Post-review hardening on the attempt-ownership commit:
- Write-time re-validation: the entry staleness check in
_restore_compressor_attempt_state runs before the durable-cooldown DB
I/O, so a fallback could claim the compressor in that window and the
stale setattr loop would still clobber its state. The in-memory writes
now re-validate AND execute under _COMPRESSOR_ATTEMPT_LOCK — the same
lock claims are taken under. The DB rollback stays outside the lock
(safe: the dangerous direction requires a prior claim, which the entry
check rejects). Both the quality reviewer and the lead's independent
pre-verification converged on this window.
New deterministic test: TestMidRestoreClaimRace (claim injected
between entry check and write via instrumented deepcopy).
- Documented gen-0 semantics on _claim_compressor_attempt: per-compressor
all-or-nothing, never mixed with gen>0 on one instance (reviewer
finding 2, verified unreachable — comment hardens against future
confusion).
Dropped after verification (reviewer finding 3): resetting
_SUMMARY_ROUTE_CONSUMED on pin_summary_route exit — the echo lives in
the worker thread's COPIED context (propagate_context_to_thread) and
dies with it; a probe confirmed the next attempt's context is clean.
Resetting it would break digests running after the with-block.
Follow-up to #96634 (stall-fallback retry, #78981) addressing
donovan-yohan's post-merge adversarial review. The stall path detaches a
timed-out primary worker (fence cancel wins; future stays on the pool)
and immediately runs the fallback against the SAME ContextCompressor,
creating two verified races:
1. Late-primary snapshot restore: the detached primary's unwind called
_restore_compressor_attempt_state with the PRIMARY's pre-attempt
snapshot. Landing after the fallback's commit it rolled
_previous_summary/cooldown/provenance/telemetry back to pre-primary
values, silently discarding fallback-owned state.
2. Shared _compression_cancelled_check: the late primary's `finally`
cleared the callback the fallback had just installed, so the
fallback's F4 cancellation consult read None.
Fix: a monotonic per-compressor attempt generation claimed under one
module lock (_claim_compressor_attempt). Snapshot restores carry their
claiming generation and no-op when stale; the cancelled-check set/clear
moves into owner-stamped helpers (_install_compression_cancelled_check /
_clear_compression_cancelled_check_if_owner) so only the installing
attempt can clear it. The commit fence keeps owning COMMIT admission;
the generation owns compressor-ATTRIBUTE writes — two boundaries.
Legacy callers (attempt_generation=None) and slotted third-party
compressors (generation 0) keep the historical unconditional behavior.
Secondary review items:
- Lean chunk digests during a stall-fallback retry now follow the
summary onto the pinned healthy route: take_pinned_summary_route()
echoes the consumed route into a context-local
_SUMMARY_ROUTE_CONSUMED, and _build_chunk_digests passes
attempt_summary_route_kwargs() (non-consuming) to call_llm. The pin's
single-use contract for the SUMMARY call is unchanged — the
main-model retry still never re-issues the pinned route.
- Worker re-run repeating pre-compression callbacks: documented as an
accepted limitation on _retry_compression_on_fallback_chain
(built-ins idempotent; resuming mid-pipeline would couple the retry
to host callback ordering).
Tests (tests/agent/test_compression_attempt_ownership.py, 10 cases):
deterministic interleavings for both races (late-primary restore
no-ops + preserves fallback state; stale finally cannot clear the
fallback's callback), legacy/slotted compatibility, digest route
follow + context-locality of the consumed echo. Mutation-checked:
reverting only the two prod files to origin/main fails the suite;
restored stack green (21 passed incl. the original #78981 suite).
The one red in the wider sweep
(test_silence_cannot_approach_double_idle_timeout) is pre-existing on
clean origin/main — verified independently.
When context-compression rotation fires mid-turn, the current user
message was persisted twice into the child session. Root cause: dedup
used id()-seeded sets of copies instead of markers on the live objects.
Replace with _DB_PERSISTED_MARKER-based dedup as the sole authority:
- _ensure_compressed_has_user_turn returns CompressedUserTurnOutcome
- After publish_compression_child succeeds, stamp the live anchor-source
row (not a drifted index) with _DB_PERSISTED_MARKER
- _sync_persisted_markers mirrors stamps from result to live lists by
scoped identity (handles direct-path, adoption divergence, _session_messages)
- Remove _flushed_db_message_ids from rotation commit path (markers replace it)
- Unconditional (loud) imports — no silent fallback
Salvage of #94996 by @fedosis, rebased on top of #95433 (stall-fallback,
already merged). Both conversation_compression.py and run_agent.py are
built from origin/main + #94996's diff applied on top, preserving the
force_terminal refactor and _publish_new_fence from #95433.
Credit: @fedosis original PR #94996.
The timeout validation (isinstance(raw, (int, float)) and not
isinstance(raw, bool) and raw > 0 → float(raw)) was duplicated
between auxiliary_client.py:_fallback_entry_timeout and
conversation_compression.py:resolve_compression_fallback_route.
