Automatic Crash Notification (ACN) API Developer Guide

Service Overview

Automatic Crash Notification (ACN) is a telematics service that automatically detects accident situations when a vehicle crash occurs and transmits accident information to the call center or emergency rescue agencies to request rescue.

Service Features

Automatic accident detection and immediate rescue request
Manual SOS button for emergency rescue requests
Transmission of accident location information and detailed data
Automatic voice call connection
Improved survival rate through reduced rescue time

Legal Requirements

EU: Mandatory eCall installation in new vehicles from 2018
Differences in service methods by country (EU - direct PSAP, US - via OEM)
Compliance with personal information protection laws
Priority processing of emergency situations

Key Scenarios

Scenario 1: Automatic Accident Detection and Emergency Call Connection

API Flow by Entity:

🚗 Vehicle (TCU):

Accident Detection: Detect accidents through airbag deployment or rollover
Data Collection: Collect MSD (Minimum Set of Data) including GPS, VIN, speed
Emergency Contact: Immediate voice call connection and data transmission

🏢 Call Center:

Event Monitoring: Receive accident alerts via SSE
Incident Creation: Create ACN record and verify location on map
Rescue Coordination: Request dispatch to rescue agencies (119/112)

📱 App (User):

Monitoring: Receive accident alerts via SSE
Status Check: Check current accident status
System Health: Check ACN system status

Scenario 2: Accident Data Processing and Status Management

API Flow by Entity:

🏢 Call Center:

Status Management: Check agent availability
Incident Assignment: Manage assigned incidents
Statistics Analysis: Monitor ACN processing volume
History Audit: Query past accident records

🚗 Vehicle (TCU):

Call Status Transmission: Transmit VCT event when call ends
Status Update: Transmit accident status change information
Data Retransmission: Retransmit data in case of communication failure
System Status Maintenance: Maintain connection with ACN system

📱 App (User App):

Real-time Status Monitoring: Receive accident processing status via SSE
Accident Location Check: Display accident location on map
System Health Status: Monitor system status

Scenario 3: Accident Completion and Follow-up Processing

API Flow by Entity:

🏢 Call Center:

Incident Closure: Close ACN incident after rescue
Result Recording: Record final rescue outcomes and closure reasons

📱 App (User):

Result Check: Check final accident processing result
History Management: View completed accident history

Key Features

📱 Features to Implement in App

1. ACN System Monitoring

System Health: Monitor overall ACN system status
Real-time Alerts: Receive accident alerts via SSE/Push
Status Query: Check current accident processing status
History Audit: Query past accident records and results

🏢 Features to Implement in Call Center

1. ACN Incident Management

Incident Monitoring: Monitor real-time vehicle accidents
Status Query: Query specific accident details
Incident Closure: Close incident after investigation
History Management: Manage past accident records

2. Agent and Statistics Analysis

Agent Status: Monitor agent availability
Assigned Incidents: Manage agent workload
Service Statistics: Analyze overall ACN performance
System Health: Monitor overall ACN system health

Sequence Diagram

ACN (Automatic Crash Notification) System Flow

ACN

API Endpoints

Refer to the Common API Specifications for headers, response codes, and error formats.

ACN Statistics Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/acn/stats" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

ACN Incident Status Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/vehicles/KMHSH81C7LU123456/acn/status?cid=ACN_20260307_001" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

ACN Incident History Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/vehicles/KMHSH81C7LU123456/acn/history" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

ACN Incident Closure

bash

curl -X POST "https://api.ecarus.run/api/v1/safety/vehicles/KMHSH81C7LU123456/acn/close" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d" \
     -H "Content-Type: application/json" \
     -d '{
       "cid": "ACN_20260307_001",
       "closureReason": "EMERGENCY_SERVICES_DISPATCHED",
       "result": "SUCCESS",
       "agentId": "AGENT_001",
       "notes": "All victims rescued and safe."
     }'

ACN Agent Status Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/acn/agents/AGENT_001/status" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

Agent Assigned ACN Incidents Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/acn/agents/AGENT_001/incidents" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

ACN System Status Query

bash

curl -X GET "https://api.ecarus.run/api/v1/safety/acn/system/health" \
     -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d"

ACN Real-time Event Reception (SSE)

