Follow-up to the END-MARKER reorder: moving the summary prefix after the
[PRIOR CONTEXT] wrapper meant _is_context_summary_content (prefix-at-start)
no longer recognized a merged-tail summary. That silently broke three
consumers — the last-real-user anchor (would pick the merged summary as a
real user turn, causing active-task loss), the carry-forward summary find,
and the auto-focus skip. _strip_summary_prefix would also carry the wrapper
+ stale tail content forward as the next summary body.
Extract the two delimiter strings into _MERGED_PRIOR_CONTEXT_HEADER /
_MERGED_SUMMARY_DELIMITER constants (writer + detector stay in sync), teach
_is_context_summary_content and _strip_summary_prefix to look past the
delimiter, and add a regression test. Standalone summaries unchanged.
When the compression summary is merged into the first tail message
(the alternation corner case where a standalone summary role would
collide with both head and tail), the old format was
SUMMARY + END_MARKER + OLD_TAIL_CONTENT — so the preserved tail content
appeared AFTER the end marker and the model could read it as a fresh
message to respond to.
Reorder so the END MARKER is always last: old tail content is wrapped in
[PRIOR CONTEXT ...][END OF PRIOR CONTEXT — COMPACTION SUMMARY BELOW]
delimiters, then the summary, then the END MARKER. _append_text_to_content
handles both string and multimodal-list content.
Salvaged from #56372 by @Gromykoss. Only the END-MARKER reorder half is
carried over. The PR's second change (a post-compaction pass that strips
user-role messages before the first summary marker on compression_count>=2)
was dropped: on 2nd+ compactions the protected head decays to system-only
(_effective_protect_first_n -> 0, #11996) so the targeted 'ghost head user'
does not occur, and where the strip does fire it deletes legitimate recent
tail user turns (data loss) and can leave consecutive assistant messages
(role-alternation violation).
The original cross-session contamination fix (#38788) only cleared
_previous_summary in on_session_end(), but on_session_reset() clears
14+ per-session variables. When a session ends (cron exit, gateway
expiry, session-id rotation) and the compressor instance is reused,
the surviving stale state causes:
- _ineffective_compression_count surviving → next session skips
compression prematurely (anti-thrashing guard misfires)
- _summary_failure_cooldown_until surviving → next session blocks
summary generation for an unrelated transient error
- _last_compress_aborted surviving → callers think compression is
still aborted
- _last_aux_model_failure_* surviving → stale error warnings shown
- _last_summary_dropped_count / _last_summary_fallback_used
surviving → misleading user warnings
- _context_probed / _context_probe_persistable surviving → stale
context-probe state
Also fix on_session_reset() which was missing _last_compress_aborted
clearing — a /new or /reset would inherit the aborted flag from the
prior conversation.
Add 6 targeted tests covering the leak vectors and a parity test
ensuring on_session_end and on_session_reset always clear the same
surface.
After the first compaction protect_first_n decays, so on a later compaction
the only protected head message can be the system prompt. Adapters like
Anthropic and Bedrock send the system prompt as a separate parameter, so the
summary becomes the first message in messages[] — and Anthropic rejects any
request whose first message is not role=user (HTTP 400). Pin the summary to
role=user when the head is system-only, and stop the collision-flip logic from
reverting it back to assistant.
Salvaged from #52167.
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
compress() eagerly reset _last_summary_auth_failure and
_last_summary_network_failure at the top of every call. On a second
compress() during the failure cooldown, _generate_summary() returns None from
the cooldown early-return WITHOUT re-asserting those flags, so the abort guard
saw False and fell through to the destructive static-fallback that drops the
middle window — the data-loss #29559/#25585 describe. Stop resetting them
eagerly; a successful summary already clears both, so letting them persist
across calls is safe and keeps the cooldown abort protection intact.
Salvaged from #52056.
Co-authored-by: srojk34 <286497132+srojk34@users.noreply.github.com>
_sanitize_tool_pairs inserted stub role="tool" results for orphaned
tool_calls. The pre-API repair_message_sequence() tracks known call IDs by
tc.get("id") while this sanitizer keys on call_id||id; when they disagree
(Codex Responses API: id != call_id) the stubs are silently dropped by the
repair pass, re-exposing the original orphans. Strip the orphaned tool_calls
at the source instead (preserving any text content, adding a placeholder for
an otherwise-empty assistant turn) to avoid the mismatch class entirely.