Extracted into _coerce_positive_timeout to prevent drift if the
config schema evolves.
Review follow-up for #95433. When the host's fence factory is absent or
raises, the retry runs on a private CompressionCommitFence() that
hard-interrupt admission never reads — /stop would serialize against the
aborted attempt's fence instead of the retry's commit boundary. Promote
the factory-failure swallow from debug to warning and warn when the retry
has no published fence, so the control-plane degradation is visible rather
than silent.
Also documents the pin's coverage (single _generate_summary call; the
lean-mode chunk digests are a separate unpinned call path).
A stalled compression summary never raises, so the auxiliary client's
exception-path fallback is unreachable from it. When the progress-aware
timeout aborts a stalled worker, re-run the summary once pinned to the
first auxiliary.compression.fallback_chain entry before degrading to
continue-without-compression.
The pin is a single-use ContextVar consumed by the context compressor's
summary call, so it cannot leak into the detached stalled worker or the
compressor's own main-model retry. A fresh fence is minted through the
host factory so a /stop during the retry still admits against the live
commit boundary.
- Reuse the existing _commit_status variable for the terminal-edge gate
instead of the parallel _compaction_succeeded boolean (derived state).
- Give the commit_fence_cancelled abort the same force_terminal=True
terminal edge as the lock-contended abort, and reword the closure
comment that overstated the lock contender as 'the one exception'.
- Inline the codex app-server path's lifecycle closure: after gating on
success it reduced to a single success-site emit, so the scaffolding
(done-flag + closure + two no-op failure-path calls) was dead.
Follow-up to PR #94531 salvage:
- classify the auxiliary boundary's terminal 'None response' /
'invalid response' errors (#7264) into the same empty-content abort
carve-out so those shapes also preserve the session (#94459's wider
classification, sibling shapes from #94448)
- register _last_summary_empty_content_failure in
_COMPRESSOR_ATTEMPT_STATE_FIELDS so pre-commit hard-cancel rollback
restores the flag (conversation_compression snapshot allow-list)
- tests: cooldown re-entry keeps aborting; both sibling shapes abort
- attribution: map zhangyswx@163.com -> YusenZhang0601
Per review: existing providers should not be retroactively re-versioned or
handed a changed payload. Version 1 is now the implicit historical
on_pre_compress() contract (best-effort, raw message list) that every
pre-existing provider is already on; the fail-closed checkpoint contract
becomes version 2. MemoryManager routes the raw transcript to v1 providers
unchanged and hands the host-normalized evidence list only to v2+ checkpoint
providers, so the plugin surface contract for shipped providers is
byte-identical with the gate off.
Addresses the review on #93996:
- gateway: hygiene and manual /compress load the memory provider only when
compression.checkpoint_required is enabled (skip_memory=not required).
The historical fast path — no provider init, no best-effort hook — is
back for everyone who did not opt in, so default behavior is truly
unchanged.
- conversation_compression: assistant messages carrying both prose and
tool_calls keep their prose in the checkpoint evidence (the tool_calls
payload is stripped, the original message is not mutated); pure
tool-call wrappers without prose are still dropped.
- tests: legacy-database regression proving the _compressed_summary column
is added by the declarative _reconcile_columns() path on a plain reopen
(no version-gated migration needed — append_message works right after),
plus coverage for the prose-preserving filter.
- docs: providers must implement idempotent, content-keyed checkpoint
writes — a fail-closed block means the next attempt re-runs
on_pre_compress over largely the same transcript.
Refs #93986
Context compression is intentionally lossy. Deployments that archive
transcript evidence to an external durable store before compaction had no
way to guarantee the archive actually happened: MemoryManager.on_pre_compress
swallows provider failures by design, so a failed archive silently degraded
into data loss.
This adds an opt-in, provider-agnostic checkpoint contract:
- memory_provider: PRE_COMPRESS_CHECKPOINT_API_VERSION = 1; providers opt in
by advertising pre_compress_checkpoint_api_version. Version 0 keeps the
historical best-effort hook semantics.
- memory_manager: supports_pre_compress_checkpoint() capability probe;
on_pre_compress(require_checkpoint=True) propagates checkpoint-provider
failures and raises when no capable provider completed the checkpoint.
- conversation_compression: new compression.checkpoint_required config key
(default false, documented in cli-config.yaml.example). When enabled,
compaction fails closed with BLOCKED_MISSING_PREREQUISITE (the
uncompressed transcript is preserved) unless a checkpoint-capable provider
confirms the durable checkpoint. Providers receive normalized direct
user/assistant evidence: tool rows, system messages, tool-call wrappers,
and prior compaction summaries are filtered host-side into one stable
contract. codex_app_server compaction is rejected under the gate because
it exposes no truthful pre-compaction transcript boundary.
- hermes_state: persistent _compressed_summary column (declarative schema
migration via _reconcile_columns) so summary provenance survives process
restarts; only the resume model history carries the marker, keeping
get_messages_as_conversation on its existing contract.
