Some releases are fireworks, others are plain repair. 2.1.231 clearly belongs to the second kind – a single CLI change, but one some people had been waiting for.
The bug: OAuth into the void
If you tried to connect Claude Code to a service like Slack over MCP, you’d been hitting a wall lately. The OAuth sign-in failed, specifically for servers that use a pre-registered OAuth client. The cause was a mismatched redirect URI: after login, the service sent you to an address Claude Code didn’t expect. The result – the connection never came together, and restarting didn’t help.
For Slack this was especially painful, because that’s exactly the pre-registered-client pattern it uses. The GitHub tracker filled up with reports: 302 redirect after OAuth not followed, permanent connection failure. Nothing you could work around yourself.
The fix
2.1.231 corrects exactly that redirect URI mismatch. With it, MCP OAuth sign-in works again for pre-registered clients – Slack front and center. There’s nothing more in this version, and that’s completely fine. A broken login isn’t a minor nuisance, it’s a hard blocker: either the connection stands or it doesn’t.
My take
I like this kind of release. No new feature to explain, just a thing that simply does what it’s supposed to again. The MCP ecosystem lives on connections to external services opening up cleanly – and OAuth is the spot where it snags most easily. A wrong redirect URI sounds like a trifle, but it paralyzes the whole integration.
The daily release cadence on Claude Code shows its strength here: a blocker like this doesn’t sit around for weeks, it gets straightened out in the next version. If you use Claude Code with Slack or another MCP service with a pre-registered client, this update is mandatory. For everyone else: grab it and move on.
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