Policy Enforcement

Policies control which API calls your agents can make. Set per-session when creating a sandbox token.

Default action

policies: {
  default: "deny",  // block uncredentialed domains
}

Or:

policies: {
  default: "allow",  // allow everything
}

Important: Domains that have credentials are implicitly allowed even with default: "deny". The default only applies to domains without credentials.

How policy evaluation works

1. Explicit rules checked first — if a rule matches the domain + method + path, it wins
2. Credential implicit allow — if no rule matched but the domain has a credential, allow it
3. Default policy — only applies if no rule AND no credential matches

This means most users just need credentials and default: "deny" — no explicit allow rules required.

Rules

Rules restrict access — limit methods, paths, or block specific patterns on otherwise-allowed domains:

policies: {
  default: "deny",
  rules: [
    // Allow only GET to specific GitHub repos (restricts the implicit allow)
    { domain: "api.github.com", methods: ["GET"], paths: ["/repos/acme/*"] },

    // Allow POST to a specific Stripe endpoint
    { domain: "api.stripe.com", methods: ["POST"], paths: ["/v1/charges"] },
  ],
}

Rules are evaluated in order. The first match wins. If no rule matches, credentials provide an implicit allow.

Rate limiting

Limit requests per domain:

policies: {
  default: "allow",
  rateLimit: {
    "api.openai.com": "20/min",
    "api.github.com": "100/hour",
  },
}

Rate limits are enforced per-session. When exceeded, requests are blocked with a 429 response.

Shadow mode

Test policies without enforcing them:

const session = await sylo.createSandboxToken({
  // ...
  shadowMode: true,
});

In shadow mode, policy violations are logged as "would-block" instead of "deny", but the request is allowed through. Useful for testing new policies in production.

Policy webhook

For complex authorization logic, delegate decisions to your own endpoint:

policies: {
  policyWebhook: "https://your-api.com/authorize",
}

Sylo sends the request details to your webhook and blocks or allows based on the response.