docs: update MCP auto-expansion list for Slack

[tembo]

What changed

Added Slack to the list of integrations whose MCP servers are enabled automatically in sessions (integrations/mcp.mdx), alongside GitHub, Linear, Sentry, and Postgres.

Why

Slack MCP auto-expansion had been silently disabled by an explicit exclusion in the expansion logic, and the docs never listed Slack in the first place. tembo/monorepo#11106 removed that exclusion, restoring the intended behavior (originally introduced by tembo/monorepo#9927), so agents now receive the organization's configured Slack tools automatically like other integrations.

Evidence

• tembo/monorepo#11106 ("Include Slack integrations when automatically expanding an organization's MCP servers") — merged, removes the integrationType === 'slack' skip in apps/api/src/agent/sandbox/mcpExpansion.ts, and updates apps/api/tests/sandbox/setupMcpServers.test.ts to assert slack-primary is included in auto-expansion.

Confidence

This is a direct, narrow correction: the code change is merged and covered by a test that explicitly asserts the previously-documented gap (Slack not auto-enabling) is fixed. No wording/positioning judgment calls were needed — only adding the integration name Slack already uses elsewhere in the docs.

cc @benja

Want tembo to make any changes? Add a comment with @tembo and i'll get back to work!

      

---

Note

Low Risk
Documentation-only wording change with no runtime or security impact.

Overview
Updates the MCP integration docs so Slack appears alongside GitHub, Linear, Sentry, and Postgres in the bullet that describes integrations whose MCP servers are enabled automatically in agent sessions.

This aligns user-facing documentation with restored product behavior (Slack is no longer excluded from organization MCP auto-expansion).

^{Reviewed by Cursor Bugbot for commit 7c5a775. Bugbot is set up for automated code reviews on this repo. Configure here.}

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated
tembo	🟢 Ready	View Preview	Sep 11, 2026, 1:07 PM

💡 Tip: Enable Automations to automatically generate PRs for you.