[BUG] OAuth login fails with "Invalid OAuth Request — Missing redirect_uri parameter"

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Version: 2.1.259 (native install)
Platform: macOS 26.2, arm64 (Apple Silicon)
Install method: Native installer (curl -fsSL https://claude.ai/install.sh | bash)

Steps to reproduce:

1. Fresh native install of the CLI, no prior login
2. Run claude auth login
3. Browser opens to a claude.ai/cai/oauth/authorize URL
4. Complete login
5. Land on https://claude.com/cai/oauth/authorize (or similar) showing: "Invalid OAuth Request — Missing redirect_uri parameter"

Also reproduced via:

• Console.anthropic.com's "Continue with Claude Pro" button (same error)
• claude setup-token (same error)
• After adding ~/.local/bin to PATH per the tool's own suggested fix (no change)

Expected: Successful login, redirected back to the CLI with an active session.
Actual: Every login path lands on the same "Missing redirect_uri parameter" error page, blocking authentication entirely.

What Should Happen?

Fix it.

Error Messages/Logs

**Version:** 2.1.259 (native install)
**Platform:** macOS 26.2, arm64 (Apple Silicon)
**Install method:** Native installer (curl -fsSL https://claude.ai/install.sh | bash)

**Steps to reproduce:**
1. Fresh native install of the CLI, no prior login
2. Run `claude auth login`
3. Browser opens to a claude.ai/cai/oauth/authorize URL
4. Complete login
5. Land on https://claude.com/cai/oauth/authorize (or similar) showing: "Invalid OAuth Request — Missing redirect_uri parameter"

**Also reproduced via:**
- Console.anthropic.com's "Continue with Claude Pro" button (same error)
- `claude setup-token` (same error)
- After adding ~/.local/bin to PATH per the tool's own suggested fix (no change)

**Expected:** Successful login, redirected back to the CLI with an active session.
**Actual:** Every login path lands on the same "Missing redirect_uri parameter" error page, blocking authentication entirely.

Steps to Reproduce

Version: 2.1.259 (native install)
Platform: macOS 26.2, arm64 (Apple Silicon)
Install method: Native installer (curl -fsSL https://claude.ai/install.sh | bash)

Steps to reproduce:

1. Fresh native install of the CLI, no prior login
2. Run claude auth login
3. Browser opens to a claude.ai/cai/oauth/authorize URL
4. Complete login
5. Land on https://claude.com/cai/oauth/authorize (or similar) showing: "Invalid OAuth Request — Missing redirect_uri parameter"

Also reproduced via:

• Console.anthropic.com's "Continue with Claude Pro" button (same error)
• claude setup-token (same error)
• After adding ~/.local/bin to PATH per the tool's own suggested fix (no change)

Expected: Successful login, redirected back to the CLI with an active session.
Actual: Every login path lands on the same "Missing redirect_uri parameter" error page, blocking authentication entirely.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

latest

Claude Code Version

newest

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Version: 2.1.259 (native install)
Platform: macOS 26.2, arm64 (Apple Silicon)
Install method: Native installer (curl -fsSL https://claude.ai/install.sh | bash)

Steps to reproduce:

1. Fresh native install of the CLI, no prior login
2. Run claude auth login
3. Browser opens to a claude.ai/cai/oauth/authorize URL
4. Complete login
5. Land on https://claude.com/cai/oauth/authorize (or similar) showing: "Invalid OAuth Request — Missing redirect_uri parameter"

Also reproduced via:

• Console.anthropic.com's "Continue with Claude Pro" button (same error)
• claude setup-token (same error)
• After adding ~/.local/bin to PATH per the tool's own suggested fix (no change)

Expected: Successful login, redirected back to the CLI with an active session.
Actual: Every login path lands on the same "Missing redirect_uri parameter" error page, blocking authentication entirely.