{"repo":"NousResearch/hermes-agent","public_id":"50394","display_label":"MCP stdio server failure isolation and reconnect resilience","summary":"These issues and fixes address how a single failing stdio MCP server can destabilize the entire MCP bridge, causing healthy servers' tools to become unavailable. The work covers isolating failing servers, adding per-server circuit breakers, and improving reconnection logic to re-register tools when a server recovers.","subsystem":"mcp","counts":{"members":4,"open_issues":0,"open_issues_distinct":0,"open_prs":0,"closed_issues":1,"merged_prs":1,"attempt_prs":2},"landed_fix":{"status":"merged_to_main","basis":"structural","pr":68660,"merged_at":"2026-07-21T19:43:27+00:00"},"resolution":{"state":"unresolved","by":null},"freshness":{"state":"verified","last_verified_at":"2026-07-21T19:43:27+00:00","is_stale":false},"grouping":{"backbone":"STRUCTURAL_SPANNING","link_density":0.5},"fix_edges":[{"issue_number":50394,"pr_number":68660,"tier":"verified","basis":"superseded_ref","confidence":0.9,"recoverable_from_timeline":false,"pr_merged_at":"2026-07-21T19:43:27+00:00"}],"members":[{"kind":"issue","number":50394,"title":"A single failing stdio MCP server churns the whole MCP bridge — healthy servers' tools become \"Unknown tool\" at runtime","url":null,"state":"closed"},{"kind":"pr","number":50482,"title":"fix(mcp): per-server connection circuit breaker to stop the restart storm (#50394)","url":null,"state":"closed","close_reason":{"refs":[{"kind":"commit","value":"472c0681594ccd137666fc2b87f4913d2e6cc5b0","number":0}],"category":"uncategorized","implication":"needs_llm"},"merged":false},{"kind":"pr","number":50589,"title":"fix(mcp): isolate a single failing stdio server from the bridge","url":null,"state":"closed","close_reason":{"refs":[{"kind":"pr","value":"#68660","number":68660}],"category":"merged_via","implication":"superseded"},"merged":false},{"kind":"pr","number":68660,"title":"fix(mcp): stdio discovery cooldown, message-less transport classification, zero-connected retry latch","url":null,"state":"merged","close_reason":{"category":"merged"},"merged":true,"is_fix_pr":true,"fix_tier":"verified","files_changed":["contributors/emails/[redacted:email]","contributors/emails/[redacted:email]","hermes_cli/mcp_startup.py","tests/hermes_cli/test_mcp_startup.py","tests/test_tui_entry_mcp_owner.py","tests/tools/test_mcp_bridge_single_failure.py","tests/tools/test_mcp_resource_content.py","tests/tools/test_mcp_tool.py","tests/tools/test_mcp_tool_session_expired.py","tools/mcp_tool.py","tui_gateway/entry.py"]}],"trust":{"default_tier":"verified","includes_suggested":false}}