linkedin-mcp-server

An MCP server that posts document/"carousel" content (e.g. a Gamma PDF export) to a personal LinkedIn profile via LinkedIn's official REST API. Built for the "post Gamma carousels to LinkedIn automatically" workflow, but the tools are generic enough for any PDF-carousel-to-LinkedIn use case.

It also hosts the LinkedIn OAuth flow itself, so you don't need a separate public server just to catch the redirect — this one is that server.

Tools

Use linkedin_upload_document + linkedin_create_post separately if you want a review step between uploading and going live; use linkedin_post_carousel for full one-shot automation.

Related MCP server: LinkedIn Post MCP

1. Create the LinkedIn app (one-time, ~5 minutes)

1. Go to https://www.linkedin.com/developers/apps → Create app.

2. Fill in the required fields. LinkedIn requires the app be associated with a Company Page even for personal-profile posting — if you don't have one, create a minimal one for this purpose.

3. On the Products tab, request "Share on LinkedIn". This is self-serve for the scopes this server needs (openid, profile, w_member_social) — no manual review wait.

4. On the Auth tab, note the Client ID and Client Secret, and add an Authorized redirect URL of:

   https://<your-deployed-host>/oauth/linkedin/callback

   (must match LINKEDIN_REDIRECT_URI exactly, including scheme/host/path)

2. Deploy the server

Two supported paths — pick based on where you want to host this.

Option A: Vercel (serverless)

Vercel Functions have no persistent disk, so the file-based token store won't survive between requests. Use the built-in Redis-backed store instead:

1. Push this repo to GitHub, then import it in Vercel (New Project → your repo). It's picked up automatically — api/index.ts is the serverless entrypoint, vercel.json routes everything there.

2. In the Vercel project, go to Storage → Marketplace Database Providers → Upstash → Redis and create one. This injects Redis env vars into your project automatically.

3. Add the rest of the environment variables (Project Settings → Environment Variables):

   LINKEDIN_CLIENT_ID=...
   LINKEDIN_CLIENT_SECRET=...
   LINKEDIN_REDIRECT_URI=https://<your-vercel-domain>/oauth/linkedin/callback
   TOKEN_STORE_DRIVER=kv
   MCP_AUTH_TOKEN=<a long random string>

4. Redeploy so the new env vars take effect.

The 4.5 MB request-body limit on Vercel Functions doesn't affect this server — the PDF is fetched by an outbound request from linkedin_post_carousel (you pass a pdf_url, not the file itself), not received as an inbound upload. The 300s default duration on every plan is comfortably more than an upload+publish needs.

Option B: A host with a real disk (Fly.io, Railway, a VPS)

npm install
npm run build
npm start   # or: node dist/index.js

Set these environment variables (see .env.example):

LINKEDIN_CLIENT_ID=...
LINKEDIN_CLIENT_SECRET=...
LINKEDIN_REDIRECT_URI=https://<your-deployed-host>/oauth/linkedin/callback
TOKEN_STORE_DRIVER=file
TOKEN_STORE_PATH=./data/tokens.json   # point this at a persistent volume
MCP_AUTH_TOKEN=<a long random string> # protects /mcp and /oauth/linkedin/start
PORT=3000
TRANSPORT=http

Either way, you need a public HTTPS URL (for the OAuth redirect and for Claude to reach /mcp).

3. Authorize (one-time human step)

Open, in a browser where you're logged into the LinkedIn account you want to post as:

https://<your-deployed-host>/oauth/linkedin/start?token=<MCP_AUTH_TOKEN>

Click Allow. You'll land back on /oauth/linkedin/callback, which exchanges the code for an access + refresh token and saves them to TOKEN_STORE_PATH. The access token is refreshed automatically by the server on subsequent tool calls (refresh tokens last ~1 year), so this step shouldn't need repeating often.

4. Register as a connector

Add https://<your-deployed-host>/mcp as a custom MCP connector, sending Authorization: Bearer <MCP_AUTH_TOKEN> on every request. Once connected, the four linkedin_* tools become available to any session that has this connector enabled.

Local development

npm run dev   # tsx watch, auto-reloads on save

For local testing you can run with TRANSPORT=stdio and connect via any stdio-based MCP client (e.g. npx @modelcontextprotocol/inspector), though you'll still need LINKEDIN_REDIRECT_URI reachable from your browser to complete the OAuth step — a tunnel like ngrok works well for this during development.

Notes / limitations

• Single-user by design (one LinkedIn account, one token file). Don't expose this server publicly without MCP_AUTH_TOKEN set.

• LinkedIn posts published via linkedin_create_post / linkedin_post_carousel cannot be edited or deleted through this API — only from the LinkedIn UI. There's no "undo" tool here on purpose; double-check the caption and PDF before calling.

• LinkedIn's native ads-only "Carousel" format has no organic API equivalent; what these tools produce is a document post, which LinkedIn renders as a swipeable carousel in the feed — visually the same thing users mean by "LinkedIn carousel."

• LINKEDIN_API_VERSION in src/constants.ts is a calendar-month version string LinkedIn requires on every REST call. Bump it periodically per LinkedIn's versioning docs.