Connect Claude.ai and Claude Desktop to StackJack

Claude.ai (web) and the Claude Desktop app add StackJack as a custom connector — a remote MCP server (MCP is the Model Context Protocol, the open standard AI tools use to call external tools). Paste the URL, leave everything else blank, and sign in.

The dialog does have optional Advanced OAuth Client ID and Secret fields. Leave them empty for StackJack. They are meant for a server that requires a pre-registered OAuth application, and StackJack registers Claude automatically instead. A StackJack MCP Client ID and Secret do not go there — those are Basic-auth credentials for a different kind of connection, and Claude has nowhere to send them.

Prerequisites

• A Claude account on any plan — custom connectors are available on Free (limited to 1 connector), Pro, Max, Team, and Enterprise.
• On Team or Enterprise, an organization Owner must add the connector for the workspace first (see below); members then connect individually.
• A StackJack account that is a member of your workspace. Any team member can connect — no admin-created credentials needed.
• Your StackJack MCP endpoint URL. Copy it from the MCP Setup page in the portal — that card shows the address for your workspace's region. The examples in this guide use the US address, https://mcp.stackjack.io/mcp; other regions have their own hostname. See Your region and your endpoint.

Connect (individual accounts)

1. In claude.ai, click Customize (bottom-left) → Connectors. In Claude Desktop: Settings → Connectors.
2. Click Add custom connector (the + button) and paste only the URL: https://mcp.stackjack.io/mcp. Leave the Advanced OAuth Client ID/Secret fields blank.
3. Click Add, then Connect. Claude registers itself with StackJack and opens a browser to sign in — use the same email, password, and MFA you use for the StackJack Portal.

Your StackJack tools then appear in Claude conversations.

Team and Enterprise workspaces

On Claude Team or Enterprise, only an organization Owner can add connectors, via Organization settings → Connectors → Add connector → Custom → add the StackJack URL. Once added, each member connects and signs in individually with their own StackJack account, so tool access and usage attribution stay per-person.

If you see a consent screen

Claude connects with just a URL, and the way it identifies itself to StackJack can be either a private per-install registration or a single shared-app identity (CIMD). If Claude connects as a shared app, StackJack shows a branded consent screen right after you sign in — headed "Authorize Claude", with a "Verify before you approve" panel listing the app identity (client_id) URL and the host your authorization is sent to. Choose Allow access to finish connecting. This is expected the first time (and on later sign-ins); read How AI tools authenticate for what each line means.

Which surface your connection then shows up on follows the same split: a shared-app authorization appears as a Connected apps entry an admin manages per member on the Team page, and a per-install connection appears as a read-only AI session (in your own MCP Setup self-view, and per member on Team for admins).

Good to know

• No StackJack keys here. The dialog takes a URL, plus optional OAuth Advanced fields you leave blank. There is nowhere to send a Basic-auth header, so a StackJack MCP Client ID and Secret do not apply to Claude.ai or Claude Desktop. Sign-in is the way in.
• Connections come from Anthropic's cloud. Even in Claude Desktop, the connector traffic originates from Anthropic's servers, not your machine. StackJack is publicly reachable, so this works without any setup — but don't expect the connection to appear from your office IP.
• Your connection shows up in the portal so admins can see last-used time and call counts: a per-install connection becomes a read-only AI session after its first tool call, and a shared-app (CIMD) authorization becomes a Connected apps entry as soon as you approve the consent screen (see above). Admins see both per member on the Team page; you see your own in the read-only Your AI connections card on the MCP Setup page. See OIDC sessions and revoking access.

Tool limits

Claude Desktop truncates a large tool list, and the way it truncates is the problem. It re-sorts the whole catalog alphabetically and then cuts it, so the tools it keeps are simply the first ones by name. No ordering on StackJack's side can protect a specific tool from being dropped. claude.ai (web) publishes no fixed number, but large catalogs still degrade it: sessions get slow or fail as your connectors add up.

StackJack tracks the observed limit for each client in one maintained place — see Client tool limits. These are observed behaviors rather than vendor guarantees, and clients change them, so check that table rather than a number quoted in a guide.

The fix is catalog mode. Switch StackJack to compact mode so it serves a small tool list and the AI finds any of your thousands of tools on demand (via stackjack_search_tools) instead of being handed the whole catalog — every tool stays reachable and every permission still applies. This may already be in effect: Claude Desktop is one of the clients StackJack recognizes as capping its tool list, so if your organization has never made an explicit catalog-mode choice and your catalog exceeds that client's cap, this connection is already served a compact catalog automatically. If your organization has explicitly turned catalog modes off, an admin re-enables them on the Settings page. Trimming your tool grants or connecting through a restricted client helps too, but catalog mode is what keeps a large catalog under the cap without hiding anything. See Choosing tools for each client and managing harness tool limits.

Claude caches the tool list. Changing catalog mode — in the Portal or via a ?tools= URL — will not reach a connector Claude has already added. To pick up the change, remove the StackJack connector and re-add it (or change its URL, which counts as a new connector).

Troubleshooting

• Sign-in says no account was found — sign up in the portal first, or ask your team admin for an invite.
• "Your access to this tenant has been revoked" — ask your admin to send a new invite.
• For anything else, see Connection troubleshooting.