Salvaged from #51225.
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
A context-compaction handoff banner is inserted with role="user" when the
protected head ends in an assistant/tool message. On a resumed or
multi-compaction session, _find_last_user_message_idx would return that
banner as the latest user turn, so _ensure_last_user_message_in_tail anchored
the tail to the summary and rolled the genuine last user message into the
next compaction — the exact active-task loss the anchor exists to prevent
(#10896/#22523).
Reuse the existing _is_context_summary_content helper to skip summary banners
when locating the last real user message.
Salvaged from #36626 by Frank Song (issue #36624). The PR's other two changes
(demoting completed tool results inside the protected tail; a preflight
compression_exhausted result) are superseded on current main by the min_tail
floor (#39170), the no-op compression counting (#40803), and the existing
413/disabled terminal-error paths.
When the last user message sits exactly at head_end (the first compressible
index), _ensure_last_user_message_in_tail's final max(last_user_idx,
head_end + 1) clamp returns head_end + 1, pushing the user into the compressed
region without its assistant reply. The summariser then records it as a
pending ask, and the next session re-executes the already-completed task
(lights off twice, file deleted twice, message re-sent).
Fix: apply Causal Coupling — a compaction boundary must never split a
(user -> assistant [-> tool results]) turn-pair. Add _find_turn_pair_end and,
when the clamp would orphan the user, push the cut forward to pair_end so the
completed pair is summarised together and marked done.
8 new tests in TestTurnPairPreservation; 133 compressor tests pass.
When the summary LLM hits a 429/transient failure, _generate_summary() sets
a cooldown and returns None; compress() inserts a static fallback marker and
returns. Tokens stay above threshold, so should_compress() kept returning
True and every subsequent agent turn re-fired _compress_context() — the CLI
appeared frozen until the cooldown expired.
Add a cooldown guard to should_compress(): return False while
_summary_failure_cooldown_until is in the future. Reuses the existing float;
no new state. Manual /compress (force=True) still clears the cooldown first.
Fixes#11529
Follow-up hardening on the salvaged #54465 backoff persistence work.
The lease refresher's loop treated ANY falsy refresh as a permanent stop
(`if not refreshed: break`), conflating two distinct cases:
- genuine lost-ownership (rowcount 0) — correct to stop, and
- a one-off transient DB error (write contention that escapes
_execute_write's retry budget) — which returned False identically.
A single transient blip therefore killed the lease for the rest of a
multi-minute compression call, silently reintroducing the exact 300s-TTL <
~361s-call expiry wedge the PR set out to fix.
Changes:
- _CompressionLockLeaseRefresher._run now tolerates a bounded run of
consecutive failures (_MAX_CONSECUTIVE_REFRESH_FAILURES = 3) before giving
up the lease; a recovered tick resets the counter. Worst-case extra hold is
cap * refresh_interval, still bounded by the acquirer's TTL.
- Replace the two remaining silent `except Exception: pass` arms in the
compression-failure-cooldown persist/clear helpers with debug logging, for
parity with their sqlite3.Error sibling arms (a non-sqlite bug was invisible).
- Document the join(timeout=1.0) quiesce bound in stop().
- Add 3 regression tests: single-blip tolerance, persistent-failure stop at the
cap, and refresh-raising tolerance.
Add compression.minimum_context_floor config key that allows users
to lower the compression threshold floor below the hardcoded 64K
default, preventing infinite tool-call loops on models whose
structured output degrades well before 64K tokens.
- agent/model_metadata.py: add get_configurable_minimum_context()
helper with 16K hard safety limit
- agent/context_compressor.py: accept minimum_context_floor param,
thread it through _compute_threshold_tokens
- agent/conversation_compression.py: use compressor's floor for
aux model context validation
- agent/agent_init.py: read compression.minimum_context_floor from
config and pass to ContextCompressor
- gateway/run.py: cache-busting includes new key
Salvaged from #31686 by @Tranquil-Flow onto current main.
Resolves conflicts with in-place compaction (#38763) and max_tokens
threshold computation (#43547) that landed after the original PR.
