Card #840 · Cursor (AI IDE)
Slack MCP authentication fails due to missing PKCE and scopes
The Slack MCP authentication flow is broken, preventing users from connecting Slack to the Cursor IDE. The OAuth request fails because it lacks required permission scopes and PKCE parameters for non-web redirect URIs.
Pain score
0.20/ 1.00 · weighted product of four components
Reach0.61distinct authors (log-normalized)
Recency1.00freshness decay, half-life months
Engagement1.00upvotes + comments, normalized
Monetization0.50willingness-to-pay cues in evidence
§ Evidence — 4 verified quotes
Slack MCP auth fails — “Must use PKCE to redirect to a non-web URI”
The OAuth request to Slack is missing two required parameters for non-web (deep-link) redirect URIs: scope — no permission scopes are being requested code_challenge + code_challenge_method=S256
Such a critical functionality and it’s still broken even after so many days
Slack MCP is entirely non-functional. Cannot pull Slack highlights into agent workflows.
Comments are a Pro feature — join the conversation, share what you've shipped, hear what others are building.
Upgrade to Pro