{
  "id": "hook-surface:pre-compact",
  "_kind": "HookSurface",
  "_file": "channels-hooks/hook-surfaces/canonical/lifecycle-and-native-stubs.yaml",
  "_cluster": "channels-hooks",
  "attributes": {
    "eventName": "PreCompact (canonical)",
    "displayName": "PreCompact (canonical)",
    "kind": "canonical",
    "direction": "pre",
    "blocking": true,
    "family": "in-process",
    "payloadSchema": {
      "type": "object",
      "required": [
        "session_id",
        "transcript_path",
        "trigger"
      ],
      "properties": {
        "session_id": {
          "type": "string"
        },
        "transcript_path": {
          "type": "string"
        },
        "trigger": {
          "type": "string",
          "enum": [
            "manual",
            "auto"
          ],
          "description": "manual = /compact slash command; auto = context-window pressure."
        },
        "custom_instructions": {
          "type": "string",
          "description": "Free-form user instructions accompanying a manual compaction."
        }
      }
    },
    "description": "Fires before a context-compaction step; can block or alter the compaction. Claude Code 1.0+."
  },
  "outgoingEdges": [],
  "incomingEdges": [
    {
      "from": "agent-core-impl:claude-agent-sdk.core@current",
      "to": "hook-surface:pre-compact",
      "kind": "fires_hook",
      "attributes": {}
    },
    {
      "from": "agent-core-impl:claude-code.core@1.x",
      "to": "hook-surface:pre-compact",
      "kind": "fires_hook",
      "attributes": {}
    },
    {
      "from": "agent-runtime-impl:claude-code.runtime@1.x",
      "to": "hook-surface:pre-compact",
      "kind": "exposes",
      "attributes": {}
    },
    {
      "from": "hook-mapping:pre-compact-claude-code",
      "to": "hook-surface:pre-compact",
      "kind": "maps_hook",
      "attributes": {}
    },
    {
      "from": "hook-mapping:pre-compact-gemini",
      "to": "hook-surface:pre-compact",
      "kind": "maps_hook",
      "attributes": {}
    },
    {
      "from": "hook-mapping:compact-before-copilot",
      "to": "hook-surface:pre-compact",
      "kind": "maps_hook",
      "attributes": {}
    },
    {
      "from": "hook-surface:claude.pre-compact",
      "to": "hook-surface:pre-compact",
      "kind": "canonicalized_to",
      "attributes": {}
    }
  ]
}