What is a Spending Policy DSL?

1 min read Updated

A specialized language for defining agent spending rules — readable, auditable, and composable without general-purpose code.

WHY IT MATTERS

Policies need review by security, compliance, developers, and auditors. A DSL provides precise yet readable common language.

Expresses: "allow USDC up to $500, to 'vendors' group, rolling $5,000/day, alert at 20 tx/hour." More expressive than contracts, more auditable than code.

Enables composability — individual policies combine and reuse across agents.

HOW POLICYLAYER USES THIS

PolicyLayer uses a declarative DSL — readable, auditable, composable. Policies evaluate in real-time against every transaction.

FREQUENTLY ASKED QUESTIONS

Why not just JSON config?
JSON can express rules but lacks readability and composability. A DSL provides operators, logical combinators, and template support that make complex policies manageable.
Learning curve?
Minimal for simple policies. The DSL reads like English and provides templates for common patterns. Complex policies require deeper knowledge.
Version control?
Yes — policies are text files that can be stored in git, diff'd, and reviewed through standard code review processes.

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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