What is an Agent Allowlist?

1 min read Updated

An allowlist is a curated set of approved addresses, contracts, or services an agent can transact with. Anything not listed is blocked — the simplest and most effective spending control.

WHY IT MATTERS

By defining exactly which addresses an agent can send to, you eliminate phishing, address poisoning, and unauthorized recipients entirely.

Typically includes: exchange addresses, verified contracts, approved vendors, fleet agents. Agent transacts freely within the set.

Best combined with other controls — allowlisted addresses still subject to limits and velocity checks. Defense in depth.

HOW POLICYLAYER USES THIS

PolicyLayer supports allowlists manageable via API or dashboard, updatable in real-time without agent restarts.

FREQUENTLY ASKED QUESTIONS

Allowlist or denylist?
Allowlists (default-deny) are more secure. Denylists (default-allow) are more permissive. For significant funds, allowlists recommended.
Managing updates?
Through PolicyLayer API/dashboard. Changes take effect immediately.
Include smart contracts?
Yes — specific addresses and even specific function selectors within contracts.

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 →
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