KYE Scenario Testing™ · kye.scenario_run.v1

Future-state testing for delegated AI actions.

Before an AI agent acts, KYE Scenario Testing™ runs the proposed action through a deterministic stress evaluator. The output: a signed kye.scenario_run.v1 with a risk level, a recommended decision, and a list of recommended controls — emitted to the PEP, the approval pipeline, and the Evidence Pack™. No surprises at execution time.

science What it is play_circle The flow tune Stressors terminal Use it verified_user Informed Approval

1 · What it is

Pre-execution simulation, deterministic, replay-safe.

A scenario is a target object (an agent action, a delegation, a policy change) plus a list of stressors — perturbations that ask "what if this dimension moves?" The scenario engine evaluates each stressor against a small lookup table, aggregates the bumps, and emits a single deterministic outcome: risk_level · recommended_decision · recommended_controls[].

4Risk levels (low / medium / high / critical)

4Recommended decisions (allow → deny)

12+Stressor kinds in the V1 lookup

same input → same outputDeterministic, replay-CI gated

Schema-conformant. Every run validates against kye.scenario_run.v1 — same artefact whether emitted by the V1 heuristic engine or the V1.1 rich engine.
Banking-grade hardening. Injectable structured logger, latency_ms on every result, no Math.random, no internal-error message leak.
Composable. The output feeds the Approval Brief™ composer and the Consequence Mapping™ engine without translation — the brief carries the scenario_run_id so the approver sees the simulation evidence inline.

2 · The flow

From action request to recommended decision.

arrow_forward 1. Action request

Agent or PEP describes the target object — id + object_type + summary.

tune 2. Stressor list

Caller (or Stress Test™ profile) supplies the list of perturbations to evaluate.

science 3. Engine evaluation

runScenario() aggregates per-stressor bumps from the V1 heuristic table; intensity multipliers apply.

verified 4. Scenario run emitted

kye.scenario_run.v1 with a deterministic scenario_run_id, risk_level, recommended_decision, recommended_controls, latency_ms.

forum 5. Hand-off

Run is referenced by the Approval Brief™ and sealed into the Approval Evidence Pack™ — auditable end-to-end.

3 · Stressor kinds (V1)

A small lookup, auditable end-to-end.

V1 ships an intentionally small set of stressor kinds — enough to cover the highest-blast-radius shapes a banking-grade tenant sees. Each entry maps to a numeric risk-bump and a list of controls the bump implies. Unknown stressor kinds contribute zero risk by safe default; the rich engine (V1.1) replaces this with a learned + counterfactual evaluator.

Stressor kind	Bump	Implied control(s)
`amount_above_threshold`	2	`dual_control:second_approver_required`
`novel_counterparty`	2	`enhanced_due_diligence`
`authority_chain_long`	1	`chain_replay`
`cross_border_transfer`	2	`sanctions_screening`
`outside_business_hours`	1	`business_hours_alert`
`sub_processor_first_use`	2	`sub_processor_review`
`scope_widening`	3	`scope_freeze`, `human_review`
`off_policy_action`	3	`policy_owner_review`
`recently_revoked_grant`	3	`block_until_reissue`
`bulk_action`	1	`batch_size_cap`
`velocity_spike`	2	`rate_cap`
`privacy_high_class_data`	2	`dp_review`

Aggregation. Per-stressor bumps are summed (multiplied by intensity: low=1, medium=2, high=3). A score of 0–2 maps to low/allow; 3–5 to medium/allow_with_constraints; 6–8 to high/require_approval; 9+ to critical/deny. Same input → same output, every time.

4 · Use it

One call from your PEP-Express or gateway.

The engine is a TypeScript edge worker library — mounted directly by PEP-Express and the runtime gateway in front of high-blast-radius agent actions. Library, not a deployed worker.

import { runScenario } from "@kye/scenario-engine";

const result = await runScenario({
  scenario_id:  "kye:scenario:payment-agent-scope-expansion",
  tenant_id:    "kye:tenant:acme-bank",
  target_object: {
    id:           "kye:agent-action:expand-payment-limit-50k",
    object_type:  "agent_action",
    summary:      "Expand per-transaction limit from $10k to $50k on FedNow."
  },
  stressors: [
    { id: "s1", kind: "scope_widening",          intensity: "high"   },
    { id: "s2", kind: "amount_above_threshold",  intensity: "high"   },
    { id: "s3", kind: "novel_counterparty",      intensity: "medium" }
  ],
  evaluated_at: "2026-05-14T09:30:00.000Z"
}, { logger });

// result.risk_level             === "critical"
// result.recommended_decision   === "deny"
// result.recommended_controls   === ["dual_control:second_approver_required",
//                                    "enhanced_due_diligence",
//                                    "human_review",
//                                    "scope_freeze"]
// result.scenario_run_id        === "kye:scenario-run:..."  (deterministic)
// result.latency_ms             === 0.42

5 · Next

Pair with Informed Approval for human sign-off.

A scenario run is the input to the Approval Brief™ — the structured, signed pack a human approver sees at decision time. No blind approvals.

verified_user Informed Approval inventory_2 Evidence Pack™ policy Decision Engine