Hook Events — Live Probe of Both Harnesses

The question: which lifecycle hook events actually fire from a headless session on the installed binaries, with what payload, and which reply does each harness honor? Leopold's rules become hooks only on events that were captured, never on a docs page or a strings dump. This page is generated by scripts/probe-hook-events.sh from the verbatim payloads it recorded; rerun it on both binaries and the page rewrites itself.

The answer in one line: 26 of the 33 events Claude Code documents fired on 2.1.259 (Claude Code); 12 of the 12 events Codex CLI documents fired on codex-cli 0.152.1. Every event that did not fire is recorded below with the trigger tried.

Versions

Component	Version
Claude Code CLI (claude --version)	2.1.259 (Claude Code)
Codex CLI (codex --version)	codex-cli 0.152.1
Claude Code model alias for the probe	haiku
Codex model (from the captured payloads)	gpt-5.6-sol
jq	jq-1.7.1-apple
Python (stubs, renderer)	Python 3.14.6
bash (hooks, driver)	3.2.57(1)-release
OS	Darwin 27.0.0 arm64
Leopold	0.22.0 (scripts/probe-hook-events.sh, scripts/probe/dump-hook.sh)
Probed at (UTC)	2026-09-03T01:36:54Z

Method (hermetic)

• A throwaway project under mktemp -d per harness (/tmp/leopold-hookprobe.gjQnXe): git init-ed, with a CLAUDE.md / AGENTS.md, a .leopold/PLAN.md and a root PLAN.md (the FileChanged control), a 120 KB file to compact against, a project command (.claude/commands/probecmd.md) and a Codex role file (.codex/agents/probe-reviewer.toml).
• scripts/probe/dump-hook.sh <event> wired on every event of each harness's documented matrix through the shared writer in extensions/lib/harness.sh — leo_wire_hooks_json into the project's .claude/settings.json, leo_wire_hooks_toml into a temp CODEX_HOME/config.toml; nothing pastes JSON or TOML by hand. The hook appends its stdin verbatim to <out>/<harness>/<event>.jsonl — the event name is its argument, so a payload without hook_event_name still files under the right name — and answers per reply mode (observe / allow / deny / exit 2 / systemMessage / additionalContext / elicitation accept / worktree).
• Claude Code: claude -p --setting-sources project --output-format stream-json --include-hook-events in a clean environment. The real config dir is only read (macOS keeps the login in the Keychain — exactly how SDK Worker Hooks run 2 authenticated); a temp CLAUDE_CONFIG_DIR is used for one pass only, the unauthenticated hooks-fire-anyway run.
• Codex CLI: codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust with stdin closed, a temp CODEX_HOME holding a copy of auth.json that is deleted when the probe ends.
• One trigger per event: a passing and a failing Bash command; the session's own edit of .leopold/PLAN.md and an append from another process; an Agent / spawn_agent spawn; a TaskCreate + TaskUpdate completion with exit-2 blocking; forced compaction (CLAUDE_CODE_AUTO_COMPACT_WINDOW / CLAUDE_AUTOCOMPACT_PCT_OVERRIDE, /compact on a resumed session; Codex -c model_auto_compact_token_limit); an API failure through ANTHROPIC_BASE_URL and a Codex model_providers.<id>.base_url pointed at a Python-stdlib stub answering 429, 529, 500 and 401; a permission request for a non-allowlisted tool with allow and deny replies; a settings.json edit mid-session; an MCP elicitation from a stdio stub; --worktree; --init / --maintenance; /model; a register_repo_root control request; SIGINT to codex exec; a Codex role file exercised by spawn_agent and by codex exec with --strict-config.
• Hermeticity is asserted, not assumed: the entry names of the real ~/.claude and ~/.codex are fingerprinted before and after (the check scripts/test-harness-lib.sh runs) and the probe fails if either changed. This run: ~/.claude unchanged, ~/.codex CHANGED.
• Payloads below are quoted verbatim; only string values longer than 480 characters are cut with an explicit …[+N chars] marker. The raw files under <out>/ hold every byte.

Matrix — Claude Code (2.1.259 (Claude Code))

Event	Fired	Runs	hook_event_name	session_id	Replies exercised
SessionStart	yes ×40	add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent	present	present	additionalContext, systemMessage
Setup	yes ×2	setup-init, setup-maintenance	present	present	—
UserPromptSubmit	yes ×33	add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent	present	present	additionalContext, exit2, systemMessage
UserPromptExpansion	yes ×2	command, command-exit2	present	present	exit2
PreToolUse	yes ×48	additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent	present	present	additionalContext, permissionDecision:deny, systemMessage
PermissionRequest	yes ×2	perm-allow, perm-deny	present	present	decision:allow, decision:allow (host prompts), decision:deny
PermissionDenied	not fired	—	—	—	—
PostToolUse	yes ×43	additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, posttool-block, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent	present	present	additionalContext, decision:block, systemMessage
PostToolUseFailure	yes ×1	tools	present	present	—
PostToolBatch	yes ×48	additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent	present	present	additionalContext, systemMessage
Notification	not fired	—	—	—	—
MessageDisplay	yes ×48	add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent	present	present	systemMessage
SubagentStart	yes ×3	subagent, subagent-exit2, worktree-agent	present	present	—
SubagentStop	yes ×6	compact-auto, compact-manual, subagent, subagent-exit2, worktree-agent	present	present	exit2
TaskCreated	yes ×2	tasks, tasks-exit2	present	present	—
TaskCompleted	yes ×2	tasks, tasks-exit2	present	present	exit2
Stop	yes ×29	add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, worktree-agent	present	present	decision:block, exit2, systemMessage
StopFailure	yes ×5	fail-500	present	present	—
TeammateIdle	not fired	—	—	—	—
InstructionsLoaded	yes ×38	add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent	present	present	additionalContext, systemMessage
ConfigChange	yes ×2	config-change, config-change-exit2	present	present	exit2
CwdChanged	yes ×2	filechanged-cwd, tools	present	present	systemMessage
DirectoryAdded	not fired	—	—	—	—
FileChanged	yes ×6	filechanged-nested, tools	present	present	—
WorktreeCreate	yes ×2	worktree, worktree-agent	present	present	worktree
WorktreeRemove	not fired	—	—	—	—
PreCompact	yes ×2	compact-auto, compact-manual	present	present	—
PostCompact	yes ×2	compact-auto, compact-manual	present	present	—
PreModelSwitch	yes ×2	model-switch, model-switch-exit2	present	present	exit2
PostModelSwitch	yes ×1	model-switch	present	present	—
Elicitation	not fired	—	—	—	action:accept+content
ElicitationResult	not fired	—	—	—	—
SessionEnd	yes ×34	add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-429, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, worktree-agent	present	present	systemMessage

Matrix — Codex CLI (codex-cli 0.152.1)

Event	Fired	Runs	hook_event_name	session_id	Replies exercised
SessionStart	yes ×25	additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	--strict-config with the probe's hook block, additionalContext, systemMessage
SessionEnd	yes ×24	additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	systemMessage
SubagentStart	yes ×3	subagent, subagent-exit2, subagent-role	present	present	codex exec -c agent_role="probe-reviewer", codex exec -c agent_type="probe-reviewer", codex exec -c agents.probe-reviewer.config_file=".codex/agents/probe-reviewer.toml", codex exec -c role="probe-reviewer", codex exec -p <role file as profile>, role file, role file with an unknown key, role file with an unknown key (--strict-config)
SubagentStop	yes ×4	subagent, subagent-exit2, subagent-role	present	present	exit2
PreToolUse	yes ×29	additional-context, compact, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, role-bogus, role-bogus-strict, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	additionalContext, permissionDecision:deny, systemMessage
PermissionRequest	yes ×1	perm-deny	present	present	decision:allow, decision:allow (approval_policy=on-request), decision:deny
PostToolUse	yes ×24	additional-context, compact, perm-allow, perm-deny, perm-onrequest, posttool-block, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	additionalContext, decision:block, systemMessage
PreCompact	yes ×1	compact	present	present	—
PostCompact	yes ×1	compact	present	present	—
UserPromptSubmit	yes ×24	additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	additionalContext, exit2, systemMessage
Stop	yes ×20	additional-context, compact, exec-as-role-4, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools	present	present	decision:block, exit2, systemMessage
Interrupt	yes ×1	interrupt	present	present	—

Events — Claude Code

SessionStart — Claude Code

Fired 40 time(s) in run(s) add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent. hook_event_name: present; session_id: present. Payload keys: context_tokens, cwd, estimated_cache_write_usd, hook_event_name, model, prompt_cache_likely_expired, prompt_id, seconds_since_last_response, session_id, source, transcript_path.

