[1/4] Add executor HTTP request protocol

[aibrahim-oai]

Why

Remote streamable HTTP MCP needs a transport-shaped executor primitive before the MCP client can move network I/O to the executor. This layer keeps the executor unaware of MCP and gives later PRs an ordered streaming surface for response bodies.

What

• Add typed http/request and http/request/bodyDelta protocol payloads.
• Add executor client helpers for buffered and streamed HTTP responses.
• Route body-delta notifications to request-scoped streams with sequence validation and cleanup when a stream finishes or is dropped.
• Document the new protocol constants, transport structs, public client methods, body-stream lifecycle, and request-scoped routing helpers.
• Add in-memory JSON-RPC client coverage for streamed HTTP response-body notifications, with comments spelling out what the test proves and each setup/exercise/assert phase.

Stack

1. [1/4] Add executor HTTP request protocol #18581 protocol
2. [2/4] Implement executor HTTP request runner #18582 runner
3. [3/4] Add executor-backed RMCP HTTP client #18583 RMCP client
4. [4/4] Honor Streamable HTTP MCP placement #18584 manager wiring and local/remote coverage

Verification

• just fmt
• cargo check -p codex-exec-server -p codex-rmcp-client --tests
• cargo check -p codex-core --test all compile-only
• git diff --check
• Online full CI is running from the full-ci branch, including the remote Rust test job.

Co-authored-by: Codex noreply@openai.com

[aibrahim-oai]

This change is part of the following stack:

• [1/4] Add executor HTTP request protocol #18581 ◀
  • [2/4] Implement executor HTTP request runner #18582
    • [3/4] Add executor-backed RMCP HTTP client #18583
      • [4/4] Honor Streamable HTTP MCP placement #18584

_{Change managed by git-spice.}

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/exec-server/src/client.rs

Lines 845 to 850 in d0f4fc9

	async fn fail_all_sessions(inner: &Arc<Inner>, message: String) {
	let sessions = inner.take_all_sessions().await;
	for (_, session) in sessions {
	session.set_failure(message.clone()).await;
	}

Clear HTTP stream routes when transport disconnects

fail_all_sessions only drains process sessions. After a disconnect, http_body_streams still holds each stream Sender, so HttpResponseBodyStream::recv() may wait forever because the channel never closes and no more deltas can arrive. It also leaves stale request_id registrations in memory until the whole client is dropped.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/exec-server/src/client.rs

Lines 849 to 855 in 1fc4cd7

	async fn fail_all_sessions(inner: &Arc<Inner>, message: String) {
	let sessions = inner.take_all_sessions().await;
	for (_, session) in sessions {
	session.set_failure(message.clone()).await;
	}
	}

Close HTTP body streams when transport disconnects

fail_all_sessions only drains process sessions and never clears http_body_streams. On RpcClientEvent::Disconnected or notification-handler failure, each stream keeps its mpsc::Sender alive, so HttpResponseBodyStream::recv() can block forever on rx.recv() instead of terminating when the transport dies. This can hang callers waiting for streamed HTTP bodies.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/exec-server/src/client.rs

Lines 869 to 874 in 5b3829a

	async fn fail_all_sessions(inner: &Arc<Inner>, message: String) {
	let sessions = inner.take_all_sessions().await;
	for (_, session) in sessions {
	session.set_failure(message.clone()).await;
	}

Close HTTP body routes on disconnect

When the RPC transport disconnects, fail_all_sessions only tears down process sessions and never touches http_body_streams. Active HttpResponseBodyStream receivers can then block forever in recv() because their sender is still retained in the routing map but no more notifications will arrive. Mid-stream network drops should terminate these streams with an error instead of hanging.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/exec-server/src/client.rs

Lines 494 to 499 in 5b3829a

	RpcClientEvent::Disconnected { reason } => {
	if let Some(inner) = weak.upgrade() {
	fail_all_sessions(&inner, disconnected_message(reason.as_deref()))
	.await;
	}
	return;

Close HTTP streams when the RPC transport disconnects

connect handles RpcClientEvent::Disconnected by failing process sessions and returning, but it never clears inner.http_body_streams. Those retained senders keep each HttpResponseBodyStream channel open, so recv() can block forever after transport loss instead of terminating with an error/EOF.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

codex/codex-rs/exec-server/src/client.rs

Lines 494 to 499 in 53977b8

	RpcClientEvent::Disconnected { reason } => {
	if let Some(inner) = weak.upgrade() {
	fail_all_sessions(&inner, disconnected_message(reason.as_deref()))
	.await;
	}
	return;

Fail active HTTP body streams when transport disconnects

Handle RpcClientEvent::Disconnected by failing process sessions only. It never closes or errors http_body_streams, so each stream's sender remains in the routing map. HttpResponseBodyStream::recv() then awaits forever after a transport drop, leaving callers stuck mid-response with no EOF/error.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 8edc1730a8

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 1a9358ff3f

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: c3159bc7a2

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 888b4d7bc6

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: fdbc9d9c78

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Isolate stream routes from reused request IDs

handle_http_body_delta_notification routes frames only by request_id. After a stream is dropped/canceled, that ID is removed and can be reused immediately, but no cancellation is sent upstream. Late bodyDelta frames from the old request can then be delivered into the new stream with the same ID, corrupting bytes or causing spurious seq failures.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0519903bcd

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Remove route after queuing a terminal body delta

handle_http_body_delta_notification does nothing on Some(Ok(())), even when terminal_delta is true. If the consumer drops before reading that queued terminal frame, Drop changes the route to Draining; since terminal has already arrived, no later notification removes it. The request id can remain permanently reserved.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 59069ca8e6

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Add missing imports for HTTP stream route types

This commit does not compile: Inner.http_body_streams uses mpsc::Sender<HttpRequestBodyDeltaNotification> but neither tokio::sync::mpsc nor HttpRequestBodyDeltaNotification is imported in client.rs. A clean cargo check -p codex-exec-server --lib at this revision fails with unresolved-name errors, so the change is not buildable.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Propagate disconnect errors when stream buffer is full

In fail_all_http_body_streams, terminal error frames are sent with tx.try_send(...) and the result is ignored. When a body stream buffer is already full, that error frame is dropped; once queued chunks drain, recv() sees channel close as Ok(None). A transport disconnect can therefore be observed as clean EOF with truncated data.

Useful? React with 👍 / 👎.