Simplify-pass finding: the safety note still cited 'skills edited' as a stable-tier input whose change mismatches the rebuilt prefix — after this PR a skill edit changes only the volatile tail (that's the point). Swap the example for genuinely stable-tier inputs.
The skills index is runtime-mutable: the agent adds and patches skills mid-session, so it is not byte-stable. Keeping it in the stable band breaks that band prefix-cache contract, because every skill edit changes the stable band and invalidates the entire cached prefix in front of it. Move it to the front of the volatile band so the stable scaffold (identity, tool guidance, model guidance) stays cacheable across skill edits.
The static-prefix reconstruction pattern (build_system_prompt_parts ->
['stable'] -> startswith gate -> fail-open) existed in three copies:
session restore (conversation_loop), compression keep-prompt path
(conversation_compression), and the new failover redecoration helper.
Hoist it into agent/system_prompt.reconstruct_static_prefix and call it
from all three sites.
Also memoize failed rebuilds per stored prompt (_static_rebuild_failed_for):
the redecoration chokepoint runs at the top of every retry attempt, and a
persistent stable-tier mismatch (restored session whose SOUL.md/skills
changed since save) would otherwise re-run the full prompt build — SOUL.md,
context files, memory I/O — on every attempt of every API call for the
life of the session. A legitimately changed stored prompt retries once.
The system prompt building code hardcoded '~/.hermes' paths instead of
using get_hermes_home(). When HERMES_HOME is set to a custom location,
the prompt text still referenced ~/.hermes, confusing the AI about
where files actually live.
Changed:
- Import get_hermes_home from hermes_constants
- Default profile hint: ~/.hermes/profiles/<name>/ → <home>/profiles/<name>/
- Non-default profile hint: ~/.hermes/... → <home>/... for all paths
Closes#66450
Follow-up on the salvaged #64611 commit: the original guard blocked the
install tree unconditionally, which would have broken the legitimate
'developing Hermes from a source clone' CLI flow (launching hermes inside
the repo and getting its AGENTS.md as project context).
Refined policy:
- resolve_context_cwd(): validates configured paths (missing dir -> None +
warning) but honors an EXPLICIT install-tree cwd verbatim — deliberate
user choice.
- build_context_files_prompt(): blocks only the cwd=None -> os.getcwd()
FALLBACK into the install tree, with a new allow_install_tree_fallback
param. system_prompt.py passes it for platform cli/tui (launch dir is
the user's real shell cwd there); desktop/gateway surfaces keep the
guard (their fallback dir is self-spawned, never user-picked).
- Warning log names the resolved dir and the terminal.cwd remedy.
E2E-verified all five scenarios: desktop fallback blocked, in-tree CLI dev
keeps AGENTS.md, explicit install-tree cwd honored, invalid TERMINAL_CWD
falls to None then blocked, normal workspace loads.
The platform hint in PLATFORM_HINTS['telegram'] always encouraged rich
Markdown constructs (tables, task lists, math, collapsible details) even
when rich_messages: false (the default). This caused the agent to produce
formatting that MarkdownV2 cannot render, especially broken on Telegram Web.
Split the hint into a base hint (MarkdownV2-compatible) and a
TELEGRAM_RICH_MESSAGES_HINT extension. The extension is conditionally
appended in system_prompt.py only when
platforms.telegram.extra.rich_messages is true.
Fixes#57122
The desktop app's chat panel reuses tui_gateway as its backend, so every chat session was stamped platform="tui". That made the agent read terminal-specific platform guidance while running in the graphical desktop chat surface.
Resolve the misclassification at its source: tui_gateway now picks platform="desktop" when HERMES_DESKTOP=1 and HERMES_DESKTOP_TERMINAL is unset, and keeps platform="tui" for the embedded terminal pane and standalone TUI. Add a PLATFORM_HINTS["desktop"] entry describing the actual chat surface (full GFM markdown, MEDIA: intercept, inline images). Move the embedded-pane clarifier to the platform-hint resolution site so it appends only to the tui hint under HERMES_DESKTOP_TERMINAL=1. Delete the now-dead desktop-hint block from build_environment_hints() that competed with the platform hint.
