{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "AHA hook answer",
  "description": "Claude Code's hook answer on stdout with exit 0. Exit 2 with a reason on stderr blocks; plain stdout at session start and prompt submit is context.",
  "type": "object",
  "properties": {
    "decision": {
      "const": "block",
      "description": "block a prompt or a tool, or keep the agent going at stop"
    },
    "reason": {
      "type": "string"
    },
    "hookSpecificOutput": {
      "type": "object",
      "properties": {
        "hookEventName": {
          "enum": [
            "SessionStart",
            "SessionEnd",
            "UserPromptSubmit",
            "PreToolUse",
            "PostToolUse",
            "Stop",
            "PreCompact"
          ]
        },
        "permissionDecision": {
          "enum": [
            "allow",
            "deny",
            "ask"
          ]
        },
        "permissionDecisionReason": {
          "type": "string"
        },
        "additionalContext": {
          "type": "string"
        },
        "updatedInput": {}
      }
    },
    "continue": {
      "type": "boolean"
    },
    "stopReason": {
      "type": "string"
    },
    "suppressOutput": {
      "type": "boolean"
    },
    "systemMessage": {
      "type": "string"
    }
  }
}