Hollow

What's New

Process Signals

• SIGTERM — graceful shutdown with configurable grace period (default 30s). Agent receives signal in inbox; daemon watchdog force-terminates if agent doesn't exit in time.
• SIGPAUSE — immediately suspends agent, preserves current_task and sets metadata["paused_at"].
• SIGINFO — delivers status snapshot (task, usage, locks, uptime) to caller's inbox. No state mutation.

Process Groups

• Agents spawned by an orchestrator share its group_id.
• POST /agents/group/{group_id}/terminate — SIGTERM all group members simultaneously.

Tombstones

• Every terminated agent gets a tombstone.json written to its workspace.
• Schema: agent_id, name, role, terminated_at, terminated_by, reason, final_usage, current_task_at_termination, children, parent_id, group_id.
• GET /tombstones, GET /tombstones/{agent_id} endpoints.

Orphan Adoption

• When a parent agent is terminated, its active children are reparented to "root" (they keep running).

MCP Tools

• agent_signal — dispatch SIGTERM/SIGPAUSE/SIGINFO via MCP.
• agent_tombstone — read tombstone(s) via MCP.
• Total: 50 MCP tools.

Integration Tests

• 6 new tests in tests/integration/test_signals.py — no Ollama required.