In order to make Codex work with connectors, we add a built-in gateway
MCP that acts as a transparent proxy between the client and the
connectors. The gateway MCP collects actions that are accessible to the
user and sends them down to the user, when a connector action is chosen
to be called, the client invokes the action through the gateway MCP as
well.
- [x] Add the system built-in gateway MCP to list and run connectors.
- [x] Add the app server methods and protocol
Enterprises want to restrict the MCP servers their users can use.
Admins can now specify an allowlist of MCPs in `requirements.toml`. The
MCP servers are matched on both Name and Transport (local path or HTTP
URL) -- both must match to allow the MCP server. This prevents
circumventing the allowlist by renaming MCP servers in user config. (It
is still possible to replace the local path e.g. rewrite say
`/usr/local/github-mcp` with a nefarious MCP. We could allow hash
pinning in the future, but that would break updates. I also think this
represents a broader, out-of-scope problem.)
We introduce a new field to Constrained: "normalizer". In general, it is
a fn(T) -> T and applies when `Constrained<T>.set()` is called. In this
particular case, it disables MCP servers which do not match the
allowlist. An alternative solution would remove this and instead throw a
ConstraintError. That would stop Codex launching if any MCP server was
configured which didn't match. I think this is bad.
We currently reuse the enabled flag on MCP servers to disable them, but
don't propagate any information about why they are disabled. I'd like to
add that in a follow up PR, possibly by switching out enabled with an
enum.
In action:
```
# MCP server config has two MCPs. We are going to allowlist one of them.
➜ codex git:(gt/restrict-mcps) ✗ cat ~/.codex/config.toml | grep mcp_servers -A1
[mcp_servers.hello_world]
command = "hello-world-mcp"
--
[mcp_servers.docs]
command = "docs-mcp"
# Restrict the MCPs to the hello_world MCP.
➜ codex git:(gt/restrict-mcps) ✗ defaults read com.openai.codex requirements_toml_base64 | base64 -d
[mcp_server_allowlist.hello_world]
command = "hello-world-mcp"
# List the MCPs, observe hello_world is enabled and docs is disabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - disabled Unsupported
hello_world hello-world-mcp - - - enabled Unsupported
# Remove the restrictions.
➜ codex git:(gt/restrict-mcps) ✗ defaults delete com.openai.codex requirements_toml_base64
# Observe both MCPs are enabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - enabled Unsupported
hello_world hello-world-mcp - - - enabled Unsupported
# A new requirements that updates the command to one that does not match.
➜ codex git:(gt/restrict-mcps) ✗ cat ~/requirements.toml
[mcp_server_allowlist.hello_world]
command = "hello-world-mcp-v2"
# Use those requirements.
➜ codex git:(gt/restrict-mcps) ✗ defaults write com.openai.codex requirements_toml_base64 "$(base64 -i /Users/gt/requirements.toml)"
# Observe both MCPs are disabled.
➜ codex git:(gt/restrict-mcps) ✗ just codex mcp list
cargo run --bin codex -- "$@"
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.75s
Running `target/debug/codex mcp list`
Name Command Args Env Cwd Status Auth
docs docs-mcp - - - disabled Unsupported
hello_world hello-world-mcp - - - disabled Unsupported
```
## Problem
The introduction of `notify_sandbox_state_change()` in #7112 caused a
regression where the blocking call in `Session::new()` waits for all MCP
servers to fully initialize before returning. This prevents the TUI
event loop from starting, resulting in `McpStartupUpdateEvent` messages
being emitted but never consumed or displayed. As a result, the app
appears to hang during startup, and users do not see the expected
"Booting MCP server: {name}" status line.
Issue: [#7827](https://github.com/openai/codex/issues/7827)
## Solution
This change moves sandbox state notification into each MCP server's
background initialization task. The notification is sent immediately
after the server transitions to the Ready state. This approach:
- Avoids blocking `Session::new()`, allowing the TUI event loop to start
promptly.
- Ensures each MCP server receives its sandbox state before handling any
tool calls.
- Restores the display of "Booting MCP server" status lines during
startup.
## Key Changes
- Added `ManagedClient::notify_sandbox_state()` method.
- Passed sandbox_state to `McpConnectionManager::initialize()`.
- Sends sandbox state notification in the background task after the
server reaches Ready status.
- Removed blocking notify_sandbox_state_change() methods.
- Added a chatwidget snapshot test for the "Booting MCP server" status
line.
## Regression Details
Regression was bisected to #7112, which introduced the blocking
behavior.
---------
Co-authored-by: Michael Bolin <bolinfest@gmail.com>
Co-authored-by: Michael Bolin <mbolin@openai.com>
### Summary
Added `mcp/servers/list` which is equivalent to `/mcp` slash command in
CLI for response. This will be used in VSCE MCP settings to show log in
status, available tools etc.
Because the GitHub MCP is one of the most popular MCPs and it
confusingly doesn't support OAuth, we should make it more clear how to
make it work so people don't think Codex is broken.
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
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
Matthew ZengandGitHub
Ahmed IbrahimandGitHub
gt-oaiandGitHub
Shijie RaoandGitHub
jif-oaiandGitHub
Gabriel PealandGitHub