Closes#31600
When context compaction's summary generation fails, the compressor's default
path (abort_on_summary_failure=False) drops the middle window and inserts a
static 'summary unavailable' marker — destroying the compacted turns. #29559
reported the field impact: a Connection error at the compaction moment dropped
124->15 messages (110 lost) for a long browser-automation task; #25585 is the
same failure mode (failed summary commits a destructive compaction anyway).
compress() already has an EXCEPTION to the historical drop default: auth
failures (401/403) ALWAYS abort and preserve the session, because rotating into
a placeholder-summary child on a broken credential strands the user. A transient
network/connection error is the same situation in reverse: it WILL recover, and
retrying then is strictly better than discarding context for a momentary blip.
Extend the always-abort carve-out to terminal connection/network failures:
- new _last_summary_network_failure flag, set in _generate_summary's terminal
failure branch when _is_connection_error(e) (reached only after any main-model
fallback is exhausted), reset alongside the auth flag;
- compress() aborts when it's set (returns messages unchanged,
_last_compress_aborted=True), independent of abort_on_summary_failure;
- a network-specific operator warning (distinct from the auth + config-flag
messages).
Scoped to connection errors only: a generic 500/400 still takes the historical
fallback-drop path (test_non_auth_failure_still_uses_fallback_path stays green).
Tests: network-failure detection + abort-despite-flag-false, both mutation-checked
(removing the flag-set fails detection; removing the carve-out fails the abort).
The compaction trigger compared estimated input against context_length *
threshold, but the provider reserves max_tokens of OUTPUT out of the same
window. With a large max_tokens (e.g. 65536 on a custom provider) the usable
input budget is materially smaller than the raw window, so sessions hit a
provider 400 before compaction ever fired.
_compute_threshold_tokens now subtracts the output reservation
(context_length - max_tokens) before applying the percentage and the
small-window 85% guard. max_tokens is stored on the compressor (threaded from
agent.max_tokens at construction) and reused across update_model() switches;
None = provider default = no reservation (full-window behavior, unchanged).
Reimplemented on the current _compute_threshold_tokens surface (the inline
threshold calc the original PR targeted was since refactored for the
small-window #14690 fix); composes with that 85% guard on the effective budget.
Credit: @kyssta-exe (#43651) — original design for the output-token
reservation in the compaction threshold.
Closes#43547.
After a compaction, the post-compression path parks last_prompt_tokens=-1 and
sets awaiting_real_usage_after_compression=True, but last_real_prompt_tokens
still holds the stale pre-compression value (above threshold). should_defer_
preflight_to_real_usage() hit the 'last_real_prompt_tokens >= threshold => False'
short-circuit and let preflight fire a SECOND compaction before the provider
reported real post-compaction usage. Add an early-return on the awaiting flag so
deferral holds for exactly one turn; update_from_response() clears it.
The flag-setting half (#36718) already landed on main via the in-place
compaction path (conversation_compression.py); this adds the missing
should_defer guard that consumes it.
Credit:
- @ashishpatel26 (#38133) — diagnosis + the should_defer early-return design
- @Tranquil-Flow (#36769) — same #36718 fix, identical guard placement
Closes#36718.
The tail-protection budget walks estimated an assistant message's tokens from content + function.arguments only, dropping each tool_call's id, type and function.name (plus JSON structure). Assistant turns that fan out into parallel tool calls were undercounted by 2-15x (a 4-tool-call turn measures ~73 vs ~1,090 real tokens), so the protected tail overshot tail_token_budget and compression ran far below its intended ratio — context kept growing.
Consolidate the three duplicated budget walks (_prune_old_tool_results and the two passes in _find_tail_cut_by_tokens) into a single _estimate_msg_budget_tokens() helper that counts the full tool_call envelope via len(str(tc)), consistent with how _estimate_message_chars estimates message size elsewhere.
Tested on Windows: new tests/agent/test_compressor_tool_call_budget.py plus the existing compression suite (test_context_compressor, compressor_image_tokens, cross_session_guard, infinite_compaction_loop) — 209 passed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
When an OpenAI-compatible proxy (e.g. cmkey.cn, one-api Anthropic channels)
returns a well-formed HTTP 200 whose summary content is null or empty/
whitespace-only, _generate_summary coerced it to "" and stored a prefix-only
summary — silently replacing the compacted turns with nothing. The model then
lost all in-progress context after compression (#11978, #11914).
_validate_llm_response already guards None / empty-choices, so those never
reach the compressor; the gap was a well-formed response with empty *content*.
Now treat empty content as a summary failure: raise so it routes through the
existing main-model fallback then transient cooldown, dropping the turns
without a summary rather than wiping context with an empty one.
