Spending Policies - SAULT

Per-agent limits are how a builder controls what an agent can spend. They are enforced server-side, before anything is signed. See Agent Permissions for the full model.

What you can set per agent

Daily spending cap — total per day. Defaults to 10 USDC when an agent is created. Leave it empty for no daily ceiling.
Per-request maximum — single-payment ceiling. Leave it empty for no per-request ceiling.

Edits take effect immediately — active agents see the new limits on their next request.

What the agent sees when a limit is hit

Limit	Error code
Daily cap	`SpendingLimitExceeded`
Per-request	`PerTxLimitExceeded`
Vault signer revoked	`SignerNotAuthorized`

The CLI and MCP return these as structured errors. An agent following its SKILL.md reports the error to the user rather than retrying — the limit will not pass on retry.

Vault signer

Separate from agent limits, every vault has a single switch: signer authorised or not. The builder authorises SAULT to sign for the vault once during onboarding, and can revoke at any time. Revocation freezes every payment from that vault, regardless of agent limits.