Fix 3 of plans/2026-07-11-concurrent-task-execution.md, the throughput one.
nomos held exactly one *mcpClient for the whole process, shared by every
/chat goroutine. Its mutex was held for the full duration of each tool
round-trip, and `run` executes its SSH command SYNCHRONOUSLY inside that
round-trip (capped at up to 10 minutes) — so while Task A was mid-`run`,
every other task's tool calls, even a trivial get_entity, queued behind that
single lock. Tasks could think (LLM calls) in parallel but never act in
parallel.
The MCP server has no per-connection state to protect (newServer returns one
shared *mcp.Server instance whose handlers close only over the DB
connection pool, already safe for concurrent use) — the mutex existed purely
because the client reused one stateful transport session. So the fix doesn't
touch the server at all:
- New mcpClientPool (cmd/nomos/main.go): one *mcpClient per session id,
created lazily (a real MCP initialize handshake) on first use and cached;
session-less traffic (the ephemeral no-DB-store path, the structured
/query endpoint) gets its own fixed, reused key instead of a fresh
connection per request. Idle clients (20 min past last use — long enough
to outlive a single slow `run`) are evicted on a 5-minute sweep ticker.
- agent.go: `client *mcpClient` → `clients *mcpClientPool`; every call site
(buildTools, fleetSnapshot, the tool-dispatch loop) now resolves its own
session's client via clients.get(sessionID) instead of reaching for one
shared field. A task's own tool calls stay sequential (already true — the
agent loop calls tools one at a time within a turn) but no longer block
anyone else's.
- main.go: handleQuery takes the pool instead of a client (keyed "query", a
fixed non-session slot); shutdown calls pool.closeAll().
Verified live against the deployed stack: fired a slow-but-ungated command
(`ping -c 15 127.0.0.1`, read-only per policy's allowlist, no approval
needed) as Task A, then — 2s into A's run — a trivial hostname lookup as
Task B, both through the real /chat endpoint. Task A's ping genuinely ran
~14.3s (confirmed via its own execution record and the agent's reported
output). Task B returned in 6s total, well before A finished — proving it
was never queued behind A's connection. Before this fix, B would have been
forced to wait out A's entire ~14.3s hold on the single shared client.
This completes plans/2026-07-11-concurrent-task-execution.md's required
scope — only the explicitly optional/deferred Fix 4 (a concurrency/cost cap,
pending real usage data) remains.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Replaces the chat right rail's ad-hoc Digest+Graph stack with a single
TaskContextPanel that renders the task's live working state, driven by the
always-on events stream (not the per-turn chat SSE) so it keeps updating
during server-side auto-continuation/resume:
- GoalHeader: goal + status pill (planning/executing/awaiting_input/done/
failed), sourced from the sessions list.
- PlanProgress: ordered steps with live status icons + progress bar, hydrated
via new GET /sessions/{id}/plan; clicking a step with a target opens its
EntitySheet (no fake "jump to transcript" — bits-ui Collapsible content
isn't force-mounted, so a DOM-scroll jump would silently no-op for
collapsed tool groups).
- OperatorQuestion: the pinned structured question card (prompt/why/entity
chips/option buttons/free-text), hydrated via new GET /sessions/{id}/
questions; answering POSTs to the existing answer endpoint.
- SessionGraph upgraded to a live entity panel: entity.touched pulses the
node (animated ring) and shows "Now touching <slug>"; health.changed shows
a transient diff badge for touched entities.
- SessionDigest gains a success/failure/partial outcome banner and now also
refetches when the task's status changes, not just on session switch.
Two bugs found and fixed while wiring this up:
- workspace.ts's status-refresh trigger only covered goal.set/task.status;
question.raised/answered didn't refresh the sessions list, so GoalHeader's
pill went stale after answering via the panel (resumeSession runs entirely
server-side — no client 'done' event to piggyback a refresh on). Now every
status-affecting event triggers the (debounced) refetch.
