linkedin-poster

Post to your own LinkedIn feed from Claude Code, a shell, or a cron job. One Cloudflare Worker, no dependencies, three surfaces: an MCP server so an agent can publish directly, an HTTP API for scripts, and a voice linter that refuses to publish text carrying the tells of machine-written prose.

Built because a good post is worth automating and a bad em-dash is not worth shipping. This README has no em-dashes in it either, which is the point.

Claude Code ──MCP──┐
                   ├──> Worker ──> LinkedIn Posts API ──> your feed
curl / CI ──HTTP───┘      │
                          ├──> KV (one 60-day token) + daily cron
                          └──> Telegram group (what happened, and what broke)

What it is not

This posts as one member: you. It is not a scheduling SaaS, not a multi-tenant tool, and it does not touch anybody else's account. Everything it needs is self-serve; no LinkedIn partner program is involved.

Related MCP server: LinkedIn MCP Server

The constraint that shapes everything

LinkedIn access tokens last 60 days, and programmatic refresh tokens are limited to approved Marketing Developer Platform partners. A self-serve app never gets one. There is no way around this, and any guide promising set-and-forget LinkedIn automation is wrong.

What there is: while your current token is still valid and you are logged into LinkedIn, hitting the authorization endpoint again skips the consent screen and just redirects. So renewal is one click every seven weeks, as long as you do it before the token dies. Miss the window and you get the consent screen back, which is two clicks instead of one.

That is why this service ships with a cron trigger. From 14 days out it puts a renewal alarm at the top of the daily summary, every morning, while silent renewal still works. See Notifications.

Setup

1. LinkedIn side (manual, about ten minutes)

1. You need a LinkedIn Page. The developer portal makes you attach the app to one and have a page admin verify it.

2. Create the app at linkedin.com/developers. Note the Client ID and Client Secret.

3. Products tab, request both (they are Open Permissions and approve instantly):

   • Sign In with LinkedIn using OpenID Connect → openid, profile

   • Share on LinkedIn → w_member_social

4. Auth tab → add the redirect URL. It must be HTTPS, absolute, and match REDIRECT_URI character for character: https://your-worker.example.com/auth/callback

2. Worker side

git clone https://github.com/stepanic/linkedin-poster.git
cd linkedin-poster
npm install

# KV to hold the token
npx wrangler kv namespace create TOKENS
npx wrangler kv namespace create TOKENS --preview
# paste both ids into wrangler.jsonc

# edit wrangler.jsonc: name, routes, REDIRECT_URI, account_id

npx wrangler secret put LINKEDIN_CLIENT_ID
npx wrangler secret put LINKEDIN_CLIENT_SECRET
npx wrangler secret put API_TOKEN     # openssl rand -hex 32, guards /post and /mcp
npx wrangler secret put SETUP_KEY     # openssl rand -hex 32, guards /auth/start
npx wrangler secret put NOTIFY_WEBHOOK    # optional, any URL taking a JSON POST
npx wrangler secret put TELEGRAM_BOT_TOKEN # optional, see Notifications below
npx wrangler secret put TELEGRAM_CHAT_ID

npm run deploy

3. Connect your account

Open https://your-worker.example.com/auth/start?key=<SETUP_KEY> in a browser, approve once, done. The page tells you the expiry date.

SETUP_KEY is not decoration. Without it, anyone who found the URL could bind their LinkedIn account to your Worker and overwrite your stored token.

Using it from Claude Code

claude mcp add --transport http linkedin https://your-worker.example.com/mcp \
  --header "Authorization: Bearer $API_TOKEN"

Three tools:

Then, in a session: "check this draft against the linter, then post it."

Using it from a shell

# dry run: lint only, publish nothing
curl -s -X POST https://your-worker.example.com/post \
  -H "Authorization: Bearer $API_TOKEN" -H 'Content-Type: application/json' \
  -d '{"text":"…","dry_run":true}'

# publish
curl -s -X POST https://your-worker.example.com/post \
  -H "Authorization: Bearer $API_TOKEN" -H 'Content-Type: application/json' \
  -d '{"text":"…","visibility":"PUBLIC"}'

# token state
curl -s https://your-worker.example.com/status -H "Authorization: Bearer $API_TOKEN"

/post returns 201 with the post URN and its public URL, 422 when the linter blocks it, 503 when the token is missing or dead.

