Secure a Local AI API

localhost limits access to the same machine. Binding to all interfaces, forwarding ports, or creating tunnels expands the boundary.

The working rule for “Confirm the bind address” is: Bind to loopback first. Trace data through prompts, logs, backups, plugins, and network listeners instead of assuming that a local label guarantees isolation.

For verification, save the model and runtime versions, source input, relevant settings, and observed output together. Repeat the step while changing only one factor, and record unexpected results and untested limits as carefully as successes before applying the guidance to private or production data.

Use a proven reverse proxy or VPN when the runtime lacks suitable access control. Do not hardcode keys; support rotation and revocation.

The working rule for “Add authentication” is: Put remote access behind a VPN or authenticated proxy. Trace data through prompts, logs, backups, plugins, and network listeners instead of assuming that a local label guarantees isolation.

Preserve the before-and-after state and the time of the check so that another run can reproduce the result. Include at least one failure condition—such as empty input, constrained resources, or a restart—to reveal the boundary of the step rather than documenting only the happy path.

Set user permissions, allowed models, input and output ceilings, concurrency, and rate limits. Huge contexts can exhaust memory.

The working rule for “Limit requests” is: Combine TLS, firewall, quotas, minimal logs, and patching. Trace data through prompts, logs, backups, plugins, and network listeners instead of assuming that a local label guarantees isolation.

Define completion with an observable result instead of a general impression. Repeat the same input, and if the output changes, isolate whether the model, runtime settings, or source data changed before moving to the next stage.

Record authentication failures, abnormal volume, errors, and resource use while minimizing prompt content. Test updates and recovery.

The working rule for “Monitor and patch” is: Bind to loopback first. Trace data through prompts, logs, backups, plugins, and network listeners instead of assuming that a local label guarantees isolation.

Use the checklist with a date and observed result beside every item. When one check fails, record its scope before continuing, then repeat the same input after the change; that turns a list of advice into evidence that the step actually works in this environment.

• TLS and authentication
• Firewall policy
• Rate, size, and concurrency limits
• Secret rotation
• Minimal sensitive logging
• Backups and patches