Web Control API

Laika includes a built-in REST API for remote control. Enable it via Settings > API > Enable Web API. Default port is 1928.

All responses include Access-Control-Allow-Origin: * for browser access.

Base URL: http://<laika-host>:1928

Download OpenAPI Spec (YAML) — import into Postman, Insomnia, or any OpenAPI-compatible tool.

Status

Get the current application state.

GET /api/status

Response:

{
  "layout": "2x2",
  "launchpad": "Studio A",
  "viewer_count": 4,
  "projected_viewer": null,
  "version": "1.0.57"
}

Field	Type	Description
layout	string	Current layout name
launchpad	string	Active launchpad name (empty if none)
viewer_count	integer	Number of viewer slots in the current layout
projected_viewer	integer or null	Index of the viewer currently projected fullscreen, or null if not projecting
version	string	Application version

Sources

List all NDI® sources currently visible on the network.

GET /api/sources

Response:

{
  "sources": [
    {
      "name": "CAMERA-1 (Studio)",
      "url": "ndi://192.168.1.10/CAMERA-1"
    },
    {
      "name": "GRAPHICS (Control Room)",
      "url": "ndi://192.168.1.20/GRAPHICS"
    }
  ]
}

Field	Type	Description
name	string	NDI® source display name
url	string	NDI® source URL

Viewers

List viewer assignments

GET /api/viewers

Response:

{
  "viewers": [
    {
      "index": 0,
      "source": "CAMERA-1 (Studio)",
      "connected": true,
      "tally": "program",
      "caption": "{source} LIVE",
      "ptz_supported": true,
      "resolution": "1920x1080",
      "fps": 59.94
    },
    {
      "index": 1,
      "source": null,
      "connected": false,
      "tally": "none",
      "caption": null,
      "ptz_supported": false,
      "resolution": null,
      "fps": null
    }
  ]
}

Field	Type	Description
index	integer	Zero-based viewer slot index
source	string or null	Assigned source name, or null if empty
connected	boolean	Whether the viewer is actively receiving frames
tally	string	Tally state: "program", "preview", or "none"
caption	string or null	Caption expression for this viewer, or null if not set
ptz_supported	boolean	Whether the assigned source supports PTZ control
resolution	string or null	Current frame resolution (e.g. "1920x1080"), or null if not connected
fps	number or null	Current frame rate, or null if not connected

Assign a source to a viewer

POST /api/viewers/{index}

Request body:

{
  "source": "CAMERA-1 (Studio)"
}

The source value must match a name from /api/sources.

Responses:

Status	Body	When
200	{ "ok": true }	Source assigned
400	{ "ok": false, "error": "Viewer index out of range" }	Invalid index or missing source
404	{ "ok": false, "error": "Source not found" }	Source name not found on network

Clear a viewer

DELETE /api/viewers/{index}

Responses:

Status	Body	When
200	{ "ok": true }	Viewer cleared
400	{ "ok": false, "error": "..." }	Invalid viewer index

Layout

Switch to a different layout.

POST /api/layout

Request body:

{
  "name": "2x2"
}

The name can be a built-in layout or a custom layout name.

Responses:

Status	Body	When
200	{ "ok": true }	Layout switched
404	{ "ok": false, "error": "Layout not found" }	Layout name not found

Launchpads

List launchpads

GET /api/launchpads

Response:

{
  "launchpads": [
    {
      "name": "Studio A",
      "layout": "2x2",
      "active": true
    },
    {
      "name": "Studio B",
      "layout": "1+5",
      "active": false
    }
  ]
}

Field	Type	Description
name	string	Launchpad preset name
layout	string	Layout used by this launchpad
active	boolean	Whether this is the currently active launchpad

Switch to a launchpad

POST /api/launchpad

Request body:

{
  "name": "Studio B"
}

Responses:

Status	Body	When
200	{ "ok": true }	Launchpad activated
404	{ "ok": false, "error": "Launchpad not found" }	Launchpad name not found

Layouts

List all available layouts, including both built-in presets and custom layouts.

