thomas be2e4afcd7 Add MCP 2026-07-28 discovery support (#35724) ...

## What changed

- Add an opt-in `mcp_2026_07_28` protocol mode while preserving the legacy
  lifecycle by default.
- Negotiate the new protocol over streamable HTTP with `server/discover`,
  including bounded responses, redirect protection, and fallback only when a
  response establishes that the endpoint is legacy-only.
- Require stdio servers to opt in with
  `CODEX_MCP_PROTOCOL_VERSION=2026-07-28`, and add a bounded local stdio
  transport for the modern lifecycle.
- Consume paginated tool, resource, and resource-template catalogs in modern
  mode, reject repeated cursors, and retain discovered server identity.
- Reconnect reusable MCP clients when their selected protocol mode changes.

## Testing

- Cover HTTP JSON and SSE discovery, legacy fallback and rejection cases,
  redirects, retries, response limits, and pagination.
- Cover local and executor stdio discovery, protocol markers, message limits,
  and legacy compatibility.

GitOrigin-RevId: f6a78816e127d2a482292d63b91c8384f1595903

2026-07-28 05:52:12 +00:00

..

src

Add MCP 2026-07-28 discovery support (#35724)

2026-07-28 05:52:12 +00:00

BUILD.bazel

Extract MCP into codex-mcp crate (#15919)

2026-04-01 19:03:26 -07:00

Cargo.toml

Initialize execution environments with the final HTTP policy (#34995)

2026-07-23 19:24:41 +00:00