Extend the pre_tool_call plugin hook return contract with a new directive:
{"action": "approve", "message": "why this needs human confirmation"}
Previously a pre_tool_call hook could only veto a tool call (action: block)
or allow it silently. It could not escalate to the existing human-approval
flow. This unlocks user-defined runtime approval rules on ANY tool (HTTP
writes, file writes to sensitive paths, email sends), enforced at runtime —
resolving #51221 as a pure plugin, with no core approval.py rule schema.
Mechanism:
- get_pre_tool_call_directive() returns (action, message) for block|approve;
get_pre_tool_call_block_message() kept as a block-only back-compat shim.
- resolve_pre_tool_block() is the single dispatch-site chokepoint: fetches
the directive and, for approve, invokes the human gate; fail-closed to a
block on denial, timeout, or gate exception. ALL FOUR tool-dispatch sites
now call it: tool_executor (concurrent + sequential), agent_runtime_helpers,
and model_tools.handle_function_call.
- request_tool_approval() escalates via the SAME machinery as Tier-2
dangerous commands: session/permanent allowlist, prompt_dangerous_approval
(CLI) / submit_pending (gateway), [o]nce/[s]ession/[a]lways/[d]eny,
timeout fail-closed, approvals.cron_mode for cron contexts.
Architecture: extracted the shared decision core into _run_approval_gate(),
called by BOTH check_dangerous_command() and request_tool_approval() so the
fail-closed / cron / gateway / yolo / persist policy lives in ONE place and
cannot drift. Fixed a latent divergence — the plugin path now honors --yolo.
Approval grain: [a]lways is keyed on tool_name + a hash of the reason (an
explicit plugin rule_key overrides), so distinct reasons on the same tool
persist independently instead of one 'always' blanketing the whole tool.
Non-interactive: cron honors approvals.cron_mode (parity with commands); any
other non-interactive non-gateway context fails CLOSED for the plugin path
(the command path keeps its historical fail-open default, unchanged).
No new config schema, no new env vars, no new hook events.