Standalone TUI sessions produce byte-identical prompts as before; the new desktop hint and clarifier are assembled once per session in the stable tier, so prompt caching is preserved.
Make the computer_use toolset platform-agnostic by driving cua-driver on
macOS, Windows, and Linux. Consumes the 8 cua-driver decoupling surfaces
(capability discovery, structuredContent AX tree, opaque element_token,
click button enum, explicit mimeType, machine-readable manifest,
structured list_windows, structured health_report), each degrading
gracefully on older drivers.
Adds `hermes computer-use doctor` (drives cua-driver health_report with a
per-OS check matrix and an exit 0/1/2 ok/degraded/blocked contract), full
typed wrappers for the previously-uncovered cua-driver tools plus a generic
call_tool escape hatch, per-session agent-cursor lifecycle, platform-aware
system-prompt guidance (host-deterministic, cache-safe), and honors
HERMES_CUA_DRIVER_CMD end-to-end.
Replaces the macOS-only skills/apple/macos-computer-use skill with a
cross-platform skills/computer-use skill, and refreshes the EN + zh-Hans
docs.
Supersedes #44221 (Windows-enablement salvage of #30660).
Co-authored-by: Teknium <127238744+teknium1@users.noreply.github.com>
Add platform_hints config so an admin can append to or replace Hermes'
built-in platform hint for a single messaging platform (WhatsApp, Slack,
Telegram, ...) without affecting other platforms. Enables enterprise
managed profiles to steer platform-aware skills (e.g. invoke a custom
table-formatting skill on WhatsApp where Markdown tables don't render)
while leaving Telegram/Slack/CLI behavior unchanged.
- hermes_cli/config.py: document platform_hints in DEFAULT_CONFIG
- agent/agent_init.py: load platform_hints -> agent._platform_hint_overrides
- agent/system_prompt.py: _resolve_platform_hint() applies append/replace
(replace wins; bare string = append shorthand); defensive on bad config
- tests: 16 cases covering append/replace/shorthand/isolation/malformed
Override only affects the platform-hint segment of the system prompt;
SOUL/context/memory tiers and general instructions are unchanged.
* Port from cline/cline#11514: encourage parallel tool calls
Add a universal system-prompt guidance block telling the model to batch
independent tool calls (reads, searches, web fetches, read-only commands)
into a single assistant turn instead of one call per turn. The runtime
already executes independent batches concurrently (read-only tools always;
non-overlapping path-scoped file ops); the open-source system prompt had
nothing steering the model to PRODUCE the batch. Fewer round-trips means
less resent context, which compounds over a long conversation.
- prompt_builder.py: new PARALLEL_TOOL_CALL_GUIDANCE block (short, static,
cache-amortised) modeled on TASK_COMPLETION_GUIDANCE.
- system_prompt.py: inject right after the task-completion block, gated by
agent.valid_tool_names + the new toggle.
- agent_init.py: read agent.parallel_tool_call_guidance (default True).
- config.py: add the default under the agent section.
- test_prompt_builder.py: behavior-contract tests (batching steer, dependent
carve-out, length bound) — invariants, not wording snapshots.
Adapted from Cline's TypeScript tool-surface guidance to hermes-agent's
Python prompt-assembly architecture and config-over-env conventions.
* fix(desktop): never persist or restore a named custom provider as bare "custom"
Custom providers vanish from the Desktop/TUI model picker with
"No LLM provider configured" — repeatedly fixed (#44062, #44109, #45578)
and repeatedly regressed (#44022, #47714) because every fix only recovered
the entry identity from a persisted base_url. When a session is
persisted/restored with the resolved provider "custom" and NO base_url, bare
"custom" leaked through verbatim; resolve_runtime_provider("custom") routes to
the OpenRouter default URL with no api_key, so the next turn/resume dies.
Bare "custom" is the resolved billing class shared by every named providers:/
custom_providers: entry — it is not a routable identity. Centralize the
"never let bare custom escape" invariant in one helper,
runtime_provider.canonical_custom_identity(), and apply it at all four leak
sites in tui_gateway/server.py:
- _ensure_session_db_row — the ORIGIN: first DB write seeds the bad row
- _runtime_model_config — live persist
- _stored_session_runtime_overrides — resume restore (heals old rows; drops
unrecoverable bare custom so resume falls back to config default)
- _make_agent — rebuild / per-turn
The helper recovers custom:<name> from the endpoint URL when present, else
from config.model.provider (the durable identity left when no base_url
survived). Regression tests in test_custom_provider_session_persistence.py
lock the no-base_url vector at every site so it cannot regress again.