Also narrow the bare 'except RuntimeError' so only genuine 'No LLM provider
configured' errors take the 600s no-provider cooldown; empty/invalid-response
RuntimeErrors from a configured provider now correctly get the main-model
fallback instead of being misrouted into the long no-provider cooldown.
Reported by @Hung2124; area identified by @annguyenNous in #39590.
The compaction threshold is max(context_length * threshold_percent,
MINIMUM_CONTEXT_LENGTH=64000). The floor prevents premature compression on
large models, but degenerates at small windows: a model at exactly 64000
ctx gets max(32000, 64000) = 64000 — a threshold equal to the ENTIRE
window. should_compress() can then never fire, because the provider
rejects the request before usage reaches 100%. Auto-compression silently
never triggers for any model whose context_length <= MINIMUM /
threshold_percent (e.g. 64K-per-slot local models).
Centralize the calc in _compute_threshold_tokens(). When the floor would
meet or exceed the context window, trigger at 85% of the window
(_MIN_CTX_TRIGGER_RATIO) — high enough that a minimum-context model uses
most of its budget before compacting (compacting at the 50% percentage
would waste half the small window), but below 100% so compaction actually
fires before the provider rejects the request. This mirrors the existing
gpt-5.5/Codex 85% autoraise rationale. Large-context behavior (floor at
64000) is unchanged; both call sites (__init__ and update_model) use the
shared helper.
Co-authored-by: soynchux <soynchuux@gmail.com>
Co-authored-by: LeonSGP43 <154585401+LeonSGP43@users.noreply.github.com>
Co-authored-by: Tranquil-Flow <tranquil_flow@protonmail.com>
ContextCompressor.update_model() recomputed context_length/threshold/budgets
but kept the cross-call calibration state (last_real_prompt_tokens,
last_rough_tokens_when_real_prompt_fit, last_compression_rough_tokens,
awaiting_real_usage_after_compression, _ineffective_compression_count) from the
PREVIOUS model.
Those fields encode 'the provider proved this prompt fit' / 'preflight can be
deferred' decisions valid only for the model that produced them. Carried across
a switch to a smaller-context model, should_defer_preflight_to_real_usage() used
the old model's 'it fit' history to SKIP a preflight compression the new model
actually needed — sending an oversized prompt the provider rejects (#23767).
update_model() now clears that state; the new model's first response repopulates
it via update_from_response(). Verified E2E: after a 200K->65,536 switch, defer
no longer suppresses and should_compress fires on an over-threshold estimate.
protect_first_n keeps the first N non-system messages verbatim through
compaction so the original task framing survives. But it was applied on
EVERY compression pass: the same early user turns were re-copied into each
child session and never summarized away, so across a long, repeatedly-
compressed session those old messages became immortal and grew the
protected head unboundedly (#11996, P1).
Decay it: protect_first_n applies on the FIRST compaction only. Once the
session has been compressed at least once (compression_count >= 1, or a
handoff summary already exists), the early turns are captured in the
summary, so _effective_protect_first_n() returns 0 and only the system
prompt stays protected. The decay is read at compress_start computation
time, before compression_count/_previous_summary are mutated at the end of
compress(), so the first pass still protects correctly.
Co-authored-by: truenorth-lj <liliangjya@gmail.com>
Co-authored-by: davidvv <david.vv@icloud.com>
When LLM summarization fails, the deterministic fallback summary rendered
the latest user ask (active_task = "User asked: '<ask>'") verbatim under
THREE headings — Historical Task Snapshot, Historical In-Progress State,
and Historical Pending User Asks. Re-presenting an already-handled ask as
unresolved in-progress/pending work made the model re-answer it AND treat
the resurrected ask as the active turn, burying the genuinely-new
post-compaction user message (#49307: answer repetition + new-instruction
loss, P1).
Keep the latest ask once, under Task Snapshot, as historical context only.
The In-Progress and Pending-Asks sections now say 'Unknown / None
recoverable from deterministic fallback' (consistent with the Active
State / Key Decisions / Resolved Questions sections) and explicitly note
the ask is historical, not outstanding. The raw turn text still appears in
the verbatim 'Last Dropped Turns' transcript — that's the dropped-turn
record, not a re-labeled instruction.
Note: the separate role=assistant standalone-summary regurgitation
(#33256) is left as-is — that role choice is constrained by strict message
alternation (user collides with a user-ending head) and is already
mitigated by the summary end-marker; forcing the role would risk the
alternation invariant.