- gateway: the lossy hygiene/auto-compact paths load the memory provider
(skip_memory=False) so a required checkpoint also guards those rewrites.
The gate arms only on an explicit boolean True (bare-MagicMock agents in
existing tests have truthy auto-attributes). Default behavior is unchanged:
checkpoint_required=false preserves best-effort semantics for all existing
providers. Contract tests, including a restart round-trip of the summary
marker, in tests/agent/test_pre_compress_checkpoint_contract.py.
Refs #93986
Review-pass follow-up on the load-time durability stamp:
- hermes_state.py: import the marker from agent.context_compressor instead
of a third synced literal (hermes_state already imports agent.* at module
level; only run_agent is circular). Old comment claimed otherwise.
- agent/turn_finalizer.py: replace the raw "_db_persisted" string at the
fill-empty-tail pop site with the shared constant (was outside the drift
guard).
- agent/conversation_compression.py: the no-op progress check now falls back
to a marker-insensitive comparison (_strip_marker_for_comparison). Loaded
rows are stamped at materialization time while compress() output is
marker-swept, so a semantically-identical no-op copy on a cold-resumed
session would previously compare unequal and take the progress branch.
Raw == still runs first so engine-returned list subclasses keep their
__eq__ semantics.
- test_marker_constant_in_sync extended to turn_finalizer + identity
assertions; new test_noop_progress_check_is_marker_insensitive
(mutation-checked: fails when the helper is neutered).
- Drop the 'aborted before its tail' no-op sentence: early aborts are
intercepted by the aborted/no-progress branches and never reach the
would-grow check, so the framing overstated its relevance (2c finding).
- Test now also asserts the durable model_config copy still holds the
armed runway after the refusal — locking in the memory==disk half of
the contract, not just the in-memory value.
compress()'s successful tail zeroes _proactive_prune_rearm_tokens in
memory — correct for a committed compaction, whose boundary already broke
the prompt-cache prefix. But compress_context's anti-growth guard can then
REFUSE the result and keep the original transcript, whose cached prefix is
intact. The refusal returned with the in-memory runway still at 0 while the
durable model_config copy kept the old value, so:
- the next eligible iteration's proactive prune fired without the regrowth
interval #79640 introduced — an immediate, unthrottled cache-breaking
rewrite (#91830's bug class), and
- memory and disk disagreed until a restart silently re-armed the throttle
from the stale durable row.
The refusal branch now restores the runway from the attempt snapshot — the
same targeted restore the rotation-failure rollback already performs.
Sibling non-commit branches audited: aborted (returns before the tail
zero), no-progress (tail zero only runs after a real boundary rewrite,
which no-progress by definition lacks), empty-transcript (built-in tail
never returns []), fence-denied (full snapshot restore already covers the
runway), in-place DB failure (in-memory transcript keeps the compacted
form, so the zeroed runway is consistent with it).
Fixes the reachable half of the structural asymmetry flagged in #91830.
Review follow-up on the salvaged #90353:
- Todo snapshot (+ coupled pruned-skill reload notice, 7a16840add) is now
reduced only as a LAST resort after reasoning/tool/summary shrink ops,
and the reload notice survives even then.
- Reuse existing helpers/constants instead of re-hardcoding:
_PRUNED_TOOL_PLACEHOLDER, _PRUNE_MIN_CHARS, _NEWEST_TURN_ONLY_BUDGET_KEYS,
and _prune_stale_reasoning_replay (codex sidecar shrink, #71058 boundary).
- Assistant-role messages without the summary metadata key are no longer
truncatable by the summary-cap heuristic.
- Caller passes budget so the estimator runs 3x, not 5x, per would-grow pass.
The anti-growth guard correctly refuses to persist a compressed
candidate larger than the original, but the rejection was never
recorded by the anti-thrashing breaker: _ineffective_compression_count
stayed at zero, the latch never tripped, and automatic compression
retried the SAME unchanged transcript on every turn - same summary
request, same refusal, same user-facing warning (#88568).
Add ContextCompressor.record_rejected_compaction(): one persisted
ineffective strike, without arming post-compaction real-usage
verification (nothing was committed) and without touching the
fallback-summary streak (no summary was accepted). The would-grow
abort path in conversation_compression calls it before returning the
original transcript. Two refusals latch the normal breaker, manual
/compress keeps bypassing it (force=True), and the existing recovery
window still allows one probe later.
Fixes#88568
The rotation path flushes its un-persisted transcript to the parent (#47202)
and only then calls publish_compression_child. The abort handler rolls back
the in-memory transcript and keeps agent.session_id on the parent - its own
comment says "keep the parent live and discard the stale compacted snapshot" -
but the rows the flush just wrote are not part of what it discards. Every
failed rotation therefore leaves the parent transcript longer than it found
it, whatever the failure was.
That is survivable for a one-off failure and pathological for a sticky one.
