This is a proposed fix for #8912
Information provided by Codex:
no_proxy means “don’t use any system proxy settings for this client,”
even if macOS has proxies configured in System Settings or via
environment. On macOS, reqwest’s proxy discovery can call into the
system-configuration framework; that’s the code path that was panicking
with “Attempted to create a NULL object.” By forcing a direct connection
for the OAuth discovery request, we avoid that proxy-resolution path
entirely, so the system-configuration crate never gets invoked and the
panic disappears.
Effectively:
With proxies: reqwest asks the OS for proxy config →
system-configuration gets touched → panic.
With no_proxy: reqwest skips proxy lookup → no system-configuration call
→ no panic.
So the fix doesn’t change any MCP protocol behavior; it just prevents
the OAuth discovery probe from touching the macOS proxy APIs that are
crashing in the reported environment.
This fix changes behavior for the OAuth discovery probe used in codex
mcp list/auth status detection. With no_proxy, that probe won’t use
system or env proxy settings, so:
If a server is only reachable via a proxy, the discovery call may fail
and we’ll show auth as Unsupported/NotLoggedIn incorrectly.
If the server is reachable directly (common case), behavior is
unchanged.
As an alternative, we could try to get a fix into the
[system-configuration](https://github.com/mullvad/system-configuration-rs)
library. It looks like this library is still under development but has
slow release pace.
This adds two new config fields to streamable http mcp servers:
`http_headers`: a map of key to value
`env_http_headers` a map of key to env var which will be resolved at
request time
All headers will be passed to all MCP requests to that server just like
authorization headers.
There is a test ensuring that headers are not passed to other servers.
Fixes#5180
1. If Codex detects that a `codex mcp add -url …` server supports oauth,
it will auto-initiate the login flow.
2. If the TUI starts and a MCP server supports oauth but isn't logged
in, it will give the user an explicit warning telling them to log in.
This adds a queryable auth status for MCP servers which is useful:
1. To determine whether a streamable HTTP server supports auth or not
based on whether or not it supports RFC 8414-3.2
2. Allow us to build a better user experience on top of MCP status
