context_breakdown._chars_to_tokens and native_compaction._approx_tokens did raw
chars//4, under-counting CJK/Cyrillic by 2-4x next to the conversation slice
that already used estimate_tokens_rough — the /context pie chart mixed two
estimators. Both now call the canonical. The four private `= 4` ratio
constants import one CHARS_PER_TOKEN from agent/model_metadata.py. Estimates
only feed UI and budgets; no prompt or message bytes change.
A native Responses compaction checkpoint is opaque ciphertext; the rough
preflight estimator counts it as text (5.17M chars -> ~1.29M tokens against
a 204K trigger) and fires local compression on a request whose real prompt is
~116K. Arm the existing one-response real-usage latch when a replayable
checkpoint is captured (build_assistant_message) or restored into a fresh
agent (_hydrate_from_history), honor it in the post-tool gate and idle
compaction, and require non-empty encrypted_content for a checkpoint.
Squash of the author's source commits from #100642 (0e3c234ea0, 771e1b3365,
bb1505a119) plus the fdf140c81d test refresh, re-based onto current main by
patch application. Source delta is byte-identical to the PR head d6ce3e236d.
Fixes#100611
For each issue anchor present in BASE 63279301bc non-test .py and absent on HEAD, the BASE comment/docstring block was re-attached at the HEAD location of the code it explained (matched by the distinctive code line / enclosing def). Sentences already covered by an existing HEAD comment were deduped; the issue number always survives. Insert-only: no code lines changed.
- prompt_caching: fold _count_cache_markers' nested _marked into one sum over
[*messages, *parts, *tools]; collapse the open-turn guard + endpoint append in
_completed_transaction_endpoint_indexes into one predicate; enumerate() in
apply_anthropic_cache_control's non_sys scan; effective_cache_ttl tail -> one
conditional; pack wrapped calls/comprehensions to <=120 cols; tighten
docstrings (every WHY kept).
- native_compaction: resolve_compact_threshold upper -> one conditional expr;
warn-once guard -> single if; _extract_item_text part loop drops the str/dict/
else ladder (candidates default (part,), non-str filtered by the same isinstance
check); _retain_summary early-return -> guarded body; pack wrapped calls and
docstrings.
Zero behavior change: E corpus (224MB) and C corpus byte-identical vs base
113f04616bd; extra corpus for warn-once/_extract_item_text edges identical;
68 test files / 1359 tests green; no symbol added/removed vs pass 1.
Use a distinct runtime_capabilities field on agents, preserve compatibility with earlier snapshots, and resolve the canonical direct OpenAI endpoint when a cross-provider switch omits base_url. Keep ambiguous proxy routes fail-closed.
Stage destination native-compaction capabilities until the complete runtime and context setup succeeds, and restore them with primary and fallback runtimes. Keep native compaction default-deny across live switches and session reconstruction.\n\nVerification: uv run --with pytest --with pyyaml python -m pytest tests/run_agent/test_switch_model_context.py tests/run_agent/test_native_compaction.py tests/run_agent/test_native_compaction_switch_capabilities.py tests/run_agent/test_switch_model_rollback.py tests/run_agent/test_fallback_reasoning_override.py tests/run_agent/test_primary_runtime_restore.py tests/run_agent/test_provider_fallback.py -q -o 'addopts='; uv run --with ruff ruff check <touched files>; git diff --check
Preserve valid normalized input_image user messages across native-compaction checkpoints at bounded one-token retention cost. Keep text extraction text-only, reject malformed or unknown multipart placeholders, and prove the production adapter path without claiming unsupported input_file behavior.
Republish the identical source tree after an unrelated nondeterministic focus-redraw test failure; this commit contains no source delta from the previously verified object.
Refs #90976 and #91477.
The fail-closed gate lived only in compress_context(), but two native
lossy owners compact without ever crossing it (review on #93996):
- codex app-server: in "native"/"off" auto-compaction mode (native is the
default) Hermes preflight is skipped and the codex agent compacts its
own thread inside run_turn() — the compress_context() rejection was
unreachable. init_agent now refuses checkpoint_required together with
api_mode=codex_app_server (BLOCKED_MISSING_PREREQUISITE, extracted as a
testable guard), and run_codex_app_server_turn() fails closed as
defense in depth before a turn can reach the codex-owned boundary.
- Responses server-side native compaction:
native_compaction_context_management() now returns None while the gate
is armed, so context_management never goes on the wire and the
checkpoint-aware Hermes compressor stays authoritative. The suppression
is logged once per process, not silently applied.
Regressions: checkpoint_required + app-server raises before run_turn()
(the session is never created); checkpoint_required keeps
context_management off the wire while the plain configuration still
produces it; the init guard refuses exactly the incompatible pair. Docs
and cli-config.yaml.example describe both bindings.
Refs #93986
prune_pre_checkpoint_items() had a hardcoded role=='user' filter that
discarded all non-user messages before a checkpoint — including Hermes'
own compression summaries (role='assistant'), causing total context amnesia
about past conversation summaries.