A parent row carrying ended_at fails the publish on every attempt and nothing
in this path clears it, so each auto-compaction appends another copy of the
current turn to the transcript it was supposed to shrink. Worse, the growth
then satisfies conversation_compression's own len(durable_parent) >
len(messages) check, so the next attempt adopts the inflated snapshot as if it
were genuine concurrent activity and the in-memory transcript doubles too.
Check that one precondition before writing. It is a plain read of the row the
publish is about to read anyway, and it raises the publish's own message, so
split_status=aborted, failure_class=session_split_failed and the rollback path
are all unchanged; a live parent reaches the flush exactly as before.
Deliberately not extended to the compression lease, which is re-acquirable - a
transient miss there would abort a rotation that would otherwise have
committed. old_session_id moves above the flush so a failure raised from here
takes the same in-memory rollback as any other pre-publish failure.
Scope: this fixes the amplification for every abort cause. It does not fix
what marks a live session as ended in the first place (#88197 Bug 1), which
needs a maintainer decision on end-reason taxonomy and is tracked on the
issue; an affected session still aborts every attempt, it just stops making
itself larger while it does.
Refs #88197
CI caught two rotation-path regressions from the unbounded clone: the #47202
pre-publish flush writes the rotator's OWN input transcript to the parent
(above the start-watermark), and the clone was duplicating it into the child
alongside the handoff. publish_compression_child gains watermark_ceiling —
the MAX(id) captured immediately BEFORE that flush — so only rows in
(watermark, ceiling] (genuinely foreign concurrent appends) clone across.
Ceiling capture failure falls back to no tail preservation (historical
behavior) rather than risking duplication. Ceiling-exclusion test added.
CI caught the sibling site the in-place fix missed: legacy (non-in-place)
compression rotates via publish_compression_child, where a mid-summary
append previously stranded in the closed parent. Same watermark + pure-SQL
column clone as archive_and_compact, with session_id rewritten to the child.
Lineage-guard test flipped to pin the appends-flow-freely contract; rotation
watermark tests added (tail follows the child; None = historical behavior).
Redesign of the #75316 class (supersedes the approach in PR #87307).
Root cause family: the compression lock fenced ORDINARY transcript appends
for the whole slow provider-summary call. Turns died as
session_persistence_failed whenever a message overlapped a compression
(#74568, #77386, #75083), stale dead-PID locks blocked writes for the full
TTL, and the busy-wait mitigation (#75264) was an order of magnitude shorter
than real summaries. Separately, the commit archived from a pre-call
snapshot, so rows appended mid-compression were swept into the archive.
Design: the commit transaction is already exclusive — no lock phases needed.
1. Appends never check compression_locks. The lock's only job is stopping
two compressions colliding; it keeps that job. The whole stale-lock /
busy-wait symptom family dies as a class.
2. Watermark captured in the DB at compression start
(get_active_message_watermark = MAX(id) of active rows) — not from
in-memory message dicts, which carry no row ids in production.
3. archive_and_compact(watermark=, lock_holder=): one transaction verifies
the holder still owns an unexpired lease (a reclaimed lease cannot
publish a stale compaction), archives the snapshot, inserts the compacted
set, and re-sequences the concurrent tail (id > watermark) via a
pure-SQL column clone — every column except id survives byte-exact
(api_content, platform_message_id, reasoning sidecars, token counts),
FTS triggers index the clones naturally, originals stay archived and
recoverable. watermark=None preserves the historical behavior.
Removed: the append-side compression fence in _check_transcript_write_guards
(with rationale note), making the _COMPRESSION_BUSY_WAIT_S retry lane
unreachable from append paths (kept for other callers).
Tests: 12 new (watermark contract, column-exact clone, commit fence incl.
lease-lost/expired/rollback failure injection, append-vs-commit race);
busy-retry suite flipped to pin the new contract; sabotage-verified (5 fail
with the watermark disabled, 12 pass restored); E2E through the real
compress_context seam with a mid-summary append landing and surviving.
Compaction re-injects the todo list verbatim (TODO_INJECTION_HEADER +
TodoStore.format_for_injection) while skill instructions are pruned down
to [SKILL_PRUNED: ...] markers — the imperative crosses the boundary
without the policy that governed it, and the agent keeps executing
preserved tasks with the guidance deleted (#84718's T6 pattern).
Close the retention asymmetry at the injection site: when the compressed
transcript carries [SKILL_PRUNED: ...] markers AND a todo snapshot is
being re-injected, append a bounded reload notice to the snapshot naming
each pruned skill with its exact skill_view() reload call, plus a
one-line instruction to re-check that preserved tasks are still
justified. Skill guidance recovery now travels in the SAME boundary
artifact as the imperative — same message, same stale-snapshot strip
lifecycle, so repeated compactions refresh rather than accumulate.