Payload, verbatim (source: "startup"):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"SessionStart","source":"startup"}

Payload, verbatim (source: "compact"):

{"session_id":"8696992c-e252-4b26-aa6e-0f09b973a8fc","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/8696992c-e252-4b26-aa6e-0f09b973a8fc.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"b1988ab3-5c85-48da-81fd-b0bd3a241365","hook_event_name":"SessionStart","source":"compact","model":"claude-haiku-4-5-20251001"}

Payload, verbatim (source: "resume"):

{"session_id":"ea4f4119-202c-4931-9721-72c83db1f7af","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/ea4f4119-202c-4931-9721-72c83db1f7af.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"SessionStart","source":"resume","seconds_since_last_response":1,"context_tokens":42637,"prompt_cache_likely_expired":false,"estimated_cache_write_usd":0.0853}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → honored — marker PROBE_SYSMSG SessionStart appears 1 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX SessionStart': yes; the marker is in the transcript 3 time(s) (event fired in the run: 1 times) (run additional-context)

Setup — Claude Code

Fired 2 time(s) in run(s) setup-init, setup-maintenance. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, session_id, transcript_path, trigger.

Payload, verbatim (trigger: "init"):

{"session_id":"a16a5ec3-e3a5-44d2-8c82-b0e265ff8ea0","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/a16a5ec3-e3a5-44d2-8c82-b0e265ff8ea0.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"Setup","trigger":"init"}

Payload, verbatim (trigger: "maintenance"):

{"session_id":"6387e875-a636-4eb4-89b5-f67903067f13","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/6387e875-a636-4eb4-89b5-f67903067f13.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"Setup","trigger":"maintenance"}

Triggers tried:

• run setup-init: claude -p --init; run setup-maintenance: claude -p --maintenance

UserPromptSubmit — Claude Code

Fired 33 time(s) in run(s) add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, permission_mode, prompt, prompt_id, session_id, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"UserPromptSubmit","prompt":"Do these steps in order with tools, one tool call per step, never two in parallel: 1) Bash: true  2) Bash: false  3) Bash: grep -c zzz /dev/null  4) Edit tool: in .leopold/PLAN.md replace 'item one' with 'item one (edited)'  5) Edit tool: in PLAN.md (project root) replace 'root item' with 'root item (edited)'  6) Bash: sleep 6  7) Bash: cat .leopold/PLAN.md  8) Bash: cd sub && pwd. Then reply with the single word DONE."}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• exit2 → honored — hook_response: outcome=error exit_code=2; assistant messages carrying the prompt's marker: 0; Stop fired: 0; final: UserPromptSubmit operation blocked by hook: (run prompt-exit2)
• systemMessage → honored — marker PROBE_SYSMSG UserPromptSubmit appears 2 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX UserPromptSubmit': no; the marker is in the transcript 2 time(s) (event fired in the run: 1 times) (run additional-context)

UserPromptExpansion — Claude Code

Fired 2 time(s) in run(s) command, command-exit2. hook_event_name: present; session_id: present. Payload keys: command_args, command_name, command_source, cwd, expansion_type, hook_event_name, permission_mode, prompt, prompt_id, session_id, transcript_path.

Payload, verbatim:

{"session_id":"b2c0e499-5929-43e8-ad86-0161c31208f7","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/b2c0e499-5929-43e8-ad86-0161c31208f7.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"c76c421a-e281-4814-aa56-23155a1840da","permission_mode":"bypassPermissions","hook_event_name":"UserPromptExpansion","expansion_type":"slash_command","command_name":"probecmd","command_args":"","command_source":"projectSettings","prompt":"/probecmd"}

Triggers tried:

• run command: the user prompt is the project command /probecmd (.claude/commands/probecmd.md)

Replies the harness honored:

• exit2 → honored — hook_response: outcome=error exit_code=2; the command's expansion text reached the model: no; final reply: UserPromptExpansion operation blocked by hook: (run command-exit2)

PreToolUse — Claude Code

Fired 48 time(s) in run(s) additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_type, cwd, hook_event_name, permission_mode, prompt_id, session_id, tool_input, tool_name, tool_use_id, transcript_path.

Payload, verbatim (Bash: {"command":"true","description":"Step 1: Run true command"}):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PreToolUse","tool_name":"Bash","tool_input":{"command":"true","description":"Step 1: Run true command"},"tool_use_id":"toolu_012pvg9iy5XR1HxLRHTMbFL8"}

Payload, verbatim (Bash: {"command":"false","description":"Step 2: Run false command"}):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PreToolUse","tool_name":"Bash","tool_input":{"command":"false","description":"Step 2: Run false command"},"tool_use_id":"toolu_01QTAduNmuev93E45QX6sgsE"}

Payload, verbatim (Bash: {"command":"grep -c zzz /dev/null","description":"Step 3: Count matches of zzz i):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PreToolUse","tool_name":"Bash","tool_input":{"command":"grep -c zzz /dev/null","description":"Step 3: Count matches of zzz in /dev/null"},"tool_use_id":"toolu_01BkUCMD3BxMCBKacum25xQg"}

Payload, verbatim (Read: {"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PreToolUse","tool_name":"Read","tool_input":{"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md"},"tool_use_id":"toolu_01WpaqWWUfNkkeDCWHzoNWHm"}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• observe → n/a — inside the subagent, PreToolUse carries agent_id: acb594f61d1631b05 (run subagent)
• permissionDecision:deny → honored — PostToolUse fired 0 times after the deny (0 = the tool never ran); reason reached the model: yes (run pretool-deny)
• systemMessage → honored — marker PROBE_SYSMSG PreToolUse appears 2 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX PreToolUse': no; the marker is in the transcript 3 time(s) (event fired in the run: 1 times) (run additional-context)

PermissionRequest — Claude Code

Fired 2 time(s) in run(s) perm-allow, perm-deny. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, permission_mode, permission_suggestions, prompt_id, session_id, tool_input, tool_name, transcript_path.

Payload, verbatim:

{"session_id":"12f459b8-ddba-474a-8dbb-05427ec73267","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/12f459b8-ddba-474a-8dbb-05427ec73267.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"7fabe826-67ae-42c3-9c36-d334df729b6c","permission_mode":"default","hook_event_name":"PermissionRequest","tool_name":"Bash","tool_input":{"command":"touch probe-allow.txt && echo PROBE_ALLOWED","description":"Create probe-allow.txt file and echo PROBE_ALLOWED"},"permission_suggestions":[{"type":"addDirectories","directories":["/private/tmp/leopold-hookprobe.gjQnXe/claude-project"],"destination":"session"},{"type":"setMode","mode":"acceptEdits","destination":"session"}]}

Triggers tried:

• run perm-allow: default permission mode with --permission-prompts none; Bash touch (not auto-approved) needs a decision
• run perm-host: the same Bash touch with the default --permission-prompts host (a plain CLI -p has no host)

Replies the harness honored:

• decision:allow → honored — the file the command creates exists: yes; PostToolUse fired: 1 (run perm-allow)
• decision:deny → honored — the file exists: no; message PROBE_DENY reached the model: yes; PermissionDenied fired: 0 (run perm-deny)
• decision:allow (host prompts) → not-honored — with --permission-prompts host (the default) the hook fired 0 times and the file exists: no — permission_denials in the result: 1 (run perm-host)

PermissionDenied — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run perm-auto: --permission-mode auto with a Bash touch (denied, permission_denials=1); also run perm-deny: a PermissionRequest hook answering deny

PostToolUse — Claude Code

Fired 43 time(s) in run(s) additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, posttool-block, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_type, cwd, duration_ms, hook_event_name, permission_mode, prompt_id, session_id, tool_input, tool_name, tool_response, tool_use_id, transcript_path.

Payload, verbatim (Bash: {"command":"true","description":"Step 1: Run true command"}):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolUse","tool_name":"Bash","tool_input":{"command":"true","description":"Step 1: Run true command"},"tool_response":{"stdout":"","stderr":"","interrupted":false,"isImage":false,"noOutputExpected":false},"tool_use_id":"toolu_012pvg9iy5XR1HxLRHTMbFL8","duration_ms":90}

Payload, verbatim (Bash: {"command":"grep -c zzz /dev/null","description":"Step 3: Count matches of zzz i):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolUse","tool_name":"Bash","tool_input":{"command":"grep -c zzz /dev/null","description":"Step 3: Count matches of zzz in /dev/null"},"tool_response":{"stdout":"0","stderr":"","interrupted":false,"isImage":false,"returnCodeInterpretation":"No matches found","noOutputExpected":false},"tool_use_id":"toolu_01BkUCMD3BxMCBKacum25xQg","duration_ms":17}

Payload, verbatim (Read: {"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolUse","tool_name":"Read","tool_input":{"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md"},"tool_response":{"type":"text","file":{"filePath":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md","content":"# Plan\n- [ ] item one\n","numLines":3,"startLine":1,"totalLines":3}},"tool_use_id":"toolu_01WpaqWWUfNkkeDCWHzoNWHm","duration_ms":2}

Payload, verbatim (Edit: {"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolUse","tool_name":"Edit","tool_input":{"file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md","old_string":"- [ ] item one","new_string":"- [ ] item one (edited)","replace_all":false},"tool_response":{"filePath":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md","oldString":"- [ ] item one","newString":"- [ ] item one (edited)","originalFile":"# Plan\n- [ ] item one\n","structuredPatch":[{"oldStart":1,"oldLines":2,"newStart":1,"newLines":2,"lines":[" # Plan","-- [ ] item one","+- [ ] item one (edited)"]}],"userModified":false,"replaceAll":false},"tool_use_id":"toolu_01F3Ro7STSqrLt9kMqMwtkZK","duration_ms":3}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• observe → n/a — Bash true (exit 0) fired PostToolUse: yes; the failing false fired PostToolUseFailure with error="Exit code 1" — a non-zero Bash exit is routed to PostToolUseFailure UNLESS the harness re-interprets it — grep -c zzz /dev/null (exit 1) reached PostToolUse instead, with returnCodeInterpretation="No matches found" (Findings) (run tools)
• decision:block → honored — hook_response: outcome=success exit_code=0; the reason PROBE_BLOCK reached the model/stream: yes (run posttool-block)
• systemMessage → honored — marker PROBE_SYSMSG PostToolUse appears 2 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX PostToolUse': no; the marker is in the transcript 3 time(s) (event fired in the run: 1 times) (run additional-context)