Context files (AGENTS.md, CLAUDE.md, .hermes.md, .cursorrules, SOUL.md) were
hard-capped at a flat 20K chars before head/tail truncation. Among the agent
harnesses we track, only Codex caps project docs at all (32 KiB); Claude Code,
OpenCode, and Cline load them whole. The flat 20K predates large context
windows and silently truncates real-world AGENTS.md files.
B — dynamic cap: when context_file_max_chars is unset (now the shipped
default), the cap scales with the model's context window
(ctx_tokens * 4 * 0.06, floor 20K, ceiling 500K). Small-context models stay at
the historical 20K; a 200K model gets 48K; large models stop truncating real
docs. An explicit context_file_max_chars still wins. Context length is resolved
once per conversation (stable -> prompt cache untouched).
C — when truncation does happen, the marker now names the concrete file path
and tells the agent to read_file it for the full content.
Validation: 154 targeted tests + full agent/ + hermes_cli/ + test_config
(0 failures); E2E against a real 60K AGENTS.md confirms small windows truncate
with the path-bearing marker, large windows load whole, and the system prompt
is byte-stable across rebuilds.
PROBLEM: Automatic context files such as SOUL.md and AGENTS.md were capped by a hardcoded CONTEXT_FILE_MAX_CHARS value. Amy's local fork had raised that constant from 20K to 25K so a larger SOUL.md would not be silently truncated, but the hardcoded 25K value changed upstream default behavior and made the patch less generally useful.
SOLUTION: Restore the upstream-compatible 20K default, add a context_file_max_chars config setting for users who intentionally keep larger identity/project-context files, keep chat-visible truncation warnings, and document the new setting. Tests cover the default, config override, explicit max_chars precedence, and the warning text.
The coding posture's names-only demotion of non-coding skill categories
(#44342) applied under the default auto mode, silently changing the skill
index for every user in a git repo. Index changes must be opt-in: demotion
now only fires under agent.coding_context=focus, alongside the toolset
collapse. auto/on leave the skill index untouched; focus semantics are
unchanged (demoted, never hidden; deny-list keeps coding-adjacent and
custom categories at full entries).
Real-world failure with the original index pruning: under the default auto
posture, an agent-created ops skill in a demoted category vanished from the
prompt's skill index mid-project, and the agent silently fell back to a
stale sibling skill instead. The "discovery-only" premise didn't hold —
models do not reach for skills_list to rediscover what the index stops
showing them, and agent-created skills are the model's accumulated project
memory (runbooks, pitfalls, operating rules).
Gating pruning behind the opt-in focus mode was the wrong fix too: users
opening a worktree don't know the config exists, so the index-noise win
would effectively never ship.
Instead, the coding posture now DEMOTES non-coding categories rather than
hiding them: each demoted category renders as a single names-only line
("gaming [names only]: allthemons10-ops, mc-backup") with a footer note
explaining the omitted descriptions. Every skill name stays in the prompt,
so memory-anchored recall ("load <name>") keeps working in every mode,
while the description noise is still cut. Applies in auto/on/focus alike;
the general posture demotes nothing. Deny-list semantics unchanged —
unknown/custom categories and coding-adjacent ones keep full entries.
API renamed to match the honest semantics: hidden_skill_categories →
compact_skill_categories, build_skills_system_prompt(hidden_categories=) →
compact_categories=.
* feat(agent): coding-context posture with per-model edit-format tuning
Hermes detects when it's running in a coding context — an interactive
surface (CLI, TUI, ACP, desktop) sitting in a code workspace (git repo or
recognised project root) — and shifts into a coding posture. Outside that
(chat platforms, non-workspaces) nothing changes.