Note: Recommended to access via browser or use a dedicated SSE client

bash

curl -N -H "Authorization: Bearer sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d" \
     "https://api.ecarus.run/api/v1/safety/acn/events"

Data Models

ACN Statistics Response

json

{
  "totalIncidents": 1250,
  "activeIncidents": 3,
  "resolvedToday": 8,
  "averageResponseTime": "4.5 min",
  "successRate": 98.2
}

ACN Status Response

json

{
  "vin": "KMHSH81C7LU123456",
  "cid": "ACN_20260307_001",
  "status": "ACTIVE",
  "timestamp": "2026-03-07T14:30:00Z",
  "location": {
    "latitude": 37.4021,
    "longitude": 127.1023,
    "accuracy": 5.2
  },
  "severity": "HIGH",
  "trigger": "AIRBAG_DEPLOYMENT",
  "rescueStatus": "DISPATCHED",
  "estimatedArrival": "2026-03-07T14:45:00Z"
}

ACN History Response

json

{
  "vin": "KMHSH81C7LU123456",
  "incidents": [
    {
      "cid": "ACN_20260307_001",
      "timestamp": "2026-03-07T14:30:00Z",
      "severity": "HIGH",
      "status": "RESOLVED",
      "duration": "45 min",
      "trigger": "AIRBAG_DEPLOYMENT",
      "location": {
        "latitude": 37.4021,
        "longitude": 127.1023
      },
      "resolution": "EMERGENCY_SERVICES_DISPATCHED"
    }
  ],
  "total": 1
}

ACN Closure Request

json

{
  "cid": "ACN_20260307_001",
  "closureReason": "EMERGENCY_SERVICES_DISPATCHED",
  "result": "SUCCESS",
  "notes": "All victims rescued and safe."
}

ACN Closure Response

json

{
  "cid": "ACN_20260307_001",
  "status": "CLOSED",
  "timestamp": "2026-03-07T15:15:00Z"
}

ACN Agent Status Response

json

{
  "agentId": "AGENT_001",
  "status": "ACTIVE",
  "currentIncidents": 2,
  "totalHandled": 145,
  "averageHandlingTime": "12.3 min",
  "lastActivity": "2026-03-07T14:45:00Z"
}

ACN Agent Incidents Response

json

{
  "agentId": "AGENT_001",
  "incidents": [
    {
      "cid": "ACN_20260307_001",
      "vin": "KMHSH81C7LU123456",
      "severity": "HIGH",
      "status": "ACTIVE",
      "timestamp": "2026-03-07T14:30:00Z",
      "location": {
        "latitude": 37.4021,
        "longitude": 127.1023
      },
      "assignedTime": "2026-03-07T14:32:00Z",
      "estimatedResolution": "2026-03-07T15:15:00Z"
    }
  ],
  "total": 1,
  "activeCount": 1
}

ACN System Status Response

json

{
  "status": "HEALTHY",
  "timestamp": "2026-03-07T15:00:00Z",
  "services": {
    "psapConnection": "ACTIVE",
    "voiceCallService": "ACTIVE",
    "dataTransmission": "ACTIVE",
    "database": "ACTIVE"
  },
  "metrics": {
    "responseTime": "0.8s",
    "uptime": "99.9%",
    "activeConnections": 45
  }
}

ACN Real-time Event (SSE)

json

{
  "type": "INCIDENT_CREATED",
  "timestamp": "2026-03-07T14:30:00Z",
  "data": {
    "cid": "ACN_20260307_001",
    "vin": "KMHSH81C7LU123456",
    "severity": "HIGH",
    "location": {
      "latitude": 37.4021,
      "longitude": 127.1023,
      "accuracy": 5.2
    },
    "trigger": "AIRBAG_DEPLOYMENT"
  }
}

Security and Privacy

Authentication and Authorization

User authentication token required (JWT/OAuth2)
Vehicle access permission verification
Emergency situation priority processing permission

Data Security

All API communication encrypted with HTTPS/TLS
Additional security measures for accident data transmission
Sensitive information stored only on server

Privacy Protection

Explicit consent for accident information collection
Specify purpose of location information collection in emergency situations
Compliance with accident data retention period policy
Guarantee right to data deletion upon user request