The fix:
- _is_summary_item delegates to the canonical
agent.context_compressor.is_compaction_summary_message provenance check
(not an ad-hoc heuristic)
- Summaries are retained whole (never byte-sliced) within a 32k token budget
- Idempotent across repeated checkpoints (dedup by identical text)
- _chat_messages_to_responses_input threads item_sources (raw chat messages)
through to the pruner, so it can read summary content directly from the
source when the Responses conversion shape is lossy (tool-result carrier
becomes function_call_output, or stale codex_message_items replay shadows
merged content)
Fixes#90975.
Salvage of #90976 by @JoaoMarcos44.
A type="compaction" item is the server-side stand-in for history that has
already been pruned, and it rides the same codex_reasoning_items sidecar as
per-turn reasoning. e00965a7e taught compaction pruning to filter that
sidecar instead of popping it so checkpoints survive on every retained
message.
The thinking-only sanitizer reaches the same sidecar from the other
direction and asks a coarser question: does any item have type ==
"reasoning"? A commentary turn carrying both a reasoning item and a
checkpoint answers yes, so the whole message is dropped from the wire copy
and the only copy of the checkpoint goes with it. The request then carries
neither the compacted history nor the checkpoint standing in for it.
Extract has_compaction_checkpoint() into agent/native_compaction.py — the
module that owns the concept, and where merge_interim_reasoning_items()
already spelled the same predicate inline — and consult it before the
thinking-only verdict. A reasoning-only carrier is still dropped.
Two reliability gaps from #82777:
1. Rejection matcher required only a field-name mention, so a transient
5xx/timeout whose body echoed the request (which contains
context_management) permanently downgraded native compaction for the
session. Now requires rejection language (unknown/unsupported/invalid/...)
alongside the field name, and when a parsed HTTP status is available,
400 specifically — non-400 statuses never match. Message-only transports
(no status attribute) keep working unchanged.
2. compression.codex_responses_native was coerced with bool(), so the
strings "false"/"off" enabled the feature. Now uses the shared
utils.is_truthy_value helper.
Conversation-loop call site passes api_error.status_code through.
Sabotage-verified: reverting the matcher to field-name-only fails the new
echo and non-400 tests.
Live verification (gpt-5.6 @ api.openai.com) proved the Responses server
renders NOTHING placed before a replayed compaction checkpoint: a fact
stated in a pre-checkpoint input item is invisible to the model, while the
same item after the checkpoint recalls perfectly. Hermes was replaying the
full pre-checkpoint transcript anyway — dead upload weight, and worse, every
plaintext user ask from before the boundary silently vanished from the
model's view, surviving only inside the opaque server summary. That is the
goal-drift failure mode reported against native compaction sessions.
Codex CLI never hits this because it rebuilds history client-side after
compaction, retaining user messages verbatim under a token budget. This
change is the wire-level equivalent: when a replayed checkpoint is present,
_chat_messages_to_responses_input restructures the input as
[newest checkpoint run] + [retained pre-checkpoint user messages,
newest-first within a 64K-token budget] + [post-checkpoint tail]
Histories without a checkpoint are returned unchanged, so non-native
sessions see a byte-identical wire.
Two corrections on top of the #71077 base (the whole bug class):
1. Turn boundary = last USER message, not last assistant message. A Codex
turn spans several assistant messages (assistant+tool_calls -> tool ->
... -> final assistant) whose reasoning items must replay together; the
last-assistant boundary would strip reasoning mid-chain from the active
turn (the gap flagged in PR #71077 review).
2. type="compaction" checkpoints (native server-side compaction, PR #81747)
are exempt: they carry already-pruned history, not per-turn reasoning.
Pruning filters items instead of popping the sidecar key.
Sibling site fixed in the same class: the Codex incomplete-continuation
dedup path blind-overwrote codex_reasoning_items on visually-duplicate
interim messages, which would drop the only copy of a checkpoint captured
on the earlier response. Extracted merge_interim_reasoning_items() into
agent/native_compaction.py; newer reasoning wins, prior checkpoints are
preserved unless the newer payload carries its own.
Opt-in via compression.codex_responses_native (default: false). When enabled,
gpt-5.6-family models on the direct OpenAI API (api.openai.com) or a ChatGPT
Codex subscription send context_management=[{type: compaction,
compact_threshold: N}] on Responses requests. OpenAI compacts server-side and
returns an encrypted compaction output item; Hermes captures it into the
existing codex_reasoning_items sidecar and replays it on later turns in place
of the pruned history — inheriting persistence, session replay, the
cross-issuer guard, and the encrypted-replay kill switch with zero new state.
Scope is deliberately hard-gated (agent/native_compaction.py, re-checked per
request): gpt-5.6 family only — gpt-5.1/5.2 fail server-side on the field
(HTTP 500 / stream stall, no structured rejection; live-verified) — and
direct OpenAI/Codex routes only; xAI, GitHub/Copilot, OpenRouter, relays,
and local servers never see the field.
Hermes' local compression stays armed as the fallback owner: the native
threshold is clamped ~8K tokens below the local trigger so the server
compacts first, and a structured provider rejection of context_management
disables native compaction for the session and retries without it
(one-shot guard in TurnRetryState).
Live-verified E2E on api.openai.com/gpt-5.6: server compaction fired at a
4K threshold, checkpoints captured and replayed, recall preserved across
3 turns; gpt-5.1 with the flag enabled stays clean (field never sent).
Direction credit: PR #76950 by @laryhorb explored native Responses
compaction; this is a minimal reimplementation on current main.