The posture is modelled as a frozen RuntimeMode selected from a small
ContextProfile registry (coding/general). A profile is data: the toolset to
collapse to, the operating brief to inject, and seams for model routing and
memory. Every domain reads the same resolved object instead of re-probing
git/config on its own:
- System prompt — RuntimeMode.system_blocks(): an operating brief (gather
context before editing, edit through tools not chat, verify with terminal,
cap retry loops) plus a live git/workspace snapshot, built once and baked
into the stable prompt tier so per-conversation caching is preserved.
- Per-model edit-format tuning — the brief nudges each model family toward
the patch mode it handles best: OpenAI/Codex toward mode='patch' (V4A
multi-file diffs), Anthropic toward mode='replace' (string replacement).
The model id rides on RuntimeMode; unknown families keep neutral wording.
- Skill index — non-coding skill categories are pruned from the prompt's
skill index (discovery-only; skills_list/skill_view still reach the full
catalog, with a disclosure note).
- Toolset — only under the opt-in 'focus' mode does the posture collapse to
the coding toolset + enabled MCP servers; the default posture is
prompt-only and never overrides configured toolsets.
Activation via agent.coding_context: auto (default), focus, on, off.
Subagents inherit the posture for free via toolset inheritance + the shared
prompt builder. Detection is not memoized so a long-lived gateway/TUI
process can't pin a stale posture across working directories.
* feat(agent): cover new-file authoring in the coding edit-format nudge
The per-model edit-format guidance only addressed editing existing code
(patch mode='patch' vs 'replace'), but authoring a brand-new file —
write_file, not patch — is a large fraction of real coding work and the
nudge was silent on it. Surfaced when building a single-file artifact where
the dominant operation was write_file and the steering offered no guidance.
Both family lines now lead with "author new files with write_file; for
edits to existing code prefer ...". Tests assert write_file appears in each
family's brief; unknown families still get neutral wording.
* docs(agent): correct memoization docstring + clarify TUI config-load asymmetry
* feat(agent): sharpen the coding posture — verify-loop facts, wider edit steering, $HOME guard
Tuning pass on the coding posture from dogfooding it as a harness:
- Workspace snapshot now hands the model its verify loop up front:
detected manifests + package manager (lockfile sniff), the exact
verify commands (package.json scripts, Makefile targets,
scripts/run_tests.sh, pytest config), and which context files
(AGENTS.md / CLAUDE.md / .cursorrules) exist at the root. Marker-only
(non-git) projects get the snapshot too instead of nothing. The
"verify before claiming done" brief line was the highest-value piece
in evals — this turns it from advice into an executable loop instead
of making the model rediscover the test command every session. Still
stat-cheap, size-guarded reads, built once at prompt time.
- Edit-format steering covers the families Hermes actually serves:
Gemini and open-weight coding models (DeepSeek, Qwen, Kimi, GLM,
Grok, Hermes, Llama, Mistral, Devstral, MiniMax) steer to
mode='replace' — their RL scaffolds use str_replace-style editors.
Previously only GPT/Codex and Claude families got steering; the
models Hermes users disproportionately run all fell to neutral.
- Operating brief gains four behaviors elite harnesses encode: batch
independent reads/searches in one turn; fix root causes and the bug
class (sibling call paths), not the reported site; no drive-by
refactors/renames/reformatting; never read, print, or commit secrets.
Plus a patch-failure escalation ladder: after the same region fails
twice, rewrite the enclosing function/file with write_file instead of
a third patch attempt.
- $HOME dotfiles guard: a git repo rooted exactly at the home directory
(or a marker sitting in it, e.g. a global ~/AGENTS.md) is user config,
not a code workspace — without the guard, every session anywhere under
a dotfiles-managed home silently flipped to the coding posture. Real
projects under such a home still detect via their own markers/repos;
'on' mode bypasses the guard.
A steer rides inside a tool result (the only role-alternation-safe slot
mid-turn), so a bare "User guidance:" line reads as untrusted tool content —
well-behaved models refuse it as suspected prompt injection (observed live:
"I only follow instructions from you directly, not ones injected through
command results").
- Wrap steers in a bounded, self-describing [OUT-OF-BAND USER MESSAGE] marker
(prompt_builder.format_steer_marker), shared by both drain sites.
