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Feature Request: Custom headers/cookies in manual server config #1915
Description
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-httporsse. - 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
- Bug: a failed server-list refresh after adding a server closes the modal with no error #1914 See companion ticket: "Failed manual connection leaves un-modifiable ghost server entry" — the file-import workaround referenced above has its own bugs.
Activity
Izelude commentedon Aug 4, 2026
its already possible or am i missing something?
brandonja991 commentedon Aug 4, 2026
@Izelude Is that after you initially add the server, or during add? For me during add, the only configuration seen is the mcp url, and name.
Here's what I See
Adding server first is not an option because of bug #1914
Izelude commentedon Aug 4, 2026
@brandonja991
that config is after adding a server when clicking on "Settings".
also i cannot reproduce whatever kind of bug you are describing in #1914, adding even a fully invalid server fully works and can be edited and removed.
Screen.Recording.2026-08-04.at.14.00.47.mov
brandonja991 commentedon Aug 4, 2026
@Izelude Ok, my reproduction steps were incomplete. MCP Inspector must be ran from within a docker container.
Was able to look into it further and create a ticket with the underlying issue and the full reproduction steps #1918
#1914 remains a separate issue because errors do not propagate and failures to add server are silent, which i consider a separate issue vs the particular failure case.
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