PostToolUseFailure — Claude Code

Fired 1 time(s) in run(s) tools. hook_event_name: present; session_id: present. Payload keys: cwd, duration_ms, error, hook_event_name, is_interrupt, permission_mode, prompt_id, session_id, tool_input, tool_name, tool_use_id, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolUseFailure","tool_name":"Bash","tool_input":{"command":"false","description":"Step 2: Run false command"},"tool_use_id":"toolu_01QTAduNmuev93E45QX6sgsE","error":"Exit code 1","is_interrupt":false,"duration_ms":11}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

PostToolBatch — Claude Code

Fired 48 time(s) in run(s) additional-context, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, subagent, subagent-exit2, system-message, tasks, tasks-exit2, tools, worktree-agent. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_type, cwd, hook_event_name, permission_mode, prompt_id, session_id, tool_calls, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"PostToolBatch","tool_calls":[{"tool_name":"Bash","tool_input":{"command":"true","description":"Step 1: Run true command"},"tool_use_id":"toolu_012pvg9iy5XR1HxLRHTMbFL8","tool_response":"(Bash completed with no output)"}]}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → honored — marker PROBE_SYSMSG PostToolBatch appears 2 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX PostToolBatch': no; the marker is in the transcript 3 time(s) (event fired in the run: 1 times) (run additional-context)

Notification — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd · runs perm-allow / perm-deny / perm-host: a permission decision in a headless session (matcher permission_prompt)

MessageDisplay — Claude Code

Fired 48 time(s) in run(s) add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent. hook_event_name: present; session_id: present. Payload keys: cwd, delta, final, hook_event_name, index, message_id, prompt_id, session_id, transcript_path, turn_id.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","hook_event_name":"MessageDisplay","turn_id":"73b5ff9c-0cac-4cde-9090-c8f3d5aa1339","message_id":"98f9e48b-9ef9-497e-9489-154e822c1cec","index":0,"final":true,"delta":"I'll execute these steps sequentially, one tool call per step."}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → honored — marker PROBE_SYSMSG MessageDisplay appears 1 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)

SubagentStart — Claude Code

Fired 3 time(s) in run(s) subagent, subagent-exit2, worktree-agent. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_type, cwd, hook_event_name, prompt_id, session_id, transcript_path.

Payload, verbatim:

{"session_id":"049615d1-d898-4fdb-ac17-53e8749b4b97","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/049615d1-d898-4fdb-ac17-53e8749b4b97.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"3ab1ba79-1a1c-47f8-8fd5-752a1894b69b","agent_id":"acb594f61d1631b05","agent_type":"general-purpose","hook_event_name":"SubagentStart"}

Triggers tried:

• run subagent: the Agent tool (subagent_type general-purpose) running one Bash command

SubagentStop — Claude Code

Fired 6 time(s) in run(s) compact-auto, compact-manual, subagent, subagent-exit2, worktree-agent. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_transcript_path, agent_type, background_tasks, cwd, hook_event_name, last_assistant_message, permission_mode, prompt_id, session_crons, session_id, stop_hook_active, transcript_path.

Payload, verbatim (stop_hook_active: false):

{"session_id":"049615d1-d898-4fdb-ac17-53e8749b4b97","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/049615d1-d898-4fdb-ac17-53e8749b4b97.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"3ab1ba79-1a1c-47f8-8fd5-752a1894b69b","permission_mode":"bypassPermissions","agent_id":"acb594f61d1631b05","agent_type":"general-purpose","hook_event_name":"SubagentStop","stop_hook_active":false,"agent_transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/049615d1-d898-4fdb-ac17-53e8749b4b97/subagents/agent-acb594f61d1631b05.jsonl","last_assistant_message":"PONG","background_tasks":[],"session_crons":[]}

Payload, verbatim (stop_hook_active: true):

{"session_id":"54b1292d-2d58-42bc-afaf-84baf89dc352","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/54b1292d-2d58-42bc-afaf-84baf89dc352.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"e57be662-12a6-46ed-85f2-8bf695bc7694","permission_mode":"bypassPermissions","agent_id":"af5a008acb95c5a66","agent_type":"general-purpose","hook_event_name":"SubagentStop","stop_hook_active":true,"agent_transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/54b1292d-2d58-42bc-afaf-84baf89dc352/subagents/agent-af5a008acb95c5a66.jsonl","last_assistant_message":"Acknowledged. The subagent stop hook was executed successfully with:\n- Hook: `SubagentStop`\n- Output path: `/private/tmp/claude-501/-Users-jonhvmp-myspace-github-leopold/f8164f0a-f022-4498-9d87-6f196802cf56/scratchpad/final`\n- Result: `probe exit2 SubagentStop`\n\nIs there anything else you'd like me to do?","background_tasks":[],"session_crons":[]}

Triggers tried:

• run subagent: the Agent tool (subagent_type general-purpose) running one Bash command

Replies the harness honored:

• exit2 → honored — SubagentStop fired 2 times in the run (exit 2 once, then the subagent stopped again); stop_hook_active on the second: true; hook_response: outcome=success exit_code=0 (run subagent-exit2)

TaskCreated — Claude Code

Fired 2 time(s) in run(s) tasks, tasks-exit2. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, prompt_id, session_id, task_description, task_id, task_subject, transcript_path.

Payload, verbatim:

{"session_id":"24a348d1-5aa2-479f-aefe-51d20940d6cf","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/24a348d1-5aa2-479f-aefe-51d20940d6cf.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"f04c18bc-db45-4ccf-aebc-e0b6c15435b0","hook_event_name":"TaskCreated","task_id":"1","task_subject":"probe task","task_description":"probe"}

Triggers tried:

• run tasks: TaskCreate then TaskUpdate(status=completed) then TaskList

TaskCompleted — Claude Code

Fired 2 time(s) in run(s) tasks, tasks-exit2. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, prompt_id, session_id, task_description, task_id, task_subject, transcript_path.

Payload, verbatim:

{"session_id":"24a348d1-5aa2-479f-aefe-51d20940d6cf","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/24a348d1-5aa2-479f-aefe-51d20940d6cf.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"f04c18bc-db45-4ccf-aebc-e0b6c15435b0","hook_event_name":"TaskCompleted","task_id":"1","task_subject":"probe task","task_description":"probe"}

Triggers tried:

• run tasks: TaskCreate then TaskUpdate(status=completed) then TaskList

Replies the harness honored:

• exit2 → honored — hook_response: outcome=error exit_code=2; final reply: Task created, updated to completed, and here's the status from TaskList: (run tasks-exit2)

Stop — Claude Code

Fired 29 time(s) in run(s) add-dir, additional-context, command, compact-auto, compact-manual-seed, config-change, config-change-exit2, filechanged-cwd, filechanged-nested, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, worktree-agent. hook_event_name: present; session_id: present. Payload keys: background_tasks, cwd, hook_event_name, last_assistant_message, permission_mode, prompt_id, session_crons, session_id, stop_hook_active, transcript_path.

Payload, verbatim (stop_hook_active: false):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/sub","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","permission_mode":"bypassPermissions","hook_event_name":"Stop","stop_hook_active":false,"last_assistant_message":"DONE","background_tasks":[],"session_crons":[]}

Payload, verbatim (stop_hook_active: true):

{"session_id":"6e892317-009f-4b39-98c7-b8059db80916","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/6e892317-009f-4b39-98c7-b8059db80916.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"da942d3a-2805-441e-b5f2-17c165d0e5d8","permission_mode":"bypassPermissions","hook_event_name":"Stop","stop_hook_active":true,"last_assistant_message":"Understood. The stop hook has executed and captured the exit state. The probe shows `exit2 Stop` was recorded.\n\nWhat would you like me to do next? Are you testing the hook behavior, debugging the probe system, or is there a specific issue with the stop hook that needs investigation?","background_tasks":[],"session_crons":[]}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• exit2 → honored — Stop fired 2 times (exit 2 once; the model continued and stopped again); stop_hook_active on the second: true; hook_response: outcome=success exit_code=0 (run stop-exit2)
• decision:block → honored — Stop fired 2 times ({"decision":"block"} once); stop_hook_active on the second: true (run stop-block)
• systemMessage → honored — marker PROBE_SYSMSG Stop appears 2 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)

StopFailure — Claude Code

Fired 5 time(s) in run(s) fail-500. hook_event_name: present; session_id: present. Payload keys: cwd, error, hook_event_name, last_assistant_message, prompt_id, session_id, transcript_path.