- Add STEER_CHANNEL_NOTE to the core system prompt so the model expects this
exact marker and trusts it as a genuine user message — while still ignoring
lookalikes buried in tool/web/file output. Static text → byte-stable prompt,
no prompt-cache regression; gated on the agent having tools.
- Desktop: steer ack is now an inline transcript note (⏩ steered · …) instead
of a toast.
Marker is intentionally static (not a per-session nonce) to honor the
byte-stable system-prompt caching policy; nonce hardening noted as follow-up.
* fix(codex): surface error code in Responses 'failed' status errors
When a Codex Responses turn ends with status=failed, the response carries
the failure details under `response.error` as
`{code, message, param, ...}`. The previous extractor pulled only
`message`, so users seeing a rate-limit failure got a bare "Slow down"
string indistinguishable from a generic stream truncation; an
internal_error with empty message degraded to a dict dump
("{'code': 'internal_error', 'message': ''}").
Extract a `_format_responses_error()` helper that:
- prefixes `code` when both code and message are present
(e.g. 'rate_limit_exceeded: Slow down')
- falls back to the bare `code` when message is empty
- accepts both dict and attribute-style payloads (SDK and JSON-RPC paths)
- preserves the prior status-only fallback when no error payload exists
Apply the same helper at the sibling site in
`codex_app_server_session.run_turn()` so codex-CLI subprocess turn
failures get the same treatment.
Tests:
- 8 new unit tests for `_format_responses_error` covering both shapes,
empty/missing fields, non-string fields, and the status-only fallback.
- 2 regression tests on `_normalize_codex_response` for failed status
with and without a code, asserting the exact RuntimeError message.
- All 3603 tests in tests/agent/ pass.
Adapted from anomalyco/opencode#28757.
* feat(prompt): universal task-completion guidance + local Python toolchain probe
Two cross-model failure modes get a single-line answer in the cached
system prompt. Both gated by config (default on), both add zero overhead
when not needed, both verified via real AIAgent prompt builds.
## What changed
`TASK_COMPLETION_GUIDANCE` — short prompt block applied to ALL models.
Targets two failure modes observed on a real Sarasota real-estate build
task: (1) Opus stopped after writing an 85-byte stub and gave a prose
response with finish_reason=stop on call #3 of 90; (2) DeepSeek pushed
through a PEP-668 wall, then returned fabricated listings instead of
admitting the blocker. Both behaviors are model-family-agnostic, so the
guidance lives outside the existing tool_use_enforcement gate (~192
tokens, paid once per session via prefix cache).
`tools/env_probe.py` — local Python toolchain probe. Detects
python3/pip/uv/PEP-668 state and emits ONE short line in the system
prompt when something is non-default. Emits NOTHING when the env is
clean (zero token cost for normal users). Skipped entirely for remote
terminal backends (docker/modal/ssh) — they have their own probe.
Example output on a broken environment (the actual case):
Python toolchain: python3=3.11.15 (no pip module),
python=missing (use python3), pip→python3.12 (mismatch),
PEP 668=yes (use venv or uv).
## Config
Both flags live under `agent.` in config.yaml, default True:
agent:
task_completion_guidance: true # universal "finish the job" block
environment_probe: true # local Python toolchain hints
Neither addition required a `_config_version` bump — deep-merge fills
defaults in for existing user configs.
## Validation
| Test surface | Result |
|---|---|
| tests/tools/test_env_probe.py | 10/10 pass (probe unit) |
| tests/run_agent/test_run_agent.py — new classes | 8/8 pass (integration) |
| TestToolUseEnforcementConfig | 17/17 pass (no regression) |
| TestBuildSystemPrompt | 9/9 pass (no regression) |
| TestInvalidateSystemPrompt | 2/2 pass (no regression) |
| tests/agent/test_prompt_builder.py | 124/124 pass (no regression) |
| tests/hermes_cli/ | 5662/5662 pass (config defaults) |
| E2E AIAgent build (broken env) | Both blocks present, 2,178 chars |
| E2E AIAgent build (clean env) | 771-char net overhead, env probe silent |
* fix(profiles): cross-profile soft guard on file-write tools + system-prompt hint
Adds a soft guard so an agent running under one Hermes profile cannot
silently edit a different profile's skills/plugins/cron/memories.
