An MCP server whose `initialize` answer is an error — a broken or version-
mismatched connector — starts fine and then never exits. `McpServer::start`
returned `Err` correctly, but the `Child` lives in the read-loop task rather
than in the returned value, so `kill_on_drop` followed a task nothing ever
drops. Every retry therefore left a live process holding three pipes and a
pidfd, and the supervisor's retry ceiling is deliberately not permanent.
The end state was not a dead connector but a dead instance: the process hit
its 1024-descriptor limit, `accept()` began failing with EMFILE, and incoming
connections queued on a socket nobody could accept from — while the process,
the port and every other connector still looked healthy. Observed in
production at ~5h from the first bad handshake to unreachable, with 229
orphaned interpreters.
`stop_server`/`stop_all` had the same hole from the other side: they document
the dropped handle as killing the process, but the task holds its end of
stdin, so the child stayed blocked on a read that would never return.
Both close with one seam. `McpServer` now owns a oneshot sender whose receiver
the read-loop selects on; nothing ever sends, so the drop is the message. That
covers a deliberate stop, the last `Arc` going away, and a `?` in `start()`
unwinding past the local binding before it was ever returned — including the
caller's `timeout`, which drops the same future. The loop then kills and, as
importantly, reaps: an unreaped child trades the orphan for a zombie holding
the same pipes.
Both leaks are covered by tests that fail without the fix.
Also raise LimitNOFILE to 65536: the installers write it, and update.sh heals
an existing unit additively, leaving an admin's own value alone. The leak is
the bug, but 1024 for a process sharing descriptors between the listener,
every user's SQLite handles and three pipes per connector is thin regardless.
TIC said nothing about what the agent does, and named the wrong thing: the
tick belongs to the scheduler, which is generic and lives outside it. The
agent's only decision is whether an incoming event deserves an interruption
— it sorts, it never acts — so it is now event-triage, matching the
functional naming of the two memory lints.
- agents/tic/ -> agents/event-triage/, module tic/ -> event_triage/,
TicManager -> EventTriageManager, TicConfig -> EventTriageConfig
- agent id and chat source: "tic" -> "event-triage"
- config keys: tic.* -> event_triage.*, and the config.yml section tic: ->
event_triage: (greenfield: previously set values fall back to defaults)
- i18n en/it/fr: Event triage / Triage eventi / Tri des evenements; dropped
the stale "TIC sessions" mention from the debug-pages description
- docs/system-agents.md, docs/index.md, docs/settings.md, CLAUDE.md, SKALD.md
Re-architects MCP from one owner table + agent-written registration into an
admin-curated catalog with two runtimes unioned per session, surfaced in the UI
as "Connectors" (mcp/schema stays neutral, §0.1).
Two runtimes behind one seam (§7):
- Global runtime: shared, stateless connectors (web-search, Tavily…) on the
HOST, connected at boot from mcp_global_servers, access-filtered per user via
mcp_global_access.
- Per-user runtime: a user's activated connectors run INSIDE their container,
started at first login from mcp_user_servers and living until restart (§9);
docker exec -i children die via kill_on_drop when the UserContext drops.
- McpProvider trait (mcp/provider.rs): the session round-loop never learns which
runtime owns a server. McpManager implements it directly (inert ownerless
bundle); UserMcpView implements global ∪ user with an accessible_global
snapshot. Both share McpManager::connect_all; McpServerSpec +
global_row_spec/user_row_spec turn a DB row into a connectable spec.
- mcp-client: McpServerConfig.launch_in runs a stdio command inside a container
via docker exec -i (set at runtime, never parsed from config).
Authorization is a capability on the role, not `if role==admin` (§0.1/§14):
role_capabilities table + db/role_capabilities.rs — register_remote and
register_local_from_catalog are self-service (seeded on every new role), while
register_local_script and manage_catalog are admin-only. admin holds every
capability by construction. This removes the agent-facing register_mcp/delete_mcp
tools and the mcp kinds of list_items/toggle_item, closing the §14 RCE vector.
Schema:
- Registry: mcp_catalog (vetted templates — schema only, no live creds),
mcp_global_servers + mcp_global_access, role_capabilities.
- Owner: mcp_user_servers (per-user activations; api_key encrypted at rest,
catalog_name a bare TEXT snapshot, never an owner→registry FK).
- Drops the old owner table mcp_servers.
API + UI: src/frontend/api/mcp.rs (admin catalog/global/access + user
available/activate/activated, all capability-gated via require_cap);
web/components/connectors.js (<connectors-page>) renders the user view always
and the admin view for role_id === 'admin'.
Deferred: interactive per-user auth (OAuth callback / QR / SSH elicitation, §15)
— only none/api_key wired; no boot seed of catalog presets; per-(user, session)
MCP grant model still open.
Daniele
dguiducci