> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sault.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Spending Policies

> Per-agent limits and how SAULT enforces them.

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](/concepts/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.