Generation

Run a prompt against a recording and fetch the generated output.

Run a prompt against a recording's transcript to generate AI content, then poll the output for the result. Generation is asynchronous — poll GET /v1/outputs/:id, or subscribe a webhook to output.completed.

Both endpoints require a completed transcript on the recording.

Tier: automation. Base URL https://app.castmagic.io.

Generate an output

POST https://app.castmagic.io/v1/recordings/:id/generate

Pass prompt_id to run a saved custom prompt (from GET /v1/prompts), or prompt to run one-off text. Provide exactly one.

Request Body

Name	Type	Description
prompt_id	String	ID of a custom prompt in the recording's space
prompt	String	One-off prompt text (alternative to prompt_id)
name	String	Optional name for a one-off prompt

Only custom prompts can be run via the API. The built-in fan-out system prompts (overview, quotes, and so on) run through automatic generation, not this endpoint.

202: Accepted

{
    "output_id": "o1...",
    "output_type": "dynamic",
    "prompt_id": "p1...",
    "status": "queued"
}

400: Bad Request Transcript not ready

{ "error": "transcript is not ready (status: processing); generation needs a completed transcript" }

Fetch an output

GET https://app.castmagic.io/v1/outputs/:id

One generated output with its text. Statuses are queued, retrying, completed, failed, and canceled.

200: OK

{
    "output": {
        "id": "o1...",
        "type": "dynamic",
        "status": "completed",
        "created_at": "2026-08-21T22:05:00Z",
        "text": "Here's your LinkedIn post...",
        "recording_id": "e1..."
    }
}

404: Not Found

{ "error": "Output not found: o1..." }