Quickstart

Get an API key, authenticate, and make your first Sprag request.

Get an API key

Sign in to Sprag.
Open API keys in the app.
Generate a key and copy it immediately. The full value is shown once and is not recoverable after you leave the page.

Store it as SPRAG_API_KEY. Treat it like a password: load it from an environment variable or a secret manager, keep it out of source control, and never put a production key in frontend code.

Key changes take up to five minutes to take effect, so a rotated or revoked key can keep authenticating for that long. Rotate before the old key has to stop working.

Authenticate

Send the key as a bearer token on every request.

Authorization: Bearer $SPRAG_API_KEY

Make your first request

curl https://api.sprag.ai/v1/audio/speech \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $SPRAG_API_KEY" \
  -d '{
    "model": "chorus",
    "input": "Hello from Sprag.",
    "response_format": "mp3"
  }' \
  --output hello.mp3

That writes an MP3 to disk. chorus covers the preset and cloned speech models; it works as a model id but does not appear in GET /v1/models, which lists chorus-voices, chorus-design, and chorus-clone separately.

To go the other direction, post an audio file to the transcriptions endpoint:

curl https://api.sprag.ai/v1/audio/transcriptions \
  -H "Authorization: Bearer $SPRAG_API_KEY" \
  -F [email protected] \
  -F model=rhythm

Rate limits

Authenticated requests are counted per organization: 60 requests per minute by default, drawn from one budget by every key and every member. Get in touch if you have a specific burst pattern or capacity need.

The in-browser playground runs without a key and has a small daily allowance per visitor. Authenticate with an API key to remove it.

Rate-limit headers appear on 429 responses only.

Header	Meaning
`Retry-After`	Seconds to wait before the window resets.
`X-RateLimit-Limit`	Requests permitted per window.
`X-RateLimit-Remaining`	Requests left in the window.

Handle errors

Status	Meaning	Fix
`400`	A field was missing, malformed, or out of range.	`error.param` names the field and `error.message` says what was wrong.
`401`	API key is missing or invalid.	Check the `Authorization` header, rotate the key if it may have leaked.
`402`	No payment method or credits available.	Add a payment method or review billing.
`404`	The model id does not exist or is not available to you.	Check it against `GET /v1/models`.
`429`	Rate limited.	Back off for `Retry-After` seconds.

See the errors reference for the full error shape and retry guidance.

Pick the guide for what you are building: speech to text, text to speech, or voices. For a spoken conversation with one model on both ends, see realtime speech.