Risk engine

The SAI Guard Risk Engine is the only component that produces the user-facing verdict. It consumes structured check results and a configured policy. It MUST NOT prompt a language model for a final yes.

The engine described here is the protect-pipeline target. v0.1 instead requires Proposer.PREPARED AND Semantic.PASS AND Safety.PASS and then demo-submits. See status.

Verdicts

Verdict	Meaning
`PROTECTED`	Required checks passed. Simulated effects correspond to intent.
`WARNING`	The transaction may be legitimate but needs explicit attention.
`BLOCKED`	A configured hard rule failed.

Verdicts are verification outcomes. They are not HTTP or SDK errors. See errors.

Policy

Example rules (policy is configurable; this is not a deployed table):

Condition	Typical verdict
Simulation failed (mandatory)	`BLOCKED`
Malicious contract	`BLOCKED`
Sanctions match	`BLOCKED`
Unexpected asset transfer	`BLOCKED`
Semantic verifier `MISMATCH`	`BLOCKED`
Phishing origin	`BLOCKED`
Semantic verifier `UNCERTAIN`	`WARNING`
Unknown contract	`WARNING`
Unlimited approval	`WARNING` or `BLOCKED`
Advisory provider failure	`WARNING`
Mandatory provider failure	`BLOCKED`
All mandatory checks pass	`PROTECTED`

A semantic MATCH MUST NOT clear a deterministic BLOCKED.

The Risk Engine MUST NOT return PROTECTED if required simulation failed.

Fail-closed

If a mandatory provider is down, times out, or returns malformed data:

do not coerce the check to pass;
WARNING if the check is advisory;
BLOCKED if the check is required for that action class.

Unknown is not safe.

Reason codes

Every non-PROTECTED result MUST carry machine-readable codes, for example:

INTENT_MISMATCH, UNEXPECTED_TRANSFER, UNLIMITED_APPROVAL, SIMULATION_FAILED, SANCTIONS_HIT, PROVIDER_UNAVAILABLE.

Internal scores, if any, MUST NOT be the primary wallet signal. See AI Transaction Protect.

Errors

Distinguish verdicts from protocol errors.

Kind	Examples
Verdict	`PROTECTED`, `WARNING`, `BLOCKED`
Protocol / API error	`INVALID_INTENT`, `INVALID_TRANSACTION`, `UNSUPPORTED_CHAIN`, `SIMULATION_UNAVAILABLE`, `PROVIDER_TIMEOUT`

v0.1 VapError codes include NOT_FOUND, STATE, MANDATE, DECODE, SEMANTIC, SAFETY, SIGNATURE, BINDING, UNSUPPORTED_CAPABILITY. Those are API failures, not protect verdicts.