# Slack MCP missing_scope

**TL;DR:** Add the missing scope to the Slack app OAuth scopes and reinstall the app in the workspace. The error names the scope you need; copy it exactly. Restart the MCP client after reinstalling so the new token is issued.

## The error

```
missing_scope
```

## Fix it

1. Read the error; it names the required scope.
   Expected: You have the scope string.
2. In the Slack app settings, add that scope under OAuth and Permissions.
   Expected: The scope is listed.
3. Reinstall the app to the workspace to issue a new token.
   Expected: Slack confirms the install.
4. Update the token in the MCP config if it changed, then restart the client.
   Expected: The tool call succeeds.

## When this applies

A specific Slack MCP tool fails with missing_scope while the token and channel membership are fine.

## When this does NOT apply

not_allowed_token_type is a token-type problem, not a scope. If the app was never installed, install it first.

## Tool compatibility

korotovsky/slack-mcp-server, recent versions

## Also seen as

- Slack MCP scope error
- Slack bot missing scope reinstall
- slack MCP needs scope reinstalled

## Why it happens

Slack issues tokens bound to the app's scope list at install time. Adding a scope later does not update existing tokens; only a reinstall mints a token with the new scope.

## Edge cases

- Workspace admins may need to approve the reinstall.
- Bot and user tokens have separate scope lists; fix the right one.
- Test with the Slack API tester to confirm the scope before reinstalling.