Properties:
- deterministic: derived only from the compressed transcript (same input,
same bytes) — no per-turn nondeterminism in the rebuilt prompt
- zero recurring cost when nothing was pruned (clean sessions unchanged)
- bounded: shares _MAX_PRUNED_SKILL_MARKERS with the summary re-injection
cap; the notice text never contains the canonical marker prefix, so it
can never feed the marker extractor at the next boundary
- rides after TODO_INJECTION_HEADER, so _strip_stale_todo_snapshot
removes snapshot + notice together and the synthetic-row classifier
(_is_synthetic_compression_user_turn) is unaffected
Tests: tests/agent/test_skill_todo_retention_parity.py — unit contract of
the notice builder (naming, dedup/order, cap, determinism, no marker
self-feed) and behavioral compaction runs through the real
_compress_context path (notice travels with the snapshot, absent when
nothing pruned, synthetic-row classification unbroken, strip lifecycle
across repeated boundaries). Sabotage-verified: disabling the append
flips the 3 behavioral tests red.
Part of #84718
The gateway rotation guard (#83339) only protects the rotate path, but
in-place compaction commits inside compress_context() via
archive_and_compact — before the gateway can inspect the result. Add the
anti-growth check at the commit site so both paths are covered: a
compression whose rough output exceeds its input is a strict no-op
(original transcript kept durable, session identity untouched).
Covers the observed failure where session hygiene persisted 426 -> 426
messages and ~379K -> ~688K tokens.
A turn writing against a session already closed by compression died with
session_persistence_failed and a misleading "this is often a full disk"
dialog, even though the store was healthy and a live continuation existed
(#82001). Depth-1 recovery (find_live_compression_child) could not resolve
lineages with >=2 compression hops (root -> mid -> tip), reproduced
independently on two- and three-hop chains.
- run_agent.py flush chokepoint: on CompressionSessionClosedError, resolve
tip = db.get_compression_tip(old_id) (canonical bounded transitive walk),
adopt only when tip != old_id AND the tip row is live, retry the flush
exactly once (adoption budget); otherwise fail closed.
- gateway/session.py append_to_transcript: replace the depth-1 live-child
lookup with the same tip + liveness contract, so gateway transcript
reroutes follow full chains.
- agent/conversation_compression.py _adopt_live_compression_child: turn-start
recovery preflight now resolves via get_compression_tip with the same
liveness check, closing the last depth-1 consumer in this family.
- classify_persistence_error: new "compression_closed" bucket; the turn-end
explanation names compression rotation and tells the client to refresh the
session id instead of blaming a full disk.
Tests: depth-1 adoption, multi-hop chain adoption (agent + gateway), fail
closed with no continuation / stale-closed (ws_orphan_reap) tip, exactly-once
adoption budget, and error-wording guards (compression-closed never mentions
disk; real disk failures keep disk guidance).
Closes#82001
Co-authored-by: Al3xand3r1987 <125030427+Al3xand3r1987@users.noreply.github.com>
Co-authored-by: yuzilongleif-collab <235949691+yuzilongleif-collab@users.noreply.github.com>
Ports Claude Code's /loop (and its /proactive alias) across every Hermes
surface. /loop [interval] <prompt> re-runs a prompt or slash command on a
recurring cadence inside the live session; omitting the interval enables
self-paced mode (starts at the floor, backs off exponentially while the
agent's replies stop changing, snaps back on change — local digest
comparison, zero extra LLM cost).
Stop conditions: agent-emitted LOOP_COMPLETE marker, --times N,
--until <condition> (judged by the existing goal_judge aux task,
fail-open), /loop stop, and a loops.max_ticks backstop budget.
Core: hermes_cli/loops.py (LoopState + LoopManager + shared
dispatch_loop_command), persisted per session in SessionDB state_meta
(loop:<sid>) so /resume picks it up; migrates across compression
boundaries like /goal. New SessionDB.list_meta_prefix() powers the
gateway's cross-session scan.
Surfaces:
- CLI: /loop handler + idle-fire and post-turn-complete hooks in
process_loop (mirrors the /goal hook shape; Ctrl+C pauses the loop)
- Gateway: /loop handler with route capture, mid-run control-verb guard,
post-turn tick completion, and a supervised loop_wakeup_watcher that
injects due wakeups into idle chats via the synthetic-message path
- TUI/dashboard/desktop: command.dispatch handler + per-session
notification-poller wakeup driver + post-turn completion in the turn
dispatcher; /loop added to the desktop slash palette
- /goal mixing: an active non-parked goal owns the idle boundary — loop
ticks defer until it finishes, pauses, or parks; real user input always
wins over both
Config: loops.{min_interval_seconds,max_ticks,self_paced_floor_seconds,
self_paced_ceiling_seconds}. Docs page + sidebar entry. 77 new tests.
Slack's 50-slash cap: /version moves to /hermes version to free the
native slot for /loop.
Continuous gateway sessions keep the Relay session scope open for days;
close-driven export means the session root span and out-of-turn marks
never export until /new or idle-end, and a crash loses the open segment
entirely.