Notifications

Without this the service fails the way every unattended service fails: quietly, and you find out on the day a post does not go out. A Telegram group fixes that for the price of one bot.

# 1. @BotFather in Telegram, /newbot, copy the token
npx wrangler secret put TELEGRAM_BOT_TOKEN

# 2. make a group, add the bot, send /start@yourbot in it
#    (a bot with privacy mode on sees only messages that mention it)

# 3. read the group id back, then store it
open "https://your-worker.example.com/telegram/chatid?key=<SETUP_KEY>"
npx wrangler secret put TELEGRAM_CHAT_ID

# 4. prove it works
open "https://your-worker.example.com/telegram/test?key=<SETUP_KEY>"

What arrives:

Two design decisions worth knowing before you change anything:

The daily summary is the heartbeat. It goes out even when nothing happened, so its absence is itself the alarm and nothing has to monitor the monitor. That is also why a renewal alarm rides on top of the summary rather than arriving as a second message: exactly one message a morning, or you train yourself to skim.

The renewal link carries a one-time nonce, not the setup key. A link with SETUP_KEY in it would park a long-lived secret in a chat log for good. The cron mints a nonce instead, valid for seven days, replaced by the next reminder, and deleted the moment a token is stored. Link previews are disabled on every message so Telegram cannot spend the nonce by prefetching it.

Set none of it and the service behaves exactly as it did before: NOTIFY_WEBHOOK if you have one, the log if you do not.

GET /telegram/preview?key=<SETUP_KEY>&kind=daily renders any message without sending it, which is how to edit the wording without spamming the group. Add &send=1 to see it on a phone.

The Bot API transport is tested against a local stub, including the supergroup migration that silently breaks Telegram bots months after setup:

npm run test:telegram

The linter

Errors block publishing; warnings do not.

Hyphens are never flagged. read-only tier, two-day sprint and per-client limits are correct and must stay. Only U+2014 and U+2013 are errors.

Editing src/lint.ts is the intended way to make this yours. The rules encode one person's writing conventions, not a universal standard.

Things that will surprise you

• The Posts API does not scrape URLs, but LinkedIn still linkifies them. Verified on a live post: a bare URL is shortened to lnkd.in/... and is clickable. What you do not get is the preview card with an image and title. For that you need a thumbnail uploaded through the Images API plus a content.article block. Not implemented here yet.

• LinkedIn-Version is mandatory and versions get sunset. 202508 went dark on 17 August 2026. Treat the value in wrangler.jsonc as a maintenance item.

• /v2/ugcPosts is deprecated. This uses /rest/posts, which replaced it.

• Changing the requested scopes invalidates every existing token. You will have to re-authorize.

• 150 requests per member per day. Per member, not per app.

Layout

Local development

cp .dev.vars.example .dev.vars   # fill in, never commit
npm run types                    # regenerate Env after editing wrangler.jsonc
npm run typecheck
npm run dev

wrangler dev --local gives you a local KV, so the whole flow short of the real LinkedIn calls can be exercised without credentials.

Notes from a real setup

docs/2026-08-27-postavljanje-i-zamke.md records what setting this up from zero actually cost: the portal rejecting any app name containing "LinkedIn", the irreversible Page association, OAuth scopes that stay empty until you refresh the page, %20 versus + in the scope parameter, a negative DNS cache that made a working deployment look dead, and how secrets were handled so none of them passed through a terminal.

docs/2026-08-27-telegram-obavijesti.md covers the notification layer: the supergroup migration that breaks Telegram bots in silence, why the heartbeat is a summary rather than a ping, and why the renewal link carries a nonce.

Licence

MIT. The rules in src/lint.ts are mine; the mechanism is yours to take.