Demo Walkthrough

This demo highlights CapFence's static scan, live gate decisions, trace replay, and audit verification workflows using the bundled fintech demo project.

Why this demo exists

Prompt guardrails are not enforcement. This demo shows a deterministic gate that blocks tool calls before execution and records a tamper-evident audit trail.

Where it sits in your stack

Agent framework -> CapFence gate -> Tool/API/DB/Shell

CapFence does not replace sandboxing or least-privilege credentials. It complements them by enforcing runtime policy at the tool boundary.

Rollout story (observe → enforce → audit)

1. Observe: scan the codebase and export machine-readable coverage.
2. Enforce: block and allow real tool calls with policy.
3. Audit: verify the hash chain and replay traces.

Prerequisites

• Python 3.10+
• Local repo checkout
• Virtual environment with CapFence installed (pip install --require-hashes -r requirements-dev.txt && pip install -e . --no-deps)

Run the demo

chmod +x ./scripts/demo.sh
./scripts/demo.sh

Optional: add a short overlay for the cast

If you share the demo cast, add a brief text overlay (or preface) that says:

"This is a deterministic gate between an agent and its tools. The demo shows scan, enforcement, simulation, and audit verification in under two minutes."

Expected output (example)

[DEMO] Running CapFence demo from repo root
[DEMO] Deterministic runtime authorization for agent tool calls, enforced before execution.
[SCAN] 8 tool(s) found in capfence-demo/src
  Gated: 8
  Ungated: 0

[SCAN] JSON report written to /tmp/capfence-demo-scan.json
[RUNTIME] blocked authorized=False decision=deny reason=policy_deny
[RUNTIME] allowed authorized=True decision=allow reason=policy_allow
Replayed 1 events:
  Authorized:         1
  Blocked:            0
  Requires Approval:  0
  Drifts/Diffs:       0
[VERIFY] Audit chain: VALID
  No tampering detected.
[POLICY] VALID: policies/production_shell_policy.yaml
  Rules: 2
  Risk levels: 0

Next steps

• Try capfence check on your own project.