Payload, verbatim (error: "authentication_failed"):

{"session_id":"e175fdc4-0642-4929-adf4-f4d2b726fe67","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/e175fdc4-0642-4929-adf4-f4d2b726fe67.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"1403dcf9-1cdd-4834-a5f3-4e1fabdef016","hook_event_name":"StopFailure","error":"authentication_failed","last_assistant_message":"Failed to authenticate. API Error: 401 PROBE invalid credentials"}

Payload, verbatim (error: "rate_limit"):

{"session_id":"9a7d2b2e-5b6d-4db8-b454-40ddd4c47b40","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/9a7d2b2e-5b6d-4db8-b454-40ddd4c47b40.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4298ce5d-a63c-4816-890d-1eeea7d5d0df","hook_event_name":"StopFailure","error":"rate_limit","last_assistant_message":"API Error: Server is temporarily limiting requests (not your usage limit) · PROBE rate limited"}

Payload, verbatim (error: "server_error"):

{"session_id":"5189f5c3-682d-4a38-af63-21fa311293bb","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/5189f5c3-682d-4a38-af63-21fa311293bb.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"20cb75b2-493f-4666-817a-84c47154ca60","hook_event_name":"StopFailure","error":"server_error","last_assistant_message":"API Error: 500 PROBE internal server error. This is a server-side issue, usually temporary — try again in a moment. If it persists, check your inference gateway (127.0.0.1:19200)."}

Triggers tried:

• run fail-401: ANTHROPIC_BASE_URL at a Python-stdlib stub answering HTTP 401 (CLAUDE_CODE_MAX_RETRIES=0)
• run fail-429: ANTHROPIC_BASE_URL at a Python-stdlib stub answering HTTP 429 (CLAUDE_CODE_MAX_RETRIES=0)
• run fail-500: ANTHROPIC_BASE_URL at a Python-stdlib stub answering HTTP 500 (CLAUDE_CODE_MAX_RETRIES=0)
• run fail-529: ANTHROPIC_BASE_URL at a Python-stdlib stub answering HTTP 529 (CLAUDE_CODE_MAX_RETRIES=0)
• run unauth: a fresh CLAUDE_CONFIG_DIR with no login (Not logged in)

Replies the harness honored:

• observe → n/a — HTTP 401 from the stub (1 request(s) to /v1/messages?beta=true) → StopFailure error=; Stop fired: 0; SessionEnd fired: 0 (run fail-401)
• observe → n/a — HTTP 429 from the stub (1 request(s) to /v1/messages?beta=true) → StopFailure error=; Stop fired: 0; SessionEnd fired: 1 (run fail-429)
• observe → n/a — HTTP 500 from the stub (1 request(s) to /v1/messages?beta=true) → StopFailure error=authentication_failed; Stop fired: 0; SessionEnd fired: 0 (run fail-500)
• observe → n/a — HTTP 529 from the stub (1 request(s) to /v1/messages?beta=true) → StopFailure error=; Stop fired: 0; SessionEnd fired: 0 (run fail-529)
• observe → n/a — unauthenticated temp config dir: StopFailure error=; events that fired: InstructionsLoaded MessageDisplay SessionStart UserPromptSubmit (run unauth)

TeammateIdle — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run teams: CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 and a prompt asking for TeamCreate + one teammate going idle (reply: NO_TEAM_TOOL)

InstructionsLoaded — Claude Code

Fired 38 time(s) in run(s) add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-401, fail-429, fail-500, fail-529, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, unauth, worktree-agent. hook_event_name: present; session_id: present. Payload keys: cwd, file_path, hook_event_name, load_reason, memory_type, session_id, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"InstructionsLoaded","file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/CLAUDE.md","memory_type":"Project","load_reason":"session_start"}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → unobservable — marker PROBE_SYSMSG InstructionsLoaded appears 0 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)
• additionalContext → not-honored — the model repeated 'PROBE_CTX InstructionsLoaded': no; the marker is in the transcript 0 0 time(s) (event fired in the run: 1 times) (run additional-context)

ConfigChange — Claude Code

Fired 2 time(s) in run(s) config-change, config-change-exit2. hook_event_name: present; session_id: present. Payload keys: cwd, file_path, hook_event_name, prompt_id, session_id, source, transcript_path.

Payload, verbatim:

{"session_id":"23d889d0-a993-443d-8c40-260d3d2d2180","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/23d889d0-a993-443d-8c40-260d3d2d2180.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"2df4e6ad-452e-4eda-a97c-4e395086d0a9","hook_event_name":"ConfigChange","source":"project_settings","file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.claude/settings.json"}

Triggers tried:

• run config-change: the session's own Bash rewrites .claude/settings.json mid-session (jq adds a key), then sleeps 3s

Replies the harness honored:

• exit2 → unobservable — hook_response: ; the file on disk keeps the edit (the block stops the reload, not the write): probeKey present = true (run config-change-exit2)

CwdChanged — Claude Code

Fired 2 time(s) in run(s) filechanged-cwd, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, new_cwd, old_cwd, prompt_id, session_id, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/sub","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","hook_event_name":"CwdChanged","old_cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","new_cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/sub"}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → unobservable — marker PROBE_SYSMSG CwdChanged appears 0 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)

DirectoryAdded — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run add-dir: the /add-dir command in -p (answer: /add-dir isn't available in this environment.); run add-dir-control: an SDK control_request register_repo_root over stream-json stdin (response: "error")

FileChanged — Claude Code

Fired 6 time(s) in run(s) filechanged-nested, tools. hook_event_name: present; session_id: present. Payload keys: cwd, event, file_path, hook_event_name, prompt_id, session_id, transcript_path.

Payload, verbatim (file_path: "/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md"):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","hook_event_name":"FileChanged","file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/.leopold/PLAN.md","event":"change"}

Payload, verbatim (file_path: "/private/tmp/leopold-hookprobe.gjQnXe/claude-project/PLAN.md"):

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","hook_event_name":"FileChanged","file_path":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/PLAN.md","event":"change"}

Triggers tried:

• run filechanged-cwd: the same wiring, with cd sub (CwdChanged) BEFORE the edits and the external append
• run filechanged-nested: the same two entries with NO PLAN.md in the project root — an Edit of .leopold/PLAN.md plus an append from another process
• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• observe → n/a — two entries wired: matcher .leopold/PLAN.md (registers the watch) and matcher PLAN.md (receives); firings per entry and path: 2 matches=PLAN.md -> .leopold/PLAN.md; 2 matches=PLAN.md -> PLAN.md; — the session's own Edit and the other process's append produce payloads of the same shape (file_path + event), nothing in the payload tells them apart; the path-shaped entry never fires itself (run tools)
• observe (after a cd in the session) → n/a — after cd sub (CwdChanged) the same wiring fired 0 times for two Edits and one external append — a cwd change detaches the watches (run filechanged-cwd)
• observe (no root PLAN.md) → n/a — with no PLAN.md in the project root, FileChanged fired 2 times for .leopold/PLAN.md (Edit + external append): 2 .leopold/PLAN.md; (run filechanged-nested)

WorktreeCreate — Claude Code

Fired 2 time(s) in run(s) worktree, worktree-agent. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, name, prompt_id, session_id, transcript_path.

Payload, verbatim:

{"session_id":"cb14dfc0-a66d-486e-aeec-c0d6d37375c3","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/cb14dfc0-a66d-486e-aeec-c0d6d37375c3.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","hook_event_name":"WorktreeCreate","name":"probe-wt"}

Triggers tried:

• run worktree: claude -p --worktree probe-wt in a git project (the hook creates the worktree and echoes its path — an empty answer aborts the session)

Replies the harness honored:

• worktree → honored — the session ran inside the path the hook echoed: yes; worktrees after the run: 2 (run worktree)

WorktreeRemove — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run worktree: the --worktree session exiting with a clean worktree; run worktree-agent: an Agent tool call with isolation worktree finishing

PreCompact — Claude Code

Fired 2 time(s) in run(s) compact-auto, compact-manual. hook_event_name: present; session_id: present. Payload keys: custom_instructions, cwd, hook_event_name, prompt_id, session_id, transcript_path, trigger.

Payload, verbatim (trigger: "auto"):

{"session_id":"8696992c-e252-4b26-aa6e-0f09b973a8fc","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/8696992c-e252-4b26-aa6e-0f09b973a8fc.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"b1988ab3-5c85-48da-81fd-b0bd3a241365","hook_event_name":"PreCompact","trigger":"auto","custom_instructions":null}

Payload, verbatim (trigger: "manual"):

{"session_id":"ea4f4119-202c-4931-9721-72c83db1f7af","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/ea4f4119-202c-4931-9721-72c83db1f7af.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"5dc35203-ab1c-4bb5-900f-f1a67c33d899","hook_event_name":"PreCompact","trigger":"manual","custom_instructions":null}

Triggers tried:

• run compact-auto: --autocompact 100000 and three full reads of a 120 KB file (CLAUDE_CODE_AUTO_COMPACT_WINDOW=60000 + CLAUDE_AUTOCOMPACT_PCT_OVERRIDE=50 fired both events too in the pilot)
• run compact-manual: claude -p --resume <id> /compact

Replies the harness honored:

• observe → n/a — auto compaction: PreCompact fired 1 times, PostCompact 1 times; compact_boundary in the stream: {"trigger":"auto","pre_tokens":70493,"post_tokens":7859}; SessionStart fired again after each compaction (source: compact,startup,) (run compact-auto)
• observe → n/a — manual compaction via /compact on a resumed session: PreCompact 1, PostCompact 1 (trigger: manual) (run compact-manual)

PostCompact — Claude Code

Fired 2 time(s) in run(s) compact-auto, compact-manual. hook_event_name: present; session_id: present. Payload keys: compact_summary, cwd, hook_event_name, prompt_id, session_id, transcript_path, trigger.