GET /api/layouts

Response:

{
  "layouts": [
    {
      "name": "2x2",
      "viewers": 4,
      "custom": false
    },
    {
      "name": "My Custom Layout",
      "viewers": 6,
      "custom": true
    }
  ]
}

Field	Type	Description
name	string	Layout name
viewers	integer	Number of viewer slots in this layout
custom	boolean	true for user-created layouts, false for built-in presets

Captions

Set or clear a caption overlay on a specific viewer. Captions support expression variables that are evaluated in real time.

Set or clear a viewer caption

POST /api/viewers/{index}/caption

Request body (set a caption):

{
  "caption": "{source} LIVE"
}

Request body (clear a caption):

{
  "caption": null
}

Expression variables:

Variable	Description
{source}	NDI® source name assigned to the viewer
{viewer}	Viewer slot index
{time}	Current time
{date}	Current date
{tally}	Current tally state (program, preview, or none)
{fps}	Current frame rate
{res}	Current resolution

Responses:

Status	Body	When
200	{ "ok": true }	Caption updated
400	{ "ok": false, "error": "Viewer index out of range" }	Invalid viewer index

Projection

Project a single viewer fullscreen, or exit back to the multiviewer layout. The currently projected viewer is also reported in the projected_viewer field of the /api/status response.

Project a viewer fullscreen

POST /api/project/{index}

Responses:

Status	Body	When
200	{ "ok": true }	Viewer projected
400	{ "ok": false, "error": "Viewer index out of range" }	Invalid viewer index

Exit projection

DELETE /api/project

Responses:

Status	Body	When
200	{ "ok": true }	Returned to multiviewer layout

Output

Get or set the NDI® output state. When enabled, Laika sends the multiviewer as an NDI® source that other receivers on the network can pick up.

Get output status

GET /api/output

Response:

{
  "enabled": true,
  "fps": 60,
  "name": "LAIKA"
}

Field	Type	Description
enabled	boolean	Whether NDI® output is active
fps	integer	Output frame rate
name	string	NDI® source name advertised on the network

Toggle output

POST /api/output

Request body:

{
  "enabled": true
}

Responses:

Status	Body	When
200	{ "ok": true }	Output state updated

PTZ Control

Send PTZ (Pan/Tilt/Zoom) commands to NDI® sources that support camera control. Check the ptz_supported field in the /api/viewers response to determine which viewers accept PTZ commands.

Send a PTZ command

POST /api/ptz

Request body:

{
  "viewer": 0,
  "command": "pan_tilt_speed",
  "pan_speed": 0.5,
  "tilt_speed": 0.0
}

Field	Type	Description
viewer	integer	Zero-based viewer slot index
command	string	PTZ command name (see table below)

Commands and parameters:

Command	Parameters	Description
pan_tilt_speed	pan_speed (float), tilt_speed (float)	Continuous pan/tilt at the given speed. Range -1.0 to 1.0. Send 0.0 to stop.
pan_tilt	pan (float), tilt (float)	Move to an absolute pan/tilt position
zoom_speed	zoom_speed (float)	Continuous zoom at the given speed. Range -1.0 to 1.0. Send 0.0 to stop.
zoom	zoom (float)	Move to an absolute zoom position
recall_preset	index (integer), speed (float, optional)	Recall a stored camera preset. Speed defaults to 1.0.
store_preset	index (integer)	Store the current position as a preset
focus_auto	(none)	Trigger auto-focus
white_balance_auto	(none)	Trigger auto white balance

Responses:

Status	Body	When
200	{ "ok": true }	Command sent
400	{ "ok": false, "error": "..." }	Invalid viewer index, missing command, or unknown command

Router

The router creates virtual NDI® sources that act as redirect endpoints. When a receiver connects to a routed source, it is transparently redirected to the target NDI® source with zero additional bandwidth on the sender side. This makes it possible to build flexible routing topologies without duplicating video streams.