Co-authored-by: r266-tech <r2668940489@gmail.com>
Co-authored-by: kyssta-exe <kyssta-exe@users.noreply.github.com>
Context compression is atomic, but a gateway interrupt (an incoming user
message while the agent is busy) could abort the in-flight summary call.
The Codex Responses aux stream polls the thread interrupt flag and raised
InterruptedError unconditionally — so compression fell back to a degraded
static 'summary unavailable' marker, losing the real handoff (#23975).
Add a thread-local interrupt-protection flag (aux_interrupt_protection
context manager) in auxiliary_client; the Codex stream's cancellation
check honors it. The compressor wraps its summary call_llm in the context
manager. Timeouts still fire (a hung call must die) and all other aux
tasks (vision, web_extract, title_generation, …) stay interruptible.
Re-entrant, so the main-model retry recursion is safe.
Co-authored-by: konsisumer <der@konsi.org>
When the auxiliary summary call fails with an authentication/permission
error (HTTP 401/403), context compression now ABORTS and preserves the
session unchanged instead of rotating into a child session with a
placeholder summary.
Before: a 401 (invalid/blocked key, or a token pointed at the wrong
inference host) fell through every transient-error check to 'return
None', and because compression.abort_on_summary_failure defaults False,
compress() took the static-fallback path and rotated the session anyway
(messages N->N). The user landed on a fresh-but-broken session that kept
failing the same way — paying for a full-context API call each turn with
no useful compression.
After: _generate_summary classifies 401/403 as a non-recoverable auth
failure (_last_summary_auth_failure) and compress() aborts on it
regardless of abort_on_summary_failure. A distinct auxiliary summary_model
that 401s still retries once on the main model first (its dedicated creds
may be the only broken thing); the abort only sticks when the main model
itself auth-fails or the fallback also auth-fails. The existing
_last_compress_aborted handling in conversation_compression.py already
skips rotation and emits a warning, so no session rotation occurs.
Tests: TestAuthFailureAborts — 401/403 flagging, compress() aborts despite
flag=False, non-auth failures keep the historical fallback path, and
aux-model auth failure recovers on main without aborting.
Summary messages (standalone insertion and merge-into-tail) now carry a
metadata flag so frontends (CLI, Desktop, gateway, TUI) can distinguish
them from real assistant/user messages without content-prefix heuristics.
Re-applied from PR #38434 onto current main (conflicted with the
_SUMMARY_END_MARKER hoist). Key renamed from the PR's
'is_compressed_summary' to '_compressed_summary': the wire sanitizers
strip underscore-prefixed message keys, so the flag stays in-process and
can never reach strict gateways (Fireworks/Mistral/Kimi reject unknown
keys with 'Extra inputs are not permitted').
Two-pronged fix for the WebUI "context compaction block in place of
last assistant response" regression.
Agent layer (the real fix). ``_find_tail_cut_by_tokens`` already had
``_ensure_last_user_message_in_tail`` to keep the most recent user
request out of the compressed middle (#10896), but no symmetric
anchor for the assistant side. When the conversation has an
oversized recent tool result or a long stretch of tool-call/result
pairs *after* the assistant's last visible reply, the token-budget
walk can stop with the previously-visible reply on the wrong side
of ``cut_idx``. The summariser then rolls it into the single
``[CONTEXT COMPACTION — REFERENCE ONLY]`` block persisted as
``role="user"`` or ``role="assistant"``, and from the operator's
perspective the WebUI session viewer
(``web/src/pages/SessionsPage.tsx``) and the TUI chat panel both
suddenly show the opaque "Context compaction" block in the slot
where they were just reading the actual answer:
User: "i cant see the output of the last message you sent,
i did see it previously, however now see 'context
compaction'"
Added ``_ensure_last_assistant_message_in_tail`` mirror of the
user-side anchor. It looks for the most recent assistant message
with non-empty text content (skipping tool-call-only assistant
"stubs" which the UI renders as small "calling tool X" indicators
rather than a readable bubble) and walks ``cut_idx`` back through
the standard ``_align_boundary_backward`` so we don't split a
tool_call/result group that immediately precedes it. The two
anchors are chained — each only walks ``cut_idx`` backward, so
the tail can only grow.
