How to Use posterly with Claude: Custom Connector to First Approved Schedule

Claude is already where you think. You do not want another dashboard just to queue Instagram. Founders keep asking for social to happen in the same thread as the strategy chat.

That is what a custom Claude connector is for. This is not a directory listing you search for. You add it yourself. Claude is the chat layer (and the approval prompt before writes). posterly is the publish layer: 18 networks, the queue, analytics. Claude does not post until you approve the tool call and you confirm the specific post.

This is a new-user walkthrough, from Customize to the first approved schedule. The long encyclopaedia is the Claude guide. Connector fields sit on poster.ly/claude.

Two layers, one conversation

• Claude is where you talk. claude.ai, Cowork, and Claude in Chrome are remote HTTP only. Claude Desktop and Claude Code can run local stdio. Free plans can add one custom connector.
• posterly is where accounts, media, and the queue live. Buy Starter + API in one checkout ($10 a month). Agency API is $29 a month on Agency. See pricing.

Chat attachments never reach posterly. On claude.ai, a laptop video goes through create_media_drop then list_media. On Claude Code or Desktop, you can pass a real file_path instead. Why: Solving the 4MB MCP limit.

1. Add the custom connector, then talk

On claude.ai: Customize, then Connectors, then Add custom connector.

• Server URL: https://www.poster.ly/api/mcp
• Auth: OAuth, or Authorization: Bearer pst_live_...

If you do not have a key yet, start in plain language. You do not need the connector for public signup.

You: I want you to set up posterly as my social scheduling agent. I do not have an account yet. Do not post anything.

Claude: I can start posterly's agent signup flow. Confirm the email I should use. You will pay and set a password in your own browser. I will not ask for the card or the password.

Claude Desktop and Claude Code can skip the hosted URL and run:

npx -y posterly-mcp-server@latest

with POSTERLY_API_KEY in the environment. Claude Code also accepts claude mcp add --transport http posterly https://www.poster.ly/api/mcp.

2. Agent-led signup (you still pay in the browser)

1. start_signup with your email, usually Starter, and api_addon=true.
2. Open checkout_redirect_url and pay in Stripe yourself.
3. get_signup_session while you set a password.
4. Claude narrates status in English, not JSON.

The same contract is on agent signup. Claude never collects a card, a posterly password, or a social password.

Claude: Checkout is ready. Open this secure posterly link. I will wait until payment lands.

You: Paid. Password set.

Claude: When the dashboard shows pst_live_..., paste it into the connector (or into Claude Code). I will not touch Instagram until whoami works.

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3. Approve the connector, then whoami

Claude asks before write tools. That extra click is not create_post confirmation. It is "Claude may call this server". Keep it on.

Then:

You: Run whoami. Do not list keys or post anything.

Claude: Authenticated. I can see your workspace. No social accounts yet. Instagram or LinkedIn first?

If whoami fails, stop. Usual causes: add-on off, key not in the connector, Free slot already used by another custom server.

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4. First connect session (OAuth stays in your browser)

1. create_connect_session for the platform you named.
2. You open connect_url and approve Meta or LinkedIn in their page.
3. Claude polls get_connect_session and reports created, opened, awaiting_provider, connected, or expired.

Sessions last 30 minutes. If you wander off, ask for a new session. Manual networks (Bluesky, Telegram) wait for a credential in posterly, not in the Claude thread.

5. Draft, validate, then say send

Claude's tool-approval prompt is not enough. posterly still needs validate_post, then create_post with confirm: true.

1. Draft in chat.
2. validate_post (no row, no queue).
3. Show account, caption, time, media.
4. You confirm that exact post this turn.
5. create_post with confirm: true.

Laptop file on claude.ai:

You: I have a video on my laptop. Call create_media_drop, send me the /drop/ link, wait, then list_media and validate_post. Do not use the paperclip.

Claude Code can instead upload_media with file_path or create_signed_upload then PUT.

You: Draft a LinkedIn post for Thursday 10:00 UK time. Validate it. Do not create it.

Claude: validate_post passed. No row exists yet. Say schedule it if you want this one queued.

You: Schedule it.

Claude: Scheduled. View in Posterly: [dashboard link]

Share that dashboard link. Skip the raw payload.

6. After the first post: Desktop, Code, batch

• Claude Code / Desktop. Local file_path is the easy media path. Hosted claude.ai is not.
• Weekly batch. List every item, confirm the set, create_posts_batch.
• Voice and analytics. get_learned_voice, generate_captions, get_account_analytics. Some insight tools need Pro.

A project instruction like "always post at 9am" is not consent for a specific caption.

7. Where this usually breaks

• Free connector slot is full. Free is one custom connector. Remove another server or upgrade.
• Paperclip on claude.ai. Chat attachments never become MCP args. Use create_media_drop.
• Stdio pasted into claude.ai. That only works in Desktop and Claude Code.
• Approved the tool, skipped confirm: true. Two different yeses. The tool refuses a missing confirm flag.
• Stale OAuth link. 30 minutes. New create_connect_session.

Start with Customize, Connectors

Add the hosted URL from the MCP setup guide, walk agent signup if you are new, then approve one validated post. The short Claude setup page has the fields. Claude Code users can stay on stdio and skip claude.ai entirely.

You keep the chat. posterly keeps the queue. Nothing publishes until you say send.