Skip to main content
The Connections API provides endpoints for viewing information about currently connected TAK clients.

​
Get Connected Clients

Retrieve a list of all currently connected TAK clients. 
curl -X GET "http://localhost:19023/Clients" \
  -H "X-Forwarded-For: 127.0.0.1"

​
Authentication

This endpoint requires IP-based authentication. The requesting IP address must be in the AllowedCLIIPs configuration list.

​
Response

Returns an array of connected client objects serialized to JSON.
​
array
array
Array of connected client objects

​
Response Example

[
  {
    "uid": "client-uid-123",
    "callsign": "ALPHA-1",
    "team": "Cyan",
    "role": "Team Leader",
    "address": "192.168.1.100",
    "lastSeen": "2024-03-04T12:30:45Z"
  },
  {
    "uid": "client-uid-456",
    "callsign": "BRAVO-2",
    "team": "Red",
    "role": "Rifleman",
    "address": "192.168.1.101",
    "lastSeen": "2024-03-04T12:31:20Z"
  }
]

​
IP-Based Authentication

The /Clients endpoint uses IP-based authentication for security. To configure allowed IPs:
  1. Edit your FreeTAKServer configuration file
  2. Add IP addresses to the AllowedCLIIPs list:
AllowedCLIIPs:
  - 127.0.0.1
  - 192.168.1.0/24
  - 10.0.0.0/8

​
Behind a Proxy

If FreeTAKServer is behind a reverse proxy (nginx, Apache, etc.), ensure the proxy forwards the real client IP using headers like:
  • X-Forwarded-For
  • X-Real-IP
The server will check these headers against the allowed IP list.

​
Connection Management

The connections API provides read-only access to connection information. To manage connections:
  • Disconnect clients: Use administrative commands or terminate connections at the CoT service level
  • Monitor activity: Use the connection timestamp to detect stale clients
  • Track teams: Group clients by team affiliation

​
Use Cases

​
Server Monitoring

Query the connections endpoint periodically to:
  • Monitor server load (number of connected clients)
  • Detect connectivity issues
  • Track team member availability
  • Generate activity reports

​
Dashboard Integration

Integrate with monitoring dashboards: 
const response = await fetch('http://localhost:19023/Clients', {
  headers: {
    'X-Forwarded-For': '127.0.0.1'
  }
});
const clients = await response.json();
console.log(`Connected clients: ${clients.length}`);

​
Team Coordination

Use connection data to:
  • Verify team members are online before missions
  • Track team composition in real-time
  • Identify missing or disconnected members

​
Connection State

Client connection information is maintained by FreeTAKServer’s CoT services:
  • TCP CoT Service: Port 8087 (default)
  • SSL CoT Service: Port 8089 (default)
Clients send periodic position updates (SA - Situation Awareness messages) which update their lastSeen timestamp.

​
Error Responses

​
401 Unauthorized
{
  "message": "endpoint can only be accessed by approved IPs"
}
Returned when the requesting IP is not in the AllowedCLIIPs list.
​
500 Internal Server Error
{
  "message": "An error occurred retrieving client details."
}
Returned when an internal error occurs while retrieving connection information.
For user management and authentication, see:
  • User Management API (certificate generation, user creation)
  • Authentication endpoints

​
Security Considerations

  1. Restrict Access: Only add trusted IPs to AllowedCLIIPs
  2. Monitor Usage: Log all requests to this endpoint
  3. Regular Audits: Periodically review the allowed IP list
  4. Network Segmentation: Place FreeTAKServer in a protected network segment
  5. Rate Limiting: Consider implementing rate limiting for this endpoint

Build docs developers (and LLMs) love

Get started for freeTalk to us