Signals and rules

Signals

Each signal is one piece of evidence. Valid JSON allows flexible shapes:

Numeric: { "metric": "accuracy", "value": 0.94 }
With context: { "component": "retrieval", "metric": "context_relevance", "value": 0.85 }
Presence-only: { "metric": "human_reviewed" } — no score; existence can drive a rule with operator: presence.

Optional top-level name and version on the signals file support audit (bump when your pipeline schema changes). See Versioning.

How rules use signals

Rules address signals by metric and optionally component (and other when fields supported by your Geval version).

Operator	Meaning
`presence`	At least one signal exists for that metric (and component if specified). Ignores numeric value.
`>`, `<`, `>=`, `<=`, `==`	Uses the first numeric value matching the metric (and component). Signals without a numeric value do not satisfy numeric comparisons.

Priorities

Within one policy, every rule priority must be unique. Lower number = higher precedence (e.g. 1 wins over 3 when both match). Geval evaluates all rules, keeps all matches, and the winning rule for the policy is the match with the smallest priority value.

Outcomes (`then`)

pass — policy contribution tends toward pass for that policy’s merge step.
block — severity BLOCK.
require_approval — severity REQUIRE_APPROVAL (human gate).

Final contract and multi-contract merging uses severity order (see How Geval works).

Example (minimal)

signals.json

{
  "name": "ci-signals",
  "version": "1.0.0",
  "signals": [
    { "metric": "accuracy", "value": 0.92 },
    { "metric": "human_reviewed" }
  ]
}

policy.yaml (illustrative — see Policy rules for full schema)

name: example-policy
version: "1.0.0"
policy:
  rules:
    - priority: 1
      name: needs_review_if_flag_present
      when:
        metric: human_reviewed
        operator: presence
      then:
        action: require_approval
    - priority: 2
      name: block_low_accuracy
      when:
        metric: accuracy
        operator: "<"
        threshold: 0.9
      then:
        action: block

Policy rules · geval check

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Signals and rules

Signals

How rules use signals

Priorities

Outcomes (`then`)

Example (minimal)

Next

​Signals

​How rules use signals

​Priorities

​Outcomes (then)

​Example (minimal)

​Next

Signals

How rules use signals

Priorities

Outcomes (`then`)

Example (minimal)

Next