loop.CompactionPolicy is the complete explicit policy attached to one Loop. It supplies no timeout, threshold, output reservation, or summary budget defaults.

Exact policy API

// package loop
type CompactionPolicy struct {
	Automatic        bool
	CounterPolicy    CounterPolicy
	CompactAt        event.BasisPoints
	RearmBelow       event.BasisPoints
	ReservedOutput   content.TokenCount
	SafetyMargin     content.TokenCount
	MaxSummaryTokens content.TokenCount
	CountTimeout     time.Duration
	Hustle           hustle.Name
}

func (p CompactionPolicy) Validate(contextcount.CounterCapability) error
func WithCompaction(CompactionPolicy) Option

CounterPolicy is CounterPolicyUnknown, CounterPolicyRequireExact, or CounterPolicyAllowConservative.

Proof: policy types and validation and policy tests.

Field requirements

Field	Requirement
`Automatic`	Enables threshold-triggered attempts when true.
`CounterPolicy`	Required for automatic mode; selects accepted count quality.
`CompactAt`	Automatic threshold, strictly below `event.FullScaleBasisPoints`.
`RearmBelow`	Automatic re-arm threshold, nonzero and strictly below `CompactAt`.
`ReservedOutput`	Positive output reservation used to resolve input limits.
`SafetyMargin`	Positive when the counter quality is heuristic.
`MaxSummaryTokens`	Positive summary output budget.
`CountTimeout`	Positive context count timeout.
`Hustle`	Valid named Hustle; Rig checks registration and compatibility.

When Automatic is false, threshold and counter-policy checks are skipped, but the common reservation, summary budget, timeout, Hustle, and heuristic margin requirements remain.

Proof: CompactionPolicy.Validate and configuration tests.

Counter compatibility

Policy	Accepted `contextcount.CountQuality`
`CounterPolicyRequireExact`	`CountQualityExactProvider`, `CountQualityExactLocal`.
`CounterPolicyAllowConservative`	Exact qualities plus `CountQualityHeuristicEstimate`.
`CounterPolicyUnknown`	None in automatic mode.

WithContextObservation and WithCompaction are mutually exclusive. Both install a context admission policy, and the Loop cannot select both.

Proof: counter policy checks and context option exclusivity tests.

Request identity

loop.RequestFingerprintInput contains SystemRevision, ToolPolicyRevision, the full model.Model, event.ContextBasis, RuntimeContextRevision, CounterCapability, and InferenceCapability. loop.RequestFingerprint validates each field and returns a SHA-256 identity. Changing any request-shape revision, model, basis, or capability invalidates a previous compaction result.

Proof: request fingerprint and fingerprint tests.

Compaction Policy

Exact policy API

Field requirements

Counter compatibility

Request identity

Source and proof