How to Gate External API Calls from AI Agents

SafeClaw by Authensor blocks external API calls from AI agents by default, preventing unauthorized interactions with third-party services, payment processors, cloud providers, and any external endpoint. Install SafeClaw with npx @authensor/safeclaw and every outbound API call is intercepted, evaluated against your allowlist, and audit-logged whether permitted or denied.

Why External API Calls Are Dangerous When AI Agents Do It

API calls carry real-world consequences. An agent calling a payment API can charge customers. An agent calling a cloud provider API can provision infrastructure that incurs costs. An agent calling a messaging API can send communications on behalf of your organization. Unlike internal function calls, external API calls cross trust boundaries — they transmit data to third parties, trigger irreversible transactions, and often authenticate with bearer tokens or API keys embedded in the request. An agent with API access can also exfiltrate sensitive data by encoding it in request parameters, headers, or POST bodies sent to attacker-controlled endpoints.

The Exact SafeClaw Policy to Gate API Calls

Add these rules to .safeclaw/policy.yaml:

rules:
  # Block known dangerous patterns
  - id: deny-api-payment
    action: network.request
    match:
      destination: "stripe.com"
    effect: deny
    audit: true
    message: "Payment API calls are permanently denied for AI agents."

- id: deny-api-payment-paypal
    action: network.request
    match:
      destination: "paypal.com"
    effect: deny
    audit: true
    message: "Payment API calls are permanently denied."

# Allowlist specific APIs
  - id: allow-api-internal
    action: network.request
    match:
      destination: "https://api.internal.company.com/*"
    effect: allow
    audit: true

- id: allow-api-github
    action: network.request
    match:
      destination: "https://api.github.com/*"
    effect: allow
    audit: true

# Approval-gate semi-trusted APIs
  - id: approve-api-openai
    action: network.request
    match:
      destination: "https://api.openai.com/*"
    effect: approval
    audit: true
    approvers:
      - role: developer
    timeout: 120
    message: "OpenAI API calls require developer approval."

# Deny all other external requests
  - id: deny-api-all
    action: network.request
    match:
      destination: "*"
    effect: deny
    audit: true
    message: "External API call not in allowlist."

This four-tier approach permanently blocks high-risk APIs (payments), allows trusted internal APIs, routes semi-trusted APIs through approval, and denies everything else. SafeClaw's network.request action type captures API calls regardless of the HTTP client library used.

What Happens When the Agent Tries

When an agent attempts to call https://api.stripe.com/v1/charges:

1. SafeClaw intercepts the network.request action.
2. The deny-api-payment rule matches stripe.com.
3. The request is blocked. No HTTP connection is established. No payment is processed.
4. Audit entry:

{
  "timestamp": "2026-02-13T11:38:44Z",
  "action": "network.request",
  "destination": "https://api.stripe.com/v1/charges",
  "effect": "deny",
  "rule": "deny-api-payment",
  "agent": "commerce-agent-01",
  "hash": "g5h2j8...chain"
}

When the agent calls https://api.github.com/repos/org/repo, the allow-api-github rule matches and the request proceeds — still audit-logged with full URL and method.

Gating by HTTP Method

For APIs where you want to allow reads but block writes:

rules:
  - id: allow-api-get
    action: network.request
    match:
      destination: "https://api.internal.company.com/*"
      method: "GET"
    effect: allow
    audit: true

- id: approve-api-post
    action: network.request
    match:
      destination: "https://api.internal.company.com/*"
      method: "POST"
    effect: approval
    audit: true
    approvers:
      - role: developer
    timeout: 180
    message: "POST to internal API requires approval."

- id: deny-api-delete
    action: network.request
    match:
      destination: "https://api.internal.company.com/*"
      method: "DELETE"
    effect: deny
    audit: true
    message: "DELETE requests to internal API are denied."

This method-level gating prevents agents from modifying resources through APIs even when the destination is allowlisted. SafeClaw works with both Claude and OpenAI agents, applying the same policy regardless of the underlying LLM provider.

Verification

npx @authensor/safeclaw simulate --action 'network.request' --destination 'https://api.stripe.com/v1/charges'
Expected: deny, rule: deny-api-payment

npx @authensor/safeclaw simulate --action 'network.request' --destination 'https://api.github.com/repos'
Expected: allow, rule: allow-api-github

Related Pages

• How to Gate Outbound Network Requests from AI Agents
• API Key Exfiltration Threat
• API Rate Limiting for AI Agents
• How to Prevent AI Agents from Sending Emails