Access Control

VIN-based vehicle access permission verification
Priority processing of permissions in emergency situations
Separate authentication procedures for external agency (rescue team) access

Exception Handling

Connection Failure: Support offline mode, cache last status
Slow Response: Loading indicator, timeout handling
Server Down: Display error message, suggest retry

Vehicle Offline: Display last accident information, notify offline status
Communication Unavailable: Process delayed accident information, retransmission logic
Voice Call Failure: Attempt alternative connection methods

Location Information Error: Estimate based on last location, Cell ID location correction
Duplicate Accidents: Filter duplicate events, prioritize latest information
Unconscious Passengers: Maintain automatic voice call connection

Test Setup

Base URL: https://api.ecarus.run/api/v1/safety
Authentication Token: sk_4f9c7b8e2d1a6c0f3e7a9b5d8c1e4f2a7c6d9e0b3f5a8c1d4e7f9b2c6a1e3d
Sample VIN: KMHSH81C7LU123456

Use Swagger UI for interactive API testing. Jennifer

Deployment Considerations

App Store Registration

Request emergency alert permissions
Clear description of location information collection
Specify emergency situation service purpose

Legal Regulation Compliance

Check country-specific eCall service regulations
Compliance with emergency rescue service related laws
Compliance with personal information protection laws (especially medical information)

Service Integration

Integration with PSAP or rescue agencies
Prepare insurance company linkage services
Agreement with towing service companies

Automatic Crash Notification (ACN) API Developer Guide ​

Service Overview ​

Service Features ​

Legal Requirements ​

Key Scenarios ​

Scenario 1: Automatic Accident Detection and Emergency Call Connection ​

Scenario 2: Accident Data Processing and Status Management ​

Scenario 3: Accident Completion and Follow-up Processing ​

Key Features ​

📱 Features to Implement in App ​

1. ACN System Monitoring ​

🏢 Features to Implement in Call Center ​

1. ACN Incident Management ​

2. Agent and Statistics Analysis ​

Sequence Diagram ​

ACN (Automatic Crash Notification) System Flow ​

API Endpoints ​

ACN Statistics Query ​

ACN Incident Status Query ​

ACN Incident History Query ​

ACN Incident Closure ​

ACN Agent Status Query ​

Agent Assigned ACN Incidents Query ​

ACN System Status Query ​

ACN Real-time Event Reception (SSE) ​

Data Models ​

ACN Statistics Response ​

ACN Status Response ​

ACN History Response ​

ACN Closure Request ​

ACN Closure Response ​

ACN Agent Status Response ​

ACN Agent Incidents Response ​

ACN System Status Response ​

ACN Real-time Event (SSE) ​

Security and Privacy ​

Authentication and Authorization ​

Data Security ​

Privacy Protection ​

Access Control ​

Exception Handling ​

Network Related ​

Vehicle Status Related ​

Emergency Related ​

Test Setup ​

Deployment Considerations ​

App Store Registration ​

Legal Regulation Compliance ​

Service Integration ​

Automatic Crash Notification (ACN) API Developer Guide

Service Overview

Service Features

Legal Requirements

Key Scenarios

Scenario 1: Automatic Accident Detection and Emergency Call Connection

Scenario 2: Accident Data Processing and Status Management

Scenario 3: Accident Completion and Follow-up Processing

Key Features

📱 Features to Implement in App

1. ACN System Monitoring

🏢 Features to Implement in Call Center

1. ACN Incident Management

2. Agent and Statistics Analysis

Sequence Diagram

ACN (Automatic Crash Notification) System Flow

API Endpoints

ACN Statistics Query

ACN Incident Status Query

ACN Incident History Query

ACN Incident Closure

ACN Agent Status Query

Agent Assigned ACN Incidents Query

ACN System Status Query

ACN Real-time Event Reception (SSE)

Data Models

ACN Statistics Response

ACN Status Response

ACN History Response

ACN Closure Request

ACN Closure Response

ACN Agent Status Response

ACN Agent Incidents Response

ACN System Status Response

ACN Real-time Event (SSE)

Security and Privacy

Authentication and Authorization

Data Security

Privacy Protection

Access Control

Exception Handling

Network Related

Vehicle Status Related

Emergency Related

Test Setup

Deployment Considerations

App Store Registration

Legal Regulation Compliance

Service Integration