Trust boundaries tutorial

This tutorial makes trust decisions visible. The runtime evaluates metadata, permissions, dependency provenance, placement, and communication rules before allowing execution.

By Enrico Piovesan Updated June 22, 2026

Tutorial route

Keep the path visible beside the tutorial so the trust rules, source folder, and neighboring chapters are easy to jump to.

Open source folder All UMA examples Previous: Service Graph Evolution Next: Architectural Tradeoffs

What you will learn

why portable systems cannot inherit trust from location alone
how undeclared permissions and untrusted dependencies fail before execution
how trust policy governs communication across services

Prerequisites

Rust 1.76 or newer
Node.js 20 or newer
a checkout of the repository

Full tutorial

Enter the example
```
cd chapter-09-trust-boundaries
```
List the trust labs
```
./scripts/list_labs.sh
```

Validate the trusted scenario

./scripts/validate_trust.sh lab1-trusted-service

Run the trusted service scenario

./scripts/run_trust_demo.sh lab1-trusted-service

Inspect an undeclared permission change

./scripts/trust_diff.sh lab1-trusted-service lab2-undeclared-permission

Run the untrusted dependency scenario

./scripts/run_trust_demo.sh lab3-untrusted-dependency

Run the restored compliance scenario

./scripts/run_trust_demo.sh lab5-restored-compliance

Run the full smoke path
```
./scripts/smoke_trust_labs.sh
```

What to inspect

After each command, look for these proof points. They are the signals that connect the code example back to the UMA architecture claim.

Outcome: allow or deny
permission.undeclared
dependency.provenance.untrusted
communication.forbidden

Acceptance check

The chapter-level validation path is:

./scripts/smoke_trust_labs.sh

Return to the repository root for the final acceptance gate:

cd ..
./scripts/smoke_reader_paths.sh

Where to go next

Chapter 10 compares architectural tradeoffs through runtime behavior.

Open source folder All UMA examples Read Chapter 10: Security and Trust → Previous: Service Graph Evolution Next: Architectural Tradeoffs