Falls back to "most recent assistant of any kind" only when no
content-bearing reply exists in the compressible region (fresh
multi-step tool sequence with no prior reply) — in that case the
agent-side fix is effectively a no-op and the existing
user-message anchor carries the load.
WebUI layer (clarity). Added ``isCompactionMessage`` detector that
recognises the ``[CONTEXT COMPACTION — REFERENCE ONLY]`` (current)
and ``[CONTEXT SUMMARY]:`` (legacy) prefixes from
``agent/context_compressor.py``, and a new ``compaction`` entry
in ``MessageBubble``'s ``ROLE_STYLES`` map. Compaction blocks
now render as muted, italicised system-style rows labelled
``Context handoff`` — clearly metadata, not the assistant's
actual reply — so an operator scrolling back through a long
session can't mistake the summary for a real answer.
Keeping the detected prefixes inline (rather than importing them)
because the WebUI bundle has no Python interop. A guardrail comment
points readers at the source-of-truth constants in
``agent/context_compressor.py``.
Follow-up to the #33346 cherry-pick:
- the marker string was duplicated at both insertion sites (standalone +
merged-into-tail); hoist to a module constant
- _strip_summary_prefix now also strips a trailing end marker so a
rehydrated handoff body doesn't leak the boundary directive into the
iterative-update summarizer prompt (it is re-appended on insertion)
When the compression summary lands as an assistant-role message (head ends
with user), the end marker was not appended. Models may regurgitate the
summary text as their own visible output when there's no clear boundary
signal (#33256).
The end marker was already appended for user-role summaries (#11475, #14521)
but the assistant-role path was missed in the original fix. This ensures ALL
standalone summary messages carry the boundary marker, preventing summary
text from leaking into user-visible chat output.
Legibility pass on the consolidated prefix: collapse the topic-overlap rule
from three overlapping sentences into one WINS sentence + one discard/no-wrap-up
sentence (same constraints, less dilution), fix the module docstring to
describe the headings that actually shipped, and correct the #10896 comment's
heading name (Historical Pending User Asks).
The prompt consolidation above retires the carveout-era prefix. Without a
frozen copy in _HISTORICAL_SUMMARY_PREFIXES, summaries persisted by
pre-upgrade builds would lose detection (_is_context_summary_content) and
renormalization (_strip_summary_prefix) — the exact regression class the
tuple exists to prevent. Adds contract tests covering every frozen prefix.
Refs #41607#38364#42812
ContextCompressor inherited a no-op on_session_end() from ContextEngine, so
per-session iterative-summary state (_previous_summary) survived a real session
boundary on a reused compressor instance. Override it to clear the summary the
moment the owning session ends, complementing the point-of-use guard in
compress(). Closes the cross-session contamination path in #38788.
Co-authored-by: dusterbloom <32869278+dusterbloom@users.noreply.github.com>
When a cron or background session compacts, it sets _previous_summary for
iterative updates. If that session ends without /new or /reset (which calls
on_session_reset()), the stale summary survives on the ContextCompressor
instance. A subsequent live messaging session's compaction then injects it as
'PREVIOUS SUMMARY:' into the summarizer prompt — contaminating the live
session with unrelated content from the prior session.
Add an else guard in compress(): when no handoff summary is found in the
current messages but _previous_summary is non-empty, discard it so
_generate_summary() starts fresh instead of iteratively updating a stale
cross-session summary.
Fixes#38788
When summary_target_ratio is large (e.g. 0.45) and the context_length is
moderate (e.g. 96000), the soft_ceiling (token_budget * 1.5) can exceed
the total transcript size. _find_tail_cut_by_tokens walks the entire
transcript without breaking early, and the resulting compress window is
either empty (compress_start >= compress_end) or a single message whose
summary-of-one overhead saves ~0 tokens.
Both outcomes cause a no-op compression that does not increment
_ineffective_compression_count, so should_compress() returns True on
every subsequent turn and the loop repeats endlessly.
Fix (two layers):
1. _find_tail_cut_by_tokens: when the backward walk consumed the entire
transcript without breaking (cut_idx <= head_end and accumulated <=
soft_ceiling), re-walk with the raw (non-inflated) token budget to
find a meaningful cut that gives the summarizer a useful middle window.
2. compress(): when compress_start >= compress_end, increment
_ineffective_compression_count and log a warning so the existing
anti-thrashing guard in should_compress() can break the loop.
