{
  "openapi": "3.1.0",
  "info": {
    "title": "Capsule Security Webhook Events API",
    "description": "Real-time event ingestion for AI agent security monitoring.\nSend agent lifecycle events to Capsule's detection pipeline for prevention and observability.\n",
    "version": "1.0.0",
    "contact": {
      "name": "Capsule Security Support",
      "email": "support@capsule.security"
    },
    "license": {
      "name": "Proprietary",
      "url": "https://capsule.security/license"
    }
  },
  "servers": [
    {
      "url": "https://api.capsule.security",
      "description": "Production API server"
    },
    {
      "url": "https://staging.api.capsule.security",
      "description": "Staging API server"
    }
  ],
  "security": [
    {
      "bearerAuth": []
    }
  ],
  "paths": {
    "/v1/generic-webhook/hooks/events": {
      "post": {
        "summary": "Send webhook event",
        "description": "Ingests agent lifecycle events for security analysis.\nBlocking events (`tool_invocation`, `user_message`) return an allow/block decision.\nObservational events (`tool_result`, `agent_message`, `session_start`, `session_end`) return `202 Accepted`.\n",
        "operationId": "sendWebhookEvent",
        "tags": [
          "Webhook Events"
        ],
        "parameters": [
          {
            "name": "x-correlation-id",
            "in": "header",
            "required": false,
            "schema": {
              "type": "string"
            },
            "description": "Trace ID for request correlation"
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/WebhookEvent"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Blocking event decision (tool_invocation, user_message)",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/BlockingResponse"
                },
                "examples": {
                  "allowed": {
                    "summary": "Action allowed",
                    "value": {
                      "apiVersion": "1",
                      "response": {
                        "action": "allow"
                      }
                    }
                  },
                  "blocked": {
                    "summary": "Action blocked",
                    "value": {
                      "apiVersion": "1",
                      "response": {
                        "action": "block",
                        "reason": "Policy violation: query accesses sensitive table"
                      }
                    }
                  }
                }
              }
            }
          },
          "202": {
            "description": "Observational event accepted (tool_result, agent_message, session_start, session_end)"
          },
          "400": {
            "description": "Malformed request body",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Problem"
                },
                "example": {
                  "type": "https://api.capsule.security/problems/invalid-request",
                  "title": "Invalid Request",
                  "status": 400,
                  "detail": "The request payload is not valid according to the schema."
                }
              }
            }
          },
          "401": {
            "description": "Invalid or expired JWT",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Problem"
                },
                "example": {
                  "type": "https://api.capsule.security/problems/unauthorized",
                  "title": "Unauthorized",
                  "status": 401,
                  "detail": "The provided JWT token is invalid or expired."
                }
              }
            }
          },
          "408": {
            "description": "Request timeout — treat as allow (fail-open)",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Problem"
                },
                "example": {
                  "type": "https://api.capsule.security/problems/timeout",
                  "title": "Request Timeout",
                  "status": 408,
                  "detail": "The request exceeded the processing timeout."
                }
              }
            }
          },
          "500": {
            "description": "Server error — treat as allow (fail-open)",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Problem"
                },
                "example": {
                  "type": "https://api.capsule.security/problems/internal-error",
                  "title": "Internal Server Error",
                  "status": 500,
                  "detail": "An unexpected error occurred."
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "WebhookEvent": {
        "oneOf": [
          {
            "$ref": "#/components/schemas/ToolInvocationEvent"
          },
          {
            "$ref": "#/components/schemas/UserMessageEvent"
          },
          {
            "$ref": "#/components/schemas/ToolResultEvent"
          },
          {
            "$ref": "#/components/schemas/AgentMessageEvent"
          },
          {
            "$ref": "#/components/schemas/SessionStartEvent"
          },
          {
            "$ref": "#/components/schemas/SessionEndEvent"
          }
        ],
        "discriminator": {
          "propertyName": "event_type",
          "mapping": {
            "tool_invocation": "#/components/schemas/ToolInvocationEvent",
            "user_message": "#/components/schemas/UserMessageEvent",
            "tool_result": "#/components/schemas/ToolResultEvent",
            "agent_message": "#/components/schemas/AgentMessageEvent",
            "session_start": "#/components/schemas/SessionStartEvent",
            "session_end": "#/components/schemas/SessionEndEvent"
          }
        }
      },
      "BaseEvent": {
        "type": "object",
        "required": [
          "event_type",
          "session_id",
          "timestamp",
          "agent",
          "user"
        ],
        "properties": {
          "event_type": {
            "type": "string"
          },
          "session_id": {
            "type": "string",
            "description": "Unique session identifier",
            "example": "sess-abc123"
          },
          "timestamp": {
            "type": "string",
            "format": "date-time",
            "description": "ISO 8601 timestamp",
            "example": "2026-03-03T10:30:00Z"
          },
          "agent": {
            "$ref": "#/components/schemas/AgentInfo"
          },
          "user": {
            "$ref": "#/components/schemas/UserInfo"
          }
        }
      },
      "ToolInvocationEvent": {
        "description": "Sent before a tool executes. Blocks until Capsule responds with allow/block.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type",
              "tool"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "tool_invocation"
              },
              "tool": {
                "$ref": "#/components/schemas/ToolInfo"
              }
            }
          }
        ],
        "example": {
          "event_type": "tool_invocation",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:30:00Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          },
          "tool": {
            "name": "database_query",
            "input": {
              "query": "SELECT * FROM users"
            }
          }
        }
      },
      "UserMessageEvent": {
        "description": "Sent before a user prompt is processed. Blocks until Capsule responds with allow/block.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type",
              "message"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "user_message"
              },
              "message": {
                "$ref": "#/components/schemas/MessageInfo"
              }
            }
          }
        ],
        "example": {
          "event_type": "user_message",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:30:00Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          },
          "message": {
            "content": "Show me all customer records from the last month"
          }
        }
      },
      "ToolResultEvent": {
        "description": "Sent after tool execution completes. Fire-and-forget.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type",
              "tool"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "tool_result"
              },
              "tool": {
                "$ref": "#/components/schemas/ToolResultInfo"
              }
            }
          }
        ],
        "example": {
          "event_type": "tool_result",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:30:05Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          },
          "tool": {
            "name": "database_query",
            "input": {
              "query": "SELECT * FROM users"
            },
            "output": {
              "row_count": 42
            }
          }
        }
      },
      "AgentMessageEvent": {
        "description": "Sent after the agent produces a response. Fire-and-forget.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type",
              "message"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "agent_message"
              },
              "message": {
                "$ref": "#/components/schemas/MessageInfo"
              }
            }
          }
        ],
        "example": {
          "event_type": "agent_message",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:30:06Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          },
          "message": {
            "content": "Here are the 42 customer records from the last month..."
