fix(mcp): MCP server loses connection mid-session causing intermittent failures

[herjarsa]

Pre-flight Checks

• I have searched existing issues and this is not a duplicate
• I understand this issue needs status:approved before a PR can be opened

Bug Description

The MCP server intermittently loses connection mid-session, causing multiple MCP tools to return "Not connected". This happens after the connection was successfully established and used.

Steps to Reproduce

1. Start an OpenCode session
2. Verify MCPs work (e.g., supabase_list_projects returns data)
3. Use multiple MCP calls over several minutes
4. Eventually, MCPs like Supabase, Desktop Commander, n8n, and Universal Brain return Not connected
5. Other MCPs with persistent connections (Telegram, MetaTrader 5) continue working

Expected Behavior

MCP connections should remain stable throughout the session, or auto-reconnect transparently.

Actual Behavior

Multiple MCPs simultaneously fail with Not connected:

• supabase_list_projects → Not connected
• desktop-commander_list_directory → Not connected
• n8n_n8n_health_check → Not connected
• universal-brain_ping → Not connected

Meanwhile, MCPs with their own persistent connections remain functional:

• telegram-mcp_get_me → ✅ Works
• metatrader_get_account_info → ✅ Works

Operating System

Windows 11

Agent / Client

OpenCode

Shell

PowerShell 5.1

Relevant Logs

# Initial connection established:
> supabase_list_projects
[
  {"name":"Signalyn","id":"sglwgnwidhzddnuwewps"},
  {"name":"alpha-forge-mt5","id":"wjnoiuliovtdngtgskeq"}
]

# Later in same session:
> supabase_list_projects
Not connected

> desktop-commander_list_directory
Not connected

Additional Context

• The failure appears to be a session drop in the OpenCode MCP server, not individual MCP config issues
• A previous memory entry confirms this happened before: "Restored and stabilized all MCPs after context compaction" (project: opencode-mcps)
• Workaround: None found. Session must be restarted.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• MCP server connection lost after context compaction — tools unavailable until new session #23556: MCP server connection lost after context compaction — tools unavailable until new session (same symptom: MCP tools lost mid-session, requires new session to restore; your additional context even mentions "Restored and stabilized all MCPs after context compaction")
• Bug: MCP tools permanently lost mid-session after single transient listTools() failure — no retry, no reconnect #17099: MCP tools permanently lost mid-session after single transient listTools() failure — no retry, no reconnect (same symptom: multiple MCP clients simultaneously lose connection mid-session while others remain working; root cause analysis and fix suggestions already documented there)

If your issue is the same, please consider adding any additional details (e.g. Windows-specific behavior) as a comment on those existing issues rather than opening a new one.