LinkedIn API Setup Guide

This document covers the setup process for LinkedIn API integration, including common issues encountered.

Prerequisites

1. LinkedIn Developer account
2. A LinkedIn app with posting permissions

Creating a LinkedIn App

1. Go to LinkedIn Developer Portal
2. Click “Create app”
3. Fill in the required information:
   • App name
   • LinkedIn Page (you can use your personal profile page)
   • App logo (optional)
4. Click “Create app”

Required Products & Scopes

Step 1: Add Required Products

In your app settings, go to the Products tab and add:

1. “Share on LinkedIn” - For posting content
2. “Sign In with LinkedIn using OpenID Connect” - For retrieving your member ID

Step 2: Configure OAuth Scopes

After adding the products, verify you have these scopes in the Auth tab:

• ✅ openid - Required for OpenID Connect
• ✅ profile - Required to get your numeric member ID
• ✅ w_member_social - Required for posting content

Getting Your Credentials

1. Get OAuth Access Token

1. In your app, go to the Auth tab
2. Scroll to OAuth 2.0 tools
3. Click “Create token” or “Generate token”
4. IMPORTANT: Make sure all three scopes are checked:
   • openid
   • profile
   • w_member_social
5. Copy the access token

Note: Access tokens expire after 60 days. You’ll need to regenerate periodically.

2. Get Your Member ID

Run the helper script with your new access token:

cd scripts
source venv/bin/activate
python get_author_id.py YOUR_ACCESS_TOKEN

Or use curl:

curl -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
     https://api.linkedin.com/v2/userinfo

The response will include your sub field, which is your numeric member ID:

{
  "sub": "123456789",
  "name": "Your Name",
  "email": "your@email.com"
}

Your author ID will be: urn:li:member:123456789

Common Issues

Issue 1: 403 Error on /v2/userinfo

Error: "Not enough permissions to access: userinfo.GET.NO_VERSION"

Cause: Your access token doesn’t have the openid and profile scopes.

Solution:

1. Add the “Sign In with LinkedIn using OpenID Connect” product to your app
2. Generate a NEW access token with openid, profile, and w_member_social scopes
3. The old token won’t automatically get new scopes - you must regenerate

Issue 2: 422 Error on Posting

Error: "urn:li:person:XXX" does not match urn:li:member:\\d+

Cause: Wrong URN format. LinkedIn’s posting API requires:

• ✅ urn:li:member:123456 (numeric ID)
• ❌ urn:li:person:ACoAAAERPDo... (alphanumeric profile ID)

Solution: Use the get_author_id.py script with a token that has profile scope to get the correct numeric ID.

Issue 3: Alphanumeric vs Numeric IDs

LinkedIn has multiple ID formats:

• Profile URN: urn:li:fsd_profile:ACoAAAERPDo... (from web interface)
• Person URN: urn:li:person:ACoAAAERPDo... (from Voyager API)
• Member URN: urn:li:member:123456 (from REST API - this is what you need)

Only the numeric member URN works with the posting API.

Issue 4: Scope Authorization Delays

Symptom: Just added OpenID Connect product but still getting 403 errors

Solution: Wait a few minutes for LinkedIn to process the authorization on their backend. If it persists beyond 10 minutes, try:

1. Regenerating your access token
2. Logging out and back into LinkedIn Developer Portal
3. Checking that the products show as “Active” in your app settings

Setting Up GitHub Actions

Once you have your credentials:

1. Go to your GitHub repository
2. Navigate to: Settings → Secrets and variables → Actions
3. Click “New repository secret”
4. Add two secrets:
   • Name: LINKEDIN_ACCESS_TOKEN, Value: Your OAuth token
   • Name: LINKEDIN_AUTHOR_ID, Value: urn:li:member:YOUR_NUMERIC_ID

The GitHub Action will use these secrets to post to LinkedIn automatically when you push to main.

Testing Your Setup

Test that everything works:

cd scripts
source venv/bin/activate

# Test getting your author ID
python get_author_id.py YOUR_ACCESS_TOKEN

# Test posting (this will create a real post!)
python linkedin_post.py ../_posts/your-post.md

Access Token Expiration

LinkedIn access tokens expire after 60 days. When your token expires:

1. Go to LinkedIn Developer Portal
2. Navigate to your app → Auth tab
3. Generate a new token with the same scopes
4. Update your .env file (local) and GitHub Secrets (for Actions)

Security Notes

• Never commit your .env file (already in .gitignore)
• Never share your access token publicly
• Rotate tokens if accidentally exposed
• Use GitHub Secrets for CI/CD - never hardcode credentials