Opt-in segmentation (both defaults OFF => scope lifecycle byte-identical
to today):
gateway.telemetry.session_segments.on_compaction: false
gateway.telemetry.session_segments.max_turns: 0
Rotation closes the current session scope and pushes the next segment
(same session_id attribute, plus hermes.session.segment=N and
segment_reason=compaction|max_turns) ONLY at a turn boundary in
begin_turn — never mid-turn (scope stack is LIFO). Compaction completion
just flags rotate_pending (observer semantics, nothing on the compaction
critical path); legacy rotating compaction closes the orphaned old
session scope so its segment exports. Both native calls ride the
existing bounded scope-op executor: a wedged rotation costs one segment
span, never the agent. Segment bookkeeping advances even on native
failure so a degraded rotation cannot retry every turn.
A session title had no notion of who set it, so two bugs followed. An
auto-generated title could clobber a name the user typed, and every
compression rotation renumbered the conversation it forked - one piece of
work reaching 'Smallville Map Architecture Plan #10' in the sidebar.
Titles now carry a source (derived < llm < user) enforced by one
compare-and-swap, so an automatic write can only ever replace a title of
strictly lower authority. Compression carries the name across unchanged.
Legacy NULL rows rank as user, so auto-titling only fills genuinely
empty titles on existing data.
Adversarial review of the salvaged recovery found a reachable fail-open:
compression continuations inherit the rotated agent's model_config
verbatim (publish_compression_child callers pass
agent._session_init_model_config), so a delegate subagent's continuation
carries _delegate_from=<the delegate's own parent>. The marker-PRESENCE
filters in reopen_orphaned_compression_session and
find_live_compression_child misclassified such a REAL continuation as a
delegate child:
- reopen: parent 'orphaned' -> reopened while a live continuation exists
-> two live heads in one lineage (verified with a live repro)
- find_live: adoption misses the continuation (fail-closed, masked the
fork pre-PR; the PR made it active)
Fix: markers only disqualify a child when they point at the queried
parent (shared _NON_CONTINUATION_CHILD_FILTER_SQL fragment, also
resolving the duplicated-SQL drift risk flagged by the reuse reviewer).
Both directions regression-tested: reopen fails closed on an
inherited-marker continuation; find_live adopts it.
Also from review: reopen-failure log raised debug->warning (the failure
hard-fails the turn moments later), commit-semantics hardening comment
on the lease DELETE path, blank-line nit.
The three read-only projection walks (get_compression_tip,
list_sessions_rich chain, resume walk) share the marker-presence shape
but fail closed (skip a continuation -> resume shows the parent), and
the fixed adoption path self-heals that case at turn start; left as-is.
/heartbeat every <interval> <prompt> gives the current session one
recurring instruction. When the session is idle and the interval has
elapsed, the prompt is injected as a plain user turn — same
conversation, same context, prompt cache and role alternation
untouched.
- CLI: idle-poll watchdog thread (wake-word watchdog pattern) feeding
_pending_input; gateway: single gateway-wide async poller injecting
through the adapter FIFO. Busy sessions coalesce their tick to the
next idle poll.
- Missed ticks coalesce (anchor resets on fire) — a busy hour yields
ONE heartbeat turn, never a backlog. Real user messages always win.
- 60s interval floor; injected prompt carries a don't-invent-work
guard so idle heartbeats don't generate busywork.
- State persists in SessionDB.state_meta (heartbeat:<session_id>),
survives /resume, migrates across compression session rotations
alongside /goal state.
- Session-scoped and in-process by design — durable cross-process
schedules remain the cron subsystem's job (docs draw the boundary).
- Slack stays under the 50-slash cap via /hermes heartbeat; ghost-text
suggester now prefers the shortest prefix match so /he still
suggests /help.
Adapted from the session-heartbeat concept in Prime Intellect's
Prime-Agent (/heartbeat).
Three review follow-ups on the salvaged #79286 commit:
- update_model() zeroed the in-memory prune runway but left the durable
model_config copy stale, breaking the method's own durable-sync
discipline (the strike reset three lines above keeps its durable copy
in sync). A restart after a model switch resurrected a runway
computed under the old model's trigger sizes. New
_clear_durable_proactive_prune_rearm() removes the persisted key via
patch_session_model_config() without touching the transcript.
- The archive_and_compact capability check ran AFTER the expensive
3-pass prune scan, so a duck-typed session store lacking the method
paid the full scan on every eligible iteration forever with pruning
permanently no-opping. Hoist it above the scan (all in-tree stores
pass a real SessionDB; this only affects third-party stores).
- _load_proactive_prune_rearm_tokens now uses the shared
get_session_model_config_value() accessor instead of inlining a 5th
copy of the model_config JSON parse, matching its sibling loaders'
typed-accessor pattern.
Also documents why the rotation-publish-failure branch restores only
the runway field rather than the full attempt snapshot.
Tests: model-switch durable clear, patch_session_model_config
merge/delete/no-op, and a guard proving incapable stores skip the scan.
The fail-fast admission path (bounded compress pool, F6) only logged a
WARNING; in the compression-attempt telemetry stream a wedged pool
looked like compression simply stopped being attempted. Emit the
existing attempt telemetry with failure_class='pool_saturated'
(commit_status=aborted, split_status=aborted) on refusal, following
_emit_compression_attempt_telemetry's existing call shape. Regression
extends the F6 saturation test (sabotage-verified).
