[BUG] claude mcp add test-mcp http://localhost:8888/endpoint -t sse -H "Authorization: Basic [base64]" ignores the -H header

[mmaunder]

Environment

• Platform (select one):
  • [ X] Anthropic API
  • [ ] AWS Bedrock
  • [ ] Google Vertex AI
  • [ ] Other:
• Claude CLI version: 1.0.17
• Operating System: OS X 15.4.1
• Terminal: Terminal App

Bug Description

See bug title. When using the following command the -H parameter which should cause a HTTP header to be passed to the MCP server, is ignored.

claude mcp add test-mcp http://localhost:8888/endpoint -t sse -H "Authorization: Basic [base64]"

Steps to Reproduce

1. Run the above command with any HTTP header in the quotes and it won't get sent to the MCP server.

Expected Behavior

I expect the HTTP header to be sent as part of the HTTP request to the MCP server.

Actual Behavior

HTTP header is not sent.

Additional Context

I've tried -H in various positions and either got an error or same result.

[skorfmann]

I can confirm this issue. When using the SSE transport with Claude Code v1.0.17, custom headers specified with the -H or --header flag are not being sent with the request.

The header appears to be stored correctly in the configuration (shows in the output when adding the server), but isn't included in the actual HTTP request.

[skorfmann]

up until 1.0.7 it was working - starting from 1.0.8 it breaks.

[ashwin-ant]

Fixed in 1.0.18

[github-actions[bot]]

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