Connect Claude: every surface, and what to do when it fails

Claude reaches your site through an MCP connector: you give Claude one URL, and Claude asks your WordPress site for permission. Nothing is copied into a config file, and no password is pasted into a chat.

You will find the URL on MCP → your server → How would you like to connect? → Connectors/Integrations/Plugins → Claude. It looks like https://example.com/wp-json/acrossai/mcp.

Before you start

Claude connects from Anthropic’s servers, not from your browser. Two things follow from that, and together they explain most failed connections:

• Your site needs a public https:// address. A local address such as mysite.local, localhost or 127.0.0.1 resolves only on your own machine, so Anthropic cannot reach it.
• Plain http:// is refused. The certificate must be valid — a self-signed certificate will fail.

Developing locally? Expose the site with a tunnel such as ngrok or Cloudflare Tunnel, or connect once the site is live.

The quickest route: Add to Claude.ai

On the Claude tab, the Add to Claude.ai button opens claude.ai with the connector name and your server URL already filled in. You still confirm on Claude’s side — nothing connects until you do.

The connector is named after your site title, lowercased with spaces and punctuation turned into hyphens — a site called My Great Site appears as my-great-site. That is the same name the MCP Clients tab writes into a config file, so one site reads the same whichever way you connected it.

Two limits worth knowing. The button is greyed out when your site is not publicly reachable, for the reason above. And it works for personal accounts only — Free, Pro, Max. Team and Enterprise Owners add connectors in Organization settings, which no link can open; see that section below.

Claude on the web — individual (Pro/Max)

1. Sign in at claude.ai in your browser.
2. Open Customize → Connectors, click “+” and choose Add custom connector.
3. Paste your MCP URL into the remote MCP server URL field. Leave Advanced settings blank — no Client ID or Client Secret is needed.
4. Click Add, then Connect, and approve the consent screen when it opens on your WordPress site.

Claude Team / Enterprise

Regular team members do not see an “Add custom connector” option on Team or Enterprise plans. Only Owners and Primary Owners can add one. Once they save it, every teammate sees a row they can connect to themselves.

1. Owner only: open Organization settings → Connectors, hover over Custom, and select Web.
2. The Owner pastes the MCP URL as the remote MCP server URL and saves.
3. Every teammate — the Owner included — then opens Customize → Connectors, finds the row, clicks Connect, and approves the consent screen.

Each person’s Claude account is authorized individually. The Owner’s save only makes the connector available; it does not connect anybody.

Claude Code (terminal / CLI)

1. Install Claude Code if you have not already: npm install -g @anthropic-ai/claude-code.
2. Run claude mcp add --transport http acrossai <your MCP URL>.
3. Follow the browser OAuth flow when Claude Code prints the authorization URL.
4. Verify with claude mcp list — the acrossai server should show as connected.

Troubleshooting

Claude says it cannot reach the server

Almost always the reachability problem above. Open your MCP URL in a private browser window on another network — a phone on mobile data is a good test. If it does not load there, Claude cannot load it either. Check for a valid certificate, and for a firewall, basic-auth prompt, or “coming soon” plugin sitting in front of the site.

The consent screen never appears

The consent screen is a page on your site, so you must be signed in to WordPress in the same browser. If you are signed out, approve-and-retry: open your site’s admin in another tab, sign in, then click Connect again.

It connects, but Claude sees no tools

The connection and the contents of the connection are separate. Check the server’s Tools and Abilities tabs — a server with nothing exposed connects perfectly and offers nothing. Also check Access Control: a user who is not allowed on this server gets an access-denied response even with a valid connection.

A client that is already connected may also keep showing its old tool list until it reconnects. Disconnect and reconnect the row in Claude to refresh it.

It worked, then stopped

If your site address changed — a move to HTTPS, a new domain, dropping www — existing authorizations were issued for the old address and are refused until each client authorizes again. Reconnect from Customize → Connectors.

A teammate cannot add the connector

Expected on Team and Enterprise plans — adding is Owner-only. Ask an Owner to add it once; teammates then connect to the existing row.

Another MCP plugin is installed

More than one MCP plugin on the same site can publish competing OAuth endpoints, and clients may pick the wrong one. If connections fail for no other visible reason, deactivate the other MCP plugins and try again.