[BUG] Stop hook with "type": "prompt" causes JSON validation error (regression from #531)

[ryanstraight]

The Stop hook in basic-memory-plugins v0.2.1 still causes a JSON validation error on every session stop in Claude Code. Issue #531 fixed the unsupported "matcher": "*" field, but the underlying problem persists: "type": "prompt" hooks on the Stop event fail validation.

Current hooks.json (v0.2.1)

"Stop": [
  {
    "hooks": [
      {
        "type": "prompt",
        "prompt": "If this conversation contained valuable insights..."
      }
    ]
  }
]

Error

● Ran 1 stop hook
  ⎿  Stop hook error: JSON validation failed

This fires on every /exit or session end.

Workaround

Removing the entire Stop section from hooks/hooks.json eliminates the error. The /remember prompt behavior is still available via CLAUDE.md instructions.

Environment

• Claude Code (latest, Feb 2026)
• basic-memory 0.18.4
• basic-memory-plugins v0.2.1
• Windows 11

Notes

• The plugins repo (basicmachines-co/basic-memory-plugins) was archived on Feb 15, 2026, so filing here instead.
• "type": "prompt" works fine on PreToolUse hooks (e.g., the mcp__basic-memory__write_note validation prompt). The issue appears specific to the Stop event.