Payload, verbatim (trigger: "auto"):

{"session_id":"8696992c-e252-4b26-aa6e-0f09b973a8fc","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/8696992c-e252-4b26-aa6e-0f09b973a8fc.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"b1988ab3-5c85-48da-81fd-b0bd3a241365","hook_event_name":"PostCompact","trigger":"auto","compact_summary":"<analysis>\nLet me carefully analyze this conversation chronologically:\n\n1. **Initial Setup**: The conversation begins with system context showing a git repository with branch \"main\" and some modified/untracked files (.leopold/PLAN.md, PLAN.md, .claude/settings.json files, probe-allow.txt).\n\n2. **User's Primary Request**: The user explicitly requests:\n   - Read big.txt (whole file, no offset/limit) three separate times, one call at a time\n   - Run Bash command: wc -c big.txt\n …[+4237 chars]"}

Payload, verbatim (trigger: "manual"):

{"session_id":"ea4f4119-202c-4931-9721-72c83db1f7af","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/ea4f4119-202c-4931-9721-72c83db1f7af.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"5dc35203-ab1c-4bb5-900f-f1a67c33d899","hook_event_name":"PostCompact","trigger":"manual","compact_summary":"<analysis>\nThe conversation history is minimal and focused on two distinct requests:\n\n1. Initial Request (Message 1): The user asked me to read big.txt in its entirety and respond with \"DONE\".\n   - I executed this request using the Read tool\n   - The Read tool returned a partial view due to character limits (showing first 24527 of 120001 characters)\n   - The file contains what appears to be encoded or random string data\n\n2. Second Request (Current Message): The user is now as…[+3716 chars]"}

Triggers tried:

• run compact-auto: --autocompact 100000 and three full reads of a 120 KB file (CLAUDE_CODE_AUTO_COMPACT_WINDOW=60000 + CLAUDE_AUTOCOMPACT_PCT_OVERRIDE=50 fired both events too in the pilot)
• run compact-manual: claude -p --resume <id> /compact

PreModelSwitch — Claude Code

Fired 2 time(s) in run(s) model-switch, model-switch-exit2. hook_event_name: present; session_id: present. Payload keys: cache_ttl, context_tokens, cwd, estimated_cache_write_usd, from_model, hook_event_name, pricing, prompt_cache_warm, prompt_id, requested_model, session_id, source, to_model, transcript_path.

Payload, verbatim:

{"session_id":"1d5b76b2-f059-4f62-8a9d-48a0f9f6f1c9","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/1d5b76b2-f059-4f62-8a9d-48a0f9f6f1c9.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"3112dde5-323d-492f-aaf9-4843adb1d9af","hook_event_name":"PreModelSwitch","from_model":"claude-haiku-4-5-20251001","to_model":"claude-sonnet-5","requested_model":"sonnet","source":"command","context_tokens":0,"prompt_cache_warm":false,"cache_ttl":"1h","estimated_cache_write_usd":0,"pricing":"catalog"}

Triggers tried:

• run model-switch: the /model sonnet command in a -p session started on haiku

Replies the harness honored:

• exit2 → honored — PostModelSwitch fired 0 times after the block (0 = the switch did not happen); final: Model switch to Sonnet 5 was blocked by a PreModelSwitch hook: [bash /Users/jonhvmp/myspace/github/leopold/scripts/probe/dump-hook.sh PreModelSwitch --out /priv (run model-switch-exit2)

PostModelSwitch — Claude Code

Fired 1 time(s) in run(s) model-switch. hook_event_name: present; session_id: present. Payload keys: cache_ttl, context_tokens, cwd, estimated_cache_write_usd, from_model, hook_event_name, pricing, prompt_cache_warm, prompt_id, requested_model, session_id, source, to_model, transcript_path.

Payload, verbatim:

{"session_id":"1d5b76b2-f059-4f62-8a9d-48a0f9f6f1c9","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/1d5b76b2-f059-4f62-8a9d-48a0f9f6f1c9.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project","prompt_id":"3112dde5-323d-492f-aaf9-4843adb1d9af","hook_event_name":"PostModelSwitch","from_model":"claude-haiku-4-5-20251001","to_model":"claude-sonnet-5","requested_model":"sonnet","source":"command","context_tokens":0,"prompt_cache_warm":false,"cache_ttl":"1h","estimated_cache_write_usd":0,"pricing":"catalog"}

Triggers tried:

• run model-switch: the /model sonnet command in a -p session started on haiku

Elicitation — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run elicit-observe: a stdio MCP stub whose tool sends elicitation/create back to the client

Replies the harness honored:

• action:accept+content → not-honored — the MCP server received the hook's answer: ; ElicitationResult fired: 0 (it fires only on the user/cancel path) (run elicit-accept)

ElicitationResult — Claude Code

Not fired on Claude Code 2.1.259 (Claude Code). Trigger tried: run elicit-observe: the same elicitation, unanswered by any hook, in a headless session (auto-cancelled)

Replies the harness honored:

• observe → n/a — with no hook answer the headless session cancelled: action=; the MCP server received: (run elicit-observe)

SessionEnd — Claude Code

Fired 34 time(s) in run(s) add-dir, additional-context, command, command-exit2, compact-auto, compact-manual, compact-manual-seed, config-change, config-change-exit2, fail-429, filechanged-cwd, filechanged-nested, model-switch, model-switch-exit2, perm-allow, perm-auto, perm-deny, perm-host, posttool-block, pretool-deny, prompt-exit2, setup-init, setup-maintenance, stop-block, stop-exit2, subagent, subagent-exit2, system-message, tasks, tasks-exit2, teams, tools, worktree-agent. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, prompt_id, reason, session_id, transcript_path.

Payload, verbatim:

{"session_id":"777e68b4-1ad1-4f6c-9d81-64d0cae95a84","transcript_path":"/Users/jonhvmp/.claude/projects/-private-tmp-leopold-hookprobe-gjQnXe-claude-project/777e68b4-1ad1-4f6c-9d81-64d0cae95a84.jsonl","cwd":"/private/tmp/leopold-hookprobe.gjQnXe/claude-project/sub","prompt_id":"4c67eb26-a782-4cfe-8201-a875dc0f7985","hook_event_name":"SessionEnd","reason":"other"}

Triggers tried:

• run tools: a headless claude -p turn in a project with a CLAUDE.md that runs true, false, grep -c zzz /dev/null, an Edit of .leopold/PLAN.md and of the root PLAN.md, sleep 6 (the driver appends to both files from another process meanwhile), cat and, last, cd sub && pwd

Replies the harness honored:

• systemMessage → unobservable — marker PROBE_SYSMSG SessionEnd appears 0 times in the stream-json output (outside hook_response echoes: 5 informational;); in the transcript: 2 PROBE_SYSMSG PostToolBatch; 2 PROBE_SYSMSG PostToolUse; 2 PROBE_SYSMSG PreToolUse; 2 PROBE_SYSMSG SessionStart; 2 PROBE_SYSMSG Stop; 1 PROBE_SYSMSG UserPromptSubmit; (run system-message)

Events — Codex CLI

SessionStart — Codex CLI

Fired 25 time(s) in run(s) additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, session_id, source, transcript_path.

Payload, verbatim (source: "startup"):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SessionStart","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","source":"startup"}

Payload, verbatim (source: "compact"):

{"session_id":"01a064f2-3530-7453-9e93-f1a7093bb39d","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-46-30-01a064f2-3530-7453-9e93-f1a7093bb39d.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SessionStart","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","source":"compact"}

Triggers tried:

• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• systemMessage → unobservable — marker PROBE_SYSMSG SessionStart in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)
• additionalContext → not-honored — the model repeated 'PROBE_CTX SessionStart': no (run additional-context)
• --strict-config with the probe's hook block → n/a — rc=0; the hook wiring the shared writer emits passes --strict-config: yes (run strict-config)

SessionEnd — Codex CLI

Fired 24 time(s) in run(s) additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, reason, session_id, transcript_path.

Payload, verbatim:

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SessionEnd","reason":"other"}

Triggers tried:

• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• systemMessage → unobservable — marker PROBE_SYSMSG SessionEnd in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)

SubagentStart — Codex CLI

Fired 3 time(s) in run(s) subagent, subagent-exit2, subagent-role. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_type, cwd, hook_event_name, model, permission_mode, session_id, transcript_path, turn_id.