Three layers:
A. agent/file_safety.classify_cross_profile_target
Classifies a write target against the active HERMES_HOME. Returns
a {active_profile, target_profile, area, target_path} dict when the
path lands in another profile's scoped area. PROFILE_SCOPED_AREAS =
(skills, plugins, cron, memories). get_cross_profile_warning()
wraps it into a model-facing error string that names both profiles,
names the area, and points at the cross_profile=True bypass.
Defense-in-depth, NOT a security boundary — the terminal tool runs
as the same OS user and can write any of these paths directly. The
guard exists to prevent confused-agent corruption, not to stop a
determined attacker. SECURITY.md §3.2 (terminal-bypass posture)
still applies.
Wired into tools/file_tools.write_file_tool and patch_tool with a
cross_profile=False kwarg. WRITE_FILE_SCHEMA and PATCH_SCHEMA both
advertise cross_profile so the model can pass it after explicit
user direction. patch_tool extracts target paths from V4A patch
bodies before checking (same shape as the existing sensitive-path
check).
skill_manage is already scoped to the active profile's SKILLS_DIR
by construction, so no extra guard wiring is needed there. The
D-side error message (below) still names other profiles when the
skill exists elsewhere.
B. agent/system_prompt
One deterministic line near the environment-hints block names the
active profile and tells the model not to modify another profile's
skills/plugins/cron/memories without explicit direction. Profile
name is stable for the lifetime of the AIAgent, so the line is
prompt-cache-safe.
D. tools/skill_manager_tool._skill_not_found_error
Replaces the bare "Skill 'X' not found." with a message that:
- names the active profile,
- searches OTHER profiles' skills dirs for the same name,
- names the profile(s) where the skill exists and the path,
- suggests `hermes -p <name>` to switch profiles, or
cross_profile=True for an explicit edit.
All 5 "not found" sites in skill_manager_tool (edit, patch, delete,
write_file, remove_file) now go through the helper.
Reference incident (May 2026): a hermes-security profile session
edited skills under both ~/.hermes/profiles/hermes-security/skills/
AND ~/.hermes/skills/ (the default profile's skills) without
realizing the second path belonged to a different profile. Three of
the four skill files needed manual restoration afterward.
What this PR does NOT do:
* No hard block. The terminal tool can still touch any of these
paths with no guard — same posture as the dangerous-command
approval flow. SECURITY.md §3.2 applies.
* No regex sweep on terminal commands for cross-profile paths.
That direction is a Skills-Guard-style arms race (cd + relative
paths, base64, etc.) and would false-positive on legitimate
cross-profile reads. Filed as a follow-up.
* No on-disk path migration. ~/.hermes/skills/ remains the
default profile's skills dir; this PR is about telling the
agent about that boundary, not changing the layout.
Tests:
tests/agent/test_file_safety_cross_profile.py (16 tests)
- _resolve_active_profile_name covers default/named/failure paths
- classify_cross_profile_target covers all four scoped areas,
both directions (default → named, named → default, named → named),
non-Hermes paths, and root-level config files
- get_cross_profile_warning covers in-profile no-op, cross-profile
message shape, and the defense-in-depth self-documentation
tests/tools/test_cross_profile_guard.py (12 tests)
- write_file: in-profile allow, cross-profile block, cross_profile=True
bypass, non-Hermes pass-through
- patch: replace-mode block, cross_profile=True bypass, V4A patch
path extraction
- skill_manage: error names the other profile (single + multiple),
missing-everywhere falls back to skills_list hint
- system prompt: contract-level checks (both branches present,
cross_profile=True mentioned, ~/.hermes/profiles/ referenced)
All 207 existing tests in file_safety/file_operations/skill_manager
still pass. 10 system-prompt tests still pass.
E2E verified: the exact incident scenario (security profile editing
default's hermes-agent-dev skill) is now blocked with the warning
message; cross_profile=True unblocks.
* fix(code_execution): add cross_profile to write_file/patch stubs
The cross_profile kwarg added to write_file_tool/patch_tool needs to
flow through the execute_code sandbox stubs in _TOOL_STUBS so the
test_stubs_cover_all_schema_params drift test passes. Without this,
scripts running inside execute_code couldn't pass cross_profile=True
through hermes_tools.write_file().
