# Decide Rulebook Runtime Decision

Status: Accepted
Date: 2026-06-12

## Decision

Decide production core evaluates a limited declarative Rulebook v1 format.
Krafthaus applications may use registered trusted adapters to produce
deterministic facts for that rulebook. Customer-supplied executable rulebooks do
not run in production.

## Why

The product needs deterministic verdicts, replayable Decision Records, and a
credible audit boundary. A generic executable rulebook runtime would make that
boundary harder to explain and harder to secure. The current system gets the
useful middle ground:

- declarative Rulebook v1 owns verdict selection
- trusted adapters own purpose-specific fact normalization
- adapter lineage is pinned by id, version, manifest hash, and implementation
  hash
- advisory artifacts may exist, but they cannot claim deterministic verdict
  authority

## Production Pattern

Use direct declarative rulebooks when the incoming facts are already narrow and
stable, such as Refund Policy Notary.

Use `trusted_adapter_facts_then_declarative_rulebook` when the workflow input needs a
deterministic fact producer before the rulebook can evaluate it, such as Solana
Execution Gate or Decision Memo Readiness.

Use advisory artifacts only after a deterministic gate allows them. The Decision
Memo Workflow follows this pattern: Decide creates the readiness Decision
Record; Krafthaus may then generate a memo recommendation artifact, but that
artifact remains advisory until the named owner accepts it.

## Non-Goals

- Do not run arbitrary customer executable code inside Decide or Krafthaus.
- Do not let advisory recommendations masquerade as Decision Records.
- Do not graduate a Krafthaus app to conformant status without a manifest,
  pinned runtime contract, declared action boundary, and explicit handoff.

## Consequence

The architecture supports both breadth and seriousness: Krafthaus can install
Decide into many workflow surfaces, while Decide keeps a small deterministic
core with replayable, testable verdict semantics.