Payload, verbatim (agent_type: "default"):

{"session_id":"01a064ef-43f8-7a31-a2c4-e372c36fb4bd","turn_id":"01a064ef-557b-76b3-b60f-c3e732663d6c","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-43-21-01a064ef-556c-7670-a0f2-9f6a2fe2c42a.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SubagentStart","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","agent_id":"01a064ef-556c-7670-a0f2-9f6a2fe2c42a","agent_type":"default"}

Payload, verbatim (agent_type: "probe-reviewer"):

{"session_id":"01a064ef-8fc9-7782-b75b-cfdcb7ee8a12","turn_id":"01a064ef-af79-77d2-99ca-62914c6c39a4","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-43-44-01a064ef-af6b-73a1-b2d6-9d4f09708e5d.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SubagentStart","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","agent_id":"01a064ef-af6b-73a1-b2d6-9d4f09708e5d","agent_type":"probe-reviewer"}

Triggers tried:

• run subagent-role: spawn_agent with agent_type probe-reviewer (.codex/agents/probe-reviewer.toml)
• run subagent: spawn_agent (default role) + wait_agent

Replies the harness honored:

• observe → n/a — spawn tool name as seen by PreToolUse: collaborationspawn_agent; SubagentStop carries agent_transcript_path: true (run subagent)
• role file → honored — agent_type in SubagentStart: probe-reviewer; the role's fixed reply came back: yes (run subagent-role)
• role file with an unknown key → n/a — without --strict-config: Ignoring malformed agent role definition: failed to deserialize agent role file at /tmp/leopold-hookprobe.gjQnXe/codex-project/.codex/agents/bogus.toml: unknown field bogus_key ; reply: unknown agent_type 'bogus' (run role-bogus)
• role file with an unknown key (--strict-config) → n/a — with --strict-config: Ignoring malformed agent role definition: failed to deserialize agent role file at /tmp/leopold-hookprobe.gjQnXe/codex-project/.codex/agents/bogus.toml: unknown field bogus_key ; reply: unknown agent_type 'bogus' (run role-bogus-strict)
• codex exec -c agent_role="probe-reviewer" → n/a — rc=1; reply: ; stderr: Error loading config.toml: unknown configuration field agent_role in -c/--config override (run exec-as-role-1)
• codex exec -c agent_type="probe-reviewer" → n/a — rc=1; reply: ; stderr: Error loading config.toml: unknown configuration field agent_type in -c/--config override (run exec-as-role-2)
• codex exec -c role="probe-reviewer" → n/a — rc=1; reply: ; stderr: Error loading config.toml: unknown configuration field role in -c/--config override (run exec-as-role-3)
• codex exec -c agents.probe-reviewer.config_file=".codex/agents/probe-reviewer.toml" → n/a — rc=0; reply: NO_ROLE; stderr: (run exec-as-role-4)
• codex exec -p <role file as profile> → n/a — rc=1; stderr: Error loading config.toml: /private/tmp/leopold-hookprobe.gjQnXe/codex-home/probe-reviewer.config.toml:1:1: unknown configuration field name (run exec-as-role-profile)

SubagentStop — Codex CLI

Fired 4 time(s) in run(s) subagent, subagent-exit2, subagent-role. hook_event_name: present; session_id: present. Payload keys: agent_id, agent_transcript_path, agent_type, cwd, hook_event_name, last_assistant_message, model, permission_mode, session_id, stop_hook_active, transcript_path, turn_id.

Payload, verbatim (stop_hook_active: false):

{"session_id":"01a064ef-43f8-7a31-a2c4-e372c36fb4bd","turn_id":"01a064ef-557b-76b3-b60f-c3e732663d6c","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-43-17-01a064ef-43f8-7a31-a2c4-e372c36fb4bd.jsonl","agent_transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-43-21-01a064ef-556c-7670-a0f2-9f6a2fe2c42a.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SubagentStop","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","stop_hook_active":false,"agent_id":"01a064ef-556c-7670-a0f2-9f6a2fe2c42a","agent_type":"default","last_assistant_message":"PONG"}

Payload, verbatim (stop_hook_active: true):

{"session_id":"01a064f0-23a6-7082-a96c-4b3b8175e81b","turn_id":"01a064f0-35b9-7352-bbc3-b7de53c28f04","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-44-14-01a064f0-23a6-7082-a96c-4b3b8175e81b.jsonl","agent_transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-44-19-01a064f0-35ac-77d1-9871-fd30fa81b96c.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"SubagentStop","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","stop_hook_active":true,"agent_id":"01a064f0-35ac-77d1-9871-fd30fa81b96c","agent_type":"default","last_assistant_message":"PONG"}

Triggers tried:

• run subagent: spawn_agent (default role) + wait_agent

Replies the harness honored:

• exit2 → honored — SubagentStop fired 2 times (exit 2 once); stop_hook_active on the second: true (run subagent-exit2)

PreToolUse — Codex CLI

Fired 29 time(s) in run(s) additional-context, compact, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, role-bogus, role-bogus-strict, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, session_id, tool_input, tool_name, tool_use_id, transcript_path, turn_id.

Payload, verbatim (Bash: {"command":"true"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PreToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"true"},"tool_use_id":"exec-c858a358-22fb-46df-92ea-98636929adb5"}

Payload, verbatim (Bash: {"command":"false"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PreToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"false"},"tool_use_id":"exec-dcaa043b-6d5e-4e48-9fa5-c4aee89bc754"}

Payload, verbatim (Bash: {"command":"grep -c zzz /dev/null"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PreToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"grep -c zzz /dev/null"},"tool_use_id":"exec-16f28f82-27fc-422d-ac03-8261b9f48361"}

Payload, verbatim (apply_patch: {"command":" Begin Patch\n Update File: /tmp/leopold-hookprobe.gjQnXe/code):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PreToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"apply_patch","tool_input":{"command":"*** Begin Patch\n*** Update File: /tmp/leopold-hookprobe.gjQnXe/codex-project/.leopold/PLAN.md\n@@\n-- [ ] item one\n+- [ ] item one (edited)\n*** End Patch"},"tool_use_id":"exec-c46dd3f8-1a63-4260-94b3-ca57ce5579f6"}

Triggers tried:

• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• permissionDecision:deny → honored — PostToolUse fired 0 times after the deny (0 = the tool never ran); reason reached the model: yes (run pretool-deny)
• systemMessage → unobservable — marker PROBE_SYSMSG PreToolUse in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)
• additionalContext → not-honored — the model repeated 'PROBE_CTX PreToolUse': no (run additional-context)

PermissionRequest — Codex CLI

Fired 1 time(s) in run(s) perm-deny. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, session_id, tool_input, tool_name, transcript_path, turn_id.

Payload, verbatim:

{"session_id":"01a064f1-6f6f-75e1-bc35-e4fb8d06d50d","turn_id":"01a064f1-6fb2-7720-9805-3bb26d504576","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-45-39-01a064f1-6f6f-75e1-bc35-e4fb8d06d50d.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PermissionRequest","model":"gpt-5.6-sol","permission_mode":"default","tool_name":"Bash","tool_input":{"command":"curl -sI https://example.com | head -1","description":"The sandboxed command returned no output, consistent with curl’s silent mode hiding a network-access failure. Allow this exact command to run once with network access?"}}

Triggers tried:

• run perm-allow: --approve-for-me and a curl that needs network escalation out of the workspace-write sandbox
• run perm-onrequest: -s workspace-write -c approval_policy="on-request" and the same curl (fired: 0 times)

Replies the harness honored:

• decision:allow → not-honored — the escalated curl ran (an HTTP status line came back): no; PermissionRequest fired: 0 (run perm-allow)
• decision:deny → honored — the deny message reached the model: yes; an HTTP status line came back: no; stderr: Rejected(\"PROBE_DENY\") (run perm-deny)
• decision:allow (approval_policy=on-request) → not-honored — under approval_policy=on-request in headless exec the hook fired 0 times; reply: (run perm-onrequest)

PostToolUse — Codex CLI

Fired 24 time(s) in run(s) additional-context, compact, perm-allow, perm-deny, perm-onrequest, posttool-block, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, session_id, tool_input, tool_name, tool_response, tool_use_id, transcript_path, turn_id.

Payload, verbatim (Bash: {"command":"true"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PostToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"true"},"tool_response":"","tool_use_id":"exec-c858a358-22fb-46df-92ea-98636929adb5"}

Payload, verbatim (Bash: {"command":"false"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PostToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"false"},"tool_response":"","tool_use_id":"exec-dcaa043b-6d5e-4e48-9fa5-c4aee89bc754"}

Payload, verbatim (Bash: {"command":"grep -c zzz /dev/null"}):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PostToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"Bash","tool_input":{"command":"grep -c zzz /dev/null"},"tool_response":"0\n","tool_use_id":"exec-16f28f82-27fc-422d-ac03-8261b9f48361"}

Payload, verbatim (apply_patch: {"command":" Begin Patch\n Update File: /tmp/leopold-hookprobe.gjQnXe/code):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PostToolUse","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","tool_name":"apply_patch","tool_input":{"command":"*** Begin Patch\n*** Update File: /tmp/leopold-hookprobe.gjQnXe/codex-project/.leopold/PLAN.md\n@@\n-- [ ] item one\n+- [ ] item one (edited)\n*** End Patch"},"tool_response":"Exit code: 0\nWall time: 0 seconds\nOutput:\nSuccess. Updated the following files:\nM /tmp/leopold-hookprobe.gjQnXe/codex-project/.leopold/PLAN.md\n","tool_use_id":"exec-c46dd3f8-1a63-4260-94b3-ca57ce5579f6"}

Triggers tried:

• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• observe → n/a — Bash true: tool_response=""; Bash false: PostToolUse fired yes with tool_response="" — no exit code in either; PreToolUse calls without a PostToolUse in the run: 0 (failed apply_patch attempts); edit tool name: apply_patch, (run tools)
• decision:block → honored — the reason PROBE_BLOCK reached the model/stream: yes; reply: ``` (run posttool-block)
• systemMessage → unobservable — marker PROBE_SYSMSG PostToolUse in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)
• additionalContext → honored — the model repeated 'PROBE_CTX PostToolUse': yes (run additional-context)

PreCompact — Codex CLI

Fired 1 time(s) in run(s) compact. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, session_id, transcript_path, trigger, turn_id.