- Forgot to rebuild the nomos container after adding the /plan and
/questions endpoints, so they silently fell through to the old default GET
handler — caught via a live curl diff against the running container,
not a code read.
Verified end-to-end against the live stack: goal/plan/question all update
without a reload as the agent works; answering a question via the panel
resumes the agent and the header pill correctly flips to Executing;
entity.touched pulses the live graph.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The last backend piece: when the agent hits a decision only the operator can
make, it surfaces a structured question instead of guessing or stalling.
- ask_operator(prompt, why?, options?, context_entities?): nomos-local tool
that records a session_questions row, moves the task to awaiting_input, emits
question.raised, and ENDS the turn (the agent loop returns after it, so the
agent can't barrel past its own question). The prompt becomes the assistant's
visible message so the question also shows inline in the transcript.
- Two resume paths, both close the question + emit question.answered + return
the task to executing:
- Panel: POST /sessions/{id}/questions/{qid}/answer → resumes the agent in the
background with the answer injected (reusing the continuation machinery,
refactored continueSession → resumeSession). Returns 202; the reply lands via
message polling.
- Chat reply: the next chat message on a task with an open question IS the
answer — auto-closed in handleChat; the turn itself is the resume.
Verified end-to-end: forcing a decision paused the task at awaiting_input with
the structured question (prompt/why/options/entities); a panel answer resumed
the agent (it acknowledged host:strong and continued); a plain chat reply
auto-closed a second question. Cleanup + tests green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The root cause behind "the agent stops at the first error and doesn't recover":
provisioning executions run ASYNCHRONOUSLY (pct_create fires the SSH work in a
goroutine and returns "running" immediately), so the agent's turn ENDS before
the result exists. The agent literally isn't running when the step fails — it
can't react to a failure it never observes. The only thing that fed results
back was the operator typing "continue" after every async step: the human was
the event loop. (In the flagged 18-message session the operator typed
continue/proceed/?? eight times while the agent correctly diagnosed each failure
but couldn't advance a step on its own.)
This makes the system the event loop instead:
- migrations/017: nomos_plan_executions links each gated execution to the chat
session that started it.
- cmd/nomos: after a tool result, any "execution <uuid>" it started is linked
to the session. A background worker (continue.go) polls for those executions
reaching a terminal state and — while the agent has an open assent window (an
approved plan is in flight) — re-invokes the agent with the result
("execution X completed/failed: <result>"), so it proceeds to the next step
or diagnoses+fixes the failure, with no operator tick. Guarded against loops
(mark-continued before running) and bounded by the 30-min window.
- chatWith(): chat() variant that injects the finished-execution note after
replayed history without persisting a fake user turn.
- DecideApproval: approving a step by ANY route (button or chat-assent) now
opens the assent window, so auto-continuation works regardless of how the
operator approved — previously only typing "go ahead" opened it.
- SOUL: the agent is told it will be auto-re-invoked when async steps finish —
don't poll get_execution_status, don't wait for "continue"; end the turn and
keep going step by step until the goal is verified or a genuine blocker.
This is the root fix, not another per-command patch: you can't enumerate every
failure of an unbounded action space, but you can give the agent a loop that
observes each result and adapts — because "do anything" always includes "the
first attempt failed."
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- Empty/refusal responses retried once, then surfaced as errors instead of silent blanks
- Chinese refusal boilerplate detected via denylist + non-ASCII heuristic
- Bulk-tool preference added to SOUL.md (list_lxcs over per-entity get_lxc_state)
- Tool results truncated to 4KB on persist; get_state_snapshot filters null-state entities
- Session delete (DELETE /sessions/{id} + confirm-on-second-click UI)
- Session titles auto-generated from assistant answer instead of raw user message
After an api (MCP server) restart, nomos held a dead session id and every
tool call failed with "unexpected end of JSON input" until nomos was manually
restarted — which happens on every deploy. The MCP client now detects a
rejected session (4xx or empty body) and transparently re-initializes and
retries once. Also raise the SSE scanner buffer to 4MB so large tool results
don't exceed the 64KB default token limit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