          }
        }
      },
      "SessionStartEvent": {
        "description": "Sent when a session begins. Fire-and-forget.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "session_start"
              }
            }
          }
        ],
        "example": {
          "event_type": "session_start",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:29:55Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          }
        }
      },
      "SessionEndEvent": {
        "description": "Sent when a session terminates. Fire-and-forget.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEvent"
          },
          {
            "type": "object",
            "required": [
              "event_type"
            ],
            "properties": {
              "event_type": {
                "type": "string",
                "const": "session_end"
              }
            }
          }
        ],
        "example": {
          "event_type": "session_end",
          "session_id": "sess-abc123",
          "timestamp": "2026-03-03T10:45:00Z",
          "agent": {
            "id": "support-agent",
            "name": "Customer Support Agent"
          },
          "user": {
            "email": "user@example.com"
          }
        }
      },
      "AgentInfo": {
        "type": "object",
        "required": [
          "id",
          "name"
        ],
        "properties": {
          "id": {
            "type": "string",
            "description": "Agent identifier",
            "example": "support-agent"
          },
          "name": {
            "type": "string",
            "description": "Human-readable agent name",
            "example": "Customer Support Agent"
          }
        }
      },
      "UserInfo": {
        "type": "object",
        "required": [
          "email"
        ],
        "properties": {
          "email": {
            "type": "string",
            "description": "User email address",
            "example": "user@example.com"
          }
        }
      },
      "ToolInfo": {
        "type": "object",
        "required": [
          "name",
          "input"
        ],
        "properties": {
          "name": {
            "type": "string",
            "description": "Tool name",
            "example": "database_query"
          },
          "input": {
            "type": "object",
            "description": "Tool input parameters",
            "example": {
              "query": "SELECT * FROM users"
            }
          }
        }
      },
      "ToolResultInfo": {
        "type": "object",
        "required": [
          "name",
          "input",
          "output"
        ],
        "properties": {
          "name": {
            "type": "string",
            "description": "Tool name",
            "example": "database_query"
          },
          "input": {
            "type": "object",
            "description": "Tool input parameters",
            "example": {
              "query": "SELECT * FROM users"
            }
          },
          "output": {
            "type": "object",
            "description": "Tool execution output",
            "example": {
              "row_count": 42
            }
          }
        }
      },
      "MessageInfo": {
        "type": "object",
        "required": [
          "content"
        ],
        "properties": {
          "content": {
            "type": "string",
            "description": "Message content",
            "example": "Show me all customer records from the last month"
          }
        }
      },
      "BlockingResponse": {
        "type": "object",
        "required": [
          "apiVersion",
          "response"
        ],
        "properties": {
          "apiVersion": {
            "type": "string",
            "const": "1",
            "example": "1"
          },
          "response": {
            "type": "object",
            "required": [
              "action"
            ],
            "properties": {
              "action": {
                "type": "string",
                "enum": [
                  "allow",
                  "block"
                ],
                "description": "Whether the action is allowed or blocked"
              },
              "reason": {
                "type": "string",
                "description": "Reason for blocking (present when action is \"block\")",
                "example": "Policy violation: query accesses sensitive table"
              }
            }
          }
        }
      },
      "Problem": {
        "type": "object",
        "properties": {
          "type": {
            "type": "string",
            "format": "uri",
            "description": "A URI reference that identifies the problem type.",
            "example": "https://api.capsule.security/problems/invalid-request"
          },
          "title": {
            "type": "string",
            "description": "A short, human-readable summary of the problem type.",
            "example": "Invalid Request"
          },
          "status": {
            "type": "integer",
            "description": "The HTTP status code.",
            "example": 400
          },
          "detail": {
            "type": "string",
            "description": "A human-readable explanation specific to this occurrence of the problem.",
            "example": "The request payload is not valid according to the schema."
          },
          "instance": {
            "type": "string",
            "format": "uri",
            "description": "A URI reference that identifies the specific occurrence of the problem.",
            "example": "/problems/invalid-request/1234"
          }
        }
      }
    },
    "securitySchemes": {
      "bearerAuth": {
        "type": "http",
        "scheme": "bearer",
        "bearerFormat": "JWT",
        "description": "JWT Bearer token for API access"
      }
    }
  }
}