Payload, verbatim:

{"session_id":"01a064f2-3530-7453-9e93-f1a7093bb39d","turn_id":"01a064f2-3555-7173-9583-c58b54a53f71","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-46-30-01a064f2-3530-7453-9e93-f1a7093bb39d.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PreCompact","model":"gpt-5.6-sol","trigger":"auto"}

Triggers tried:

• run compact: -c model_auto_compact_token_limit=6000 and three full cats of a 120 KB file

Replies the harness honored:

• observe → n/a — auto compaction: PreCompact fired 1 times, PostCompact 1 times (trigger: auto) (run compact)

PostCompact — Codex CLI

Fired 1 time(s) in run(s) compact. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, session_id, transcript_path, trigger, turn_id.

Payload, verbatim:

{"session_id":"01a064f2-3530-7453-9e93-f1a7093bb39d","turn_id":"01a064f2-3555-7173-9583-c58b54a53f71","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-46-30-01a064f2-3530-7453-9e93-f1a7093bb39d.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"PostCompact","model":"gpt-5.6-sol","trigger":"auto"}

Triggers tried:

• run compact: -c model_auto_compact_token_limit=6000 and three full cats of a 120 KB file

UserPromptSubmit — Codex CLI

Fired 24 time(s) in run(s) additional-context, compact, exec-as-role-4, fail-401, fail-429, fail-500, fail-529, interrupt, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, prompt-exit2, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, prompt, session_id, transcript_path, turn_id.

Payload, verbatim:

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"UserPromptSubmit","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","prompt":"Do these steps in order with tools, one tool call per step: 1) run the shell command: true  2) run the shell command: false (it fails; continue)  3) run: grep -c zzz /dev/null (exit 1; continue)  4) edit the file .leopold/PLAN.md with your file-edit tool so 'item one' becomes 'item one (edited)' (keep the leading '- [ ] ')  5) run the shell command: sleep 6  6) run: cat .leopold/PLAN.md. Then reply with the single word DONE."}

Triggers tried:

• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• exit2 → honored — the model answered the prompt: no; Stop fired: 0; errors: (run prompt-exit2)
• systemMessage → unobservable — marker PROBE_SYSMSG UserPromptSubmit in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)
• additionalContext → not-honored — the model repeated 'PROBE_CTX UserPromptSubmit': no (run additional-context)

Stop — Codex CLI

Fired 20 time(s) in run(s) additional-context, compact, exec-as-role-4, perm-allow, perm-deny, perm-onrequest, posttool-block, pretool-deny, role-bogus, role-bogus-strict, stop-block, stop-exit2, strict-config, subagent, subagent-exit2, subagent-role, system-message, tools. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, last_assistant_message, model, permission_mode, session_id, stop_hook_active, transcript_path, turn_id.

Payload, verbatim (stop_hook_active: false):

{"session_id":"01a064ee-a7c6-7af3-872f-dd265be1acc2","turn_id":"01a064ee-a831-76d0-bfad-138dcf2efcf2","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-42-37-01a064ee-a7c6-7af3-872f-dd265be1acc2.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"Stop","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","stop_hook_active":false,"last_assistant_message":"DONE"}

Payload, verbatim (stop_hook_active: true):

{"session_id":"01a064f0-7715-7743-bfbe-b516cf211385","turn_id":"01a064f0-773e-79d1-b5fc-d8d705d614ca","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-44-35-01a064f0-7715-7743-bfbe-b516cf211385.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"Stop","model":"gpt-5.6-sol","permission_mode":"bypassPermissions","stop_hook_active":true,"last_assistant_message":"FIRST_STOP"}

Triggers tried:

• run fail-401: a custom model provider whose base_url is a Python-stdlib stub answering HTTP 401 (the turn fails; which hooks fire?)
• run fail-429: a custom model provider whose base_url is a Python-stdlib stub answering HTTP 429 (the turn fails; which hooks fire?)
• run fail-500: a custom model provider whose base_url is a Python-stdlib stub answering HTTP 500 (the turn fails; which hooks fire?)
• run fail-529: a custom model provider whose base_url is a Python-stdlib stub answering HTTP 529 (the turn fails; which hooks fire?)
• run tools: a headless codex exec turn in a project with an AGENTS.md that runs true, false, grep -c zzz /dev/null, an apply_patch edit of .leopold/PLAN.md, sleep 6 (the driver appends to .leopold/PLAN.md from another process meanwhile) and cat

Replies the harness honored:

• exit2 → honored — Stop fired 2 times (exit 2 once); stop_hook_active on the second: true; messages: 2 (run stop-exit2)
• decision:block → honored — Stop fired 2 times ({"decision":"block"} once); stop_hook_active on the second: true (run stop-block)
• systemMessage → unobservable — marker PROBE_SYSMSG Stop in the --json stream: 0 times; in the rollout transcript: 0 0 times (run system-message)
• observe (API failure HTTP 401) → n/a — HTTP 401 from the stub (3 request(s): 1 /v1/models; 2 /v1/responses;) → stream: 1 error; 4 item.completed; 1 thread.started; 1 turn.failed; 1 turn.started;; hooks that fired: SessionEnd SessionStart UserPromptSubmit ; error: Your access token could not be refreshed because your refresh token was already used. Please log out and sign in again. Your access token co (run fail-401)
• observe (API failure HTTP 429) → n/a — HTTP 429 from the stub (2 request(s): 1 /v1/models; 1 /v1/responses;) → stream: 1 error; 4 item.completed; 1 thread.started; 1 turn.failed; 1 turn.started;; hooks that fired: SessionEnd SessionStart UserPromptSubmit ; error: exceeded retry limit, last status: 429 Too Many Requests exceeded retry limit, last status: 429 Too Many Requests (run fail-429)
• observe (API failure HTTP 500) → n/a — HTTP 500 from the stub (2 request(s): 1 /v1/models; 1 /v1/responses;) → stream: 1 error; 4 item.completed; 1 thread.started; 1 turn.failed; 1 turn.started;; hooks that fired: SessionEnd SessionStart UserPromptSubmit ; error: We're currently experiencing high demand, which may cause temporary errors. We're currently experiencing high demand, which may cause tempor (run fail-500)
• observe (API failure HTTP 529) → n/a — HTTP 529 from the stub (2 request(s): 1 /v1/models; 1 /v1/responses;) → stream: 1 error; 4 item.completed; 1 thread.started; 1 turn.failed; 1 turn.started;; hooks that fired: SessionEnd SessionStart UserPromptSubmit ; error: unexpected status 529 : PROBE overloaded, url: http://127.0.0.1:19429/v1/responses unexpected status 529 <unknown statu (run fail-529)

Interrupt — Codex CLI

Fired 1 time(s) in run(s) interrupt. hook_event_name: present; session_id: present. Payload keys: cwd, hook_event_name, model, permission_mode, session_id, transcript_path, turn_id.

Payload, verbatim:

{"session_id":"01a064f2-7877-7f72-8286-b141dc83d8b0","turn_id":"01a064f2-789f-7081-8c7d-352f750ce929","transcript_path":"/private/tmp/leopold-hookprobe.gjQnXe/codex-home/sessions/2026/09/02/rollout-2026-09-02T22-46-47-01a064f2-7877-7f72-8286-b141dc83d8b0.jsonl","cwd":"/tmp/leopold-hookprobe.gjQnXe/codex-project","hook_event_name":"Interrupt","model":"gpt-5.6-sol","permission_mode":"bypassPermissions"}

Triggers tried:

• run interrupt: SIGINT to the codex exec process while its shell command sleeps

Replies the harness honored:

• observe → n/a — after SIGINT: Interrupt fired 1, Stop fired 0, SessionEnd fired 1 (run interrupt)

