How to post to LinkedIn via API in TypeScript

Step-by-step guide to posting text updates, articles, and images to LinkedIn Company Pages and personal profiles via API — including partner token setup and content type rules.

LinkedIn's API requires partner-level access for most publishing features — but Aether is already approved. You get LinkedIn posting without the 6-month review process. Here's how to go from zero to publishing in under an hour.

Prerequisites

An Aether account — free tier supports 3 connected accounts
A LinkedIn Company Page (for Page posts) or a personal LinkedIn account
Node.js 18+ in your project

1. Install the SDK

npm install aether

2. Connect a LinkedIn account

Aether supports two LinkedIn profile types: personal profiles ( type: "person") and Company Pages (type: "page"). Use platform: "linkedin" for both — the OAuth flow lets the user choose which pages to grant access to.

import Aether from "aether";

const aether = new Aether({ apiKey: process.env.AETHER_API_KEY });

// Generate an OAuth link — choose "linkedin" for personal profiles
// or "linkedin_page" for Company Pages
const link = await aether.connectLinks.create({
  platform: "linkedin",
  redirectUrl: "https://yourapp.com/oauth/linkedin/callback",
});

// Redirect your user to link.url
console.log(link.url);

LinkedIn tokens expire after 60 days. Aether's token-refresh worker proactively renews them 24 hours before expiry — your users won't need to reconnect.

3. List connected profiles

// List all connected LinkedIn profiles
const profiles = await aether.profiles.list({ platform: "linkedin" });

// profiles.data looks like:
// [
//   { id: "li_abc123", displayName: "Acme Corp", type: "page" },
//   { id: "li_xyz789", displayName: "Jane Smith", type: "person" }
// ]

const pageId   = profiles.data.find(p => p.type === "page")?.id;
const personId = profiles.data.find(p => p.type === "person")?.id;

4. Publish a text post

LinkedIn text posts support up to 3,000 characters. Line breaks render correctly — use them to structure your update. Aether handles the UGC post API call and returns the live post URL.

// Post a text update to a LinkedIn Company Page
const post = await aether.posts.create({
  profileIds: [pageId],
  text: "We just shipped v2.0 of our API platform. Here's what's new 👇\n\n" +
        "• Unified inbox across 7 platforms\n" +
        "• Real-time webhooks with retry logic\n" +
        "• MCP server for AI agent integration\n\n" +
        "Full changelog: https://aetherhq.dev/changelog",
});

console.log(post.status); // "published"
console.log(post.platformResults?.linkedin?.url); // LinkedIn post URL

Posting images and cross-posting

LinkedIn image posts require a two-step upload: register the asset, then attach it to the post. Aether handles both steps when you pass a mediaUrls array. You can also post to a Company Page and personal profile simultaneously with a single API call.

// Post with an image — provide a publicly accessible URL
const imagePost = await aether.posts.create({
  profileIds: [pageId],
  text: "Behind the scenes of our engineering team 📸",
  overrides: {
    linkedin: {
      mediaUrls: ["https://yourcdn.com/team-photo.jpg"],
      altText: "The Aether engineering team at our offsite in Lisbon",
    },
  },
});

// Post to both personal profile and company page in one call
const crossPost = await aether.posts.create({
  profileIds: [pageId, personId],
  text: "Excited to announce our Series A 🎉",
  overrides: {
    linkedin: {
      // LinkedIn strips links from body text — add a commentary field instead
      commentary: "We raised $8M to build the social media API infrastructure layer.",
    },
  },
});

LinkedIn-specific rules to know

LinkedIn enforces a 150 API calls/day limit per token — avoid high-frequency polling
URLs in post body text are automatically converted to preview cards by LinkedIn, but the URL itself is not clickable in the native app — add your link in the commentary field for best UX
Hashtags work in body text: #buildinpublic — up to 3 is best practice
Company Page posts require the connected user to be a Super Admin or Content Admin of the page

Next steps

Use scheduled posts to queue your LinkedIn content calendar
Subscribe to the post.published webhook to sync post URLs back to your CRM
Pull post-level analytics — impressions, clicks, reactions — with the analytics API