Fixes#40803
Compaction summaries now receive the current date and instruct the
summarizer to rewrite completed actions as absolute, dated, past-tense
facts (e.g. "email John about the proposal" -> "Sent the proposal email
to John on 2026-06-07"). A resumed conversation no longer re-issues work
that already happened or treats a finished action as still pending.
The date is resolved via hermes_time.now() (date-only, user-configured
timezone) inside _generate_summary. The compaction summary is a
mid-conversation message that is never part of the cached prefix, so the
date does not affect prompt-cache stability. Date resolution is
best-effort: a clock failure omits the rule rather than blocking
compaction. The rule rides the shared template, so both first-compaction
and iterative-update prompts carry it.
Inspired by Poke's summarization (temporal anchoring + semantic
preservation).
A handoff persisted under an older SUMMARY_PREFIX can be inherited into a
resumed lineage. _strip_summary_prefix only matched the current/legacy
literal, so on re-compaction the old 'resume exactly from Active Task'
directive stayed embedded in the body and kept hijacking replies to new,
unrelated user messages.
- Add _HISTORICAL_SUMMARY_PREFIXES (pre-#35344 prefix) and strip/recognize
them in _strip_summary_prefix + _is_context_summary_content so resumed
stale handoffs are re-normalized to the current latest-message-wins prefix.
- Reconcile the overlapping Active Task template edits from the salvaged
#26290 (reverse-signal cancellation) and #32787 (capture open questions /
decisions, don't write None too eagerly) — both intents kept.
- Regression coverage in tests/agent/test_resume_stale_active_task.py.
- AUTHOR_MAP entries for both salvaged contributors.
The Active Task field in compression summaries is the single most important
field for task continuity across context boundaries. The previous template
described it narrowly as a 'task assignment' or 'request', which caused the
summary LLM to write 'None' whenever the user's most recent input was a
question, a decision request, or a discussion turn rather than an
imperative command. The assistant on the other side of the compaction then
treated the conversation as resolved and gave a generic recap instead of
answering the still-open question.
Expand the template guidance to cover:
* explicit task assignments
* questions awaiting an answer
* decisions awaiting input (A vs B)
* ongoing discussions where the assistant owes the next substantive reply
Reserve 'None' for the rare case where the last exchange was fully
resolved (e.g. user said 'thanks, that's all').
Also tighten the trailing CRITICAL instruction in the summary prompt so the
LLM cannot fall back to the old 'no imperative command → None' heuristic.
No behavioural code changes — template strings only. All 83 existing
compressor tests pass.
SUMMARY_PREFIX previously contained two contradictory directives:
1. "treat it as background reference, NOT as active instructions"
"Do NOT answer questions or fulfill requests mentioned in this summary"
"Respond ONLY to the latest user message that appears AFTER this summary"
2. "Your current task is identified in the '## Active Task' section of the
summary — resume exactly from there."
When the latest user message contradicted Active Task (e.g. 'stop the
i18n refactor', 'never mind, look at grafana instead'), models tended to
follow (2) anyway because 'resume exactly' is a strong, unambiguous
directive — leading to repeated re-surfacing of already-cancelled work
across turns, even after explicit 'stop'/'don't keep bringing that up'
messages from the user.
This change:
- Removes the conflicting 'resume exactly from Active Task' clause.
- Makes the precedence explicit: latest user message is the single source
of truth; it WINS on conflict; cancelled Active Task / In Progress /
Pending User Asks / Remaining Work must be discarded entirely (no
'wrap up the old task first').
- Names canonical reverse signals (stop, undo, roll back, never mind,
just verify, topic change) so the model recognizes them as cancellation
triggers, not background context.
- Updates the summarizer template instruction so the LLM doesn't
mechanically copy a cancelled task into Active Task on the next
compaction (it's instructed to copy the reverse signal verbatim).
- Preserves: REFERENCE ONLY framing, MEMORY.md/USER.md authority, and
the 'don't repeat work already reflected in session state' clause.
Adds tests/agent/test_summary_prefix_semantics.py to pin invariants so
the conflict can't regress.
Tested:
- All compaction tests pass: tests/agent/test_context_compressor.py,
tests/agent/test_context_compressor_summary_continuity.py,
tests/run_agent/test_413_compression.py,
tests/run_agent/test_compression_persistence.py,
tests/run_agent/test_compression_boundary_hook.py,
tests/cli/test_manual_compress.py — 117/117 passing.
- Tested on macOS.
