Summary
When manually configuring an MCP server using the streamable-http or sse transport, there is no way to specify custom HTTP headers or cookies. The only workaround is to import a server configuration from a file, which has its own separate issues (see linked ticket). Adding this option to the manual configuration flow would remove the need for that workaround.
Environment
- Tool: MCP Inspector v2
- Affected transports:
streamable-http, sse (manual configuration flow)
Current Behavior
- Open MCP Inspector > Add server > Add manually.
- Set transport to
streamable-http or sse.
- There is no field for adding custom request headers or cookies.
No UI option exists to add headers or cookies. Users must fall back to importing a config from a file to set headers, which is a less convenient workflow and has separate bugs.
Requested Behavior
The manual server configuration form should allow adding one or more custom headers (including cookie headers) to be sent with requests to the MCP server.
Justification / Use Case
Our MCP server runs in a shared, hosted dev environment used by multiple developers simultaneously. We use a cookie to indicate which developer's source-code branch/location should be loaded by the server, allowing multiple devs to test different code against a single shared hosted instance without needing separate deployments per developer.
This pattern (using headers/cookies to route to per-developer code in a shared dev environment) is not unique to our team — it's a fairly common workaround for shared hosted dev/test environments. More broadly, different environments and setups will have different auth/header/cookie requirements, which justifies giving users the ability to manually configure headers/cookies rather than requiring a config file import.
Suggested Implementation
Add an optional "Headers" (key/value pairs) section to the manual server configuration form for streamable-http and sse transports, similar to what's available via file-based config import.
Related Issues
Summary
When manually configuring an MCP server using the
streamable-httporssetransport, there is no way to specify custom HTTP headers or cookies. The only workaround is to import a server configuration from a file, which has its own separate issues (see linked ticket). Adding this option to the manual configuration flow would remove the need for that workaround.Environment
streamable-http,sse(manual configuration flow)Current Behavior
streamable-httporsse.No UI option exists to add headers or cookies. Users must fall back to importing a config from a file to set headers, which is a less convenient workflow and has separate bugs.
Requested Behavior
The manual server configuration form should allow adding one or more custom headers (including cookie headers) to be sent with requests to the MCP server.
Justification / Use Case
Our MCP server runs in a shared, hosted dev environment used by multiple developers simultaneously. We use a cookie to indicate which developer's source-code branch/location should be loaded by the server, allowing multiple devs to test different code against a single shared hosted instance without needing separate deployments per developer.
This pattern (using headers/cookies to route to per-developer code in a shared dev environment) is not unique to our team — it's a fairly common workaround for shared hosted dev/test environments. More broadly, different environments and setups will have different auth/header/cookie requirements, which justifies giving users the ability to manually configure headers/cookies rather than requiring a config file import.
Suggested Implementation
Add an optional "Headers" (key/value pairs) section to the manual server configuration form for
streamable-httpandssetransports, similar to what's available via file-based config import.Related Issues