The policy decides.
Not the model.
KARTA — spend control for AI agents. One signed envelope per task, enforced outside the model. Every check below is deterministic: same input, same rule, same verdict. No wallet, no funds, no signup.
Pick a scenario. The envelope and the request are shown; the verdict is produced by the same engine the API and MCP use.
Free tier: 20 checks a day · spend audit · signed receipts · run a 30-day pilot