx status, so fetch(...).ok is true; branch on the status code and on post.status. Error handling covers the envelope.

Related

• Connecting accounts: the OAuth flow and the organization selection step.
• Create post and Edit post: every field of the request.
• LinkedIn mentions: resolve profile and company URLs to mention URNs for post content.
• Media uploads: upload images, videos and documents instead of hosting them.
• Comments: the inbox API.
• Pricing: what analytics, the inbox and outbound messages cost, and which replies count.