The fence-cancel poll loops (sync host wait in conversation_compression,
async hygiene wait in gateway/run) spun at 1kHz while the worker held
the fence through its lock-setup window — which rides SessionDB write
patience and can last seconds. 25ms keeps sub-tick cancel latency
without the spin.
The compression heartbeat's terminal 'context compression completed'
stamp force-persists against the PARENT session id (agent.session_id at
stamp time). After the out-of-place rotation the parent is archived but
kept advertising a fresh last_activity_at + terminal label forever.
Clear the parent row's activity labels best-effort after a committed
rotation (keeps last_activity_at so idle clocks stay continuous; the
child carries live labels). Regression asserts the archived parent's
labels are cleared while the child's lineage is intact
(sabotage-verified).
revoke_commit_admission() used to invoke the holder-qualified lease
release unconditionally — including while an admitted commit was still
mutating SessionDB — letting a second compressor acquire the durable
lock mid-commit and interleave with the first commit's writes.
The admission_revoked flag store stays lock-free, but the lease-release
decision now coordinates with the fence lock:
- revoke acquires the fence lock non-blocking; on success no commit can
be in flight (an admitted commit retains the lock until finish_commit)
and the release runs immediately, still under the lock so a racing
begin_commit cannot slip between the check and the release.
- on failure the release is deferred: finish_commit() re-checks
_admission_revoked and performs it AFTER the commit completes (prompt
even if the worker thread is later parked), and the begin_commit
refusal path does the same for a revoke that lost the race to a
transient lock-setup/cancel boundary. All paths are idempotent with
the worker's own outer cleanup (DB release is holder-qualified).
Invariant encoded + tested: no second compressor can acquire the durable
lock while an admitted commit is still mutating; after a post-revoke
commit finishes the lease is released promptly. Both regressions
(revoke-during-commit deferral, revoke-before-commit immediate release +
refused begin_commit) are sabotage-verified.
Rebase onto origin/main brought in 'let explicit interrupts cancel safely',
which predates this branch's pooled progress-timeout + F1-F6 fence rework.
Reconcile the two:
- begin_commit(cancel_event) re-checks the hard-cancel Event under the
fence lock again (lost in the mechanical rebase).
- compress_context: restore aux_interrupt_protection around the summary
call, the post-return frozen-cause AuxiliaryExplicitCancellation check,
and the full rollback/telemetry handler for explicit interrupts.
- run_agent._compress_context: recreate the per-attempt fence registration
(_active_compression_commit_fence) that hard_interrupt() uses to
serialize cancel admission, and thread that exact fence through both
the direct and pooled paths (run_compress_context_with_progress_timeout
now accepts an external fence).
- test: the pooled worker isolates the live transcript (F3), so the
hard-interrupt rollback regression mutates the engine's input snapshot
rather than reaching around it to the caller's list.
Both progress-aware waits (sync compress wrapper and gateway session
hygiene) slept a FULL idle interval and only then compared progress, so
progress early in an interval let silence approach 2x the configured
idle timeout before the waiter noticed. Compute each wait slice as
idle_timeout - elapsed_since_last_progress instead.
Regression: a worker that reports progress early and then goes silent is
timed out in ~1x the idle budget, not ~2x.
PR #76354 review, 'idle timeout can allow nearly twice that silence'.
The process-wide 4-worker pool retained the stdlib executor's unbounded
queue: four hung summaries wedged every slot, a fifth compression queued
silently, waited out its whole budget without starting, and remained
eligible to run later as an expensive stale job whose fence was already
cancelled (the first fence check used to sit AFTER the summary call).
- Bounded admission: submission fails fast (messages returned unchanged,
loud warning) when all pool slots are occupied; slots are freed by a
future done-callback. Recovery contract documented at the constant: new
work fails fast while wedged, wedged workers are fence-cancelled and
restore service when they return; a worker that never returns costs its
slot — bounded, observable degradation instead of unbounded queueing.
- Not-yet-started futures are cancel()ed on timeout.
- The cancelled fence is checked BEFORE any expensive summary work, both
in the pooled wrapper (stale queued job) and inside compress_context
(pre-summary gate), so a stale job never burns an LLM call or acquires
session state.
Saturation regression: 4 event-blocked summaries wedge the pool, a 5th
submission fails fast (asserted while the four are provably still
blocked), the refused job never runs after worker recovery, and a fresh
submission after recovery succeeds.
PR #76354 review, blocking finding 6 / merge gate 7.
A host timeout previously left the timed-out worker holding the durable
per-session compression lock AND refreshing its lease indefinitely, so a
truly hung summary blocked every later compression attempt; and a LATE
successful summary could clear the failure cooldown the host had just
recorded.
