Nine deterministic gates. One reproducible verdict.

Astra Verdix's evaluation engine is deliberately not a single opaque model call. It is a nine-gate pipeline built against a fully-tested reference engine with parity verified across 594 fixture combinations. Determinism is a feature, not a limitation.

The pipeline

1. 01

   Normalization

   Collapses proposal text, evidence, and metadata into a canonical, hashable shape. Everything downstream evaluates the same normalized artifact so verdicts are reproducible byte-for-byte.

2. 02

   Policy classification

   Maps the request to a policy scope (read, write, external comm, identity, infrastructure, disclosure) using the semantic classifier plus laundering detection. Catches cases where narrative wrapping hides the real action class.

3. 03

   Scope

   Checks the classified action against the active policy's allow / block / support lists. Explicit blocks short-circuit here with a clean deny reason.

4. 04

   Consequence & materiality (CVG)

   Computes the harm band and materiality of the proposed action against the tenant's consequence model. Low-consequence internal reads flow. High-consequence external actions escalate.

5. 05

   Temporal

   Enforces freshness windows on evidence and validates the write / decision window is still open. Stale approvals do not automatically ripen.

6. 06

   Exclusions

   Applies tenant-specific exclusion rules — jurisdictions, data classes, counterparties, prior incident state — before the request can proceed further.

7. 07

   Reversibility

   Blocks or defers irreversible actions that lack a documented rollback path. Reversible drafts, revocable grants, and reversible writes get lighter treatment than one-way commits.

8. 08

   Judgment

   For requests that survive the deterministic gates but sit in the ambiguous band, an analyst / challenger / classifier judgment loop applies restrictive and counter pressure. Deterministic fallback engages if the LLM path errors.

9. 09

   Arbitration

   Aggregates every prior gate outcome into the final verdict — proceed, defer, or block — with a full reason family, harm band, and the ordered gate sequence attached to the evaluation record.

Why deterministic-first matters

A verdict you cannot reproduce is a verdict you cannot audit. Every gate reads a hashed, canonical input and writes a structured outcome. The same policy plus the same request always yields the same result — across runs, across engineers, across environments. The judgment gate is the one place probabilistic reasoning is allowed, and even there it operates inside restrictive + counter framing with a deterministic fallback path.