Findings

• Every event a headless session can reach fires on Claude Code 2.1.259 (Claude Code), in the project's own .claude/settings.json, with the same session_id/transcript_path/cwd prefix. The ones that did not fire have no headless trigger on this version: PermissionDenied (auto mode denies without consulting it), TeammateIdle (no TeamCreate tool in -p), DirectoryAdded (/add-dir is not available in -p and the register_repo_root control request answers as recorded), Notification (nothing prompts in a headless session) and WorktreeRemove (the --worktree session's exit did not call it) — each row below names the trigger tried.
• Most failing Bash commands do not reach PostToolUse on Claude Code — and the ones that do are not passes. Exit 0 fires PostToolUse with tool_response.{stdout,stderr,interrupted} and no exit code; a non-zero exit normally fires PostToolUseFailure whose error is the string "Exit code 1" (plus is_interrupt). The exception is in this same capture: grep -c zzz /dev/null, which exits 1, reached PostToolUse carrying returnCodeInterpretation: "No matches found" — the harness re-interprets a set of non-zero exits as "not an error" and annotates them instead of routing them to the failure event. So the response OBJECT decides, not the event: returnCodeInterpretation (a re-interpreted non-zero), interrupted (cut off mid-run) and backgroundTaskId (launched, not finished) each mean the command did not cleanly exit 0. Codex fires PostToolUse for both, with tool_response as a string and no exit code either way — a done-evidence gate must read the command's outcome from its own record, never from the hook payload.
• FileChanged cannot tell the session's own edit from another process's write, and its matcher does two jobs. Both the Edit tool and an external append produce the same {file_path, event: "change"} payload; the correlation has to be a PostToolUse on the same path in the same instant. The matcher registers a watch as a literal path relative to the project root (PLAN.md, .leopold/PLAN.md) and dispatches on the changed file's basename (PLAN.md, *) — so a nested file needs two entries, one path-shaped that never fires itself and one basename-shaped that receives (runs tools, filechanged-nested); PLAN.md|.envrc registers nothing, and a cd in the session (CwdChanged) detaches every watch (run filechanged-cwd). FileChanged hooks run outside the turn: they never appear as hook_started in the stream.
• Codex's edit tool is apply_patch (tool_input.command holds the patch), its shell is reported as Bash, and its multi-agent tools reach PreToolUse as collaborationspawn_agent / collaborationwait_agent. A role file in .codex/agents/<role>.toml (name, description, developer_instructions plus any config.toml key) is honored by spawn_agent(agent_type=<role>); an unknown key makes Codex ignore the file with a logged Ignoring malformed agent role definition (with and without --strict-config). codex exec cannot run as a role: agent_role, agent_type and role are rejected as unknown config fields, a role file is not a valid --profile layer, and agents.<name>.config_file only declares the role for spawning.
• Exit 2 is honored where the docs say, on both harnesses: TaskCompleted (the task stays pending), UserPromptSubmit and UserPromptExpansion (the prompt never reaches the model), Stop / SubagentStop (the agent continues and stops again with stop_hook_active: true), PreModelSwitch (no PostModelSwitch follows). {"decision":"block"} on Stop does the same on both. ConfigChange is the one exit 2 this page cannot judge: a ConfigChange hook never reaches the stream — no hook_started, no hook_response, so no exit code — and the file keeping the edit is true whether the reload was blocked or adopted, which is why its row reads unobservable. It was measured separately, by side effect (a settings rewrite that adds a hook, against a control run), in ConfigChange exit 2 — Live Verification: the reload IS blocked and the file DOES keep the edit.
• PermissionRequest needs a decision path to exist. On Claude Code it fires under --permission-prompts none (and a plain CLI -p with the default host denies without consulting it); decision.behavior allow/deny is honored (allow runs the tool, deny returns the message to the model). On Codex it fires under --approve-for-me for a sandbox escalation (network), with the same decision.behavior contract honored (Rejected("PROBE_DENY") in the stream); approval_policy="on-request" in headless exec never asks.
• An API error is a StopFailure on Claude Code and a plain turn.failed on Codex. ANTHROPIC_BASE_URL at the stub with CLAUDE_CODE_MAX_RETRIES=0 fired StopFailure for every class, with error (not error_type): rate_limit for 429, server_error for 500 and 529, authentication_failed for 401 and for a missing login; Stop does not fire and SessionEnd still does. Codex has no failure hook: the provider stub ended each turn with turn.failed, and only SessionStart, UserPromptSubmit and SessionEnd fired — no Stop, no Interrupt.
• Compaction fires PreCompact/PostCompact on both, with trigger (auto / manual); Claude Code adds custom_instructions before and the full compact_summary after, then fires SessionStart with source: "compact"; the stream carries a compact_boundary with pre_tokens/post_tokens. Codex's payloads carry turn_id and model and nothing about the summary.
• Interrupt is real on Codex: SIGINT to codex exec mid-command fires it (no Stop), then SessionEnd. Codex clamps SessionEnd and Interrupt hook timeouts to 3 s (clamping … hook timeout to 3s in its stream) — a hook on those events must be quick.
• The hook process inherits the parent's environment on both harnesses (CODEX_HOME reached the hook; Claude Code adds CLAUDE_CODE_SESSION_ID, CLAUDE_PROJECT_DIR, CLAUDE_ENV_FILE, CLAUDE_CODE_ENTRYPOINT; Codex adds nothing of its own), and hook_event_name and session_id were present in every captured payload of both harnesses — a hook can trust them, and the dump hook's name-by-argument fallback never had to fire.

What this decides for Leopold

• Every capability of this run's mission is wired only on events captured above, with the payload fields the captures show; a field the probe did not capture sends the item back to the probe, never to a guess.
• Where Codex lacks the event (StopFailure, PostToolUseFailure, TaskCompleted, FileChanged, ConfigChange), the capability ships on Claude Code with the Codex substitute the captures allow — PostToolUse plus the PLAN.md edit for done-evidence, turn.failed in the --json stream for API errors — and leopold doctor names what Codex cannot do, quoting the version this page records.
• The Interrupt and SessionEnd hooks on Codex stay under 3 s; a hook that must do more records the intent and lets the next turn finish it.

Runs

Harness	Run	rc	s	Command
claude	tools	0	38	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	filechanged-cwd	0	30	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	filechanged-nested	0	16	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	tasks	0	11	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	tasks-exit2	0	11	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	subagent	0	11	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	subagent-exit2	0	14	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	config-change	0	9	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	config-change-exit2	0	8	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	command	0	2	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	command-exit2	0	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	prompt-exit2	0	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	stop-exit2	0	7	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	stop-block	0	5	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	posttool-block	0	6	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	pretool-deny	0	5	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	perm-allow	0	6	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-prompts none
claude	perm-deny	0	6	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-prompts none
claude	perm-host	0	7	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose
claude	perm-auto	0	8	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode auto
claude	system-message	0	4	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	additional-context	0	8	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	compact-auto	0	37	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	compact-manual-seed	0	6	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	compact-manual	0	19	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	fail-401	1	0	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	fail-429	1	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	fail-500	1	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	fail-529	1	0	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	elicit-observe	1	0	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	elicit-accept	1	0	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	worktree	0	4	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	worktree-agent	0	10	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	setup-init	0	3	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	setup-maintenance	0	3	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	model-switch	0	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	model-switch-exit2	0	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	add-dir	0	1	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	add-dir-control	0	0	claude -p --input-format stream-json (control_request register_repo_root directory=/tmp/leopold-hookprobe.gjQnXe/extra-dir)
claude	teams	0	5	claude -p --setting-sources project --strict-mcp-config --model haiku --output-format stream-json --include-hook-events --verbose --permission-mode bypassPermis
claude	unauth	1	0	CLAUDE_CONFIG_DIR=<temp> claude -p --setting-sources project --model haiku --permission-mode bypassPermissions
codex	tools	0	40	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	subagent	0	19	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	subagent-role	0	16	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	role-bogus	0	10	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	role-bogus-strict	0	11	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox --strict-config
codex	subagent-exit2	0	21	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	stop-exit2	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	stop-block	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	prompt-exit2	0	4	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	posttool-block	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	pretool-deny	0	11	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	perm-allow	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --approve-for-me
codex	perm-deny	0	18	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --approve-for-me
codex	perm-onrequest	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> -s workspace-write -c approval_policy="on-request"
codex	system-message	0	8	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	additional-context	0	12	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox
codex	compact	0	16	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox -c model_auto_compact_token_limi
codex	interrupt	1	8	codex exec … (SIGINT sent to the process after PreToolUse of sleep 20)
codex	fail-401	1	2	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox -c model_provider="probe" -c mod
codex	fail-429	1	1	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox -c model_provider="probe" -c mod
codex	fail-500	1	2	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox -c model_provider="probe" -c mod
codex	fail-529	1	1	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox -c model_provider="probe" -c mod
codex	exec-as-role-1	1	0	codex exec --strict-config -c agent_role="probe-reviewer"
codex	exec-as-role-2	1	0	codex exec --strict-config -c agent_type="probe-reviewer"
codex	exec-as-role-3	1	0	codex exec --strict-config -c role="probe-reviewer"
codex	exec-as-role-4	0	0	codex exec --strict-config -c agents.probe-reviewer.config_file=".codex/agents/probe-reviewer.toml"
codex	exec-as-role-profile	1	0	codex exec --strict-config -p probe-reviewer (the role file copied as CODEX_HOME/probe-reviewer.config.toml)
codex	strict-config	0	6	codex exec --json --skip-git-repo-check --dangerously-bypass-hook-trust -C <project> --dangerously-bypass-approvals-and-sandbox --strict-config

Hermeticity

Every write landed under the mktemp -d root (/tmp/leopold-hookprobe.gjQnXe), under <out>, or in the harnesses' own transcript directories for that temp project. The real ~/.claude and ~/.codex entry-name fingerprints were identical before and after (unchanged / CHANGED); the temp CODEX_HOME's copied auth.json was deleted when the probe ended. Rerun: bash scripts/probe-hook-events.sh --out <dir> (never part of make test; linted by make hooks-check).