How to Set Spending Limits for AI Agents

1 min read Updated

An agent spending limit is a configurable cap on how much crypto an AI agent can spend within a scope — per transaction, per time period, per recipient, or per session. The most fundamental spending control.

WHY IT MATTERS

Spending limits are the first defense against runaway costs. Without them, a single bug or hallucination could drain a wallet. Even well-functioning agents should have limits as safety nets.

Effective limits work at multiple levels: per-transaction (no single large mistake), rolling period (no slow drain), session (scoped to task). Defense in depth.

Setting levels is a balance — too restrictive hamstrings the agent, too generous doesn't protect. Start conservative, adjust based on observed patterns.

HOW POLICYLAYER USES THIS

PolicyLayer lets you define per-agent, per-session, per-transaction limits with rolling windows — in tokens or USD equivalent, varying by recipient, token, or time of day.

FREQUENTLY ASKED QUESTIONS

What's reasonable?
Depends on use case. Trading agent: $10,000/day. Data agent: $50/day. Start with minimum needed, increase based on behavior.
Tokens or USD?
USD-denominated is safer — accounts for price volatility. '1000 USDC' is stable; '1 ETH' could mean $2,000 or $5,000.
What happens at the limit?
Transaction blocked. May trigger HITL approval for excess, or agent waits for rolling window reset.

FURTHER READING

Enforce policies on every tool call

Intercept is the open-source MCP proxy that enforces YAML policies on AI agent tool calls. No code changes needed.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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