List routes

GET /api/router

Response:

{
  "routes": [
    {
      "index": 0,
      "name": "Output 1",
      "target": "CAMERA-1 (Studio)",
      "connections": 2
    },
    {
      "index": 1,
      "name": "Output 2",
      "target": null,
      "connections": 0
    }
  ]
}

Field	Type	Description
index	integer	Zero-based route index
name	string	Route display name (advertised as an NDI® source)
target	string or null	Currently routed NDI® source name, or null if unrouted
connections	integer	Number of NDI® receivers currently connected to this route

Create a route

POST /api/router

Request body:

{
  "name": "Output 1"
}

Responses:

Status	Body	When
200	{ "ok": true, "index": 0 }	Route created (index returned)
500	{ "ok": false, "error": "..." }	Creation failed

Delete a route

DELETE /api/router/{index}

Responses:

Status	Body	When
200	{ "ok": true }	Route deleted
400	{ "ok": false, "error": "..." }	Invalid route index

Set a route target

Point a route at an NDI® source. Receivers connecting to the route will be transparently redirected to this source.

POST /api/router/{index}/route

Request body:

{
  "source": "CAMERA-1 (Studio)"
}

The source value must match a name from /api/sources.

Responses:

Status	Body	When
200	{ "ok": true }	Route target set
400	{ "ok": false, "error": "..." }	Invalid route index
404	{ "ok": false, "error": "Source not found" }	Source name not found on network

Clear a route target

Remove the target from a route. Connected receivers will lose their stream.

DELETE /api/router/{index}/route

Responses:

Status	Body	When
200	{ "ok": true }	Route target cleared
400	{ "ok": false, "error": "..." }	Invalid route index

Error format

All error responses follow the same shape:

{
  "ok": false,
  "error": "Human-readable error message"
}

Example: curl

# Check what sources are available
curl http://localhost:1928/api/sources

# Assign CAMERA-2 to viewer slot 0
curl -X POST http://localhost:1928/api/viewers/0 \
  -H "Content-Type: application/json" \
  -d '{"source": "CAMERA-2 (Studio)"}'

# Switch to a 4-up layout
curl -X POST http://localhost:1928/api/layout \
  -H "Content-Type: application/json" \
  -d '{"name": "2x2"}'

# Load the Studio B launchpad
curl -X POST http://localhost:1928/api/launchpad \
  -H "Content-Type: application/json" \
  -d '{"name": "Studio B"}'

# Set a caption on viewer 0
curl -X POST http://localhost:1928/api/viewers/0/caption \
  -H "Content-Type: application/json" \
  -d '{"caption": "{source} LIVE"}'

# Clear a caption
curl -X POST http://localhost:1928/api/viewers/0/caption \
  -H "Content-Type: application/json" \
  -d '{"caption": null}'

# Project viewer 0 fullscreen
curl -X POST http://localhost:1928/api/project/0

# Exit projection
curl -X DELETE http://localhost:1928/api/project

# Pan a PTZ camera to the right
curl -X POST http://localhost:1928/api/ptz \
  -H "Content-Type: application/json" \
  -d '{"viewer": 0, "command": "pan_tilt_speed", "pan_speed": 0.5, "tilt_speed": 0.0}'

# Stop PTZ movement
curl -X POST http://localhost:1928/api/ptz \
  -H "Content-Type: application/json" \
  -d '{"viewer": 0, "command": "pan_tilt_speed", "pan_speed": 0.0, "tilt_speed": 0.0}'

# Recall PTZ preset 1
curl -X POST http://localhost:1928/api/ptz \
  -H "Content-Type: application/json" \
  -d '{"viewer": 0, "command": "recall_preset", "index": 1}'

# Create a router output
curl -X POST http://localhost:1928/api/router \
  -H "Content-Type: application/json" \
  -d '{"name": "Output 1"}'

# Route a source to the output
curl -X POST http://localhost:1928/api/router/0/route \
  -H "Content-Type: application/json" \
  -d '{"source": "CAMERA-1 (Studio)"}'

# Clear a route target
curl -X DELETE http://localhost:1928/api/router/0/route

# Delete a route
curl -X DELETE http://localhost:1928/api/router/0

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