ContextWindowCompactionStrategy Class

Definition

Namespace:

Microsoft.Agents.AI.Compaction

Assembly:

Microsoft.Agents.AI.dll

Package:

Microsoft.Agents.AI v1.13.0

A compaction strategy that derives token thresholds from a model's context window size and maximum output tokens, applying a two-phase compaction pipeline:

1. Tool result eviction (ToolResultCompactionStrategy) — collapses old tool call groups into concise summaries when the token count exceeds the ToolEvictionThreshold.
2. Truncation (TruncationCompactionStrategy) — removes the oldest non-system message groups when the token count exceeds the TruncationThreshold.

public sealed class ContextWindowCompactionStrategy : Microsoft.Agents.AI.Compaction.CompactionStrategy

type ContextWindowCompactionStrategy = class
    inherit CompactionStrategy

Public NotInheritable Class ContextWindowCompactionStrategy
Inherits CompactionStrategy

Inheritance

Object

CompactionStrategy

ContextWindowCompactionStrategy

Remarks

The input budget is defined as maxContextWindowTokens - maxOutputTokens, representing the maximum number of tokens available for the conversation input (including system messages, tools, and history).

This strategy is a convenience wrapper around PipelineCompactionStrategy that automates threshold calculation from model specifications.

Constructors

Name	Description
ContextWindowCompactionStrategy(Int32, Int32, Double, Double)	Initializes a new instance of the ContextWindowCompactionStrategy class.

Fields

Name	Description
DefaultToolEvictionThreshold	The default fraction of the input budget at which tool result eviction triggers.
DefaultTruncationThreshold	The default fraction of the input budget at which truncation triggers.

Properties

Name	Description
InputBudgetTokens	Gets the computed input budget in tokens (MaxContextWindowTokens minus MaxOutputTokens).
MaxContextWindowTokens	Gets the maximum context window size in tokens.
MaxOutputTokens	Gets the maximum output tokens per response.
Target	Gets the target predicate that controls when compaction stops. Strategies re-evaluate this after each incremental exclusion and stop when it returns true. (Inherited from CompactionStrategy)
ToolEvictionThreshold	Gets the fraction of the input budget at which tool result eviction triggers.
Trigger	Gets the trigger predicate that controls when compaction proceeds. (Inherited from CompactionStrategy)
TruncationThreshold	Gets the fraction of the input budget at which truncation triggers.

Methods

Name	Description
CompactAsync(CompactionMessageIndex, ILogger, CancellationToken)	Evaluates the Trigger and, when it fires, delegates to CompactCoreAsync(CompactionMessageIndex, ILogger, CancellationToken) and reports compaction metrics. (Inherited from CompactionStrategy)
CompactCoreAsync(CompactionMessageIndex, ILogger, CancellationToken)	Applies the strategy-specific compaction logic to the specified message index. (Inherited from CompactionStrategy)

Extension Methods

Name	Description
AsChatReducer(CompactionStrategy)	Returns an IChatReducer that applies this CompactionStrategy to reduce a list of messages.