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Build deterministic media systems.
Fixed Seed gives your backend one contract for uploads, queued inference, language models, request state, results, and prepaid usage. Run the quickstart Create an API key Base URL
text https://run.fixedseed.com
Every path in these docs is relative to this base URL. Send your API key on each request; see Authentication .
How requests move
- If the model takes media, upload it first through a private file slot, or pass a public HTTPS URL.
- Queue a request with your API key; add an idempotency key so retries are safe.
- Poll the request until it finishes, or receive a signed webhook.
- Fetch the result; media URLs are signed fresh on every read.
Try models in the Playground
The Playground on fixedseed.com runs many of the same models in your browser. It spends Playground credits from a plan or top-up, while API requests spend your API balance in dollars; the two never pay for each other.
Open PlaygroundEvery model with its current inputs and prices: the machine-readable API reference and the live model catalog (JSON).