Prompts don't enforce budgets. Signatures do.
A spending limit written in a prompt is not a control. It is a piece of text, sitting in the same context window as everything else the model reads, competing for the model's attention with the task, the tool output, and whatever a third party managed to get in front of it. When that limit and an instruction to spend disagree, nothing technical decides between them. The model decides. That is the…
Spending limits written in prompts are merely pieces of text within the same context window as the model's other inputs. When a spending limit conflicts with an instruction to spend, the model decides, not a technical enforcement mechanism. Veyline addresses this issue by enforcing budget controls outside the model through server-side checks.
The four properties of real enforcement are that the check occurs outside the model, the authorization is scoped and signed, and it fails closed. In practice, this means Veyline checks a scoped, signed authorization before any money moves. The free preflight evaluation allows users to test this enforcement without actually executing any transactions.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
