Averment

Rules

Rules define what is allowed, restricted, or blocked in your system and give you full control over how Averment behaves.

What is a rule?

A rule is a set of conditions that evaluate an action and influence the final decision. Each rule can increase or decrease risk, override decisions, or directly enforce an action (block, allow, etc.).

Rule structure

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Rule anatomy

Each rule has three parts:

1. Condition (when)

Defines when the rule applies.

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2. Effect (effect)

Controls risk scoring.

Effect	Meaning
increase	Increase risk
decrease	Reduce risk
override	Override scoring

3. Decision Effect (decision_effect)

Directly controls enforcement.

Action	Behavior
allow	Execute
caution	Soft gate; proceed with awareness
review	Require active attention
block	Stop action
escalate_one_level	Increase severity
deescalate_one_level	Reduce severity

decision_effect overrides everything else when set.

Writing policies

Simple Rule (Recommended)

Full DSL (Advanced)

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Supported operators

Operator	What it does	Works with	Example
eq	equals	string, number, boolean	context.role eq "admin"
neq	not equal	string, number, boolean	context.country neq "US"
gt	greater than	number	numbers.requests gt 100
gte	greater than or equal	number	numbers.age gte 18
lt	less than	number	numbers.score lt 50
lte	less than or equal	number	numbers.attempts lte 3
contains	text includes value	string / array	context.command contains "rm -rf"
starts_with	starts with value	string	context.email starts_with "admin"
ends_with	ends with value	string	context.email ends_with "@temp.com"
in	matches one of values	array	context.role in ["admin","moderator"]
exists	field is present	any	context.device exists

Available fields

Decision fields (system info)

Field	What it means
decision.type	Type of action
decision.action	Action category
decision.summary	Human-readable description

Context fields (your data)

The most flexible part. You pass this data when calling decide().

Then reference it in policies:

Typed fields (structured access)

Type	Prefix	Example
Numbers	numbers.*	numbers.requests
Booleans	booleans.*	booleans.is_external_api
Strings	strings.*	strings.email

Important notes

Missing fields don't match: If a field isn't provided, the rule doesn't trigger.
Use the right prefix: numbers use Numbers.*, booleans use booleans.*, everything else uses context.*.
Context is your control layer: You decide what data to send, and more context means better decisions.

Priority & weight

Weight (0–100)

Controls how strongly a rule affects the decision. Higher weight = stronger influence.

Priority

Determines which rule runs first. Higher priority = executes first.

Next steps

Now that you understand policies, learn how to plug in your own LLM for semantic interpretation.

Bring Your Own LLM (BYOLLM)

Replace Averment's default semantic backend with your own LLM (OpenAI, Anthropic, Gemini, or any custom endpoint.)