# NousResearch/hermes-agent · MCP stdio transport fail-fast on session/process death

## Open now

- Nothing open on GitHub.

These items address a bug where in-flight MCP tool calls remain attached to a dead stdio subprocess or restarted transport session until a full timeout expires, rather than failing immediately. The fixes introduce fail-fast behavior when the subprocess dies or the transport session restarts.

## TL;DR

- 3 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 0 merged PR(s), 2 PR(s) closed without merging.
- No fix has been merged to main; one or more PRs were attempted (see below).
- **Recommended:** review the prior/competing PR(s) below. A fix was attempted but not merged; your case may extend or revive that work.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `unresolved`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.67`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #81995: \[Bug\]: Stalled stdio MCP cold-spawn leaves in-flight tool call attached to dead subprocess for full 300s timeout — no fail-fast on supervisor respawn

## Prior & competing PRs

- **#82071: fix(mcp): fail RPCs when transport sessions restart**. closed without merge
  - maintainer direction: category `duplicate_of`; implication `duplicate`; refs `#48069`
- **#82219: fix(mcp): fail-fast in-flight tool calls when stdio subprocess dies (#81995)**. closed without merge
  - maintainer direction: category `superseded_by_pr`; implication `superseded`; refs `#48069`, `#81995`, `#82071`

## Fix status

- No merged fix on record.
- Subsystem: `mcp`