Caught by CI on PR #31290.
Salvages #24402 by @RyanRana. The KANBAN_GUIDANCE block (~835 tokens)
is session-static — the dispatcher decides at spawn time whether the
process is a kanban worker via the kanban_show tool's check_fn (gated
on HERMES_KANBAN_TASK env var). Re-checking 'kanban_show' in
valid_tool_names and re-loading the reference on every system-prompt
rebuild (init + each context compression) is wasted work.
Caches the resolved string on agent._kanban_worker_guidance once in
agent_init and consumes it in system_prompt.build_system_prompt(),
with a getattr fallback for code paths that bypass agent_init.
The system prompt's 'Conversation started:' line carried minute precision
(%I:%M %p), making it byte-unstable across every rebuild path. Within a
CLI session the in-memory cache held, but on the gateway path (fresh
AIAgent per turn → restore from session DB), any silent failure in the
read or write path dropped the cache stem and forced a full re-prefill
on every subsequent turn. Local prefix-caching backends (llama.cpp /
vLLM) saw this as KV-cache invalidation; remote prefix-caching providers
saw it as an Anthropic-style cache miss.
Three changes:
1. Date-only timestamp ('Sunday, May 17, 2026' instead of '... 03:42 PM').
System prompt now byte-stable for the full day. The model can still
query exact time via tools when it actually needs it. Credit:
@iamfoz (PR #20451).
2. Loud logging on session DB write failures. The update_system_prompt
call used to log at DEBUG, hiding disk-full / locked-database / schema
drift behind a silent fall-through that forced fresh rebuilds on
every subsequent turn. Now WARN with the session id and exception so
persistent issues show up in agent.log without verbose mode.
3. Three-way stored-state distinction on read. The previous
'session_row.get("system_prompt") or None' collapsed three states
into one (missing row / null column / empty string). Now we tell them
apart and WARN when a continuing session lands on null/empty (which
means the previous turn's write never persisted — every subsequent
turn rebuilds and the prefix cache misses every time).
The restore block is extracted into _restore_or_build_system_prompt()
so the prefix-cache path can be unit-tested in isolation.
E2E proof: fresh AIAgent constructed for turn 2 across a minute-boundary
sleep restores byte-identical bytes from the session DB. NULL stored
prompt fires the new warning. Date-only timestamp survives the rebuild
path. All on real SessionDB, no mocks.
Tests:
- tests/agent/test_system_prompt_restore.py (10 new tests)
- tests/run_agent/test_run_agent.py::TestBuildSystemPrompt::
test_datetime_is_date_only_not_minute_precision
Closes#20451 (date-only), #18547 (prefix stabilization),
#8689 (stabilize timestamp across compression), #15866 (timestamp
caching question), #8687 (compression timestamp), #27339
(claim #3: live timestamp in cached system prompt).
Co-authored-by: Martyn Forryan <9133432+iamfoz@users.noreply.github.com>
Grok models hit the same failure modes that OPENAI_MODEL_EXECUTION_GUIDANCE
addresses for GPT/Codex: claiming completion without tool calls
('to be honest, I didn't create the file yet'), suggesting workarounds
instead of using existing tools (proposing a folder-based memory system
when the memory tool exists), replying with plans instead of executing.
TOOL_USE_ENFORCEMENT_GUIDANCE was already injected for any model whose
name contains 'grok' (TOOL_USE_ENFORCEMENT_MODELS). This extends the
follow-on family-specific block — OPENAI_MODEL_EXECUTION_GUIDANCE
(tool_persistence / mandatory_tool_use / act_dont_ask / prerequisite_checks
/ verification / missing_context) — to grok-named models too.
The OPENAI_ prefix is retained for backwards compat with imports/tests;
docstring + inline comment now note that the body is family-agnostic and
the prefix reflects origin, not exclusivity.
Tests cover the OpenRouter slug (x-ai/grok-4.3) and the xai-oauth bare
name (grok-4.3), plus a negative control on claude.
E2E verified against a real AIAgent build of the system prompt for both
xai-oauth and openrouter grok models.