API Mode

The API mode is a FastAPI application that exposes a REST API to interact with the ACAS X. This endpoint can be used to create new applications with the ACAS X running on a secondary system.

Usage

The API mode is per default included in the acasx command option. Thus, to start the API mode, simply run:

pycasx acasx

This will start the API mode on the default port of 8008. To change the port, use the api.port option:

pycasx acasx api.port 8080

Endpoints

The following endpoints are available to query.

/docs

The documentation for the API is available at /docs. The full URL is http://localhost:8008/docs by default.

/

The root endpoint (http://localhost:8008/) is used to query the status of the ACAS X. It returns a JSON object with the following fields:

{
    "hcas": {
        "advisory": {
            "value": 0,
            "name": "COC"
        },
        "connector": "adsb"
    },
    "vcas": {
        "advisory": {
            "value": 4,
            "name": "CL1500"
        },
        "connector": "adsb"
    },
    "timestamp": 1318377600.0
}

/ownship

This endpoint returns the current state of the ownship.

{
    "call_sign": "FG-4229",
    "altitude": 10732.387208,
    "vertical_speed": -0.037046,
    "true_airspeed": 507.070057184784,
    "heading": 0.652215,
    "latitude": 72.135595,
    "longitude": -22.531261,
    "timestamp": 1706103314.730101
}

/intruders and /intruders/{call_sign}

This endpoint returns a list of all intruders currently tracked by the ACAS X. The default units are:

Default units for the intruder description

Parameter	Unit
Altitude	ft
Vertical speed	ft/s
Airspeed	kt
Heading	deg
Latitude	deg
Longitude	deg
Rho	ft
Theta	deg
Psi	deg
V_own	ft/s
V_int	ft/s
Tau	s
h	ft
hdot_own	ft/min
hdot_int	ft/min

For example for /intruders this will be similar to:

{
    "INTRUDER": {
        "aircraft": {
            "call_sign": "INTRUDER",
            "altitude": 10000.0,
            "vertical_speed": 0.0,
            "airspeed": 451.0,
            "heading": 179.977692,
            "latitude": 64.954861,
            "longitude": -22.649997000000003
        },
        "triggers_nmac": false,
        "hcas_advisory": -1,
        "vcas_advisory": -1,
        "hcas_state_variables": {
            "rho": 80576.60919363388,
            "theta": -178.61455181770793,
            "psi": 181.25831800000003,
            "v_own": 242.19262819699622,
            "v_int": 761.2022455526394,
            "tau": -80.29262490733487,
            "s_adv": -1
        },
        "vcas_state_variables": {
            "h": 8222.950633,
            "hdot_own": -1299.29958,
            "hdot_int": 0.0,
            "tau": -80.29262490733487,
            "s_adv": -1
        },
        "timestamp": 1318377600.0
    },
    "LH857": {
        "aircraft": {
            "call_sign": "LH857",
            "altitude": 170.0,
            "vertical_speed": 0.0,
            "airspeed": 0.0,
            "heading": 44.19180200000001,
            "latitude": 63.99276900000001,
            "longitude": -22.625786
        },
        "triggers_nmac": false,
        "hcas_advisory": -1,
        "vcas_advisory": -1,
        "hcas_state_variables": {
            "rho": 86663.27074856794,
            "theta": -178.8139020362879,
            "psi": 317.044208,
            "v_own": 242.19262819699622,
            "v_int": 0.0,
            "tau": -357.8277279156412,
            "s_adv": -1
        },
        "vcas_state_variables": {
            "h": -1607.049367,
            "hdot_own": -1299.29958,
            "hdot_int": 0.0,
            "tau": -357.8277279156412,
            "s_adv": -1
        },
        "timestamp": 1318377600.0
    },
    "timestamp": 1318377600.0
}

and for /intruders/INTRUDER similar to:

{
    "aircraft": {
        "call_sign": "INTRUDER",
        "altitude": 10000.0,
        "vertical_speed": 0.0,
        "airspeed": 451.0,
        "heading": 179.951324,
        "latitude": 64.916918,
        "longitude": -22.649914
    },
    "triggers_nmac": false,
    "hcas_advisory": -1,
    "vcas_advisory": -1,
    "hcas_state_variables": {
        "rho": 81163.99381904684,
        "theta": -178.58743469905303,
        "psi": 182.94445599999997,
        "v_own": 237.5529283537475,
        "v_int": 761.2022455526394,
        "tau": -81.2774401291326,
        "s_adv": -1
    },
    "vcas_state_variables": {
        "h": 9991.170899,
        "hdot_own": -511.55333999999993,
        "hdot_int": 0.0,
        "tau": -81.2774401291326,
        "s_adv": -1
    },
    "timestamp": 1318377600.0
}

/hcas and /vcas

These endpoints return just the status of the current CAS system, similar to the root endpoint.

/connector

This endpoints can be used to PUT a new connector for the ACAS X to use. The only connector currently supported is the generic adsb connector.

An exemplary PUT request would be:

curl -X 'PUT' 'http://0.0.0.0:8008/connector?connection=adsb' -H 'accept: application/json'r