highascg

AMCP REST API Reference (legacy)

Canonical docs: wiki/api/README.md — full endpoint list, Caspar gate, OpenAPI openapi.yaml, and per-topic examples.

HighAsCG maps subset functionality of the underlying CasparCG AMCP protocol into an easy-to-use HTTP REST JSON API. All endpoints are accessible via http://localhost:<PORT>/api.

All server responses include standard headers and use the application/json format.

Channel numbers (WO-868): the examples use the default numbering, where channel 1 is PGM of Screen 1. With Operator GUI first on (Devices → Caspar server page, casparServer.operator_gui_first), channel 1 is the operator GUI and every other channel moves up by one (PGM Screen 1 = 2). A request without channel still means PGM Screen 1.

Table of Contents

1. Basic Playback Commands
2. Mixer Commands
3. CG (Template) Commands
4. Data & Project Commands
5. State & Query Commands
6. Thumbnail & Media Commands
7. System & Control Commands

---

1. Basic Playback Commands

POST /api/play

Play a clip on a channel and layer.

• Body:

  {
    "channel": 1,
    "layer": 10,
    "clip": "AMB",
    "loop": true,
    "transition": "MIX",
    "duration": 50,
    "tween": "easeInCubic",
    "auto": false,
    "parameters": ""
  }
  

• Example:

  curl -X POST -H "Content-Type: application/json" -d '{"clip":"AMB","loop":true,"channel":1,"layer":10}' http://localhost:4200/api/play
  

  fetch('/api/play', { method: 'POST', body: JSON.stringify({ clip: 'AMB', channel: 1, layer: 10, loop: true }) })
  

POST /api/load, POST /api/loadbg

Loads a clip (or loads it into the background) onto a channel and layer. Wait for POST /api/play to trigger if BG.

• Body Schema: Same as /api/play.

POST /api/pause, POST /api/resume, POST /api/stop, POST /api/clear

Controls the playback state or clears the layer content entirely.

• Body: { "channel": 1, "layer": 10 }

POST /api/print, POST /api/log/level, POST /api/log/category

Controls CasparCG disk writing/logging settings.

• Bodies:
  • print: { "channel": 1 }
  • log/level: { "level": "trace" }
  • log/category: { "category": "calltrace", "enable": true }

---

2. Mixer Commands

Mixer commands can be accessed via POST (to mutate) or GET (to query properties).

POST /api/mixer/:command

Changes mixer configurations for a layer.

• Path parameters: command can be keyer, blend, chroma, invert, straight_alpha, opacity, brightness, saturation, contrast, levels, fill, clip, anchor, crop, rotation, volume, mastervolume, grid, commit, clear.
• keyer: per-layer blend mode in Caspar’s mixer — not the same as DeckLink “external keyer” in hardware logs. See reference/amcp-mapping.md (Mixer) for detail.
• Body Defaults: { "channel": 1, "layer": 10 }
• Example (opacity):

  {
    "channel": 1, 
    "layer": 10,
    "opacity": 0.5,
    "duration": 25,
    "tween": "linear"
  }
  

GET /api/mixer/:command?channel=X&layer=Y

Queries the value of the mixer property (e.g. GET /api/mixer/opacity?channel=1&layer=10).

• Response:

  {
    "ok": true,
    "data": "0.5"
  }
  

---

3. CG (Template) Commands

Controls HTML and Flash templates running in the CG layer.

POST /api/cg/add

Adds a template to a specific host layer.

• Body:

  {
    "channel": 1,
    "layer": 20,
    "templateHostLayer": 1,
    "template": "my-template",
    "playOnLoad": true,
    "data": "<templateData><componentData id=\"f0\"><data id=\"text\" value=\"Hello World\"/></componentData></templateData>"
  }
  

POST /api/cg/update

Updates template parameters.

• Body: { "channel": 1, "layer": 20, "templateHostLayer": 1, "data": "<xml...>" }

POST /api/cg/play, POST /api/cg/stop, POST /api/cg/next, POST /api/cg/invoke

Controls playback of templates, triggers animations, or invokes JS methods.

---

4. Data & Project Commands

Stores and retrieves raw strings to CasparCG disk (for memory caching) as well as handles project states.

POST /api/data/store

• Body: { "name": "my_dataset", "data": "<dataset>..." }

POST /api/data/retrieve, POST /api/data/remove

• Body: { "name": "my_dataset" }

POST /api/data/list

Lists datasets stored in CasparCG.

POST /api/project/save, POST /api/project/load

Saves and loads a full HighAsCG project payload into a Caspar dataset (casparcg_web_project).

---

5. State & Query Commands

Extracts core statuses and telemetry from CasparCG.

GET /api/state

Returns the merged state tree of the HighAsCG app + Caspar variables and channels.

GET /api/server, GET /api/server/queues, GET /api/server/threads, GET /api/server/gl

Gets information about the underlying CasparCG running server.

GET /api/fonts, GET /api/help/:command

Returns all fonts available and documentation on commands.

GET /api/channels/:id, GET /api/channels/:id/delay

Fetches parsed XML info arrays of what is loaded inside a channel (INFO X).

---

6. Thumbnail & Media Commands

GET /api/thumbnails

Lists all available thumbnails.

GET /api/thumbnail/:filename

Returns a binary PNG response of the requested media thumbnail.

POST /api/thumbnails/generate, POST /api/thumbnails/generate-all

Commands Caspar to regenerate base64 thumb streams.

• Generate Body: { "filename": "AMB" }

---

7. System & Control Commands

POST /api/restart, POST /api/kill

Restarts the underlying AMCP connections and internal structures, or sends KILL to shut off the CasparCG instance entirely.

• Body: {}

POST /api/diag, POST /api/gl/gc

Show diagnostic screens or trigger OpenGL Garbage Collection.

• Body: {}

POST /api/raw

Arbitrary AMCP payload dispatching.

• Body: { "cmd": "PLAY 1-1 AMB LOOP" }

GET /api/system/operator-first, POST /api/system/operator-first

“Operator GUI first” (WO-868): Caspar channel 1 = the operator GUI, its monitor leftmost, every other channel up by one.

• GET: { enabled, refusals, warnings, channels: { before, after } }
• POST body: { "enable": true, "dryRun": true }. dryRun (default true) only plans: channel table, remap, the stores it would rewrite, the X layout before/after, refusals and warnings. "dryRun": false backs up to ~/.highascg/backup/wo868-<time>/, renumbers projects / state / settings, sets the flag and runs the full apply (Caspar restart). "force": true overrides only the on-air refusal.

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