Transplant the lease-cancellation invariants from PR #71569
(@ciabata-git): the worker publishes an idempotent, holder-scoped release
hook on the fence once it owns the durable lock (begin_lock_setup /
register_cancelled_lock_release close the acquire→publish race), the
refresher start is serialized against the release path, and the host
invokes the hook on idle timeout, hygiene timeout, and every unwind
(revoke_commit_admission now also releases). ABA safety: the SessionDB
release is holder-qualified (DELETE ... WHERE holder = ?), so a stale
release can never free a replacement holder's lease.
State ordering: the compressor consults a fence-cancellation check BEFORE
clearing the failure cooldown, so a late worker cannot undo the host's
timeout cooldown; the check is installed only for the fenced call and
removed in a finally.
Regression implements the reviewer's exact 5-step scenario: summary
blocked indefinitely → host timeout → a NEW compressor acquires the
durable lock while the old summary is STILL blocked → old worker released
→ it cannot clear cooldown, release the new holder's lease, or publish
stale state.
PR #76354 review, blocking finding 4 / merge gates 4 + 5.
Co-authored-by: ciabata-git <ciabata-git@users.noreply.github.com>
The pooled worker closure captured the caller's live `messages` list and
compress_context explicitly supports plugin/legacy context engines that
mutate that list in place — so after a host timeout, a late engine could
rewrite the live conversation (roles, ordering, persisted content)
concurrently with the resumed turn.
The worker now deep-snapshots the transcript on the worker thread before
any engine code runs; the caller's list object is never handed to pooled
code. Results reach caller-visible state only through the returned value
of an ADMITTED commit (the host discards results on timeout/cancel), and
durable SessionDB mutation was already gated behind the commit fence.
No-op passes map the unchanged snapshot back to the caller's original
list so identity-based no-op detection and flush dedup keep working.
Document the thread-safety contract for context-engine and
memory-provider extension points (they now run on pooled threads) in the
module docstring and the context-engine plugin guide.
Regression: an in-place-mutating engine plus host timeout proves the
caller's live transcript is byte-identical WHILE the worker is still
blocked inside the engine (released only after the assertions).
PR #76354 review, blocking finding 3 / merge gate 3.
The sync compress wrapper only handled concurrent.futures.TimeoutError;
KeyboardInterrupt, task cancellation, or any other exception while
waiting let the host unwind while the detached worker kept full commit
authority — it could later enter the commit fence and mutate durable
state (in-place archival, session rotation) behind the caller's back.
Wrap the whole host wait in try/finally: any exit that did not settle the
worker (returned result or won the fence race) revokes future commit
admission via a new lock-free CompressionCommitFence.revoke_commit_admission()
(begin_commit re-checks the flag under the fence lock, so no admitted
commit is ever abandoned mid-mutation). The gateway hygiene wait gets the
same guarantee via a BaseException handler that revokes admission and
defers helper cleanup until the worker actually returns.
Reconciliation with PR #74449 (suparious): that PR routes EXPLICIT host
interrupts into auxiliary-call cancellation; this change is the
complementary host-side guarantee that no unwind — explicit or not —
leaves an unfenced worker. The two compose (fence revocation here is the
outer safety net; #74449's aux cancellation remains the fast path) rather
than duplicating one another.
Regressions: KeyboardInterrupt and generic-exception unwinds assert the
fence is revoked WHILE the worker is still blocked pre-commit, then
release the worker and prove begin_commit() is refused.
PR #76354 review, blocking finding 2 / merge gate 2.
begin_commit() retains the fence lock until finish_commit(), so a hung
SessionDB commit made try_cancel_before_commit() return None forever and
the host spun ahead of the overrun-warning loop — a genuinely hung commit
stayed unbounded AND silent. Add a lock-free phase marker (threading.Event
set inside begin_commit while the lock is held, readable without it) and
break the host spin on commit_in_flight so the bounded overrun loop — and
its WARNING + on_commit_overrun surfacing — is reachable WHILE the commit
is still blocked. Applies to both the sync compress wrapper and the
gateway session-hygiene wait.
Regression asserts the warning and callback fire while the event-gated
fake commit is still blocked; the test releases the worker only after
those assertions (addresses helix4u's released-before-asserting callout).
PR #76354 review, blocking finding 1 / merge gate 1.
The post-begin_commit() waiter previously called unbounded future.result(),
so the advertised compression.context_total_ceiling_seconds was silently
unenforced for commit-phase hangs. The commit still must complete (abandoning
an in-flight SessionDB mutation would diverge live messages from durable
state), but the wait is now bounded in increments against the remaining
ceiling: on ceiling breach the overrun is logged (WARNING escalating to
ERROR), surfaced once through the user-visible warning channel via the new
on_commit_overrun callback (wired to _emit_warning in run_agent.py), and the
host keeps waiting in bounded slices until the commit finishes.
Documented guarantee (config comment + docs, en/zh): summary phase bounded
by the ceiling; commit phase logged + surfaced if it exceeds it — never
silently hung, never abandoned mid-commit.
Test updated to assert the surfacing fires (previously accepted a silent
over-ceiling wait); adds coverage that a raising overrun callback cannot
break the commit wait.
kshitijk4poor